[clang] [llvm] [Clang][AIX] Add -mloadtime-comment-vars flag to preserve identifying variables (PR #187986)

[Hubert Tong via cfe-commits]

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@@ -0,0 +1,28 @@
+// RUN: %clang -### -target powerpc-ibm-aix -mloadtime-comment-vars=sccsid,version %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target x86_64-linux-gnu -mloadtime-comment-vars=sccsid,version %s 2>&1 | FileCheck %s --check-prefix=NONAIX
+
+// RUN: %clang -### -target powerpc-ibm-aix -mloadtime-comment-vars=sccsid -mloadtime-comment-vars=version,build %s 2>&1 | FileCheck %s --check-prefix=MULTI
+// RUN: %clang -### -target x86_64-linux-gnu -mloadtime-comment-vars=sccsid -mloadtime-comment-vars=version %s 2>&1 | FileCheck %s --check-prefix=NONAIX-MULTI
+
+// Verify the option is forwarded verbatim to cc1 for a supported target.
+// CHECK: "-cc1"
+// CHECK-SAME: "-mloadtime-comment-vars=sccsid,version"
+
+// Verify a warning is emitted and the option is NOT forwarded for an
+// unsupported target.
+// NONAIX: warning: ignoring '-mloadtime-comment-vars=' option as it is not currently supported for target 'x86_64-unknown-linux-gnu'
+// NONAIX: "-cc1"
+// NONAIX-NOT: "-mloadtime-comment-vars=sccsid,version"
+
+// Verify every occurrence is forwarded, in order; cc1 combines the lists.
+// MULTI: "-cc1"
+// MULTI-SAME: "-mloadtime-comment-vars=sccsid"
+// MULTI-SAME: "-mloadtime-comment-vars=version,build"
+
+// Verify a repeated option on an unsupported target warns once and forwards
+// nothing.
+// NONAIX-MULTI: warning: ignoring '-mloadtime-comment-vars=' option as it is not currently supported for target 'x86_64-unknown-linux-gnu'
+// NONAIX-MULTI: "-cc1"
+// NONAIX-MULTI-NOT: "-mloadtime-comment-vars=
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hubert-reinterpretcast wrote:

It should be possible to reuse the check lines for `NONAIX` to handle this. Please take care to retain in the comments the documentation that the test verifies that the warning is emitted only once.

https://github.com/llvm/llvm-project/pull/187986