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author | Chuanqi Xu <yedeng.yd@linux.alibaba.com> | 2024-04-03 16:15:30 +0800 |
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committer | Chuanqi Xu <yedeng.yd@linux.alibaba.com> | 2024-04-03 16:28:05 +0800 |
commit | 72c29fa9e226a928b3d3a01d74f6b44a0b31b7d4 (patch) | |
tree | a229874b804955d3afc72bee2c72ee629989badf | |
parent | 4dd103e9c65de7d3dbf12e76fbb72724127ec325 (diff) | |
download | llvm-72c29fa9e226a928b3d3a01d74f6b44a0b31b7d4.zip llvm-72c29fa9e226a928b3d3a01d74f6b44a0b31b7d4.tar.gz llvm-72c29fa9e226a928b3d3a01d74f6b44a0b31b7d4.tar.bz2 |
[C++20] [Modules] [Driver] Emit unused argument warning if we use '-fmodule-output' with non-module input
We required the file name of an 'importable module unit' should end
with .cppm (or .ccm, .cxxm, .c++m).
But the driver can accept '-fmodule-output' for files with normal
suffixes (e.g., .cpp). This is somewhat inconsistency.
In this patch, we only claim the option `-fmodule-output` is used if
the type of the input file is modules related. Then now the compiler
will emit 'unused argument' warnings if the input file is not modules
related.
-rw-r--r-- | clang/docs/ReleaseNotes.rst | 3 | ||||
-rw-r--r-- | clang/lib/Driver/ToolChains/Clang.cpp | 15 | ||||
-rw-r--r-- | clang/test/Driver/module-output.cppm | 8 |
3 files changed, 23 insertions, 3 deletions
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index d5ce54e..3237842 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -328,6 +328,9 @@ Improvements to Clang's diagnostics - New ``-Wformat-signedness`` diagnostic that warn if the format string requires an unsigned argument and the argument is signed and vice versa. +- Clang now emits ``unused argument`` warning when the -fmodule-output flag is used + with an input that is not of type c++-module. + Improvements to Clang's time-trace ---------------------------------- diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index b03ac60..7fd6ad6 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -4045,9 +4045,18 @@ static bool RenderModulesOptions(Compilation &C, const Driver &D, // module fragment. CmdArgs.push_back("-fskip-odr-check-in-gmf"); - // Claim `-fmodule-output` and `-fmodule-output=` to avoid unused warnings. - Args.ClaimAllArgs(options::OPT_fmodule_output); - Args.ClaimAllArgs(options::OPT_fmodule_output_EQ); + // We need to include the case the input file is a module file here. + // Since the default compilation model for C++ module interface unit will + // create temporary module file and compile the temporary module file + // to get the object file. Then the `-fmodule-output` flag will be + // brought to the second compilation process. So we have to claim it for + // the case too. + if (Input.getType() == driver::types::TY_CXXModule || + Input.getType() == driver::types::TY_PP_CXXModule || + Input.getType() == driver::types::TY_ModuleFile) { + Args.ClaimAllArgs(options::OPT_fmodule_output); + Args.ClaimAllArgs(options::OPT_fmodule_output_EQ); + } return HaveModules; } diff --git a/clang/test/Driver/module-output.cppm b/clang/test/Driver/module-output.cppm index d0cab0cb..dea9cf9 100644 --- a/clang/test/Driver/module-output.cppm +++ b/clang/test/Driver/module-output.cppm @@ -33,6 +33,9 @@ // RUN: %clang -std=c++20 %t/Hello.cppm -fmodule-output=%t/Hello.pcm -fmodule-output -c -fsyntax-only \ // RUN: -### 2>&1 | FileCheck %t/Hello.cppm --check-prefix=CHECK-NOT-USED +// Test that we can emit a warning if the type of the input file is not a module interface unit. +// RUN: %clang -std=c++20 %t/a.cpp -fmodule-output -c -o %t/a.o -### 2>&1 | FileCheck %t/a.cpp + //--- Hello.cppm export module Hello; @@ -55,3 +58,8 @@ export module AnotherModule; // CHECK: "-emit-obj" {{.*}}"-main-file-name" "Hello.cppm" {{.*}}"-o" "{{.*}}/Hello-{{.*}}.o" "-x" "pcm" "{{.*}}/Hello.pcm" // CHECK: "-emit-module-interface" {{.*}}"-main-file-name" "AnotherModule.cppm" {{.*}}"-o" "{{.*}}/AnotherModule.pcm" "-x" "c++" "{{.*}}/AnotherModule.cppm" // CHECK: "-emit-obj" {{.*}}"-main-file-name" "AnotherModule.cppm" {{.*}}"-o" "{{.*}}/AnotherModule-{{.*}}.o" "-x" "pcm" "{{.*}}/AnotherModule.pcm" + +//--- a.cpp +export module a; + +// CHECK: warning: argument unused during compilation: '-fmodule-output' |