[Sema] Fix format-strings test on AIX

[luporl]

Simplify the conditional compilation and skip the problematic warnings only on 32-bit Arm.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Leandro Lupori (luporl)

Changes

On AIX, long has the same size as int.

---

Full diff: https://github.com/llvm/llvm-project/pull/180566.diff

1 Files Affected:

• (modified) clang/test/Sema/format-strings.c (+4-2)

diff --git a/clang/test/Sema/format-strings.c b/clang/test/Sema/format-strings.c
index 3a2c2701cfcfc..0c13a70fa32eb 100644
--- a/clang/test/Sema/format-strings.c
+++ b/clang/test/Sema/format-strings.c
@@ -988,12 +988,14 @@ void test_promotion(void) {
 
 void test_bool(_Bool b, _Bool* bp)
 {
-#if SIZE_MAX != UINT_MAX
+  // Expect a warning if size_t/ptrdiff_t size is greater than a _Bool promoted
+  // to an int or if it might be a long int, with the same size of an int.
+#if SIZE_MAX > UINT_MAX || UINT_MAX == ULONG_MAX
   printf("%zu", b); // expected-warning-re{{format specifies type 'size_t' (aka '{{.+}}') but the argument has type '_Bool'}}
 #else
   printf("%zu", b); // no-warning
 #endif
-#if PTRDIFF_MAX != INT_MAX
+#if PTRDIFF_MAX > INT_MAX || INT_MAX == LONG_MAX
   printf("%td", b); // expected-warning-re{{format specifies type 'ptrdiff_t' (aka '{{.+}}') but the argument has type '_Bool'}}
 #else
   printf("%td", b); // no-warning

[luporl]

The code formatting failure is a GitHub issue:
github.GithubException.GithubException: 429 {"message": "This endpoint is temporarily being throttled." ... }

[azhan92]

Thanks, LGTM

[amy-kwan]

Caught this failure a bit late for the release, so I will attempt to cherry-pick it.
/cherry-pick 8f37bf6

[llvmbot]

/pull-request #182755

[mgorny]

Sorry to be late to the party but this change breaks tests on 32-bit x86 Linux:

FAIL: Clang :: Sema/format-strings.c (19698 of 24038)
******************** TEST 'Clang :: Sema/format-strings.c' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/var/tmp/portage/llvm-core/clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/clang -cc1 -internal-isystem /var/tmp/portage/llvm-core/
clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/../../../../lib/clang/23/include -nostdsysteminc -fblocks -fsyntax-only -verify -Wf
ormat-nonliteral -isystem /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/Inputs /var/tmp/portage/llvm-core/clang-23.
0.0.9999/work/clang/test/Sema/format-strings.c
# executed command: /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/clang -cc1 -internal-isystem /var/tm
p/portage/llvm-core/clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/../../../../lib/clang/23/include -nostdsysteminc -fblocks -fsyn
tax-only -verify -Wformat-nonliteral -isystem /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/Inputs /var/tmp/portage
/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/format-strings.c
# .---command stderr------------
# | error: 'expected-warning' diagnostics expected but not seen: 
# |   File /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/format-strings.c Line 990: format specifies type 'size_t' 
(aka '{{.+}}') but the argument has type '_Bool'
# |   File /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/format-strings.c Line 991: format specifies type 'ptrdiff_
t' (aka '{{.+}}') but the argument has type '_Bool'
# | 2 errors generated.
# `-----------------------------
# error: command failed with exit status: 1

--

********************

[nikic]

Can you please explain what the issue on AIX actually was?

[nikic]

@mgorny There is a PR to fix i686 at #181800.

[mgorny]

@mgorny There is a PR to fix i686 at #181800.

… which pretty much reverts the change here, except for using another define.

[luporl]

Can you please explain what the issue on AIX actually was?

The issue on AIX was reported here: #178450 (comment)

File /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/Sema/format-strings.c Line 994: format specifies type 'size_t' (aka 'unsigned long') but the argument has type '_Bool'
File /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-ppc64-aix/llvm-project/clang/test/Sema/format-strings.c Line 999: format specifies type 'ptrdiff_t' (aka 'long') but the argument has type '_Bool'

AFAIK, the problem is that on PPC64 AIX both integers and longs have 64 bits and size_t/ptrdiff_t are long.
Because of this the warnings still occur after _Bool is promoted to int. It has the same size as long, but it's still a different type.

[nikic]

Looking at that buildbot, the triple it actually uses is powerpc-ibm-aix, even though the buildbot name is clang-ppc64-aix. And yes, for 32-bit AIX we have that size_t is long, which is the same size as int.

I think the right fix for the issue is to just drop the no-warning lines, as I've suggested here: https://github.com/llvm/llvm-project/pull/181800/changes#r2840874528 If the sizes don't match there should definitely be a warning. If they do match, then it depends on the exact type definitions, and we shouldn't test either way.

(Though at a higher level, if we ignore the immediate test issue here, IMHO, for this specific case of _Bool we should really be always warning regardless of what the underlying type definitions are. Using _Bool with %zu is both non-sensical and non-portable.)