[PATCH] D87426: Disallow fbasic-block-sections on non-ELF, non-x86 targets.

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added inline comments.


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Comment at: clang/lib/Driver/ToolChains/Clang.cpp:4892
+    } else {
+      D.Diag(diag::warn_drv_unsupported_opt_for_target)
+          << A->getAsString(Args) << TripleStr;
----------------
snehasish wrote:
> MaskRay wrote:
> > This should be an error
> Sure, can you provide a reference/guidance for when err vs warn is appropriate for driver checks? Most of the code in this file uses err but there are some cases of warn being used.
I think a warning is suitable for some GCC specific optimization options where a clang port either does not make sense or is not very necessary. This only applies to very common options which ease porting to clang. For clang specific optimizations, especially  these with complex setup, I  think an error is more useful.


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Comment at: clang/test/Driver/fbasic-block-sections.c:12
 // CHECK-OPT-LABELS: "-fbasic-block-sections=labels"
+// CHECK-TRIPLE-NOT: "-fbasic-block-sections=all"
+// CHECK-TRIPLE:     error: unsupported option '-fbasic-block-sections=all' for target
----------------
The NOT pattern is not useful when testing an error.


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Comment at: clang/test/Driver/fbasic-block-sections.c:5
+// RUN: %clang -### -target x86_64-linux-gnu -fbasic-block-sections=labels %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-LABELS %s
+// RUN: %clang -### -target arm-unknown-linux -fbasic-block-sections=all %s -S 2>&1 | FileCheck -check-prefix=CHECK-TRIPLE %s
+// RUN: %clang -### -target x86_64-apple-darwin10 -fbasic-block-sections=all %s -S 2>&1 | FileCheck -check-prefix=CHECK-TRIPLE %s
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snehasish wrote:
> MaskRay wrote:
> > `%clang -###` -> `not %clang -fsyntax-only`
> What I really want to check for is the absence of the flag for the particular triple. Using -fsyntax-only means that the cc1 args are not emitted. I've added a check for the diagnostic message but retained `-###` so that I can keep the check for the absence of `-fbasic-block-sections=all`.
Then you can switch to -c

The idea of `not %clang` is that it makes things clear that it is an error.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87426/new/

https://reviews.llvm.org/D87426