[X86] Fix implicit sign conversion warnings in X86 headers.

[pgousseau]

Summary

Warnings in emmintrin.h and xmmintrin.h are reported by -fsanitize=implicit-integer-sign-change

[RKSimon]

Rename test file to x86-header-warnings.c or something similarly specific?

clang/test/Headers/warn-cleanup.c

10 ↗

(On Diff #254784)

Use x8intrin.h directly so its easier to expand in the future?

[pgousseau]

Renaming test and including x86intrin.h instead.

[RKSimon]

@craig.topper Any comments? Hopefully we can add extra tests as time goes on (for instance I'm intending to add Wdocumentation test coverage for PR35949).

clang/test/Headers/x86-header-warnings.c

12

Add a LABEL check as well

[craig.topper]

Seems fine to me.

[RKSimon]

LGTM with the minor addition an extra CHECK-LABEL

[pgousseau]

Added label

[thakis]

clang/test/Headers/x86-header-warnings.c

3

Does Wsystem-headers add too much noise?

[pgousseau]

clang/test/Headers/x86-header-warnings.c

3

Thanks for the suggestion, I did not thought about adding Wsystem-headers, I tested Wsystem-headers now though and cant seem to pick up on that particular issue without the preprocessing step.

12

Adding label sounds good, went ahead and commited without checking the test was not failing anymore, sorry will revert.

[pgousseau]

Reopening to fix false negative test.

[pgousseau]

Fix false negative test introduce while attempting to add label check.

[probinson]

It looks like you're not actually interested in the compiled output, but just whether warnings occurred; in that case you'd be better off with -verify -fsyntax-only and // expected-no-diagnostics.

[pgousseau]

In D77393#1969419, @probinson wrote:

It looks like you're not actually interested in the compiled output, but just whether warnings occurred; in that case you'd be better off with -verify -fsyntax-only and // expected-no-diagnostics.

Sounds good! Committed at https://github.com/llvm/llvm-project/commit/937e63b8d5e961c2a7da25558bbcdd5388182b67
Thanks!

clang/test/Headers/x86-header-warnings.c

 // Fix sign conversion warnings found by fsanitize=implicit-integer-sign-change
 // in intrinsic headers.
 // Preprocess file to workaround no warnings in system headers.
-// RUN: %clang_cc1 %s -triple x86_64-pc-linux-gnu -ffreestanding -E 2>&1 \
-// RUN:     | %clang_cc1 -x c - -triple x86_64-pc-linux-gnu -ffreestanding -Wsign-conversion -E -o - 2>&1 \
-// RUN:     | FileCheck --allow-empty %s
+// RUN: %clang_cc1 %s -triple x86_64-pc-linux-gnu -ffreestanding -E -CC 2>&1 \
+// RUN:     | %clang_cc1 -x c - -triple x86_64-pc-linux-gnu -Wsign-conversion -fsyntax-only -verify
 // REQUIRES: x86-registered-target
 
 #include <x86intrin.h>
 
 void test0() {
-  // CHECK-LABEL: test0
-  // CHECK-NOT: warning:
+  // expected-no-diagnostics
   _MM_SET_DENORMALS_ZERO_MODE(_MM_DENORMALS_ZERO_ON);
   _MM_SET_DENORMALS_ZERO_MODE(_MM_DENORMALS_ZERO_OFF);
   _MM_SET_DENORMALS_ZERO_MODE(_MM_DENORMALS_ZERO_MASK);
 
   _MM_SET_EXCEPTION_STATE(_MM_EXCEPT_INVALID);
   _MM_SET_EXCEPTION_STATE(_MM_EXCEPT_DENORM);
   _MM_SET_EXCEPTION_STATE(_MM_EXCEPT_DIV_ZERO);
   _MM_SET_EXCEPTION_STATE(_MM_EXCEPT_OVERFLOW);
   _MM_SET_EXCEPTION_STATE(_MM_EXCEPT_UNDERFLOW);