[clang-cl]: Add /std:c++23preview and update _MSVC_LANG for C++23 #112378
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zmodem
added
clang:driver
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clang
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@llvm/pr-subscribers-clang @llvm/pr-subscribers-platform-windows Author: Hans (zmodem) ChangesAs discussed in https://discourse.llvm.org/t/clang-cl-adding-std-c-23preview/82553 Full diff: https://github.com/llvm/llvm-project/pull/112378.diff 5 Files Affected:
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 6491e9ac73ce99..3390367173a29d 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -8526,7 +8526,7 @@ def _SLASH_execution_charset : CLCompileJoined<"execution-charset:">,
HelpText<"Set runtime encoding, supports only UTF-8">,
Alias<fexec_charset_EQ>;
def _SLASH_std : CLCompileJoined<"std:">,
- HelpText<"Set language version (c++14,c++17,c++20,c++latest,c11,c17)">;
+ HelpText<"Set language version (c++14,c++17,c++20,c++23preview,c++latest,c11,c17)">;
def _SLASH_U : CLJoinedOrSeparate<"U">, HelpText<"Undefine macro">,
MetaVarName<"<macro>">, Alias<U>;
def _SLASH_validate_charset : CLFlag<"validate-charset">,
diff --git a/clang/lib/Basic/Targets/OSTargets.cpp b/clang/lib/Basic/Targets/OSTargets.cpp
index b56e2c7ca9c494..ff4d2df163e613 100644
--- a/clang/lib/Basic/Targets/OSTargets.cpp
+++ b/clang/lib/Basic/Targets/OSTargets.cpp
@@ -215,8 +215,7 @@ static void addVisualCDefines(const LangOptions &Opts, MacroBuilder &Builder) {
if (Opts.isCompatibleWithMSVC(LangOptions::MSVC2015)) {
if (Opts.CPlusPlus23)
- // TODO update to the proper value.
- Builder.defineMacro("_MSVC_LANG", "202004L");
+ Builder.defineMacro("_MSVC_LANG", "202302L");
else if (Opts.CPlusPlus20)
Builder.defineMacro("_MSVC_LANG", "202002L");
else if (Opts.CPlusPlus17)
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 9d2f7a8960b45f..ca8f10c337e1e9 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -7217,6 +7217,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
.Case("c++17", "-std=c++17")
.Case("c++20", "-std=c++20")
// TODO add c++23 and c++26 when MSVC supports it.
+ .Case("c++23preview", "-std=c++23")
.Case("c++latest", "-std=c++26")
.Default("");
if (LanguageStandard.empty())
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index 48d281bcd447e7..8191fda97788c1 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -605,6 +605,9 @@
// RUN: %clang_cl -fmsc-version=1900 -TP -std:c++20 -### -- %s 2>&1 | FileCheck -check-prefix=STDCXX20 %s
// STDCXX20: -std=c++20
+// RUN: %clang_cl -fmsc-version=1900 -TP -std:c++23preview -### -- %s 2>&1 | FileCheck -check-prefix=STDCXX23PREVIEW %s
+// STDCXX23PREVIEW: -std=c++23
+
// RUN: %clang_cl -fmsc-version=1900 -TP -std:c++latest -### -- %s 2>&1 | FileCheck -check-prefix=STDCXXLATEST %s
// STDCXXLATEST: -std=c++26
diff --git a/clang/test/Preprocessor/predefined-win-macros.c b/clang/test/Preprocessor/predefined-win-macros.c
index 7d29e45c7d5ac6..e7988501afa689 100644
--- a/clang/test/Preprocessor/predefined-win-macros.c
+++ b/clang/test/Preprocessor/predefined-win-macros.c
@@ -56,7 +56,7 @@
// RUN: %clang_cc1 %s -x c++ -E -dM -triple i686-pc-win32 -fms-extensions -fms-compatibility \
// RUN: -fms-compatibility-version=19.00 -std=c++23 -o - | FileCheck -match-full-lines %s --check-prefix=CHECK-MS-CPP2B
// CHECK-MS-CPP2B: #define _MSC_VER 1900
-// CHECK-MS-CPP2B: #define _MSVC_LANG 202004L
+// CHECK-MS-CPP2B: #define _MSVC_LANG 202302L
// RUN: %clang_cc1 -triple i386-windows %s -E -dM -o - \
// RUN: | FileCheck -match-full-lines %s --check-prefix=CHECK-X86-WIN
|
|
@llvm/pr-subscribers-clang-driver Author: Hans (zmodem) ChangesAs discussed in https://discourse.llvm.org/t/clang-cl-adding-std-c-23preview/82553 Full diff: https://github.com/llvm/llvm-project/pull/112378.diff 5 Files Affected:
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 6491e9ac73ce99..3390367173a29d 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -8526,7 +8526,7 @@ def _SLASH_execution_charset : CLCompileJoined<"execution-charset:">,
HelpText<"Set runtime encoding, supports only UTF-8">,
Alias<fexec_charset_EQ>;
def _SLASH_std : CLCompileJoined<"std:">,
- HelpText<"Set language version (c++14,c++17,c++20,c++latest,c11,c17)">;
+ HelpText<"Set language version (c++14,c++17,c++20,c++23preview,c++latest,c11,c17)">;
def _SLASH_U : CLJoinedOrSeparate<"U">, HelpText<"Undefine macro">,
MetaVarName<"<macro>">, Alias<U>;
def _SLASH_validate_charset : CLFlag<"validate-charset">,
diff --git a/clang/lib/Basic/Targets/OSTargets.cpp b/clang/lib/Basic/Targets/OSTargets.cpp
index b56e2c7ca9c494..ff4d2df163e613 100644
--- a/clang/lib/Basic/Targets/OSTargets.cpp
+++ b/clang/lib/Basic/Targets/OSTargets.cpp
@@ -215,8 +215,7 @@ static void addVisualCDefines(const LangOptions &Opts, MacroBuilder &Builder) {
if (Opts.isCompatibleWithMSVC(LangOptions::MSVC2015)) {
if (Opts.CPlusPlus23)
- // TODO update to the proper value.
- Builder.defineMacro("_MSVC_LANG", "202004L");
+ Builder.defineMacro("_MSVC_LANG", "202302L");
else if (Opts.CPlusPlus20)
Builder.defineMacro("_MSVC_LANG", "202002L");
else if (Opts.CPlusPlus17)
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 9d2f7a8960b45f..ca8f10c337e1e9 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -7217,6 +7217,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
.Case("c++17", "-std=c++17")
.Case("c++20", "-std=c++20")
// TODO add c++23 and c++26 when MSVC supports it.
+ .Case("c++23preview", "-std=c++23")
.Case("c++latest", "-std=c++26")
.Default("");
if (LanguageStandard.empty())
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index 48d281bcd447e7..8191fda97788c1 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -605,6 +605,9 @@
// RUN: %clang_cl -fmsc-version=1900 -TP -std:c++20 -### -- %s 2>&1 | FileCheck -check-prefix=STDCXX20 %s
// STDCXX20: -std=c++20
+// RUN: %clang_cl -fmsc-version=1900 -TP -std:c++23preview -### -- %s 2>&1 | FileCheck -check-prefix=STDCXX23PREVIEW %s
+// STDCXX23PREVIEW: -std=c++23
+
// RUN: %clang_cl -fmsc-version=1900 -TP -std:c++latest -### -- %s 2>&1 | FileCheck -check-prefix=STDCXXLATEST %s
// STDCXXLATEST: -std=c++26
diff --git a/clang/test/Preprocessor/predefined-win-macros.c b/clang/test/Preprocessor/predefined-win-macros.c
index 7d29e45c7d5ac6..e7988501afa689 100644
--- a/clang/test/Preprocessor/predefined-win-macros.c
+++ b/clang/test/Preprocessor/predefined-win-macros.c
@@ -56,7 +56,7 @@
// RUN: %clang_cc1 %s -x c++ -E -dM -triple i686-pc-win32 -fms-extensions -fms-compatibility \
// RUN: -fms-compatibility-version=19.00 -std=c++23 -o - | FileCheck -match-full-lines %s --check-prefix=CHECK-MS-CPP2B
// CHECK-MS-CPP2B: #define _MSC_VER 1900
-// CHECK-MS-CPP2B: #define _MSVC_LANG 202004L
+// CHECK-MS-CPP2B: #define _MSVC_LANG 202302L
// RUN: %clang_cc1 -triple i386-windows %s -E -dM -o - \
// RUN: | FileCheck -match-full-lines %s --check-prefix=CHECK-X86-WIN
|
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With STL's test program from the thread on Discourse, this outputs: |
cor3ntin
reviewed
Oct 15, 2024
| @@ -215,8 +215,7 @@ static void addVisualCDefines(const LangOptions &Opts, MacroBuilder &Builder) { | |||
|
|
|||
| if (Opts.isCompatibleWithMSVC(LangOptions::MSVC2015)) { | |||
| if (Opts.CPlusPlus23) | |||
| // TODO update to the proper value. | |||
| Builder.defineMacro("_MSVC_LANG", "202004L"); | |||
| Builder.defineMacro("_MSVC_LANG", "202302L"); | |||
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STL mention setting _MSVC_LANG to 202600 in C++26, we should probably follow suite
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Good point. My only concern is that Clang currently sets __cplusplus to 202400L in C++26 mode, so they wouldn't match which is weird. But maybe we could bump that to 202600 also?
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Clang and GCC both use 202400L: https://godbolt.org/z/7er4doE6h -- maybe Microsoft wants to consider using the same value?
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202400L seems perfectly reasonable. I'll throw it over the fence.
EDIT: Poked our internal email chain to get approval (or at least lack of disapproval) from stakeholders and added a comment to Stephan's PR linking back here.
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From a user perspective, having compilers align on a particular value in the range "greater than C++23's value, but less than C++26's final value" doesn't seem important. But from Clang's perspective, I can see how it would be simpler to avoid having to vary depending on whether you're imitating MSVC or not. I'll make this change for our implementation.
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I've updated the PR to set _MSVC_LANG to 202400L for C++26.
tru
approved these changes
Oct 15, 2024
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Question for @StephanTLavavej and @CaseyCarter -- are there plans to do something similar for C23 as done for C++23? (Anything else we need to do on our end?) |
AaronBallman
approved these changes
Oct 15, 2024
No plans at this time. (We don't have the same scenario of the Standard Library getting ahead of the compiler.) |
Thank you for confirming! |
CaseyCarter
approved these changes
Oct 15, 2024
|
@StephanTLavavej @CaseyCarter What is your timetable? I'm wondering whether we should do any back port effort (otherwise it will land in Clang 20 in ~february) |
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We can use |
Sure, will do. |
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/30/builds/8330 Here is the relevant piece of the build log for the reference |
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You really should backport this. A 19.1.x release will probably happen before we release 17.13, so you can claim compatibility with future MSVC. 🔮 |
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As discussed in https://discourse.llvm.org/t/clang-cl-adding-std-c-23preview/82553