https://github.com/xbjfk created https://github.com/llvm/llvm-project/pull/68690
This commit adds the /Zc:__STDC__ argument from MSVC, which defines __STDC__. This means, alongside stronger feature parity with MSVC, that things that rely on __STDC__, such as autoconf, can work. Link to MSVC documentation of this flag: https://learn.microsoft.com/en-us/cpp/build/reference/zc-stdc?view=msvc-170 >From 49681eace80c60d22e4d9ced4fabe2872f716bab Mon Sep 17 00:00:00 2001 From: Reagan Bohan <xbjfk.git...@gmail.com> Date: Tue, 10 Oct 2023 11:32:47 +0000 Subject: [PATCH] [clang] Add /Zc:__STDC__ flag to clang-cl This commit adds the /Zc:__STDC__ argument from MSVC, which defines __STDC__. This means, alongside stronger feature parity with MSVC, that things that rely on __STDC__, such as autoconf, can work. --- clang/include/clang/Basic/LangOptions.def | 2 +- clang/include/clang/Driver/Options.td | 7 +++++++ clang/lib/Driver/ToolChains/Clang.cpp | 11 ++++++++++- clang/lib/Frontend/InitPreprocessor.cpp | 2 +- clang/test/Driver/cl-zc.cpp | 4 ++++ 5 files changed, 23 insertions(+), 3 deletions(-) diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def index c0ea4ecb9806a5b..97101d0166a135a 100644 --- a/clang/include/clang/Basic/LangOptions.def +++ b/clang/include/clang/Basic/LangOptions.def @@ -282,7 +282,7 @@ LANGOPT(HIPUseNewLaunchAPI, 1, 0, "Use new kernel launching API for HIP") LANGOPT(OffloadUniformBlock, 1, 0, "Assume that kernels are launched with uniform block sizes (default true for CUDA/HIP and false otherwise)") LANGOPT(HIPStdPar, 1, 0, "Enable Standard Parallel Algorithm Acceleration for HIP (experimental)") LANGOPT(HIPStdParInterposeAlloc, 1, 0, "Replace allocations / deallocations with HIP RT calls when Standard Parallel Algorithm Acceleration for HIP is enabled (Experimental)") - +LANGOPT(MSVCEnableStdcMacro , 1, 0, "define __STDC__ with -fms-compatability") LANGOPT(SizedDeallocation , 1, 0, "sized deallocation") LANGOPT(AlignedAllocation , 1, 0, "aligned allocation") LANGOPT(AlignedAllocationUnavailable, 1, 0, "aligned allocation functions are unavailable") diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index c272a7f1c398aa6..fae1dcc2b5117f7 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -2821,6 +2821,10 @@ def fms_compatibility : Flag<["-"], "fms-compatibility">, Group<f_Group>, Visibility<[ClangOption, CC1Option, CLOption]>, HelpText<"Enable full Microsoft Visual C++ compatibility">, MarshallingInfoFlag<LangOpts<"MSVCCompat">>; +def fms_define_stdc : Flag<["-"], "fms-define-stdc">, Group<f_Group>, + Visibility<[ClangOption, CC1Option]>, + HelpText<"Define __STDC__ in MSVC Compatibility mode">, + MarshallingInfoFlag<LangOpts<"MSVCEnableStdcMacro">>; def fms_extensions : Flag<["-"], "fms-extensions">, Group<f_Group>, Visibility<[ClangOption, CC1Option, CLOption]>, HelpText<"Accept some non-standard constructs supported by the Microsoft compiler">, @@ -7933,6 +7937,9 @@ def _SLASH_vd : CLJoined<"vd">, HelpText<"Control vtordisp placement">, Alias<vtordisp_mode_EQ>; def _SLASH_X : CLFlag<"X">, HelpText<"Do not add %INCLUDE% to include search path">, Alias<nostdlibinc>; +def _SLASH_Zc___STDC__ : CLFlag<"Zc:__STDC__">, + HelpText<"Define __STDC__">, + Alias<fms_define_stdc>; def _SLASH_Zc_sizedDealloc : CLFlag<"Zc:sizedDealloc">, HelpText<"Enable C++14 sized global deallocation functions">, Alias<fsized_deallocation>; diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index bfd6c5c2864abf7..b8f3ff6cd4c91e4 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -6744,8 +6744,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, options::OPT_fms_compatibility, options::OPT_fno_ms_compatibility, (IsWindowsMSVC && Args.hasFlag(options::OPT_fms_extensions, options::OPT_fno_ms_extensions, true))); - if (IsMSVCCompat) + if (IsMSVCCompat) { CmdArgs.push_back("-fms-compatibility"); + bool IsMSVCDefineStdc = Args.hasArg(options::OPT_fms_define_stdc); + if (IsMSVCDefineStdc) + CmdArgs.push_back("-fms-define-stdc"); + } + if (Triple.isWindowsMSVCEnvironment() && !D.IsCLMode() && Args.hasArg(options::OPT_fms_runtime_lib_EQ)) @@ -7922,6 +7927,10 @@ void Clang::AddClangCLArgs(const ArgList &Args, types::ID InputType, CmdArgs.push_back("-fno-wchar"); } + if (Args.hasArg(options::OPT_fms_define_stdc)) { + CmdArgs.push_back("-fms-define-stdc"); + } + if (Args.hasArg(options::OPT__SLASH_kernel)) { llvm::Triple::ArchType Arch = getToolChain().getArch(); std::vector<std::string> Values = diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp index 846e5fce6de7b2c..46399f613257a74 100644 --- a/clang/lib/Frontend/InitPreprocessor.cpp +++ b/clang/lib/Frontend/InitPreprocessor.cpp @@ -423,7 +423,7 @@ static void InitializeStandardPredefinedMacros(const TargetInfo &TI, // [C++] Whether __STDC__ is predefined and if so, what its value is, // are implementation-defined. // (Removed in C++20.) - if (!LangOpts.MSVCCompat && !LangOpts.TraditionalCPP) + if ((!LangOpts.MSVCCompat || LangOpts.MSVCEnableStdcMacro) && !LangOpts.TraditionalCPP) Builder.defineMacro("__STDC__"); // -- __STDC_HOSTED__ // The integer literal 1 if the implementation is a hosted diff --git a/clang/test/Driver/cl-zc.cpp b/clang/test/Driver/cl-zc.cpp index c7cf5b1b6525bea..bb955222c647af3 100644 --- a/clang/test/Driver/cl-zc.cpp +++ b/clang/test/Driver/cl-zc.cpp @@ -123,6 +123,10 @@ // CHECK-CHAR8_T_: "-fno-char8_t" +// RUN: %clang_cl /dev/null /E -Xclang -dM 2> /dev/null | FileCheck -match-full-lines %s --check-prefix=STDCOFF +// RUN: %clang_cl /dev/null /E -Xclang -dM /Zc:__STDC__ 2> /dev/null | FileCheck -match-full-lines %s --check-prefix=STDCON +// STDCON: #define __STDC__ 1 +// STDCOFF-NOT: #define __STDC__ 1 // These never warn, but don't have an effect yet. _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
