llvm-project/clang/test/Sema/format-strings-fixit-ssize_t.c
YexuanXiao 7c402b8b81
Reland [Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types (#149613)
The checks for the 'z' and 't' format specifiers added in the original
PR #143653 had some issues and were overly strict, causing some build
failures and were consequently reverted at
4c85bf2fe8.

In the latest commit
27c58629ec,
I relaxed the checks for the 'z' and 't' format specifiers, so warnings
are now only issued when they are used with mismatched types.

The original intent of these checks was to diagnose code that assumes
the underlying type of `size_t` is `unsigned` or `unsigned long`, for
example:

```c
printf("%zu", 1ul); // Not portable, but not an error when size_t is unsigned long
```  

However, it produced a significant number of false positives. This was
partly because Clang does not treat the `typedef` `size_t` and
`__size_t` as having a common "sugar" type, and partly because a large
amount of existing code either assumes `unsigned` (or `unsigned long`)
is `size_t`, or they define the equivalent of size_t in their own way
(such as
sanitizer_internal_defs.h).2e67dcfdcd/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h (L203)
2025-07-19 03:44:14 -03:00

23 lines
767 B
C

// RUN: cp %s %t
// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -std=c99 -pedantic -Wall -fixit %t
// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -std=c99 -fsyntax-only -pedantic -Wall -Werror %t
// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -std=c99 -E -o - %t | FileCheck %s
/* This is a test of the various code modification hints that are
provided as part of warning or extension diagnostics. All of the
warnings will be fixed by -fixit, and the resulting file should
compile cleanly with -Werror -pedantic. */
int printf(char const *, ...);
int scanf(const char *, ...);
typedef long ssize_t;
void test(void) {
printf("%f", (ssize_t) 42);
ssize_t s;
scanf("%f", &s);
}
// CHECK: printf("%zd", (ssize_t) 42);
// CHECK: scanf("%zd", &s)