[PATCH] D152570: [clang] Fix filename remapping in template arguments

[Fangrui Song via Phabricator via cfe-commits]

MaskRay accepted this revision.
MaskRay added a comment.
This revision is now accepted and ready to land.

Looks great!

> [clang] Fix filename remapping in template arguments

Personally I don't consider this a bug fix, but this changes does move into a desired direction, by making `-fmacro-prefix-map=` add local determinism.
I wonder whether `Make -fmacro-prefix-map= apply to anonymous tag in TypePrinter` will be more meaningful subject without being too verbose.



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Comment at: clang/test/CodeGenCXX/file-prefix-map-lambda.cpp:1
+// RUN: %clang_cc1 -triple x86_64-unknown-freebsd -fmacro-prefix-map=%p=./UNLIKELY_PATH/empty -S %s -emit-llvm -o - | FileCheck %s
+
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You can use `-triple x86_64` to test generic ELF behavior, if you don't want to write `linux-gnu` :)

For this test, perhaps `-triple %itanium_abi_triple` is better (coverage for non-x86 targets).


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Comment at: clang/test/CodeGenCXX/file-prefix-map-lambda.cpp:2
+// RUN: %clang_cc1 -triple x86_64-unknown-freebsd -fmacro-prefix-map=%p=./UNLIKELY_PATH/empty -S %s -emit-llvm -o - | FileCheck %s
+
+template<typename f>
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For the new test file, I was thinking of https://maskray.me/blog/2021-08-08-toolchain-testing#the-test-checks-at-the-wrong-layer#i-dont-know-an-existing-test-can-be-enhanced.

The main C++ test `CodeGenCXX/predefined-expr.cpp` does not say about `__PRETTY_FUNCTION__` in its filename, so a new file seems fine.

If we are going to retain this new test, I think `macro-prefix-map-` is a better prefix. 
`-fmacro-prefix-map=` is more specific to `-ffile-prefix-map=`.


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Comment at: clang/test/CodeGenCXX/file-prefix-map-lambda.cpp:11
+  auto *s = lambdatest([](){});
+// CHECK: @"__PRETTY_FUNCTION__._Z10lambdatestIZ4mainE3$_0EDaOT_" = private unnamed_addr constant [{{[0-9]+}} x i8] c"auto lambdatest(f &&) [f = (lambda at ./UNLIKELY_PATH/empty{{/|\\\\}}{{.*}}.cpp:10:24)]\00", align 1
+
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10 should be replaced with `[[#@LINE-1]]` so that adding more tests will not easily make this stale.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D152570/new/

https://reviews.llvm.org/D152570