https://github.com/Luhaocong updated https://github.com/llvm/llvm-project/pull/74439
>From 899e18d1ca94efad41c2e09dff0a3213d7fb0f7e Mon Sep 17 00:00:00 2001 From: Lu Haocong <haocon...@qq.com> Date: Tue, 5 Dec 2023 16:45:22 +0800 Subject: [PATCH] [Sema] Warning for _Float16 passed to format specifier '%f' According to https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2844.pdf, there are no default argument promotions for _FloatN types. A warning is needed to notice user to promote _Float16 to double explicitly, and then pass it to format specifier '%f', which is consistent with GCC. --- clang/lib/AST/FormatString.cpp | 1 - clang/test/AST/variadic-promotion.c | 5 +++++ clang/test/Sema/attr-format.c | 7 +++++++ clang/test/SemaCXX/attr-format.cpp | 1 + clang/test/SemaCXX/format-strings-scanf.cpp | 16 ++++++++++------ 5 files changed, 23 insertions(+), 7 deletions(-) diff --git a/clang/lib/AST/FormatString.cpp b/clang/lib/AST/FormatString.cpp index e0c9e18cfe3a24..c5d14b4af7ff15 100644 --- a/clang/lib/AST/FormatString.cpp +++ b/clang/lib/AST/FormatString.cpp @@ -488,7 +488,6 @@ ArgType::matchesType(ASTContext &C, QualType argTy) const { return NoMatchPromotionTypeConfusion; break; case BuiltinType::Half: - case BuiltinType::Float16: case BuiltinType::Float: if (T == C.DoubleTy) return MatchPromotion; diff --git a/clang/test/AST/variadic-promotion.c b/clang/test/AST/variadic-promotion.c index 41c7fec8d7943e..7cbadb832ca806 100644 --- a/clang/test/AST/variadic-promotion.c +++ b/clang/test/AST/variadic-promotion.c @@ -18,3 +18,8 @@ void test_floating_promotion(__fp16 *f16, float f32, double f64) { // CHECK: ImplicitCastExpr {{.*}} 'double' <FloatingCast> // CHECK-NEXT: 'float' } + +void test_Float16_no_default_promotion(_Float16 f16) { + variadic(1, f16); +// CHECK-NOT: ImplicitCastExpr {{.*}} 'double' <FloatingCast> +} diff --git a/clang/test/Sema/attr-format.c b/clang/test/Sema/attr-format.c index 1f4c864d4f78bd..bdfd8425c4e9a5 100644 --- a/clang/test/Sema/attr-format.c +++ b/clang/test/Sema/attr-format.c @@ -16,6 +16,8 @@ typedef const char *xpto; void j(xpto c, va_list list) __attribute__((format(printf, 1, 0))); // no-error void k(xpto c) __attribute__((format(printf, 1, 0))); // no-error +void l(char *a, _Float16 b) __attribute__((format(printf, 1, 2))); // expected-warning {{GCC requires a function with the 'format' attribute to be variadic}} + void y(char *str) __attribute__((format(strftime, 1, 0))); // no-error void z(char *str, int c, ...) __attribute__((format(strftime, 1, 2))); // expected-error {{strftime format attribute requires 3rd parameter to be 0}} @@ -93,6 +95,11 @@ void call_nonvariadic(void) { d3("%s", 123); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} } +void call_no_default_promotion(void) { + a("%f", (_Float16)1.0); // expected-warning{{format specifies type 'double' but the argument has type '_Float16'}} + l("%f", (_Float16)1.0); // expected-warning{{format specifies type 'double' but the argument has type '_Float16'}} +} + __attribute__((format(printf, 1, 2))) void forward_fixed(const char *fmt, _Bool b, char i, short j, int k, float l, double m) { // expected-warning{{GCC requires a function with the 'format' attribute to be variadic}} forward_fixed(fmt, b, i, j, k, l, m); diff --git a/clang/test/SemaCXX/attr-format.cpp b/clang/test/SemaCXX/attr-format.cpp index adc05fc46776ca..4509c3a95e8efa 100644 --- a/clang/test/SemaCXX/attr-format.cpp +++ b/clang/test/SemaCXX/attr-format.cpp @@ -81,6 +81,7 @@ void do_format() { format("%c %c %hhd %hd %d\n", (char)'a', 'a', 'a', (short)123, (int)123); format("%f %f %f\n", (__fp16)123.f, 123.f, 123.); + format("%f", (_Float16)123.f);// expected-warning{{format specifies type 'double' but the argument has type '_Float16'}} format("%Lf", (__fp16)123.f); // expected-warning{{format specifies type 'long double' but the argument has type '__fp16'}} format("%Lf", 123.f); // expected-warning{{format specifies type 'long double' but the argument has type 'float'}} format("%hhi %hhu %hi %hu %i %u", b, b, b, b, b, b); diff --git a/clang/test/SemaCXX/format-strings-scanf.cpp b/clang/test/SemaCXX/format-strings-scanf.cpp index 25fe5346791a0d..406c2069e28ca7 100644 --- a/clang/test/SemaCXX/format-strings-scanf.cpp +++ b/clang/test/SemaCXX/format-strings-scanf.cpp @@ -22,6 +22,7 @@ union bag { unsigned long long ull; signed long long sll; __fp16 f16; + _Float16 Float16; float ff; double fd; long double fl; @@ -51,18 +52,21 @@ void test(void) { // expected-warning@+1{{format specifies type 'int *' but the argument has type 'short *'}} scan("%hhi %i %li", &b.ss, &b.ss, &b.ss); - // expected-warning@+3{{format specifies type 'float *' but the argument has type '__fp16 *'}} + // expected-warning@+4{{format specifies type 'float *' but the argument has type '__fp16 *'}} + // expected-warning@+3{{format specifies type 'float *' but the argument has type '_Float16 *'}} // expected-warning@+2{{format specifies type 'float *' but the argument has type 'double *'}} // expected-warning@+1{{format specifies type 'float *' but the argument has type 'long double *'}} - scan("%f %f %f", &b.f16, &b.fd, &b.fl); + scan("%f %f %f %f", &b.f16, &b.Float16, &b.fd, &b.fl); - // expected-warning@+3{{format specifies type 'double *' but the argument has type '__fp16 *'}} + // expected-warning@+4{{format specifies type 'double *' but the argument has type '__fp16 *'}} + // expected-warning@+3{{format specifies type 'double *' but the argument has type '_Float16 *'}} // expected-warning@+2{{format specifies type 'double *' but the argument has type 'float *'}} // expected-warning@+1{{format specifies type 'double *' but the argument has type 'long double *'}} - scan("%lf %lf %lf", &b.f16, &b.ff, &b.fl); + scan("%lf %lf %lf %lf", &b.f16, &b.Float16, &b.ff, &b.fl); - // expected-warning@+3{{format specifies type 'long double *' but the argument has type '__fp16 *'}} + // expected-warning@+4{{format specifies type 'long double *' but the argument has type '__fp16 *'}} + // expected-warning@+3{{format specifies type 'long double *' but the argument has type '_Float16 *'}} // expected-warning@+2{{format specifies type 'long double *' but the argument has type 'float *'}} // expected-warning@+1{{format specifies type 'long double *' but the argument has type 'double *'}} - scan("%Lf %Lf %Lf", &b.f16, &b.ff, &b.fd); + scan("%Lf %Lf %Lf %Lf", &b.f16, &b.Float16, &b.ff, &b.fd); } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits