[clang] 88501dc - [Sema] -Wformat: support C23 format specifier %b %B
Fangrui Song via cfe-commits
cfe-commits at lists.llvm.org
Thu Aug 4 10:26:36 PDT 2022
Author: Fangrui Song
Date: 2022-08-04T10:26:31-07:00
New Revision: 88501dc74911b00186298fe1fffe8dfb1f09b1c1
URL: https://github.com/llvm/llvm-project/commit/88501dc74911b00186298fe1fffe8dfb1f09b1c1
DIFF: https://github.com/llvm/llvm-project/commit/88501dc74911b00186298fe1fffe8dfb1f09b1c1.diff
LOG: [Sema] -Wformat: support C23 format specifier %b %B
Close #56885: WG14 N2630 added %b to fprintf/fscanf and recommended %B for
fprintf. This patch teaches -Wformat %b for the printf/scanf family of functions
and %B for the printf family of functions.
glibc 2.35 and latest Android bionic added %b/%B printf support. From
https://www.openwall.com/lists/libc-coord/2022/07/ no scanf support is available
yet.
Like GCC, we don't test library support.
GCC 12 -Wformat -pedantic emits a warning:
> warning: ISO C17 does not support the ‘%b’ gnu_printf format [-Wformat=]
The behavior is not ported.
Note: `freebsd_kernel_printf` uses %b differently.
Reviewed By: aaron.ballman, dim, enh
Differential Revision: https://reviews.llvm.org/D131057
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/AST/FormatString.h
clang/lib/AST/FormatString.cpp
clang/lib/AST/PrintfFormatString.cpp
clang/lib/AST/ScanfFormatString.cpp
clang/test/Sema/format-strings-fixit.c
clang/test/Sema/format-strings-scanf.c
clang/test/Sema/format-strings.c
clang/test/SemaObjC/format-strings-objc.m
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 85d360eb9cdac..b9729a6a047f0 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -69,6 +69,9 @@ Improvements to Clang's diagnostics
`Issue 50055: <https://github.com/llvm/llvm-project/issues/50055>`_.
- Clang will now check compile-time determinable string literals as format strings.
This fixes `Issue 55805: <https://github.com/llvm/llvm-project/issues/55805>`_.
+- ``-Wformat`` now recognizes ``%b`` for the ``printf``/``scanf`` family of
+ functions and ``%B`` for the ``printf`` family of functions. Fixes
+ `Issue 56885: <https://github.com/llvm/llvm-project/issues/56885>`_.
Non-comprehensive list of changes in this release
-------------------------------------------------
diff --git a/clang/include/clang/AST/FormatString.h b/clang/include/clang/AST/FormatString.h
index d7933382f13d6..0f1f6b1340ff1 100644
--- a/clang/include/clang/AST/FormatString.h
+++ b/clang/include/clang/AST/FormatString.h
@@ -127,8 +127,12 @@ class ConversionSpecifier {
dArg,
DArg, // Apple extension
iArg,
+ // C23 conversion specifiers.
+ bArg,
+ BArg,
+
IntArgBeg = dArg,
- IntArgEnd = iArg,
+ IntArgEnd = BArg,
oArg,
OArg, // Apple extension
diff --git a/clang/lib/AST/FormatString.cpp b/clang/lib/AST/FormatString.cpp
index 1a1dddcbacfd9..1a763434c7561 100644
--- a/clang/lib/AST/FormatString.cpp
+++ b/clang/lib/AST/FormatString.cpp
@@ -624,6 +624,8 @@ analyze_format_string::LengthModifier::toString() const {
const char *ConversionSpecifier::toString() const {
switch (kind) {
+ case bArg: return "b";
+ case BArg: return "B";
case dArg: return "d";
case DArg: return "D";
case iArg: return "i";
@@ -753,6 +755,8 @@ bool FormatSpecifier::hasValidLengthModifier(const TargetInfo &Target,
case LengthModifier::AsSizeT:
case LengthModifier::AsPtrDiff:
switch (CS.getKind()) {
+ case ConversionSpecifier::bArg:
+ case ConversionSpecifier::BArg:
case ConversionSpecifier::dArg:
case ConversionSpecifier::DArg:
case ConversionSpecifier::iArg:
@@ -908,6 +912,8 @@ bool FormatSpecifier::hasStandardLengthModifier() const {
bool FormatSpecifier::hasStandardConversionSpecifier(
const LangOptions &LangOpt) const {
switch (CS.getKind()) {
+ case ConversionSpecifier::bArg:
+ case ConversionSpecifier::BArg:
case ConversionSpecifier::cArg:
case ConversionSpecifier::dArg:
case ConversionSpecifier::iArg:
diff --git a/clang/lib/AST/PrintfFormatString.cpp b/clang/lib/AST/PrintfFormatString.cpp
index d972c120ebac5..4f5fbdc9da25e 100644
--- a/clang/lib/AST/PrintfFormatString.cpp
+++ b/clang/lib/AST/PrintfFormatString.cpp
@@ -326,6 +326,14 @@ static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
case 's': k = ConversionSpecifier::sArg; break;
case 'u': k = ConversionSpecifier::uArg; break;
case 'x': k = ConversionSpecifier::xArg; break;
+ // C23.
+ case 'b':
+ if (isFreeBSDKPrintf)
+ k = ConversionSpecifier::FreeBSDbArg; // int followed by char *
+ else
+ k = ConversionSpecifier::bArg;
+ break;
+ case 'B': k = ConversionSpecifier::BArg; break;
// POSIX specific.
case 'C': k = ConversionSpecifier::CArg; break;
case 'S': k = ConversionSpecifier::SArg; break;
@@ -337,11 +345,6 @@ static PrintfSpecifierResult ParsePrintfSpecifier(FormatStringHandler &H,
case '@': k = ConversionSpecifier::ObjCObjArg; break;
// Glibc specific.
case 'm': k = ConversionSpecifier::PrintErrno; break;
- // FreeBSD kernel specific.
- case 'b':
- if (isFreeBSDKPrintf)
- k = ConversionSpecifier::FreeBSDbArg; // int followed by char *
- break;
case 'r':
if (isFreeBSDKPrintf)
k = ConversionSpecifier::FreeBSDrArg; // int
@@ -961,8 +964,10 @@ bool PrintfSpecifier::hasValidAlternativeForm() const {
if (!HasAlternativeForm)
return true;
- // Alternate form flag only valid with the oxXaAeEfFgG conversions
+ // Alternate form flag only valid with the bBoxXaAeEfFgG conversions
switch (CS.getKind()) {
+ case ConversionSpecifier::bArg:
+ case ConversionSpecifier::BArg:
case ConversionSpecifier::oArg:
case ConversionSpecifier::OArg:
case ConversionSpecifier::xArg:
@@ -988,8 +993,10 @@ bool PrintfSpecifier::hasValidLeadingZeros() const {
if (!HasLeadingZeroes)
return true;
- // Leading zeroes flag only valid with the diouxXaAeEfFgG conversions
+ // Leading zeroes flag only valid with the bBdiouxXaAeEfFgG conversions
switch (CS.getKind()) {
+ case ConversionSpecifier::bArg:
+ case ConversionSpecifier::BArg:
case ConversionSpecifier::dArg:
case ConversionSpecifier::DArg:
case ConversionSpecifier::iArg:
@@ -1080,8 +1087,10 @@ bool PrintfSpecifier::hasValidPrecision() const {
if (Precision.getHowSpecified() == OptionalAmount::NotSpecified)
return true;
- // Precision is only valid with the diouxXaAeEfFgGsP conversions
+ // Precision is only valid with the bBdiouxXaAeEfFgGsP conversions
switch (CS.getKind()) {
+ case ConversionSpecifier::bArg:
+ case ConversionSpecifier::BArg:
case ConversionSpecifier::dArg:
case ConversionSpecifier::DArg:
case ConversionSpecifier::iArg:
diff --git a/clang/lib/AST/ScanfFormatString.cpp b/clang/lib/AST/ScanfFormatString.cpp
index 7679f02e04abd..73454a2c554e6 100644
--- a/clang/lib/AST/ScanfFormatString.cpp
+++ b/clang/lib/AST/ScanfFormatString.cpp
@@ -161,6 +161,7 @@ static ScanfSpecifierResult ParseScanfSpecifier(FormatStringHandler &H,
default:
break;
case '%': k = ConversionSpecifier::PercentArg; break;
+ case 'b': k = ConversionSpecifier::bArg; break;
case 'A': k = ConversionSpecifier::AArg; break;
case 'E': k = ConversionSpecifier::EArg; break;
case 'F': k = ConversionSpecifier::FArg; break;
@@ -267,6 +268,7 @@ ArgType ScanfSpecifier::getArgType(ASTContext &Ctx) const {
llvm_unreachable("Unsupported LengthModifier Type");
// Unsigned int.
+ case ConversionSpecifier::bArg:
case ConversionSpecifier::oArg:
case ConversionSpecifier::OArg:
case ConversionSpecifier::uArg:
diff --git a/clang/test/Sema/format-strings-fixit.c b/clang/test/Sema/format-strings-fixit.c
index e6d638b75a71d..64614e1c53fcd 100644
--- a/clang/test/Sema/format-strings-fixit.c
+++ b/clang/test/Sema/format-strings-fixit.c
@@ -21,6 +21,7 @@ void test(void) {
printf("%s", (int) 123);
printf("abc%0f", "testing testing 123");
printf("%u", (long) -12);
+ printf("%b", (long) -13);
printf("%p", 123);
printf("%c\n", "x");
printf("%c\n", 1.23);
@@ -160,6 +161,7 @@ void test2(int intSAParm[static 2]) {
scanf("%f", (my_int_type*)&intVar);
// Preserve the original formatting.
+ scanf("%b", &longVar);
scanf("%o", &longVar);
scanf("%u", &longVar);
scanf("%x", &longVar);
@@ -179,6 +181,7 @@ void test2(int intSAParm[static 2]) {
// CHECK: printf("%d", (int) 123);
// CHECK: printf("abc%s", "testing testing 123");
// CHECK: printf("%ld", (long) -12);
+// CHECK: printf("%ld", (long) -13);
// CHECK: printf("%d", 123);
// CHECK: printf("%s\n", "x");
// CHECK: printf("%f\n", 1.23);
@@ -246,6 +249,7 @@ void test2(int intSAParm[static 2]) {
// CHECK: scanf("%ju", (my_uintmax_type*)&uIntmaxVar);
// CHECK: scanf("%td", (my_ptr
diff _type*)&ptr
diff Var);
// CHECK: scanf("%d", (my_int_type*)&intVar);
+// CHECK: scanf("%ld", &longVar);
// CHECK: scanf("%lo", &longVar);
// CHECK: scanf("%lu", &longVar);
// CHECK: scanf("%lx", &longVar);
diff --git a/clang/test/Sema/format-strings-scanf.c b/clang/test/Sema/format-strings-scanf.c
index 7b864bfdd237e..d6e403148a5c4 100644
--- a/clang/test/Sema/format-strings-scanf.c
+++ b/clang/test/Sema/format-strings-scanf.c
@@ -40,9 +40,11 @@ void test(const char *s, int *i) {
scanf("%0d", i); // expected-warning{{zero field width in scanf format string is unused}}
scanf("%00d", i); // expected-warning{{zero field width in scanf format string is unused}}
scanf("%d%[asdfasdfd", i, s); // expected-warning{{no closing ']' for '%[' in scanf format string}}
+ scanf("%B", i); // expected-warning{{invalid conversion specifier 'B'}}
unsigned short s_x;
scanf ("%" "hu" "\n", &s_x); // no-warning
+ scanf("%hb", &s_x);
scanf("%y", i); // expected-warning{{invalid conversion specifier 'y'}}
scanf("%%"); // no-warning
scanf("%%%1$d", i); // no-warning
@@ -57,6 +59,7 @@ void test(const char *s, int *i) {
scanf("%s", (signed char*)0); // no-warning
scanf("%s", (unsigned char*)0); // no-warning
scanf("%hhu", (signed char*)0); // no-warning
+ scanf("%hhb", (signed char*)0); // no-warning
}
void bad_length_modifiers(char *s, void *p, wchar_t *ws, long double *ld) {
@@ -193,6 +196,7 @@ void test_qualifiers(const int *cip, volatile int* vip,
void test_size_types(void) {
size_t s = 0;
scanf("%zu", &s); // No warning.
+ scanf("%zb", &s);
double d1 = 0.;
scanf("%zu", &d1); // expected-warning-re{{format specifies type 'size_t *' (aka '{{.+}}') but the argument has type 'double *'}}
@@ -213,6 +217,7 @@ void test_size_types(void) {
void test_ptr
diff _t_types(void) {
__UNSIGNED_PTRDIFF_TYPE__ p1 = 0;
scanf("%tu", &p1); // No warning.
+ scanf("%tb", &p1);
double d1 = 0.;
scanf("%tu", &d1); // expected-warning-re{{format specifies type 'unsigned ptr
diff _t *' (aka '{{.+}}') but the argument has type 'double *'}}
diff --git a/clang/test/Sema/format-strings.c b/clang/test/Sema/format-strings.c
index 85052d57fc47c..919bd74de392f 100644
--- a/clang/test/Sema/format-strings.c
+++ b/clang/test/Sema/format-strings.c
@@ -199,7 +199,7 @@ void check_writeback_specifier(void)
void check_invalid_specifier(FILE* fp, char *buf)
{
- printf("%s%lb%d","unix",10,20); // expected-warning {{invalid conversion specifier 'b'}} expected-warning {{data argument not used by format string}}
+ printf("%s%lv%d","unix",10,20); // expected-warning {{invalid conversion specifier 'v'}} expected-warning {{data argument not used by format string}}
fprintf(fp,"%%%l"); // expected-warning {{incomplete format specifier}}
sprintf(buf,"%%%%%ld%d%d", 1, 2, 3); // expected-warning{{format specifies type 'long' but the argument has type 'int'}}
snprintf(buf, 2, "%%%%%ld%;%d", 1, 2, 3); // expected-warning{{format specifies type 'long' but the argument has type 'int'}} expected-warning {{invalid conversion specifier ';'}} expected-warning {{data argument not used by format string}}
@@ -304,6 +304,7 @@ void test10(int x, float f, int i, long long lli) {
printf("%qp", (void *)0); // expected-warning{{length modifier 'q' results in undefined behavior or no effect with 'p' conversion specifier}}
printf("hhX %hhX", (unsigned char)10); // no-warning
printf("llX %llX", (long long) 10); // no-warning
+ printf("%llb %llB", (long long) 10, (long long) 10); // no-warning
// This is fine, because there is an implicit conversion to an int.
printf("%d", (unsigned char) 10); // no-warning
printf("%d", (long long) 10); // expected-warning{{format specifies type 'int' but the argument has type 'long long'}}
@@ -429,6 +430,7 @@ void bug7377_bad_length_mod_usage(void) {
// Bad flag usage
printf("%#p", (void *) 0); // expected-warning{{flag '#' results in undefined behavior with 'p' conversion specifier}}
printf("%0d", -1); // no-warning
+ printf("%0b%0B", -1u, -1u); // no-warning
printf("%-p", (void *) 0); // no-warning
#if !defined(__ANDROID__) && !defined(__Fuchsia__)
printf("%#n", (int *) 0); // expected-warning{{flag '#' results in undefined behavior with 'n' conversion specifier}}
@@ -499,6 +501,7 @@ void rdar8332221(va_list ap, int *x, long *y) {
void pr8641(void) {
printf("%#x\n", 10);
printf("%#X\n", 10);
+ printf("%#b %#15.8B\n", 10, 10u);
}
void posix_extensions(void) {
@@ -508,6 +511,8 @@ void posix_extensions(void) {
printf("%'i\n", 123456789); // no-warning
printf("%'f\n", (float) 1.0); // no-warning
printf("%'p\n", (void*) 0); // expected-warning{{results in undefined behavior with 'p' conversion specifier}}
+ printf("%'b\n", 123456789); // expected-warning{{results in undefined behavior with 'b' conversion specifier}}
+ printf("%'B\n", 123456789); // expected-warning{{results in undefined behavior with 'B' conversion specifier}}
}
// PR8486
@@ -540,6 +545,7 @@ void check_char(unsigned char x, signed char y) {
printf("%hhi", x); // no-warning
printf("%c", x); // no-warning
printf("%hhu", y); // no-warning
+ printf("%hhb %hhB", x, x); // no-warning
}
// Test suppression of individual warnings.
diff --git a/clang/test/SemaObjC/format-strings-objc.m b/clang/test/SemaObjC/format-strings-objc.m
index 71f22c07e2323..51638f9fa4a08 100644
--- a/clang/test/SemaObjC/format-strings-objc.m
+++ b/clang/test/SemaObjC/format-strings-objc.m
@@ -56,7 +56,7 @@ +(instancetype)stringWithFormat:(NSAttributedString *)fmt, ...
void check_nslog(unsigned k) {
NSLog(@"%d%%", k); // no-warning
- NSLog(@"%s%lb%d", "unix", 10, 20); // expected-warning {{invalid conversion specifier 'b'}} expected-warning {{data argument not used by format string}}
+ NSLog(@"%s%lv%d", "unix", 10, 20); // expected-warning {{invalid conversion specifier 'v'}} expected-warning {{data argument not used by format string}}
}
// Check type validation
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