[flang-commits] [flang] [flang] Support \u Unicode escape sequences (PR #76757)
via flang-commits
flang-commits at lists.llvm.org
Tue Jan 2 14:19:38 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-parser
Author: Peter Klausler (klausler)
<details>
<summary>Changes</summary>
Support \uNNNN and \uNNNNNNNN escape sequences for CHARACTER(KIND=2) and CHARACTER(KIND=4) literal constants for better GNU Fortran compatibility.
Fixes llvm-test-suite/Fortran/gfortran/regression/achar_6.F90 and .../widechar_1.f90.
---
Full diff: https://github.com/llvm/llvm-project/pull/76757.diff
5 Files Affected:
- (modified) flang/docs/Extensions.md (+2-1)
- (modified) flang/include/flang/Parser/characters.h (+17)
- (modified) flang/lib/Evaluate/character.h (+3-10)
- (modified) flang/lib/Parser/characters.cpp (+24-1)
- (added) flang/test/Semantics/modfile60.f90 (+19)
``````````diff
diff --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
index 16eb67f2e27c81..02ccd51dcb686a 100644
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -322,7 +322,8 @@ end
### Extensions supported when enabled by options
* C-style backslash escape sequences in quoted CHARACTER literals
- (but not Hollerith) [-fbackslash]
+ (but not Hollerith) [-fbackslash], including Unicode escapes
+ with `\U`.
* Logical abbreviations `.T.`, `.F.`, `.N.`, `.A.`, `.O.`, and `.X.`
[-flogical-abbreviations]
* `.XOR.` as a synonym for `.NEQV.` [-fxor-operator]
diff --git a/flang/include/flang/Parser/characters.h b/flang/include/flang/Parser/characters.h
index b3b82a4f0b9f7f..dae0d3e2a0cfff 100644
--- a/flang/include/flang/Parser/characters.h
+++ b/flang/include/flang/Parser/characters.h
@@ -237,6 +237,23 @@ void EmitQuotedChar(char32_t ch, const NORMAL &emit, const INSERTED &insert,
}};
if (ch <= 0x7f) {
emitOneByte(ch);
+ } else if (useHexadecimalEscapeSequences) {
+ insert('\\');
+ insert('u');
+ if (ch > 0xffff) {
+ unsigned c1{(ch >> 28) & 0xf}, c2{(ch >> 24) & 0xf}, c3{(ch >> 20) & 0xf},
+ c4{(ch >> 16) & 0xf};
+ insert(c1 > 9 ? 'a' + c1 - 10 : '0' + c1);
+ insert(c2 > 9 ? 'a' + c2 - 10 : '0' + c2);
+ insert(c3 > 9 ? 'a' + c3 - 10 : '0' + c3);
+ insert(c4 > 9 ? 'a' + c4 - 10 : '0' + c4);
+ }
+ unsigned c1{(ch >> 12) & 0xf}, c2{(ch >> 8) & 0xf}, c3{(ch >> 4) & 0xf},
+ c4{ch & 0xf};
+ insert(c1 > 9 ? 'a' + c1 - 10 : '0' + c1);
+ insert(c2 > 9 ? 'a' + c2 - 10 : '0' + c2);
+ insert(c3 > 9 ? 'a' + c3 - 10 : '0' + c3);
+ insert(c4 > 9 ? 'a' + c4 - 10 : '0' + c4);
} else {
EncodedCharacter encoded{EncodeCharacter(encoding, ch)};
for (int j{0}; j < encoded.bytes; ++j) {
diff --git a/flang/lib/Evaluate/character.h b/flang/lib/Evaluate/character.h
index ca24dd8e9413d2..2d6747741161bf 100644
--- a/flang/lib/Evaluate/character.h
+++ b/flang/lib/Evaluate/character.h
@@ -13,9 +13,7 @@
#include <string>
// Provides implementations of intrinsic functions operating on character
-// scalars. No assumption is made regarding character encodings other than they
-// must be compatible with ASCII (else, NEW_LINE, ACHAR and IACHAR need to be
-// adapted).
+// scalars.
namespace Fortran::evaluate {
@@ -34,13 +32,8 @@ template <int KIND> class CharacterUtils {
// contain ASCII
static std::int64_t ICHAR(const Character &c) {
CHECK(c.length() == 1);
- if constexpr (std::is_same_v<CharT, char>) {
- // char may be signed, so cast it first to unsigned to avoid having
- // ichar(char(128_4)) returning -128
- return static_cast<unsigned char>(c[0]);
- } else {
- return c[0];
- }
+ // Convert first to an unsigned integer type to avoid sign extension
+ return static_cast<common::HostUnsignedIntType<(8 * KIND)>>(c[0]);
}
static Character NEW_LINE() { return Character{{NewLine()}}; }
diff --git a/flang/lib/Parser/characters.cpp b/flang/lib/Parser/characters.cpp
index dce20a4e5fe478..f6ac777ea874ca 100644
--- a/flang/lib/Parser/characters.cpp
+++ b/flang/lib/Parser/characters.cpp
@@ -235,7 +235,30 @@ template <Encoding ENCODING>
DecodedCharacter DecodeCharacter(
const char *cp, std::size_t bytes, bool backslashEscapes) {
if (backslashEscapes && bytes >= 2 && *cp == '\\') {
- return DecodeEscapedCharacters<ENCODING>(cp, bytes);
+ if (ENCODING == Encoding::UTF_8 && bytes >= 6 &&
+ ToLowerCaseLetter(cp[1]) == 'u' && IsHexadecimalDigit(cp[2]) &&
+ IsHexadecimalDigit(cp[3]) && IsHexadecimalDigit(cp[4]) &&
+ IsHexadecimalDigit(cp[5])) {
+ char32_t ch{
+ static_cast<char32_t>(4096 * HexadecimalDigitValue(cp[2]) +
+ 256 * HexadecimalDigitValue(cp[3]) +
+ 16 * HexadecimalDigitValue(cp[4]) + HexadecimalDigitValue(cp[5])),
+ };
+ if (bytes >= 10 && IsHexadecimalDigit(cp[6]) &&
+ IsHexadecimalDigit(cp[7]) && IsHexadecimalDigit(cp[8]) &&
+ IsHexadecimalDigit(cp[9])) {
+ return {(ch << 16) |
+ (4096 * HexadecimalDigitValue(cp[6]) +
+ 256 * HexadecimalDigitValue(cp[7]) +
+ 16 * HexadecimalDigitValue(cp[8]) +
+ HexadecimalDigitValue(cp[9])),
+ 10};
+ } else {
+ return {ch, 6};
+ }
+ } else {
+ return DecodeEscapedCharacters<ENCODING>(cp, bytes);
+ }
} else {
return DecodeRawCharacter<ENCODING>(cp, bytes);
}
diff --git a/flang/test/Semantics/modfile60.f90 b/flang/test/Semantics/modfile60.f90
new file mode 100644
index 00000000000000..fdb0f8930fe063
--- /dev/null
+++ b/flang/test/Semantics/modfile60.f90
@@ -0,0 +1,19 @@
+! RUN: %python %S/test_modfile.py %s %flang_fc1 -fbackslash
+! Test Unicode escape sequences
+module m
+ integer, parameter :: wide = 4
+ character(kind=wide, len=20), parameter :: ch = wide_"\u1234 \u56789abc"
+ integer, parameter :: check(2) = [ iachar(ch(1:1)), iachar(ch(3:3)) ]
+ logical, parameter :: valid = all(check == [int(z'1234'), int(z'56789abc')])
+end
+
+!Expect: m.mod
+!module m
+!integer(4),parameter::wide=4_4
+!character(20_4,4),parameter::ch=4_"\341\210\264 \375\226\236\211\252\274 "
+!integer(4),parameter::check(1_8:2_8)=[INTEGER(4)::4660_4,1450744508_4]
+!intrinsic::iachar
+!logical(4),parameter::valid=.true._4
+!intrinsic::all
+!intrinsic::int
+!end
``````````
</details>
https://github.com/llvm/llvm-project/pull/76757
More information about the flang-commits
mailing list