[flang-commits] [flang] [llvm] [flang][flang-rt] Implement F202X leading-zero control edit descriptors LZ, LZS, and LZP for formatted output (F, E, D, and G editing) (PR #183500)
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https://github.com/laoshd updated https://github.com/llvm/llvm-project/pull/183500
>From e2922a19918f526805dcd58205d770c14c04abdf Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 26 Feb 2026 05:03:53 -0600
Subject: [PATCH 01/12] [flang][flang-rt][F202X][Issue #178494] Implement F202X
leading-zero control edit descriptors LZ, LZS, and LZP for formatted output
(F, E, D, and G editing): LZ: processor-dependent (default, flang prints
leading zero); LZS: suppress the optional leading zero before the decimal
point; LZP: print the optional leading zero before the decimal point. Changes
span the source parser, compile-time format validator, runtime format
processing, and runtime output formatting. Includes semantic test (io16.f90)
and documentation updates.
---
.../flang-rt/runtime/format-implementation.h | 29 +++++-
flang-rt/include/flang-rt/runtime/format.h | 7 ++
flang-rt/lib/runtime/edit-output.cpp | 47 +++++++--
flang/docs/F202X.md | 9 ++
flang/docs/FortranStandardsSupport.md | 2 +-
flang/include/flang/Common/format.h | 45 ++++++++-
.../flang/Parser/format-specification.h | 3 +
flang/lib/Parser/io-parsers.cpp | 9 +-
flang/lib/Parser/unparse.cpp | 3 +
flang/test/Semantics/io16.f90 | 99 +++++++++++++++++++
10 files changed, 235 insertions(+), 18 deletions(-)
create mode 100644 flang/test/Semantics/io16.f90
diff --git a/flang-rt/include/flang-rt/runtime/format-implementation.h b/flang-rt/include/flang-rt/runtime/format-implementation.h
index d510adbb5ba46..8b341def2b3ce 100644
--- a/flang-rt/include/flang-rt/runtime/format-implementation.h
+++ b/flang-rt/include/flang-rt/runtime/format-implementation.h
@@ -193,7 +193,7 @@ static RT_API_ATTRS bool AbsoluteTabbing(CONTEXT &context, int n) {
template <typename CONTEXT>
static RT_API_ATTRS void HandleControl(
- CONTEXT &context, char ch, char next, int n) {
+ CONTEXT &context, char ch, char next, int n, char next2 = '\0') {
MutableModes &modes{context.mutableModes()};
switch (ch) {
case 'B':
@@ -251,6 +251,21 @@ static RT_API_ATTRS void HandleControl(
return;
}
break;
+ case 'L':
+ if (next == 'Z') {
+ if (next2 == 'S') {
+ // LZS - suppress leading zeros
+ modes.leadingZero = MutableModes::LeadingZeroMode::Suppress;
+ } else if (next2 == 'P') {
+ // LZP - print leading zero
+ modes.leadingZero = MutableModes::LeadingZeroMode::Print;
+ } else {
+ // LZ - processor-dependent (default behavior)
+ modes.leadingZero = MutableModes::LeadingZeroMode::Processor;
+ }
+ return;
+ }
+ break;
case 'S':
if (next == 'P') {
modes.editingFlags |= signPlus;
@@ -455,6 +470,7 @@ RT_API_ATTRS int FormatControl<CONTEXT>::CueUpNextDataEdit(
} else if (ch >= 'A' && ch <= 'Z') {
int start{offset_ - 1};
CharType next{'\0'};
+ CharType next2{'\0'};
if (ch != 'P') { // 1PE5.2 - comma not required (C1302)
CharType peek{Capitalize(PeekNext())};
if (peek >= 'A' && peek <= 'Z') {
@@ -464,6 +480,15 @@ RT_API_ATTRS int FormatControl<CONTEXT>::CueUpNextDataEdit(
// Assume a two-letter edit descriptor
next = peek;
++offset_;
+ } else if (ch == 'L' && peek == 'Z') {
+ // LZ, LZS, or LZP control edit descriptor
+ next = peek;
+ ++offset_;
+ CharType peek2{Capitalize(PeekNext())};
+ if (peek2 == 'S' || peek2 == 'P') {
+ next2 = peek2;
+ ++offset_;
+ }
} else {
// extension: assume a comma between 'ch' and 'peek'
}
@@ -484,7 +509,7 @@ RT_API_ATTRS int FormatControl<CONTEXT>::CueUpNextDataEdit(
repeat = GetIntField(context);
}
HandleControl(context, static_cast<char>(ch), static_cast<char>(next),
- repeat ? *repeat : 1);
+ repeat ? *repeat : 1, static_cast<char>(next2));
}
} else if (ch == '/') {
context.AdvanceRecord(repeat && *repeat > 0 ? *repeat : 1);
diff --git a/flang-rt/include/flang-rt/runtime/format.h b/flang-rt/include/flang-rt/runtime/format.h
index 79a7dd713b1a1..787772935ce8c 100644
--- a/flang-rt/include/flang-rt/runtime/format.h
+++ b/flang-rt/include/flang-rt/runtime/format.h
@@ -44,6 +44,12 @@ struct MutableModes {
return editingFlags & decimalComma ? char32_t{','} : char32_t{'.'};
}
+ enum class LeadingZeroMode : std::uint8_t {
+ Processor, // LZ: processor-dependent (default)
+ Suppress, // LZS: suppress optional leading zero
+ Print, // LZP: print optional leading zero
+ };
+
std::uint8_t editingFlags{0}; // BN, DP, SS
enum decimal::FortranRounding round{
executionEnvironment
@@ -53,6 +59,7 @@ struct MutableModes {
short scale{0}; // kP
bool inNamelist{false}; // skip ! comments
bool nonAdvancing{false}; // ADVANCE='NO', or $ or \ in FORMAT
+ LeadingZeroMode leadingZero{LeadingZeroMode::Processor}; // LZ/LZS/LZP
};
// A single edit descriptor extracted from a FORMAT
diff --git a/flang-rt/lib/runtime/edit-output.cpp b/flang-rt/lib/runtime/edit-output.cpp
index 73dba35ff08d9..d0aa8638102a9 100644
--- a/flang-rt/lib/runtime/edit-output.cpp
+++ b/flang-rt/lib/runtime/edit-output.cpp
@@ -411,10 +411,26 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditEorDOutput(
if (totalLength > width || !exponent) {
return EmitRepeated(io_, '*', width);
}
- if (totalLength < width && digitsBeforePoint == 0 &&
- zeroesBeforePoint == 0) {
- zeroesBeforePoint = 1;
- ++totalLength;
+ if (digitsBeforePoint == 0 && zeroesBeforePoint == 0 && scale <= 0) {
+ // Optional leading zero position (F202X leading zero control).
+ // When scale > 0 (kP with k > 0), digits are moved before the decimal
+ // point, so the leading zero position is not optional -- skip this.
+ // Value has no digits before the decimal point: "0.xxxE+yy" vs ".xxxE+yy"
+ switch (edit.modes.leadingZero) {
+ case MutableModes::LeadingZeroMode::Print:
+ // LZP: always print the optional leading zero
+ zeroesBeforePoint = 1;
+ ++totalLength;
+ break;
+ case MutableModes::LeadingZeroMode::Suppress:
+ // LZS: never print the optional leading zero
+ break;
+ case MutableModes::LeadingZeroMode::Processor:
+ // LZ: processor-defined; flang chooses to print it
+ zeroesBeforePoint = 1;
+ ++totalLength;
+ break;
+ }
}
if (totalLength < width && editWidth == 0) {
width = totalLength;
@@ -544,7 +560,24 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
if (digitsBeforePoint + zeroesBeforePoint + zeroesAfterPoint +
digitsAfterPoint + trailingZeroes ==
0) {
- zeroesBeforePoint = 1; // "." -> "0."
+ zeroesBeforePoint = 1; // "."--> "0." (bare decimal point)
+ } else if (digitsBeforePoint == 0 && zeroesBeforePoint == 0 &&
+ expo <= 0) {
+ // Optional leading zero position (F202X leading zero control).
+ // Value magnitude < 1: "0.xxx" vs ".xxx"
+ switch (edit.modes.leadingZero) {
+ case MutableModes::LeadingZeroMode::Print:
+ // LZP: always print the optional leading zero
+ zeroesBeforePoint = 1;
+ break;
+ case MutableModes::LeadingZeroMode::Suppress:
+ // LZS: never print the optional leading zero
+ break;
+ case MutableModes::LeadingZeroMode::Processor:
+ // LZ: processor-defined; flang chooses to print it
+ zeroesBeforePoint = 1;
+ break;
+ }
}
int totalLength{signLength + digitsBeforePoint + zeroesBeforePoint +
1 /*'.'*/ + zeroesAfterPoint + digitsAfterPoint + trailingZeroes +
@@ -553,10 +586,6 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
if (totalLength > width) {
return EmitRepeated(io_, '*', width);
}
- if (totalLength < width && digitsBeforePoint + zeroesBeforePoint == 0) {
- zeroesBeforePoint = 1;
- ++totalLength;
- }
return EmitPrefix(edit, totalLength, width) &&
EmitAscii(io_, convertedStr, signLength + digitsBeforePoint) &&
EmitRepeated(io_, '0', zeroesBeforePoint) &&
diff --git a/flang/docs/F202X.md b/flang/docs/F202X.md
index d1940a1858db1..6a303981cf264 100644
--- a/flang/docs/F202X.md
+++ b/flang/docs/F202X.md
@@ -261,6 +261,15 @@ The `AT` edit descriptor automatically trims character output. The `LZP`,
`LZS`, and `LZ` control edit descriptors and `LEADING_ZERO=` specifier provide a
means for controlling the output of leading zero digits.
+Implementation status:
+- `LZ`, `LZS`, `LZP` control edit descriptors, affect only F, E, D, and G
+ editing of an output statement: Implemented
+ - `LZ` - Processor-dependent, default (e.g., `0.2`)
+ - `LZS` - Suppress leading zeros (e.g., `.2`)
+ - `LZP` - Print leading zero (e.g. `0.2`)
+- `AT` edit descriptor: Not yet implemented
+- `LEADING_ZERO=specifier` in OPEN statement: Not yet implemented
+
#### Intrinsic Module Extensions
Addressing some issues and omissions in intrinsic modules:
diff --git a/flang/docs/FortranStandardsSupport.md b/flang/docs/FortranStandardsSupport.md
index f57956cd6d6b8..02e4653280f12 100644
--- a/flang/docs/FortranStandardsSupport.md
+++ b/flang/docs/FortranStandardsSupport.md
@@ -48,7 +48,7 @@ status of all important Fortran 2023 features. The table entries are based on th
| Extensions for c_f_pointer intrinsic | Y | |
| Procedures for converting between fortran and c strings | N | |
| The at edit descriptor | N | |
-| Control over leading zeros in output of real values | N | |
+| Control over leading zeros in output of real values | P | LZ/LZS/LZP edit descriptors implemented; LEADING_ZERO=specifier not yet implemented |
| Extensions for Namelist | N | |
| Allow an object of a type with a coarray ultimate component to be an array or allocatable | N | |
| Put with Notify | N | |
diff --git a/flang/include/flang/Common/format.h b/flang/include/flang/Common/format.h
index 1e64acb823616..60bcc8e81ee38 100644
--- a/flang/include/flang/Common/format.h
+++ b/flang/include/flang/Common/format.h
@@ -114,7 +114,7 @@ struct FormatMessage {
// This declaration is logically private to class FormatValidator.
// It is placed here to work around a clang compilation problem.
ENUM_CLASS(TokenKind, None, A, B, BN, BZ, D, DC, DP, DT, E, EN, ES, EX, F, G, I,
- L, O, P, RC, RD, RN, RP, RU, RZ, S, SP, SS, T, TL, TR, X, Z, Colon, Slash,
+ L, LZ, LZP, LZS, O, P, RC, RD, RN, RP, RU, RZ, S, SP, SS, T, TL, TR, X, Z, Colon, Slash,
Backslash, // nonstandard: inhibit newline on output
Dollar, // nonstandard: inhibit newline on output on terminals
Star, LParen, RParen, Comma, Point, Sign,
@@ -219,7 +219,7 @@ template <typename CHAR = char> class FormatValidator {
std::int64_t knrValue_{-1}; // -1 ==> not present
std::int64_t scaleFactorValue_{}; // signed k in kP
std::int64_t wValue_{-1};
- char argString_[3]{}; // 1-2 character msg arg; usually edit descriptor name
+ char argString_[4]{}; // 1-3 character msg arg; usually edit descriptor name
bool formatHasErrors_{false};
bool unterminatedFormatError_{false};
bool suppressMessageCascade_{false};
@@ -390,7 +390,25 @@ template <typename CHAR> void FormatValidator<CHAR>::NextToken() {
token_.set_kind(TokenKind::I);
break;
case 'L':
- token_.set_kind(TokenKind::L);
+ switch (LookAheadChar()) {
+ case 'Z':
+ // Advance past 'Z', then look ahead for 'S' or 'P'
+ Advance(TokenKind::LZ);
+ switch (LookAheadChar()) {
+ case 'S':
+ Advance(TokenKind::LZS);
+ break;
+ case 'P':
+ Advance(TokenKind::LZP);
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ token_.set_kind(TokenKind::L);
+ break;
+ }
break;
case 'O':
token_.set_kind(TokenKind::O);
@@ -674,9 +692,22 @@ template <typename CHAR> bool FormatValidator<CHAR>::Check() {
ReportError("Unexpected '%s' in format expression", signToken);
}
// Default message argument.
- // Alphabetic edit descriptor names are one or two characters in length.
+ // Alphabetic edit descriptor names are one to three characters in length.
argString_[0] = toupper(format_[token_.offset()]);
- argString_[1] = token_.length() > 1 ? toupper(*cursor_) : 0;
+ if (token_.length() > 2) {
+ // Three-character descriptor names (e.g., LZP, LZS).
+ // token_.offset() has the first character and *cursor_ has the last;
+ // find the middle character by scanning past any blanks.
+ const CHAR *mid{format_ + token_.offset() + 1};
+ while (mid < cursor_ && IsWhite(*mid)) {
+ ++mid;
+ }
+ argString_[1] = toupper(*mid);
+ argString_[2] = toupper(*cursor_);
+ } else {
+ argString_[1] = token_.length() > 1 ? toupper(*cursor_) : 0;
+ argString_[2] = 0;
+ }
// Process one format edit descriptor or do format list management.
switch (token_.kind()) {
case TokenKind::A:
@@ -794,6 +825,9 @@ template <typename CHAR> bool FormatValidator<CHAR>::Check() {
case TokenKind::BZ:
case TokenKind::DC:
case TokenKind::DP:
+ case TokenKind::LZ:
+ case TokenKind::LZS:
+ case TokenKind::LZP:
case TokenKind::RC:
case TokenKind::RD:
case TokenKind::RN:
@@ -807,6 +841,7 @@ template <typename CHAR> bool FormatValidator<CHAR>::Check() {
// R1318 blank-interp-edit-desc -> BN | BZ
// R1319 round-edit-desc -> RU | RD | RZ | RN | RC | RP
// R1320 decimal-edit-desc -> DC | DP
+ // F202X leading-zero-edit-desc -> LZ | LZS | LZP
check_r(false);
NextToken();
break;
diff --git a/flang/include/flang/Parser/format-specification.h b/flang/include/flang/Parser/format-specification.h
index 28c8affd7bde0..5d37a9c2c0060 100644
--- a/flang/include/flang/Parser/format-specification.h
+++ b/flang/include/flang/Parser/format-specification.h
@@ -95,6 +95,9 @@ struct ControlEditDesc {
RP,
DC,
DP,
+ LZ, // F202X: processor-dependent leading zero, default
+ LZS, // F202X: suppress leading zeros
+ LZP, // F202X: print leading zero
Dollar, // extension: inhibit newline on output
Backslash, // ditto, but only on terminals
};
diff --git a/flang/lib/Parser/io-parsers.cpp b/flang/lib/Parser/io-parsers.cpp
index cb3e68a05c94d..9da8c4f01d7dc 100644
--- a/flang/lib/Parser/io-parsers.cpp
+++ b/flang/lib/Parser/io-parsers.cpp
@@ -629,7 +629,8 @@ TYPE_PARSER(construct<format::IntrinsicTypeDataEditDesc>(
"X " >> pure(format::IntrinsicTypeDataEditDesc::Kind::EX) ||
pure(format::IntrinsicTypeDataEditDesc::Kind::E)) ||
"G " >> pure(format::IntrinsicTypeDataEditDesc::Kind::G) ||
- "L " >> pure(format::IntrinsicTypeDataEditDesc::Kind::L),
+ ("L "_tok / !letter /* don't occlude LZ, LZS, & LZP */) >>
+ pure(format::IntrinsicTypeDataEditDesc::Kind::L),
noInt, noInt, noInt)))
// R1307 data-edit-desc (part 2 of 2)
@@ -677,6 +678,12 @@ TYPE_PARSER(construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::BN)) ||
"Z " >> construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::BZ))) ||
+ "L " >> ("Z " >> ("S " >> construct<format::ControlEditDesc>(
+ pure(format::ControlEditDesc::Kind::LZS)) ||
+ "P " >> construct<format::ControlEditDesc>(
+ pure(format::ControlEditDesc::Kind::LZP)) ||
+ construct<format::ControlEditDesc>(
+ pure(format::ControlEditDesc::Kind::LZ)))) ||
"R " >> ("U " >> construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::RU)) ||
"D " >> construct<format::ControlEditDesc>(
diff --git a/flang/lib/Parser/unparse.cpp b/flang/lib/Parser/unparse.cpp
index 3d8ea9f703b2f..8ad1f9b8ff618 100644
--- a/flang/lib/Parser/unparse.cpp
+++ b/flang/lib/Parser/unparse.cpp
@@ -1549,6 +1549,9 @@ class UnparseVisitor {
FMT(RP);
FMT(DC);
FMT(DP);
+ FMT(LZ);
+ FMT(LZS);
+ FMT(LZP);
#undef FMT
case format::ControlEditDesc::Kind::Dollar:
Put('$');
diff --git a/flang/test/Semantics/io16.f90 b/flang/test/Semantics/io16.f90
new file mode 100644
index 0000000000000..559d98f0d5ceb
--- /dev/null
+++ b/flang/test/Semantics/io16.f90
@@ -0,0 +1,99 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+
+! F202X leading-zero control edit descriptors: LZ, LZS, LZP
+
+ ! Valid uses of LZ, LZP, LZS in FORMAT statements
+1001 format(LZ, F10.3)
+1002 format(LZP, F10.3)
+1003 format(LZS, F10.3)
+1004 format(LZ, E10.3)
+1005 format(LZP, E10.3)
+1006 format(LZS, E10.3)
+1007 format(LZS, D10.3)
+1008 format(LZ, G10.3)
+
+ ! Valid uses with blanks inside keywords (Fortran ignores blanks)
+1009 format(L Z, F10.3)
+1010 format(L Z P, F10.3)
+1011 format(L Z S, F10.3)
+
+ ! Combining with other control edit descriptors
+1012 format(LZP, DC, F10.3)
+1013 format(BN, LZS, F10.3)
+1014 format(LZ, SS, RZ, F10.3)
+
+ ! Multiple groups
+1015 format(LZP, 3F10.3, LZS, 2E12.4)
+
+ ! C1302 : multiple edit descriptors without ',' separation; no errors
+1016 format(LZF10.3)
+1017 format(LZPF10.3)
+1018 format(LZSF10.3)
+1019 format(LZE10.3)
+1020 format(LZPE10.3)
+1021 format(LZSD10.3)
+1022 format(LZG10.3)
+1023 format(LZPDCF10.3)
+1024 format(BNLZSF10.3)
+1025 format(LZPF10.3LZSF10.3)
+1026 format(LZP3F10.3LZS2E12.4)
+
+ ! In WRITE format strings
+ write(*, '(LZ, F10.3)') 0.5
+ write(*, '(LZP, F10.3)') 0.5
+ write(*, '(LZS, F10.3)') 0.5
+ write(*, '(LZP,E10.3)') 0.5
+ write(*, '(LZS,D10.3)') 0.5
+
+ ! C1302 : WRITE format strings without ',' separation; no errors
+ write(*, '(LZF10.3)') 0.5
+ write(*, '(LZPF10.3)') 0.5
+ write(*, '(LZSF10.3)') 0.5
+ write(*, '(LZPE10.3)') 0.5
+ write(*, '(LZP3F10.3LZS2E12.4)') 0.5, 0.5, 0.5, 0.5, 0.5
+
+ ! FMT= specifier with comma-separated descriptors
+ write(*, fmt='(LZ, F10.3)') 0.5
+ write(*, fmt='(LZP, F10.3)') 0.5
+ write(*, fmt='(LZS, F10.3)') 0.5
+ write(*, fmt='(LZP, E10.3)') 0.5
+ write(*, fmt='(LZS, D10.3)') 0.5
+ write(*, fmt='(LZP, DC, F10.3)') 0.5
+ write(*, fmt='(BN, LZS, F10.3)') 0.5
+
+ ! FMT= specifier without ',' separation; no errors
+ write(*, fmt='(LZF10.3)') 0.5
+ write(*, fmt='(LZPF10.3)') 0.5
+ write(*, fmt='(LZSF10.3)') 0.5
+ write(*, fmt='(LZPE10.3)') 0.5
+ write(*, fmt='(LZP3F10.3LZS2E12.4)') 0.5, 0.5, 0.5, 0.5, 0.5
+
+ ! FMT= specifier with FORMAT label reference
+ write(*, fmt=1001) 0.5
+ write(*, fmt=1002) 0.5
+ write(*, fmt=1017) 0.5
+
+ ! LZ/LZP/LZS coexisting with abbreviated L (no width) data edit descriptor
+ write(*, '(LZP, F10.3, L)') 0.5, .true.
+ write(*, '(LZS, F10.3, L)') 0.5, .true.
+
+ ! Error: repeat specifier before LZ/LZP/LZS in WRITE format strings
+ !ERROR: Repeat specifier before 'LZ' edit descriptor
+ write(*, '(3LZ, F10.3)') 0.5
+
+ !ERROR: Repeat specifier before 'LZP' edit descriptor
+ write(*, '(2LZP, F10.3)') 0.5
+
+ !ERROR: Repeat specifier before 'LZS' edit descriptor
+ write(*, '(2LZS, F10.3)') 0.5
+
+ ! Error: repeat specifier before LZ/LZP/LZS in FORMAT statements
+ !ERROR: Repeat specifier before 'LZ' edit descriptor
+2001 format(3LZ, F10.3)
+
+ !ERROR: Repeat specifier before 'LZP' edit descriptor
+2002 format(2LZP, F10.3)
+
+ !ERROR: Repeat specifier before 'LZS' edit descriptor
+2003 format(2LZS, F10.3)
+end
>From 4955f1dbb6a27f5ba0a9a75a9f53f86cad6db28d Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 26 Feb 2026 10:58:11 -0600
Subject: [PATCH 02/12] [flang][flang-rt][F202X][Issue #178494] Re-add tests
for leading-zero control edit descriptors in FORMAT statements,
flang/test/Semantics/io17.f90. Previously added io16.f90 was used.
---
flang/test/Semantics/io17.f90 | 99 +++++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)
create mode 100644 flang/test/Semantics/io17.f90
diff --git a/flang/test/Semantics/io17.f90 b/flang/test/Semantics/io17.f90
new file mode 100644
index 0000000000000..559d98f0d5ceb
--- /dev/null
+++ b/flang/test/Semantics/io17.f90
@@ -0,0 +1,99 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+
+! F202X leading-zero control edit descriptors: LZ, LZS, LZP
+
+ ! Valid uses of LZ, LZP, LZS in FORMAT statements
+1001 format(LZ, F10.3)
+1002 format(LZP, F10.3)
+1003 format(LZS, F10.3)
+1004 format(LZ, E10.3)
+1005 format(LZP, E10.3)
+1006 format(LZS, E10.3)
+1007 format(LZS, D10.3)
+1008 format(LZ, G10.3)
+
+ ! Valid uses with blanks inside keywords (Fortran ignores blanks)
+1009 format(L Z, F10.3)
+1010 format(L Z P, F10.3)
+1011 format(L Z S, F10.3)
+
+ ! Combining with other control edit descriptors
+1012 format(LZP, DC, F10.3)
+1013 format(BN, LZS, F10.3)
+1014 format(LZ, SS, RZ, F10.3)
+
+ ! Multiple groups
+1015 format(LZP, 3F10.3, LZS, 2E12.4)
+
+ ! C1302 : multiple edit descriptors without ',' separation; no errors
+1016 format(LZF10.3)
+1017 format(LZPF10.3)
+1018 format(LZSF10.3)
+1019 format(LZE10.3)
+1020 format(LZPE10.3)
+1021 format(LZSD10.3)
+1022 format(LZG10.3)
+1023 format(LZPDCF10.3)
+1024 format(BNLZSF10.3)
+1025 format(LZPF10.3LZSF10.3)
+1026 format(LZP3F10.3LZS2E12.4)
+
+ ! In WRITE format strings
+ write(*, '(LZ, F10.3)') 0.5
+ write(*, '(LZP, F10.3)') 0.5
+ write(*, '(LZS, F10.3)') 0.5
+ write(*, '(LZP,E10.3)') 0.5
+ write(*, '(LZS,D10.3)') 0.5
+
+ ! C1302 : WRITE format strings without ',' separation; no errors
+ write(*, '(LZF10.3)') 0.5
+ write(*, '(LZPF10.3)') 0.5
+ write(*, '(LZSF10.3)') 0.5
+ write(*, '(LZPE10.3)') 0.5
+ write(*, '(LZP3F10.3LZS2E12.4)') 0.5, 0.5, 0.5, 0.5, 0.5
+
+ ! FMT= specifier with comma-separated descriptors
+ write(*, fmt='(LZ, F10.3)') 0.5
+ write(*, fmt='(LZP, F10.3)') 0.5
+ write(*, fmt='(LZS, F10.3)') 0.5
+ write(*, fmt='(LZP, E10.3)') 0.5
+ write(*, fmt='(LZS, D10.3)') 0.5
+ write(*, fmt='(LZP, DC, F10.3)') 0.5
+ write(*, fmt='(BN, LZS, F10.3)') 0.5
+
+ ! FMT= specifier without ',' separation; no errors
+ write(*, fmt='(LZF10.3)') 0.5
+ write(*, fmt='(LZPF10.3)') 0.5
+ write(*, fmt='(LZSF10.3)') 0.5
+ write(*, fmt='(LZPE10.3)') 0.5
+ write(*, fmt='(LZP3F10.3LZS2E12.4)') 0.5, 0.5, 0.5, 0.5, 0.5
+
+ ! FMT= specifier with FORMAT label reference
+ write(*, fmt=1001) 0.5
+ write(*, fmt=1002) 0.5
+ write(*, fmt=1017) 0.5
+
+ ! LZ/LZP/LZS coexisting with abbreviated L (no width) data edit descriptor
+ write(*, '(LZP, F10.3, L)') 0.5, .true.
+ write(*, '(LZS, F10.3, L)') 0.5, .true.
+
+ ! Error: repeat specifier before LZ/LZP/LZS in WRITE format strings
+ !ERROR: Repeat specifier before 'LZ' edit descriptor
+ write(*, '(3LZ, F10.3)') 0.5
+
+ !ERROR: Repeat specifier before 'LZP' edit descriptor
+ write(*, '(2LZP, F10.3)') 0.5
+
+ !ERROR: Repeat specifier before 'LZS' edit descriptor
+ write(*, '(2LZS, F10.3)') 0.5
+
+ ! Error: repeat specifier before LZ/LZP/LZS in FORMAT statements
+ !ERROR: Repeat specifier before 'LZ' edit descriptor
+2001 format(3LZ, F10.3)
+
+ !ERROR: Repeat specifier before 'LZP' edit descriptor
+2002 format(2LZP, F10.3)
+
+ !ERROR: Repeat specifier before 'LZS' edit descriptor
+2003 format(2LZS, F10.3)
+end
>From b4a013fd28bb64b28538704d7d4588c2675802c6 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 26 Feb 2026 18:33:56 -0600
Subject: [PATCH 03/12] [flang][flang-rt][F202X][Issue #178494] Minor updates
on comments and docs format; Add flang-rt test, LeadingZeroTest.cpp.
---
flang-rt/lib/runtime/edit-output.cpp | 3 +-
flang-rt/unittests/Runtime/CMakeLists.txt | 1 +
.../unittests/Runtime/LeadingZeroTest.cpp | 256 ++++++++++++++++++
flang/include/flang/Common/format.h | 3 +-
flang/lib/Parser/io-parsers.cpp | 8 +-
5 files changed, 264 insertions(+), 7 deletions(-)
create mode 100644 flang-rt/unittests/Runtime/LeadingZeroTest.cpp
diff --git a/flang-rt/lib/runtime/edit-output.cpp b/flang-rt/lib/runtime/edit-output.cpp
index d0aa8638102a9..fbfcef6e7d13a 100644
--- a/flang-rt/lib/runtime/edit-output.cpp
+++ b/flang-rt/lib/runtime/edit-output.cpp
@@ -561,8 +561,7 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
digitsAfterPoint + trailingZeroes ==
0) {
zeroesBeforePoint = 1; // "."--> "0." (bare decimal point)
- } else if (digitsBeforePoint == 0 && zeroesBeforePoint == 0 &&
- expo <= 0) {
+ } else if (digitsBeforePoint == 0 && zeroesBeforePoint == 0 && expo <= 0) {
// Optional leading zero position (F202X leading zero control).
// Value magnitude < 1: "0.xxx" vs ".xxx"
switch (edit.modes.leadingZero) {
diff --git a/flang-rt/unittests/Runtime/CMakeLists.txt b/flang-rt/unittests/Runtime/CMakeLists.txt
index fca064b226200..31f7fcb5da812 100644
--- a/flang-rt/unittests/Runtime/CMakeLists.txt
+++ b/flang-rt/unittests/Runtime/CMakeLists.txt
@@ -22,6 +22,7 @@ add_flangrt_unittest(RuntimeTests
Format.cpp
InputExtensions.cpp
Inquiry.cpp
+ LeadingZeroTest.cpp
ListInputTest.cpp
LogicalFormatTest.cpp
Matmul.cpp
diff --git a/flang-rt/unittests/Runtime/LeadingZeroTest.cpp b/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
new file mode 100644
index 0000000000000..95b1e06513d04
--- /dev/null
+++ b/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
@@ -0,0 +1,256 @@
+//===-- unittests/Runtime/LeadingZeroTest.cpp --------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Tests for F202X leading-zero control edit descriptors: LZ, LZP, LZS.
+// LZ - processor-dependent (flang prints leading zero)
+// LZP - print the optional leading zero
+// LZS - suppress the optional leading zero
+//
+//===----------------------------------------------------------------------===//
+
+#include "CrashHandlerFixture.h"
+#include "flang-rt/runtime/descriptor.h"
+#include "flang/Runtime/io-api.h"
+#include <algorithm>
+#include <cstring>
+#include <gtest/gtest.h>
+#include <string>
+#include <tuple>
+#include <vector>
+
+using namespace Fortran::runtime;
+using namespace Fortran::runtime::io;
+
+static bool CompareFormattedStrings(
+ const std::string &expect, const std::string &got) {
+ std::string want{expect};
+ want.resize(got.size(), ' ');
+ return want == got;
+}
+
+// Perform format on a double and return the trimmed result
+static std::string FormatReal(const char *format, double x) {
+ char buffer[800];
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, x));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ return got;
+}
+
+static bool CompareFormatReal(
+ const char *format, double x, const char *expect, std::string &got) {
+ got = FormatReal(format, x);
+ return CompareFormattedStrings(expect, got);
+}
+
+struct LeadingZeroTests : CrashHandlerFixture {};
+
+// LZP with F editing: value < 1 should print "0." before decimal digits
+TEST(LeadingZeroTests, LZP_F_editing) {
+ static constexpr std::pair<const char *, const char *> cases[]{
+ {"(LZP,F6.1)", " 0.2"},
+ {"(LZP,F10.3)", " 0.200"},
+ {"(LZP,F6.1)", " 0.5"},
+ {"(LZP,F4.1)", " 0.1"},
+ };
+ double values[]{0.2, 0.2, 0.5, 0.1};
+ for (int i = 0; i < 4; ++i) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ << "Failed: format=" << cases[i].first << " value=" << values[i]
+ << ", expected '" << cases[i].second << "', got '" << got << "'";
+ }
+}
+
+// LZS with F editing: value < 1 should suppress the leading zero
+TEST(LeadingZeroTests, LZS_F_editing) {
+ static constexpr std::pair<const char *, const char *> cases[]{
+ {"(LZS,F6.1)", " .2"},
+ {"(LZS,F10.3)", " .200"},
+ {"(LZS,F6.1)", " .5"},
+ {"(LZS,F4.1)", " .1"},
+ };
+ double values[]{0.2, 0.2, 0.5, 0.1};
+ for (int i = 0; i < 4; ++i) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ << "Failed: format=" << cases[i].first << " value=" << values[i]
+ << ", expected '" << cases[i].second << "', got '" << got << "'";
+ }
+}
+
+// LZ (processor-dependent, flang prints leading zero) with F editing
+TEST(LeadingZeroTests, LZ_F_editing) {
+ static constexpr std::pair<const char *, const char *> cases[]{
+ {"(LZ,F6.1)", " 0.2"},
+ {"(LZ,F10.3)", " 0.200"},
+ };
+ double values[]{0.2, 0.2};
+ for (int i = 0; i < 2; ++i) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ << "Failed: format=" << cases[i].first << " value=" << values[i]
+ << ", expected '" << cases[i].second << "', got '" << got << "'";
+ }
+}
+
+// LZP with E editing: value < 1 should print "0." before decimal digits
+TEST(LeadingZeroTests, LZP_E_editing) {
+ static constexpr std::pair<const char *, const char *> cases[]{
+ {"(LZP,E10.3)", " 0.200E+00"},
+ {"(LZP,E12.5)", " 0.20000E+00"},
+ };
+ double values[]{0.2, 0.2};
+ for (int i = 0; i < 2; ++i) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ << "Failed: format=" << cases[i].first << " value=" << values[i]
+ << ", expected '" << cases[i].second << "', got '" << got << "'";
+ }
+}
+
+// LZS with E editing: value < 1 should suppress the leading zero
+TEST(LeadingZeroTests, LZS_E_editing) {
+ static constexpr std::pair<const char *, const char *> cases[]{
+ {"(LZS,E10.3)", " .200E+00"},
+ {"(LZS,E12.5)", " .20000E+00"},
+ };
+ double values[]{0.2, 0.2};
+ for (int i = 0; i < 2; ++i) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ << "Failed: format=" << cases[i].first << " value=" << values[i]
+ << ", expected '" << cases[i].second << "', got '" << got << "'";
+ }
+}
+
+// LZP with D editing
+TEST(LeadingZeroTests, LZP_D_editing) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal("(LZP,D10.3)", 0.2, " 0.200D+00", got))
+ << "Expected ' 0.200D+00', got '" << got << "'";
+}
+
+// LZS with D editing
+TEST(LeadingZeroTests, LZS_D_editing) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal("(LZS,D10.3)", 0.2, " .200D+00", got))
+ << "Expected ' .200D+00', got '" << got << "'";
+}
+
+// LZP with G editing — G routes to F when exponent is in range
+TEST(LeadingZeroTests, LZP_G_editing_F_path) {
+ std::string got;
+ // 0.2 with G10.3: exponent 0 is in [0,3], so G uses F editing
+ ASSERT_TRUE(CompareFormatReal("(LZP,G10.3)", 0.2, " 0.200 ", got))
+ << "Expected ' 0.200 ', got '" << got << "'";
+}
+
+// LZS with G editing — G routes to F when exponent is in range
+TEST(LeadingZeroTests, LZS_G_editing_F_path) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal("(LZS,G10.3)", 0.2, " .200 ", got))
+ << "Expected ' .200 ', got '" << got << "'";
+}
+
+// LZP with G editing — G routes to E when exponent is out of range
+TEST(LeadingZeroTests, LZP_G_editing_E_path) {
+ std::string got;
+ // 0.0002 with G10.3: exponent -3 is < 0, so G uses E editing
+ ASSERT_TRUE(CompareFormatReal("(LZP,G10.3)", 0.0002, " 0.200E-03", got))
+ << "Expected ' 0.200E-03', got '" << got << "'";
+}
+
+// LZS with G editing — G routes to E when exponent is out of range
+TEST(LeadingZeroTests, LZS_G_editing_E_path) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal("(LZS,G10.3)", 0.0002, " .200E-03", got))
+ << "Expected ' .200E-03', got '" << got << "'";
+}
+
+// Switching between LZP and LZS in the same format
+TEST(LeadingZeroTests, SwitchBetweenLZPandLZS) {
+ char buffer[800];
+ const char *format{"(LZP,F6.1,LZS,F6.1)"};
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ std::string expect{" 0.5 .5"};
+ ASSERT_TRUE(CompareFormattedStrings(expect, got))
+ << "Expected '" << expect << "', got '" << got << "'";
+}
+
+// LZP/LZS with negative values < 1 in magnitude
+TEST(LeadingZeroTests, NegativeValues) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal("(LZP,F7.1)", -0.2, " -0.2", got))
+ << "Expected ' -0.2', got '" << got << "'";
+ ASSERT_TRUE(CompareFormatReal("(LZS,F7.1)", -0.2, " -.2", got))
+ << "Expected ' -.2', got '" << got << "'";
+}
+
+// LZP/LZS should not affect values >= 1 (leading zero is not optional)
+TEST(LeadingZeroTests, ValuesGreaterThanOne) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal("(LZP,F6.1)", 1.2, " 1.2", got))
+ << "Expected ' 1.2', got '" << got << "'";
+ ASSERT_TRUE(CompareFormatReal("(LZS,F6.1)", 1.2, " 1.2", got))
+ << "Expected ' 1.2', got '" << got << "'";
+ ASSERT_TRUE(CompareFormatReal("(LZP,F6.1)", 12.3, " 12.3", got))
+ << "Expected ' 12.3', got '" << got << "'";
+ ASSERT_TRUE(CompareFormatReal("(LZS,F6.1)", 12.3, " 12.3", got))
+ << "Expected ' 12.3', got '" << got << "'";
+}
+
+// LZP/LZS with zero value
+TEST(LeadingZeroTests, ZeroValue) {
+ std::string got;
+ // LZP: zero value still prints leading zero before decimal point
+ ASSERT_TRUE(CompareFormatReal("(LZP,F6.1)", 0.0, " 0.0", got))
+ << "Expected ' 0.0', got '" << got << "'";
+ // LZS: zero has magnitude < 1, so the leading zero is optional and suppressed
+ ASSERT_TRUE(CompareFormatReal("(LZS,F6.1)", 0.0, " .0", got))
+ << "Expected ' .0', got '" << got << "'";
+}
+
+// LZP/LZS with scale factor (1P) — leading zero not optional when scale > 0
+TEST(LeadingZeroTests, WithScaleFactor) {
+ std::string got;
+ // With 1P, E editing puts one digit before the decimal point,
+ // so LZS should not suppress it (it's not an optional zero)
+ ASSERT_TRUE(CompareFormatReal("(LZP,1P,E10.3)", 0.2, " 2.000E-01", got))
+ << "Expected ' 2.000E-01', got '" << got << "'";
+ ASSERT_TRUE(CompareFormatReal("(LZS,1P,E10.3)", 0.2, " 2.000E-01", got))
+ << "Expected ' 2.000E-01', got '" << got << "'";
+}
+
+// LZP without comma separator (C1302 extension)
+TEST(LeadingZeroTests, WithoutCommaSeparator) {
+ std::string got;
+ ASSERT_TRUE(CompareFormatReal("(LZPF6.1)", 0.2, " 0.2", got))
+ << "Expected ' 0.2', got '" << got << "'";
+ ASSERT_TRUE(CompareFormatReal("(LZSF6.1)", 0.2, " .2", got))
+ << "Expected ' .2', got '" << got << "'";
+ ASSERT_TRUE(CompareFormatReal("(LZF6.1)", 0.2, " 0.2", got))
+ << "Expected ' 0.2', got '" << got << "'";
+}
diff --git a/flang/include/flang/Common/format.h b/flang/include/flang/Common/format.h
index f7b0835f91287..7c9a763d86bae 100644
--- a/flang/include/flang/Common/format.h
+++ b/flang/include/flang/Common/format.h
@@ -114,7 +114,8 @@ struct FormatMessage {
// This declaration is logically private to class FormatValidator.
// It is placed here to work around a clang compilation problem.
ENUM_CLASS(TokenKind, None, A, B, BN, BZ, D, DC, DP, DT, E, EN, ES, EX, F, G, I,
- L, LZ, LZP, LZS, O, P, RC, RD, RN, RP, RU, RZ, S, SP, SS, T, TL, TR, X, Z, Colon, Slash,
+ L, LZ, LZP, LZS, O, P, RC, RD, RN, RP, RU, RZ, S, SP, SS, T, TL, TR, X, Z,
+ Colon, Slash,
Backslash, // nonstandard: inhibit newline on output
Dollar, // nonstandard: inhibit newline on output on terminals
Star, LParen, RParen, Comma, Point, Sign,
diff --git a/flang/lib/Parser/io-parsers.cpp b/flang/lib/Parser/io-parsers.cpp
index 9da8c4f01d7dc..bcbeb49f8e01f 100644
--- a/flang/lib/Parser/io-parsers.cpp
+++ b/flang/lib/Parser/io-parsers.cpp
@@ -680,10 +680,10 @@ TYPE_PARSER(construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::BZ))) ||
"L " >> ("Z " >> ("S " >> construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::LZS)) ||
- "P " >> construct<format::ControlEditDesc>(
- pure(format::ControlEditDesc::Kind::LZP)) ||
- construct<format::ControlEditDesc>(
- pure(format::ControlEditDesc::Kind::LZ)))) ||
+ "P " >> construct<format::ControlEditDesc>(
+ pure(format::ControlEditDesc::Kind::LZP)) ||
+ construct<format::ControlEditDesc>(
+ pure(format::ControlEditDesc::Kind::LZ)))) ||
"R " >> ("U " >> construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::RU)) ||
"D " >> construct<format::ControlEditDesc>(
>From deaaf8a69b40fc25ec6e9c6e099f3ec5b477aac4 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 26 Feb 2026 19:04:38 -0600
Subject: [PATCH 04/12] [flang][flang-rt][F202X][Issue #178494] Update code
format based on PR review.
---
flang/lib/Parser/io-parsers.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/flang/lib/Parser/io-parsers.cpp b/flang/lib/Parser/io-parsers.cpp
index bcbeb49f8e01f..93aa4e9d21911 100644
--- a/flang/lib/Parser/io-parsers.cpp
+++ b/flang/lib/Parser/io-parsers.cpp
@@ -680,8 +680,8 @@ TYPE_PARSER(construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::BZ))) ||
"L " >> ("Z " >> ("S " >> construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::LZS)) ||
- "P " >> construct<format::ControlEditDesc>(
- pure(format::ControlEditDesc::Kind::LZP)) ||
+ "P " >> construct<format::ControlEditDesc>(pure(
+ format::ControlEditDesc::Kind::LZP)) ||
construct<format::ControlEditDesc>(
pure(format::ControlEditDesc::Kind::LZ)))) ||
"R " >> ("U " >> construct<format::ControlEditDesc>(
>From 4e7bdcaced4e3f0db85d9042d8a01e24d64619a6 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 26 Feb 2026 19:22:31 -0600
Subject: [PATCH 05/12] [flang][flang-rt] Update code format based on PR
review.
---
flang-rt/unittests/Runtime/LeadingZeroTest.cpp | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/flang-rt/unittests/Runtime/LeadingZeroTest.cpp b/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
index 95b1e06513d04..d151e03923239 100644
--- a/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
+++ b/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
@@ -1,4 +1,5 @@
-//===-- unittests/Runtime/LeadingZeroTest.cpp --------------------*- C++ -*-===//
+//===-- unittests/Runtime/LeadingZeroTest.cpp --------------------*- C++
+//-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -68,7 +69,8 @@ TEST(LeadingZeroTests, LZP_F_editing) {
double values[]{0.2, 0.2, 0.5, 0.1};
for (int i = 0; i < 4; ++i) {
std::string got;
- ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ ASSERT_TRUE(
+ CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
<< "Failed: format=" << cases[i].first << " value=" << values[i]
<< ", expected '" << cases[i].second << "', got '" << got << "'";
}
@@ -85,7 +87,8 @@ TEST(LeadingZeroTests, LZS_F_editing) {
double values[]{0.2, 0.2, 0.5, 0.1};
for (int i = 0; i < 4; ++i) {
std::string got;
- ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ ASSERT_TRUE(
+ CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
<< "Failed: format=" << cases[i].first << " value=" << values[i]
<< ", expected '" << cases[i].second << "', got '" << got << "'";
}
@@ -100,7 +103,8 @@ TEST(LeadingZeroTests, LZ_F_editing) {
double values[]{0.2, 0.2};
for (int i = 0; i < 2; ++i) {
std::string got;
- ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ ASSERT_TRUE(
+ CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
<< "Failed: format=" << cases[i].first << " value=" << values[i]
<< ", expected '" << cases[i].second << "', got '" << got << "'";
}
@@ -115,7 +119,8 @@ TEST(LeadingZeroTests, LZP_E_editing) {
double values[]{0.2, 0.2};
for (int i = 0; i < 2; ++i) {
std::string got;
- ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ ASSERT_TRUE(
+ CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
<< "Failed: format=" << cases[i].first << " value=" << values[i]
<< ", expected '" << cases[i].second << "', got '" << got << "'";
}
@@ -130,7 +135,8 @@ TEST(LeadingZeroTests, LZS_E_editing) {
double values[]{0.2, 0.2};
for (int i = 0; i < 2; ++i) {
std::string got;
- ASSERT_TRUE(CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
+ ASSERT_TRUE(
+ CompareFormatReal(cases[i].first, values[i], cases[i].second, got))
<< "Failed: format=" << cases[i].first << " value=" << values[i]
<< ", expected '" << cases[i].second << "', got '" << got << "'";
}
>From 9d453826cb83d3dcefc3f3c8facd4387f15abe33 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 5 Mar 2026 08:25:24 -0600
Subject: [PATCH 06/12] Change file name io17.f90 to io18.f90 in
flang/test/Semantics to resolve conflict: io17.f90 has been used.
---
flang/test/Semantics/{io17.f90 => io18.f90} | 0
1 file changed, 0 insertions(+), 0 deletions(-)
rename flang/test/Semantics/{io17.f90 => io18.f90} (100%)
diff --git a/flang/test/Semantics/io17.f90 b/flang/test/Semantics/io18.f90
similarity index 100%
rename from flang/test/Semantics/io17.f90
rename to flang/test/Semantics/io18.f90
>From c733fab2e00f376d004e536614efcae75fc6da22 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Fri, 6 Mar 2026 10:31:38 -0600
Subject: [PATCH 07/12] Fix a flang-rt failure for 'F0.d': print leading zero
only when field has room for LZ
---
flang-rt/lib/runtime/edit-output.cpp | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/flang-rt/lib/runtime/edit-output.cpp b/flang-rt/lib/runtime/edit-output.cpp
index 80d3ee23e895a..e3d39f8874e41 100644
--- a/flang-rt/lib/runtime/edit-output.cpp
+++ b/flang-rt/lib/runtime/edit-output.cpp
@@ -434,9 +434,11 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditEorDOutput(
// LZS: never print the optional leading zero
break;
case MutableModes::LeadingZeroMode::Processor:
- // LZ: processor-defined; flang chooses to print it
- zeroesBeforePoint = 1;
- ++totalLength;
+ // LZ: processor-defined; add leading zero only when field has room
+ if (totalLength < width) {
+ zeroesBeforePoint = 1;
+ ++totalLength;
+ }
break;
}
}
@@ -581,9 +583,7 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
// LZS: never print the optional leading zero
break;
case MutableModes::LeadingZeroMode::Processor:
- // LZ: processor-defined; flang chooses to print it
- zeroesBeforePoint = 1;
- break;
+ break; // handled below after width computation
}
}
int totalLength{signLength + digitsBeforePoint + zeroesBeforePoint +
@@ -593,6 +593,11 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
if (totalLength > width) {
return EmitRepeated(io_, '*', width);
}
+ if (edit.modes.leadingZero == MutableModes::LeadingZeroMode::Processor &&
+ totalLength < width && digitsBeforePoint + zeroesBeforePoint == 0) {
+ zeroesBeforePoint = 1;
+ ++totalLength;
+ }
return EmitPrefix(edit, totalLength, width) &&
EmitAscii(io_, convertedStr, signLength + digitsBeforePoint) &&
EmitRepeated(io_, '0', zeroesBeforePoint) &&
>From 5b68726689eec6c837ff967ac66e56bd345c0898 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Wed, 11 Mar 2026 18:53:27 -0500
Subject: [PATCH 08/12] Remove unnecessary default parameter value.
---
flang-rt/include/flang-rt/runtime/format-implementation.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/flang-rt/include/flang-rt/runtime/format-implementation.h b/flang-rt/include/flang-rt/runtime/format-implementation.h
index 8b341def2b3ce..0781816f562e1 100644
--- a/flang-rt/include/flang-rt/runtime/format-implementation.h
+++ b/flang-rt/include/flang-rt/runtime/format-implementation.h
@@ -193,7 +193,7 @@ static RT_API_ATTRS bool AbsoluteTabbing(CONTEXT &context, int n) {
template <typename CONTEXT>
static RT_API_ATTRS void HandleControl(
- CONTEXT &context, char ch, char next, int n, char next2 = '\0') {
+ CONTEXT &context, char ch, char next, int n, char next2) {
MutableModes &modes{context.mutableModes()};
switch (ch) {
case 'B':
>From 29253eced419423ea4633f2cd1690aacecf79864 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 12 Mar 2026 12:06:27 -0500
Subject: [PATCH 09/12] Re-implement with editingFlags replacing enum.
---
.../flang-rt/runtime/format-implementation.h | 9 +---
flang-rt/include/flang-rt/runtime/format.h | 10 +----
flang-rt/lib/runtime/edit-output.cpp | 45 +++----------------
3 files changed, 11 insertions(+), 53 deletions(-)
diff --git a/flang-rt/include/flang-rt/runtime/format-implementation.h b/flang-rt/include/flang-rt/runtime/format-implementation.h
index 0781816f562e1..e469ba627f32c 100644
--- a/flang-rt/include/flang-rt/runtime/format-implementation.h
+++ b/flang-rt/include/flang-rt/runtime/format-implementation.h
@@ -254,14 +254,9 @@ static RT_API_ATTRS void HandleControl(
case 'L':
if (next == 'Z') {
if (next2 == 'S') {
- // LZS - suppress leading zeros
- modes.leadingZero = MutableModes::LeadingZeroMode::Suppress;
- } else if (next2 == 'P') {
- // LZP - print leading zero
- modes.leadingZero = MutableModes::LeadingZeroMode::Print;
+ modes.editingFlags |= leadingZeroSuppress; // LZS
} else {
- // LZ - processor-dependent (default behavior)
- modes.leadingZero = MutableModes::LeadingZeroMode::Processor;
+ modes.editingFlags &= ~leadingZeroSuppress; // LZ or LZP
}
return;
}
diff --git a/flang-rt/include/flang-rt/runtime/format.h b/flang-rt/include/flang-rt/runtime/format.h
index 787772935ce8c..c36abaaf15b55 100644
--- a/flang-rt/include/flang-rt/runtime/format.h
+++ b/flang-rt/include/flang-rt/runtime/format.h
@@ -33,6 +33,7 @@ enum EditingFlags {
blankZero = 1, // BLANK=ZERO or BZ edit
decimalComma = 2, // DECIMAL=COMMA or DC edit
signPlus = 4, // SIGN=PLUS or SP edit
+ leadingZeroSuppress = 8, // LZS edit; clear for LZ & LZP
};
struct MutableModes {
@@ -44,13 +45,7 @@ struct MutableModes {
return editingFlags & decimalComma ? char32_t{','} : char32_t{'.'};
}
- enum class LeadingZeroMode : std::uint8_t {
- Processor, // LZ: processor-dependent (default)
- Suppress, // LZS: suppress optional leading zero
- Print, // LZP: print optional leading zero
- };
-
- std::uint8_t editingFlags{0}; // BN, DP, SS
+ std::uint8_t editingFlags{0}; // BN, DP, SS, LZS
enum decimal::FortranRounding round{
executionEnvironment
.defaultOutputRoundingMode}; // RP/ROUND='PROCESSOR_DEFAULT'
@@ -59,7 +54,6 @@ struct MutableModes {
short scale{0}; // kP
bool inNamelist{false}; // skip ! comments
bool nonAdvancing{false}; // ADVANCE='NO', or $ or \ in FORMAT
- LeadingZeroMode leadingZero{LeadingZeroMode::Processor}; // LZ/LZS/LZP
};
// A single edit descriptor extracted from a FORMAT
diff --git a/flang-rt/lib/runtime/edit-output.cpp b/flang-rt/lib/runtime/edit-output.cpp
index e3d39f8874e41..dc90a2a3a16cc 100644
--- a/flang-rt/lib/runtime/edit-output.cpp
+++ b/flang-rt/lib/runtime/edit-output.cpp
@@ -419,28 +419,11 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditEorDOutput(
if (totalLength > width || !exponent) {
return EmitRepeated(io_, '*', width);
}
- if (digitsBeforePoint == 0 && zeroesBeforePoint == 0 && scale <= 0) {
- // Optional leading zero position (F202X leading zero control).
- // When scale > 0 (kP with k > 0), digits are moved before the decimal
- // point, so the leading zero position is not optional -- skip this.
- // Value has no digits before the decimal point: "0.xxxE+yy" vs ".xxxE+yy"
- switch (edit.modes.leadingZero) {
- case MutableModes::LeadingZeroMode::Print:
- // LZP: always print the optional leading zero
- zeroesBeforePoint = 1;
- ++totalLength;
- break;
- case MutableModes::LeadingZeroMode::Suppress:
- // LZS: never print the optional leading zero
- break;
- case MutableModes::LeadingZeroMode::Processor:
- // LZ: processor-defined; add leading zero only when field has room
- if (totalLength < width) {
- zeroesBeforePoint = 1;
- ++totalLength;
- }
- break;
- }
+ if (totalLength < width && digitsBeforePoint == 0 &&
+ zeroesBeforePoint == 0 &&
+ !(edit.modes.editingFlags & leadingZeroSuppress)) {
+ zeroesBeforePoint = 1;
+ ++totalLength;
}
if (totalLength < width && editWidth == 0) {
width = totalLength;
@@ -571,20 +554,6 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
digitsAfterPoint + trailingZeroes ==
0) {
zeroesBeforePoint = 1; // "."--> "0." (bare decimal point)
- } else if (digitsBeforePoint == 0 && zeroesBeforePoint == 0 && expo <= 0) {
- // Optional leading zero position (F202X leading zero control).
- // Value magnitude < 1: "0.xxx" vs ".xxx"
- switch (edit.modes.leadingZero) {
- case MutableModes::LeadingZeroMode::Print:
- // LZP: always print the optional leading zero
- zeroesBeforePoint = 1;
- break;
- case MutableModes::LeadingZeroMode::Suppress:
- // LZS: never print the optional leading zero
- break;
- case MutableModes::LeadingZeroMode::Processor:
- break; // handled below after width computation
- }
}
int totalLength{signLength + digitsBeforePoint + zeroesBeforePoint +
1 /*'.'*/ + zeroesAfterPoint + digitsAfterPoint + trailingZeroes +
@@ -593,8 +562,8 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
if (totalLength > width) {
return EmitRepeated(io_, '*', width);
}
- if (edit.modes.leadingZero == MutableModes::LeadingZeroMode::Processor &&
- totalLength < width && digitsBeforePoint + zeroesBeforePoint == 0) {
+ if (totalLength < width && digitsBeforePoint + zeroesBeforePoint == 0 &&
+ !(edit.modes.editingFlags & leadingZeroSuppress)) {
zeroesBeforePoint = 1;
++totalLength;
}
>From f3571876967282f14e1cd9f5966c9e7eacebfff9 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Sat, 14 Mar 2026 00:50:55 -0500
Subject: [PATCH 10/12] Implement LEADING_ZERO= specifier for OPEN, INQUIRE and
WRITE statements; Improve comments and doc wordings.
---
.../flang-rt/runtime/format-implementation.h | 4 +-
flang-rt/lib/runtime/edit-output.cpp | 2 +-
flang-rt/lib/runtime/io-api.cpp | 23 ++++
flang-rt/lib/runtime/io-stmt.cpp | 8 ++
.../unittests/Runtime/LeadingZeroTest.cpp | 117 ++++++++++++++++++
flang/docs/F202X.md | 8 +-
flang/docs/FortranStandardsSupport.md | 2 +-
flang/include/flang/Parser/parse-tree.h | 16 ++-
flang/include/flang/Runtime/io-api.h | 6 +-
flang/include/flang/Support/Fortran.h | 6 +-
flang/lib/Lower/IO.cpp | 13 +-
flang/lib/Parser/io-parsers.cpp | 11 ++
flang/lib/Parser/unparse.cpp | 16 ++-
flang/lib/Semantics/check-io.cpp | 16 +++
flang/test/Semantics/io18.f90 | 27 ++++
15 files changed, 252 insertions(+), 23 deletions(-)
diff --git a/flang-rt/include/flang-rt/runtime/format-implementation.h b/flang-rt/include/flang-rt/runtime/format-implementation.h
index e469ba627f32c..812802b07ac9f 100644
--- a/flang-rt/include/flang-rt/runtime/format-implementation.h
+++ b/flang-rt/include/flang-rt/runtime/format-implementation.h
@@ -193,7 +193,7 @@ static RT_API_ATTRS bool AbsoluteTabbing(CONTEXT &context, int n) {
template <typename CONTEXT>
static RT_API_ATTRS void HandleControl(
- CONTEXT &context, char ch, char next, int n, char next2) {
+ CONTEXT &context, char ch, char next, char next2, int n) {
MutableModes &modes{context.mutableModes()};
switch (ch) {
case 'B':
@@ -504,7 +504,7 @@ RT_API_ATTRS int FormatControl<CONTEXT>::CueUpNextDataEdit(
repeat = GetIntField(context);
}
HandleControl(context, static_cast<char>(ch), static_cast<char>(next),
- repeat ? *repeat : 1, static_cast<char>(next2));
+ static_cast<char>(next2), repeat ? *repeat : 1);
}
} else if (ch == '/') {
context.AdvanceRecord(repeat && *repeat > 0 ? *repeat : 1);
diff --git a/flang-rt/lib/runtime/edit-output.cpp b/flang-rt/lib/runtime/edit-output.cpp
index dc90a2a3a16cc..ded76f073aa1a 100644
--- a/flang-rt/lib/runtime/edit-output.cpp
+++ b/flang-rt/lib/runtime/edit-output.cpp
@@ -553,7 +553,7 @@ RT_API_ATTRS bool RealOutputEditing<KIND>::EditFOutput(const DataEdit &edit) {
if (digitsBeforePoint + zeroesBeforePoint + zeroesAfterPoint +
digitsAfterPoint + trailingZeroes ==
0) {
- zeroesBeforePoint = 1; // "."--> "0." (bare decimal point)
+ zeroesBeforePoint = 1; // "." -> "0." (avoid bare decimal point)
}
int totalLength{signLength + digitsBeforePoint + zeroesBeforePoint +
1 /*'.'*/ + zeroesAfterPoint + digitsAfterPoint + trailingZeroes +
diff --git a/flang-rt/lib/runtime/io-api.cpp b/flang-rt/lib/runtime/io-api.cpp
index f2a1666a0571d..aa3ad9254fe0c 100644
--- a/flang-rt/lib/runtime/io-api.cpp
+++ b/flang-rt/lib/runtime/io-api.cpp
@@ -688,6 +688,29 @@ bool IODEF(SetSign)(Cookie cookie, const char *keyword, std::size_t length) {
}
}
+bool IODEF(SetLeadingZero)(
+ Cookie cookie, const char *keyword, std::size_t length) {
+ IoStatementState &io{*cookie};
+ if (auto *open{io.get_if<OpenStatementState>()}) {
+ open->set_mustBeFormatted();
+ }
+ static const char *keywords[]{
+ "PRINT", "PROCESSOR_DEFINED", "SUPPRESS", nullptr};
+ switch (IdentifyValue(keyword, length, keywords)) {
+ case 0: // LZP, print leading zero, if the field has room for it
+ case 1: // LZ, processor default, treated as LZP
+ io.mutableModes().editingFlags &= ~leadingZeroSuppress;
+ return true;
+ case 2:
+ io.mutableModes().editingFlags |= leadingZeroSuppress;
+ return true;
+ default:
+ io.GetIoErrorHandler().SignalError(IostatErrorInKeyword,
+ "Invalid LEADING_ZERO='%.*s'", static_cast<int>(length), keyword);
+ return false;
+ }
+}
+
bool IODEF(SetAccess)(Cookie cookie, const char *keyword, std::size_t length) {
IoStatementState &io{*cookie};
auto *open{io.get_if<OpenStatementState>()};
diff --git a/flang-rt/lib/runtime/io-stmt.cpp b/flang-rt/lib/runtime/io-stmt.cpp
index 6d3b01af6c792..62044a1d957cf 100644
--- a/flang-rt/lib/runtime/io-stmt.cpp
+++ b/flang-rt/lib/runtime/io-stmt.cpp
@@ -1278,6 +1278,12 @@ bool InquireUnitState::Inquire(
: mutableModes().editingFlags & decimalComma ? "COMMA"
: "POINT";
break;
+ case HashInquiryKeyword("Leading_Zero"):
+ str = !unit().IsConnected() || unit().isUnformatted.value_or(true)
+ ? "UNDEFINED"
+ : mutableModes().editingFlags & leadingZeroSuppress ? "SUPPRESS"
+ : "PRINT";
+ break;
case HashInquiryKeyword("DELIM"):
if (!unit().IsConnected() || unit().isUnformatted.value_or(true)) {
str = "UNDEFINED";
@@ -1503,6 +1509,7 @@ bool InquireNoUnitState::Inquire(
case HashInquiryKeyword("DECIMAL"):
case HashInquiryKeyword("DELIM"):
case HashInquiryKeyword("FORM"):
+ case HashInquiryKeyword("Leading_Zero"):
case HashInquiryKeyword("NAME"):
case HashInquiryKeyword("PAD"):
case HashInquiryKeyword("POSITION"):
@@ -1591,6 +1598,7 @@ bool InquireUnconnectedFileState::Inquire(
case HashInquiryKeyword("DECIMAL"):
case HashInquiryKeyword("DELIM"):
case HashInquiryKeyword("FORM"):
+ case HashInquiryKeyword("Leading_Zero"):
case HashInquiryKeyword("PAD"):
case HashInquiryKeyword("POSITION"):
case HashInquiryKeyword("ROUND"):
diff --git a/flang-rt/unittests/Runtime/LeadingZeroTest.cpp b/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
index d151e03923239..a36a95b3c0476 100644
--- a/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
+++ b/flang-rt/unittests/Runtime/LeadingZeroTest.cpp
@@ -260,3 +260,120 @@ TEST(LeadingZeroTests, WithoutCommaSeparator) {
ASSERT_TRUE(CompareFormatReal("(LZF6.1)", 0.2, " 0.2", got))
<< "Expected ' 0.2', got '" << got << "'";
}
+
+// LEADING_ZERO= specifier via SetLeadingZero runtime API
+TEST(LeadingZeroTests, SetLeadingZero_Suppress) {
+ // LEADING_ZERO='SUPPRESS' should suppress the optional leading zero
+ char buffer[800];
+ const char *format{"(F6.1)"};
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ IONAME(SetLeadingZero)(cookie, "SUPPRESS", 8);
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ ASSERT_TRUE(CompareFormattedStrings(" .5", got))
+ << "Expected ' .5', got '" << got << "'";
+}
+
+TEST(LeadingZeroTests, SetLeadingZero_Print) {
+ // LEADING_ZERO='PRINT' should print the optional leading zero
+ char buffer[800];
+ const char *format{"(F6.1)"};
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ IONAME(SetLeadingZero)(cookie, "PRINT", 5);
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ ASSERT_TRUE(CompareFormattedStrings(" 0.5", got))
+ << "Expected ' 0.5', got '" << got << "'";
+}
+
+TEST(LeadingZeroTests, SetLeadingZero_ProcessorDefined) {
+ // LEADING_ZERO='PROCESSOR_DEFINED' should behave like PRINT (flang default)
+ char buffer[800];
+ const char *format{"(F6.1)"};
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ IONAME(SetLeadingZero)(cookie, "PROCESSOR_DEFINED", 17);
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ ASSERT_TRUE(CompareFormattedStrings(" 0.5", got))
+ << "Expected ' 0.5', got '" << got << "'";
+}
+
+// LEADING_ZERO= overridden by LZS/LZP edit descriptors in format
+TEST(LeadingZeroTests, SetLeadingZero_OverriddenByEditDescriptor) {
+ // Set LEADING_ZERO='PRINT' but format uses LZS — LZS should win
+ char buffer[800];
+ const char *format{"(LZS,F6.1)"};
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ IONAME(SetLeadingZero)(cookie, "PRINT", 5);
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ ASSERT_TRUE(CompareFormattedStrings(" .5", got))
+ << "Expected ' .5', got '" << got << "'";
+}
+
+// LEADING_ZERO= specifier via SetLeadingZero runtime API
+TEST(LeadingZeroTests, SetLeadingZeroSuppressViaAPI) {
+ char buffer[800];
+ const char *format{"(F6.1)"};
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ // Set LEADING_ZERO='SUPPRESS'
+ EXPECT_TRUE(IONAME(SetLeadingZero)(cookie, "SUPPRESS", 8));
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ ASSERT_TRUE(CompareFormattedStrings(" .5", got))
+ << "Expected ' .5', got '" << got << "'";
+}
+
+TEST(LeadingZeroTests, SetLeadingZeroPrintViaAPI) {
+ char buffer[800];
+ const char *format{"(F6.1)"};
+ auto cookie{IONAME(BeginInternalFormattedOutput)(
+ buffer, sizeof buffer, format, std::strlen(format))};
+ // Set LEADING_ZERO='PRINT'
+ EXPECT_TRUE(IONAME(SetLeadingZero)(cookie, "PRINT", 5));
+ EXPECT_TRUE(IONAME(OutputReal64)(cookie, 0.5));
+ auto status{IONAME(EndIoStatement)(cookie)};
+ EXPECT_EQ(status, 0);
+ std::string got{buffer, sizeof buffer};
+ auto lastNonBlank{got.find_last_not_of(" ")};
+ if (lastNonBlank != std::string::npos) {
+ got.resize(lastNonBlank + 1);
+ }
+ ASSERT_TRUE(CompareFormattedStrings(" 0.5", got))
+ << "Expected ' 0.5', got '" << got << "'";
+}
diff --git a/flang/docs/F202X.md b/flang/docs/F202X.md
index 6a303981cf264..c510b03b1820c 100644
--- a/flang/docs/F202X.md
+++ b/flang/docs/F202X.md
@@ -264,11 +264,11 @@ means for controlling the output of leading zero digits.
Implementation status:
- `LZ`, `LZS`, `LZP` control edit descriptors, affect only F, E, D, and G
editing of an output statement: Implemented
- - `LZ` - Processor-dependent, default (e.g., `0.2`)
- - `LZS` - Suppress leading zeros (e.g., `.2`)
- - `LZP` - Print leading zero (e.g. `0.2`)
+ - `LZ` - Processor-dependent (flang treats as LZP)
+ - `LZS` - Suppress leading zero (e.g., `.2`)
+ - `LZP` - Print leading zero when the field is wide enough (e.g., `0.2`)
- `AT` edit descriptor: Not yet implemented
-- `LEADING_ZERO=specifier` in OPEN statement: Not yet implemented
+- `LEADING_ZERO=` specifier in OPEN, WRITE and INQUIRE statements: Implemented
#### Intrinsic Module Extensions
diff --git a/flang/docs/FortranStandardsSupport.md b/flang/docs/FortranStandardsSupport.md
index 02e4653280f12..06a2fce637167 100644
--- a/flang/docs/FortranStandardsSupport.md
+++ b/flang/docs/FortranStandardsSupport.md
@@ -48,7 +48,7 @@ status of all important Fortran 2023 features. The table entries are based on th
| Extensions for c_f_pointer intrinsic | Y | |
| Procedures for converting between fortran and c strings | N | |
| The at edit descriptor | N | |
-| Control over leading zeros in output of real values | P | LZ/LZS/LZP edit descriptors implemented; LEADING_ZERO=specifier not yet implemented |
+| Control over leading zeros in output of real values | Y | |
| Extensions for Namelist | N | |
| Allow an object of a type with a coarray ultimate component to be an array or allocatable | N | |
| Put with Notify | N | |
diff --git a/flang/include/flang/Parser/parse-tree.h b/flang/include/flang/Parser/parse-tree.h
index 4aec99c80bdae..034b2d63983de 100644
--- a/flang/include/flang/Parser/parse-tree.h
+++ b/flang/include/flang/Parser/parse-tree.h
@@ -2630,6 +2630,7 @@ using FileNameExpr = ScalarDefaultCharExpr;
// ENCODING = scalar-default-char-expr | ERR = label |
// FILE = file-name-expr | FORM = scalar-default-char-expr |
// IOMSG = iomsg-variable | IOSTAT = scalar-int-variable |
+// LEADING_ZERO = scalar-default-char-expr |
// NEWUNIT = scalar-int-variable | PAD = scalar-default-char-expr |
// POSITION = scalar-default-char-expr | RECL = scalar-int-expr |
// ROUND = scalar-default-char-expr | SIGN = scalar-default-char-expr |
@@ -2644,7 +2645,7 @@ struct ConnectSpec {
UNION_CLASS_BOILERPLATE(ConnectSpec);
struct CharExpr {
ENUM_CLASS(Kind, Access, Action, Asynchronous, Blank, Decimal, Delim,
- Encoding, Form, Pad, Position, Round, Sign,
+ Encoding, Form, Leading_Zero, Pad, Position, Round, Sign,
/* extensions: */ Carriagecontrol, Convert, Dispose)
TUPLE_CLASS_BOILERPLATE(CharExpr);
std::tuple<Kind, ScalarDefaultCharExpr> t;
@@ -2692,7 +2693,9 @@ WRAPPER_CLASS(IdVariable, ScalarIntVariable);
// DECIMAL = scalar-default-char-expr |
// DELIM = scalar-default-char-expr | END = label | EOR = label |
// ERR = label | ID = id-variable | IOMSG = iomsg-variable |
-// IOSTAT = scalar-int-variable | PAD = scalar-default-char-expr |
+// IOSTAT = scalar-int-variable |
+// LEADING_ZERO = scalar-default-char-expr |
+// PAD = scalar-default-char-expr |
// POS = scalar-int-expr | REC = scalar-int-expr |
// ROUND = scalar-default-char-expr | SIGN = scalar-default-char-expr |
// SIZE = scalar-int-variable
@@ -2701,7 +2704,8 @@ WRAPPER_CLASS(EorLabel, Label);
struct IoControlSpec {
UNION_CLASS_BOILERPLATE(IoControlSpec);
struct CharExpr {
- ENUM_CLASS(Kind, Advance, Blank, Decimal, Delim, Pad, Round, Sign)
+ ENUM_CLASS(Kind, Advance, Blank, Decimal, Delim, Leading_Zero, Pad, Round,
+ Sign)
TUPLE_CLASS_BOILERPLATE(CharExpr);
std::tuple<Kind, ScalarDefaultCharExpr> t;
};
@@ -2837,6 +2841,7 @@ WRAPPER_CLASS(FlushStmt, std::list<PositionOrFlushSpec>);
// FORMATTED = scalar-default-char-variable |
// ID = scalar-int-expr | IOMSG = iomsg-variable |
// IOSTAT = scalar-int-variable |
+// LEADING_ZERO = scalar-default-char-variable |
// NAME = scalar-default-char-variable |
// NAMED = scalar-logical-variable |
// NEXTREC = scalar-int-variable | NUMBER = scalar-int-variable |
@@ -2861,8 +2866,9 @@ struct InquireSpec {
UNION_CLASS_BOILERPLATE(InquireSpec);
struct CharVar {
ENUM_CLASS(Kind, Access, Action, Asynchronous, Blank, Decimal, Delim,
- Direct, Encoding, Form, Formatted, Iomsg, Name, Pad, Position, Read,
- Readwrite, Round, Sequential, Sign, Stream, Status, Unformatted, Write,
+ Direct, Encoding, Form, Formatted, Iomsg, Leading_Zero, Name, Pad,
+ Position, Read, Readwrite, Round, Sequential, Sign, Stream, Status,
+ Unformatted, Write,
/* extensions: */ Carriagecontrol, Convert, Dispose)
TUPLE_CLASS_BOILERPLATE(CharVar);
std::tuple<Kind, ScalarDefaultCharVariable> t;
diff --git a/flang/include/flang/Runtime/io-api.h b/flang/include/flang/Runtime/io-api.h
index fe49af2f61683..86cd4490c2990 100644
--- a/flang/include/flang/Runtime/io-api.h
+++ b/flang/include/flang/Runtime/io-api.h
@@ -238,6 +238,8 @@ bool IODECL(SetRec)(Cookie, std::int64_t);
bool IODECL(SetRound)(Cookie, const char *, std::size_t);
// SIGN=PLUS, SUPPRESS, PROCESSOR_DEFINED
bool IODECL(SetSign)(Cookie, const char *, std::size_t);
+// LEADING_ZERO=PRINT, PROCESSOR_DEFINED, SUPPRESS
+bool IODECL(SetLeadingZero)(Cookie, const char *, std::size_t);
// Data item transfer for modes other than NAMELIST:
// Any data object that can be passed as an actual argument without the
@@ -298,8 +300,8 @@ bool IODECL(InputDerivedType)(
// Additional specifier interfaces for the connection-list of
// on OPEN statement (only). SetBlank(), SetDecimal(),
-// SetDelim(), GetIoMsg(), SetPad(), SetRound(), SetSign(),
-// & SetAsynchronous() are also acceptable for OPEN.
+// SetDelim(), GetIoMsg(), SetLeadingZero(), SetPad(), SetRound(),
+// SetSign(), & SetAsynchronous() are also acceptable for OPEN.
// ACCESS=SEQUENTIAL, DIRECT, STREAM
bool IODECL(SetAccess)(Cookie, const char *, std::size_t);
// ACTION=READ, WRITE, or READWRITE
diff --git a/flang/include/flang/Support/Fortran.h b/flang/include/flang/Support/Fortran.h
index 5ca7882da32fd..dc6f7ec900e74 100644
--- a/flang/include/flang/Support/Fortran.h
+++ b/flang/include/flang/Support/Fortran.h
@@ -48,9 +48,9 @@ ENUM_CLASS(Intent, Default, In, Out, InOut)
// Union of specifiers for all I/O statements.
ENUM_CLASS(IoSpecKind, Access, Action, Advance, Asynchronous, Blank, Decimal,
Delim, Direct, Encoding, End, Eor, Err, Exist, File, Fmt, Form, Formatted,
- Id, Iomsg, Iostat, Name, Named, Newunit, Nextrec, Nml, Number, Opened, Pad,
- Pending, Pos, Position, Read, Readwrite, Rec, Recl, Round, Sequential, Sign,
- Size, Status, Stream, Unformatted, Unit, Write,
+ Id, Iomsg, Iostat, Leading_Zero, Name, Named, Newunit, Nextrec, Nml, Number,
+ Opened, Pad, Pending, Pos, Position, Read, Readwrite, Rec, Recl, Round,
+ Sequential, Sign, Size, Status, Stream, Unformatted, Unit, Write,
Carriagecontrol, // nonstandard
Convert, // nonstandard
Dispose, // nonstandard
diff --git a/flang/lib/Lower/IO.cpp b/flang/lib/Lower/IO.cpp
index de2afb70636d5..e38bee79abb9c 100644
--- a/flang/lib/Lower/IO.cpp
+++ b/flang/lib/Lower/IO.cpp
@@ -84,8 +84,9 @@ static constexpr std::tuple<
mkIOKey(SetAccess), mkIOKey(SetAction), mkIOKey(SetAdvance),
mkIOKey(SetAsynchronous), mkIOKey(SetBlank), mkIOKey(SetCarriagecontrol),
mkIOKey(SetConvert), mkIOKey(SetDecimal), mkIOKey(SetDelim),
- mkIOKey(SetEncoding), mkIOKey(SetFile), mkIOKey(SetForm), mkIOKey(SetPad),
- mkIOKey(SetPos), mkIOKey(SetPosition), mkIOKey(SetRec), mkIOKey(SetRecl),
+ mkIOKey(SetEncoding), mkIOKey(SetFile), mkIOKey(SetForm),
+ mkIOKey(SetLeadingZero), mkIOKey(SetPad), mkIOKey(SetPos),
+ mkIOKey(SetPosition), mkIOKey(SetRec), mkIOKey(SetRecl),
mkIOKey(SetRound), mkIOKey(SetSign), mkIOKey(SetStatus)>
newIOTable;
} // namespace Fortran::lower
@@ -1246,6 +1247,10 @@ mlir::Value genIOOption<Fortran::parser::ConnectSpec::CharExpr>(
case Fortran::parser::ConnectSpec::CharExpr::Kind::Form:
ioFunc = fir::runtime::getIORuntimeFunc<mkIOKey(SetForm)>(loc, builder);
break;
+ case Fortran::parser::ConnectSpec::CharExpr::Kind::Leading_Zero:
+ ioFunc =
+ fir::runtime::getIORuntimeFunc<mkIOKey(SetLeadingZero)>(loc, builder);
+ break;
case Fortran::parser::ConnectSpec::CharExpr::Kind::Pad:
ioFunc = fir::runtime::getIORuntimeFunc<mkIOKey(SetPad)>(loc, builder);
break;
@@ -1312,6 +1317,10 @@ mlir::Value genIOOption<Fortran::parser::IoControlSpec::CharExpr>(
case Fortran::parser::IoControlSpec::CharExpr::Kind::Delim:
ioFunc = fir::runtime::getIORuntimeFunc<mkIOKey(SetDelim)>(loc, builder);
break;
+ case Fortran::parser::IoControlSpec::CharExpr::Kind::Leading_Zero:
+ ioFunc =
+ fir::runtime::getIORuntimeFunc<mkIOKey(SetLeadingZero)>(loc, builder);
+ break;
case Fortran::parser::IoControlSpec::CharExpr::Kind::Pad:
ioFunc = fir::runtime::getIORuntimeFunc<mkIOKey(SetPad)>(loc, builder);
break;
diff --git a/flang/lib/Parser/io-parsers.cpp b/flang/lib/Parser/io-parsers.cpp
index 4e969fdec77ad..2d046f613b86d 100644
--- a/flang/lib/Parser/io-parsers.cpp
+++ b/flang/lib/Parser/io-parsers.cpp
@@ -96,6 +96,9 @@ TYPE_PARSER(first(construct<ConnectSpec>(maybe("UNIT ="_tok) >> fileUnitNumber),
scalarDefaultCharExpr)),
construct<ConnectSpec>("IOMSG =" >> msgVariable),
construct<ConnectSpec>("IOSTAT =" >> statVariable),
+ construct<ConnectSpec>(construct<ConnectSpec::CharExpr>(
+ "LEADING_ZERO =" >> pure(ConnectSpec::CharExpr::Kind::Leading_Zero),
+ scalarDefaultCharExpr)),
construct<ConnectSpec>(construct<ConnectSpec::Newunit>(
"NEWUNIT =" >> scalar(integer(variable)))),
construct<ConnectSpec>(construct<ConnectSpec::CharExpr>(
@@ -217,6 +220,10 @@ TYPE_PARSER(first(construct<IoControlSpec>("UNIT =" >> ioUnit),
construct<IoControlSpec>("ID =" >> idVariable),
construct<IoControlSpec>("IOMSG = " >> msgVariable),
construct<IoControlSpec>("IOSTAT = " >> statVariable),
+ construct<IoControlSpec>("LEADING_ZERO =" >>
+ construct<IoControlSpec::CharExpr>(
+ pure(IoControlSpec::CharExpr::Kind::Leading_Zero),
+ scalarDefaultCharExpr)),
construct<IoControlSpec>("PAD =" >>
construct<IoControlSpec::CharExpr>(
pure(IoControlSpec::CharExpr::Kind::Pad), scalarDefaultCharExpr)),
@@ -430,6 +437,10 @@ TYPE_PARSER(first(construct<InquireSpec>(maybe("UNIT ="_tok) >> fileUnitNumber),
construct<InquireSpec>("IOSTAT =" >>
construct<InquireSpec::IntVar>(pure(InquireSpec::IntVar::Kind::Iostat),
scalar(integer(variable)))),
+ construct<InquireSpec>(
+ "LEADING_ZERO =" >> construct<InquireSpec::CharVar>(
+ pure(InquireSpec::CharVar::Kind::Leading_Zero),
+ scalarDefaultCharVariable)),
construct<InquireSpec>("NAME =" >>
construct<InquireSpec::CharVar>(
pure(InquireSpec::CharVar::Kind::Name), scalarDefaultCharVariable)),
diff --git a/flang/lib/Parser/unparse.cpp b/flang/lib/Parser/unparse.cpp
index c31eac0b3ff68..26c542b5232eb 100644
--- a/flang/lib/Parser/unparse.cpp
+++ b/flang/lib/Parser/unparse.cpp
@@ -1258,7 +1258,10 @@ class UnparseVisitor {
return true;
},
[&](const ConnectSpec::CharExpr &y) {
- Walk(y.t, "=");
+ Walk(std::get<ConnectSpec::CharExpr::Kind>(
+ y.t));
+ Put('=');
+ Walk(std::get<ScalarDefaultCharExpr>(y.t));
return false;
},
[&](const MsgVariable &) {
@@ -1343,7 +1346,11 @@ class UnparseVisitor {
[&](const IoUnit &) { Word("UNIT="); },
[&](const Format &) { Word("FMT="); },
[&](const Name &) { Word("NML="); },
- [&](const IoControlSpec::CharExpr &y) { Walk(y.t, "="); },
+ [&](const IoControlSpec::CharExpr &y) {
+ Walk(std::get<IoControlSpec::CharExpr::Kind>(y.t));
+ Put('=');
+ Walk(std::get<ScalarDefaultCharExpr>(y.t));
+ },
[&](const IoControlSpec::Asynchronous &) { Word("ASYNCHRONOUS="); },
[&](const EndLabel &) { Word("END="); },
[&](const EorLabel &) { Word("EOR="); },
@@ -1425,7 +1432,10 @@ class UnparseVisitor {
return true;
},
[&](const InquireSpec::CharVar &y) {
- Walk(y.t, "=");
+ Walk(std::get<InquireSpec::CharVar::Kind>(
+ y.t));
+ Put('=');
+ Walk(std::get<ScalarDefaultCharVariable>(y.t));
return false;
},
[&](const InquireSpec::IntVar &y) {
diff --git a/flang/lib/Semantics/check-io.cpp b/flang/lib/Semantics/check-io.cpp
index 2d7e419e76ce0..2c1f8658448b2 100644
--- a/flang/lib/Semantics/check-io.cpp
+++ b/flang/lib/Semantics/check-io.cpp
@@ -137,6 +137,9 @@ void IoChecker::Enter(const parser::ConnectSpec::CharExpr &spec) {
case ParseKind::Form:
specKind = IoSpecKind::Form;
break;
+ case ParseKind::Leading_Zero:
+ specKind = IoSpecKind::Leading_Zero;
+ break;
case ParseKind::Pad:
specKind = IoSpecKind::Pad;
break;
@@ -380,6 +383,9 @@ void IoChecker::Enter(const parser::InquireSpec::CharVar &spec) {
case ParseKind::Iomsg:
specKind = IoSpecKind::Iomsg;
break;
+ case ParseKind::Leading_Zero:
+ specKind = IoSpecKind::Leading_Zero;
+ break;
case ParseKind::Name:
specKind = IoSpecKind::Name;
break;
@@ -520,6 +526,9 @@ void IoChecker::Enter(const parser::IoControlSpec::CharExpr &spec) {
case ParseKind::Delim:
specKind = IoSpecKind::Delim;
break;
+ case ParseKind::Leading_Zero:
+ specKind = IoSpecKind::Leading_Zero;
+ break;
case ParseKind::Pad:
specKind = IoSpecKind::Pad;
break;
@@ -827,6 +836,7 @@ void IoChecker::Leave(const parser::ReadStmt &readStmt) {
LeaveReadWrite();
CheckForProhibitedSpecifier(IoSpecKind::Delim); // C1212
CheckForProhibitedSpecifier(IoSpecKind::Sign); // C1212
+ CheckForProhibitedSpecifier(IoSpecKind::Leading_Zero); // C1212
CheckForProhibitedSpecifier(IoSpecKind::Rec, IoSpecKind::End); // C1220
if (specifierSet_.test(IoSpecKind::Size)) {
// F'2023 C1214 - allow with a warning
@@ -882,6 +892,8 @@ void IoChecker::Leave(const parser::WriteStmt &writeStmt) {
CheckForProhibitedSpecifier(IoSpecKind::Size); // C1213
CheckForRequiredSpecifier(
IoSpecKind::Sign, flags_.test(Flag::FmtOrNml), "FMT or NML"); // C1227
+ CheckForRequiredSpecifier(IoSpecKind::Leading_Zero,
+ flags_.test(Flag::FmtOrNml), "FMT or NML"); // C1227
CheckForRequiredSpecifier(IoSpecKind::Delim,
flags_.test(Flag::StarFmt) || specifierSet_.test(IoSpecKind::Nml),
"FMT=* or NML"); // C1228
@@ -922,6 +934,8 @@ void IoChecker::LeaveReadWrite() const {
"FMT or NML"); // C1227
CheckForRequiredSpecifier(IoSpecKind::Round, flags_.test(Flag::FmtOrNml),
"FMT or NML"); // C1227
+ CheckForRequiredSpecifier(IoSpecKind::Leading_Zero,
+ flags_.test(Flag::FmtOrNml), "FMT or NML"); // C1227
CheckForUselessIomsg();
}
@@ -956,6 +970,8 @@ void IoChecker::CheckStringValue(IoSpecKind specKind, const std::string &value,
{IoSpecKind::Round,
{"COMPATIBLE", "DOWN", "NEAREST", "PROCESSOR_DEFINED", "UP", "ZERO"}},
{IoSpecKind::Sign, {"PLUS", "PROCESSOR_DEFINED", "SUPPRESS"}},
+ {IoSpecKind::Leading_Zero,
+ {"PRINT", "PROCESSOR_DEFINED", "SUPPRESS"}},
{IoSpecKind::Status,
// Open values; Close values are {"DELETE", "KEEP"}.
{"NEW", "OLD", "REPLACE", "SCRATCH", "UNKNOWN"}},
diff --git a/flang/test/Semantics/io18.f90 b/flang/test/Semantics/io18.f90
index 559d98f0d5ceb..686ba648ec3dd 100644
--- a/flang/test/Semantics/io18.f90
+++ b/flang/test/Semantics/io18.f90
@@ -2,6 +2,9 @@
! F202X leading-zero control edit descriptors: LZ, LZS, LZP
+ real :: x
+ character(20) :: lz_val
+
! Valid uses of LZ, LZP, LZS in FORMAT statements
1001 format(LZ, F10.3)
1002 format(LZP, F10.3)
@@ -96,4 +99,28 @@
!ERROR: Repeat specifier before 'LZS' edit descriptor
2003 format(2LZS, F10.3)
+
+ ! LEADING_ZERO= specifier tests
+
+ ! Valid LEADING_ZERO= on OPEN
+ open(10, file='test.dat', form='formatted', leading_zero='print')
+ open(10, file='test.dat', form='formatted', leading_zero='suppress')
+ open(10, file='test.dat', form='formatted', leading_zero='processor_defined')
+
+ ! Valid LEADING_ZERO= on WRITE
+ write(10, '(F10.3)', leading_zero='print') 0.5
+ write(10, '(F10.3)', leading_zero='suppress') 0.5
+
+ ! Error: LEADING_ZERO= on READ (prohibited, like SIGN=)
+ !ERROR: READ statement must not have a LEADING_ZERO specifier
+ read(10, '(F10.3)', leading_zero='print') x
+
+ ! Error: invalid LEADING_ZERO= value
+ !ERROR: Invalid LEADING_ZERO value 'bogus'
+ open(10, file='test.dat', form='formatted', leading_zero='bogus')
+
+ ! Valid LEADING_ZERO= on INQUIRE
+ inquire(10, leading_zero=lz_val)
+
+ close(10)
end
>From 4ced144808bc0f143b7441ffdbf3075550403223 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Sat, 14 Mar 2026 01:29:45 -0500
Subject: [PATCH 11/12] Update code format to be compliant with
git-clang-format
---
flang-rt/lib/runtime/io-stmt.cpp | 2 +-
flang/include/flang/Parser/parse-tree.h | 4 ++--
flang/lib/Lower/IO.cpp | 4 ++--
flang/lib/Parser/unparse.cpp | 6 ++----
flang/lib/Semantics/check-io.cpp | 3 +--
5 files changed, 8 insertions(+), 11 deletions(-)
diff --git a/flang-rt/lib/runtime/io-stmt.cpp b/flang-rt/lib/runtime/io-stmt.cpp
index 62044a1d957cf..9eb2dad8e457d 100644
--- a/flang-rt/lib/runtime/io-stmt.cpp
+++ b/flang-rt/lib/runtime/io-stmt.cpp
@@ -1282,7 +1282,7 @@ bool InquireUnitState::Inquire(
str = !unit().IsConnected() || unit().isUnformatted.value_or(true)
? "UNDEFINED"
: mutableModes().editingFlags & leadingZeroSuppress ? "SUPPRESS"
- : "PRINT";
+ : "PRINT";
break;
case HashInquiryKeyword("DELIM"):
if (!unit().IsConnected() || unit().isUnformatted.value_or(true)) {
diff --git a/flang/include/flang/Parser/parse-tree.h b/flang/include/flang/Parser/parse-tree.h
index 034b2d63983de..a0106cac84620 100644
--- a/flang/include/flang/Parser/parse-tree.h
+++ b/flang/include/flang/Parser/parse-tree.h
@@ -2704,8 +2704,8 @@ WRAPPER_CLASS(EorLabel, Label);
struct IoControlSpec {
UNION_CLASS_BOILERPLATE(IoControlSpec);
struct CharExpr {
- ENUM_CLASS(Kind, Advance, Blank, Decimal, Delim, Leading_Zero, Pad, Round,
- Sign)
+ ENUM_CLASS(
+ Kind, Advance, Blank, Decimal, Delim, Leading_Zero, Pad, Round, Sign)
TUPLE_CLASS_BOILERPLATE(CharExpr);
std::tuple<Kind, ScalarDefaultCharExpr> t;
};
diff --git a/flang/lib/Lower/IO.cpp b/flang/lib/Lower/IO.cpp
index e38bee79abb9c..d9bbf12dc108b 100644
--- a/flang/lib/Lower/IO.cpp
+++ b/flang/lib/Lower/IO.cpp
@@ -86,8 +86,8 @@ static constexpr std::tuple<
mkIOKey(SetConvert), mkIOKey(SetDecimal), mkIOKey(SetDelim),
mkIOKey(SetEncoding), mkIOKey(SetFile), mkIOKey(SetForm),
mkIOKey(SetLeadingZero), mkIOKey(SetPad), mkIOKey(SetPos),
- mkIOKey(SetPosition), mkIOKey(SetRec), mkIOKey(SetRecl),
- mkIOKey(SetRound), mkIOKey(SetSign), mkIOKey(SetStatus)>
+ mkIOKey(SetPosition), mkIOKey(SetRec), mkIOKey(SetRecl), mkIOKey(SetRound),
+ mkIOKey(SetSign), mkIOKey(SetStatus)>
newIOTable;
} // namespace Fortran::lower
diff --git a/flang/lib/Parser/unparse.cpp b/flang/lib/Parser/unparse.cpp
index 26c542b5232eb..2a95f121bd306 100644
--- a/flang/lib/Parser/unparse.cpp
+++ b/flang/lib/Parser/unparse.cpp
@@ -1258,8 +1258,7 @@ class UnparseVisitor {
return true;
},
[&](const ConnectSpec::CharExpr &y) {
- Walk(std::get<ConnectSpec::CharExpr::Kind>(
- y.t));
+ Walk(std::get<ConnectSpec::CharExpr::Kind>(y.t));
Put('=');
Walk(std::get<ScalarDefaultCharExpr>(y.t));
return false;
@@ -1432,8 +1431,7 @@ class UnparseVisitor {
return true;
},
[&](const InquireSpec::CharVar &y) {
- Walk(std::get<InquireSpec::CharVar::Kind>(
- y.t));
+ Walk(std::get<InquireSpec::CharVar::Kind>(y.t));
Put('=');
Walk(std::get<ScalarDefaultCharVariable>(y.t));
return false;
diff --git a/flang/lib/Semantics/check-io.cpp b/flang/lib/Semantics/check-io.cpp
index 2c1f8658448b2..e46df33b4b85c 100644
--- a/flang/lib/Semantics/check-io.cpp
+++ b/flang/lib/Semantics/check-io.cpp
@@ -970,8 +970,7 @@ void IoChecker::CheckStringValue(IoSpecKind specKind, const std::string &value,
{IoSpecKind::Round,
{"COMPATIBLE", "DOWN", "NEAREST", "PROCESSOR_DEFINED", "UP", "ZERO"}},
{IoSpecKind::Sign, {"PLUS", "PROCESSOR_DEFINED", "SUPPRESS"}},
- {IoSpecKind::Leading_Zero,
- {"PRINT", "PROCESSOR_DEFINED", "SUPPRESS"}},
+ {IoSpecKind::Leading_Zero, {"PRINT", "PROCESSOR_DEFINED", "SUPPRESS"}},
{IoSpecKind::Status,
// Open values; Close values are {"DELETE", "KEEP"}.
{"NEW", "OLD", "REPLACE", "SCRATCH", "UNKNOWN"}},
>From ee77ec7b67eb0ee117dc3dccd89db60e9178dc44 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Fri, 20 Mar 2026 06:13:28 -0500
Subject: [PATCH 12/12] Add SetLeadingZero function to RuntimeFunctions.inc and
update tests in set-runtime-call-attributes.fir and
verify-known-runtime-functions.fir
---
.../flang/Optimizer/Transforms/RuntimeFunctions.inc | 1 +
.../test/Transforms/set-runtime-call-attributes.fir | 12 ++++++++++++
.../Transforms/verify-known-runtime-functions.fir | 1 +
3 files changed, 14 insertions(+)
diff --git a/flang/include/flang/Optimizer/Transforms/RuntimeFunctions.inc b/flang/include/flang/Optimizer/Transforms/RuntimeFunctions.inc
index cb4bf4ecf559d..22243c96eced0 100644
--- a/flang/include/flang/Optimizer/Transforms/RuntimeFunctions.inc
+++ b/flang/include/flang/Optimizer/Transforms/RuntimeFunctions.inc
@@ -96,6 +96,7 @@ KNOWN_IO_FUNC(SetDelim),
KNOWN_IO_FUNC(SetEncoding),
KNOWN_IO_FUNC(SetFile),
KNOWN_IO_FUNC(SetForm),
+KNOWN_IO_FUNC(SetLeadingZero),
KNOWN_IO_FUNC(SetPad),
KNOWN_IO_FUNC(SetPos),
KNOWN_IO_FUNC(SetPosition),
diff --git a/flang/test/Transforms/set-runtime-call-attributes.fir b/flang/test/Transforms/set-runtime-call-attributes.fir
index bdc47c84f4d13..c3d6e4dd5797f 100644
--- a/flang/test/Transforms/set-runtime-call-attributes.fir
+++ b/flang/test/Transforms/set-runtime-call-attributes.fir
@@ -868,6 +868,17 @@ module {
%0 = fir.call @_FortranAioSetForm(%arg0, %arg1, %arg2) : (!fir.ref<i8>, !fir.ref<i8>, i64) -> i1
return %0 : i1
}
+// CHECK-LABEL: func.func @test__FortranAioSetLeadingZero(
+// CHECK-SAME: %[[VAL_0:[0-9]+|[a-zA-Z$._-][a-zA-Z0-9$._-]*]]: !fir.ref<i8>,
+// CHECK-SAME: %[[VAL_1:[0-9]+|[a-zA-Z$._-][a-zA-Z0-9$._-]*]]: !fir.ref<i8>,
+// CHECK-SAME: %[[VAL_2:[0-9]+|[a-zA-Z$._-][a-zA-Z0-9$._-]*]]: i64) -> i1 {
+// CHECK: %[[VAL_3:.*]] = fir.call @_FortranAioSetLeadingZero(%[[VAL_0]], %[[VAL_1]], %[[VAL_2]]) {fir.llvm_memory = #llvm.memory_effects<other = none, argMem = readwrite, inaccessibleMem = readwrite, errnoMem = none, targetMem0 = none, targetMem1 = none>, llvm.nocallback, llvm.nosync} : (!fir.ref<i8>, !fir.ref<i8>, i64) -> i1
+// CHECK: return %[[VAL_3]] : i1
+// CHECK: }
+ func.func @test__FortranAioSetLeadingZero(%arg0: !fir.ref<i8>, %arg1: !fir.ref<i8>, %arg2: i64) -> i1 {
+ %0 = fir.call @_FortranAioSetLeadingZero(%arg0, %arg1, %arg2) : (!fir.ref<i8>, !fir.ref<i8>, i64) -> i1
+ return %0 : i1
+ }
// CHECK-LABEL: func.func @test__FortranAioSetPad(
// CHECK-SAME: %[[VAL_0:[0-9]+|[a-zA-Z$._-][a-zA-Z0-9$._-]*]]: !fir.ref<i8>,
// CHECK-SAME: %[[VAL_1:[0-9]+|[a-zA-Z$._-][a-zA-Z0-9$._-]*]]: !fir.ref<i8>,
@@ -1028,6 +1039,7 @@ module {
func.func private @_FortranAioSetEncoding(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
func.func private @_FortranAioSetFile(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
func.func private @_FortranAioSetForm(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
+ func.func private @_FortranAioSetLeadingZero(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
func.func private @_FortranAioSetPad(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
func.func private @_FortranAioSetPos(!fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
func.func private @_FortranAioSetPosition(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
diff --git a/flang/test/Transforms/verify-known-runtime-functions.fir b/flang/test/Transforms/verify-known-runtime-functions.fir
index 902d701424f6f..e87fac5601c56 100644
--- a/flang/test/Transforms/verify-known-runtime-functions.fir
+++ b/flang/test/Transforms/verify-known-runtime-functions.fir
@@ -90,6 +90,7 @@
// CHECK-NEXT: func.func private @_FortranAioSetEncoding(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
// CHECK-NEXT: func.func private @_FortranAioSetFile(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
// CHECK-NEXT: func.func private @_FortranAioSetForm(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
+// CHECK-NEXT: func.func private @_FortranAioSetLeadingZero(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
// CHECK-NEXT: func.func private @_FortranAioSetPad(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
// CHECK-NEXT: func.func private @_FortranAioSetPos(!fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
// CHECK-NEXT: func.func private @_FortranAioSetPosition(!fir.ref<i8>, !fir.ref<i8>, i64) -> i1 attributes {fir.io, fir.runtime}
- Previous message: [flang-commits] [flang] [llvm] [flang][flang-rt] Implement F202X leading-zero control edit descriptors LZ, LZS, and LZP for formatted output (F, E, D, and G editing) (PR #183500)
- Next message: [flang-commits] [flang] [llvm] [flang][flang-rt] Implement F202X leading-zero control edit descriptors LZ, LZS, and LZP for formatted output (F, E, D, and G editing) (PR #183500)
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