From 8e55d9ccb026f6ed09396161e87d29fc49a9750d Mon Sep 17 00:00:00 2001 From: Nico Weber Date: Tue, 20 Aug 2019 16:28:11 +0000 Subject: [PATCH] win: Enable /Zc:twoPhase by default if targeting MSVC 2017 update 3 or newer MSVC 2017 update 3 (_MSC_VER 1911) enables /Zc:twoPhase by default, and so should clang-cl: https://docs.microsoft.com/en-us/cpp/build/reference/zc-twophase clang-cl takes the MSVC version it emulates from the -fmsc-version flag, or if that's not passed it tries to check what the installed version of MSVC is and uses that, and failing that it uses a default version that's currently 1911. So this changes the default if no -fmsc-version flag is passed and no installed MSVC is detected. (It also changes the default if -fmsc-version is passed or MSVC is detected, and either indicates _MSC_VER >= 1911.) As mentioned in the MSDN article, the Windows SDK header files in version 10.0.15063.0 (Creators Update or Redstone 2) and earlier versions do not work correctly with /Zc:twoPhase. If you need to use these old SDKs with a new clang-cl, explicitly pass /Zc:twoPhase- to get the old behavior. Fixes PR43032. Differential Revision: https://reviews.llvm.org/D66394 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@369402 91177308-0d34-0410-b5e6-96231b3b80d8 --- docs/ReleaseNotes.rst | 3 +++ include/clang/Driver/CLCompatOptions.td | 4 ++-- lib/Driver/ToolChains/Clang.cpp | 12 +++++++----- test/Driver/cl-options.c | 18 ++++++++++++------ 4 files changed, 24 insertions(+), 13 deletions(-) diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index f3291137bc..0585438d75 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -90,6 +90,9 @@ Attribute Changes in Clang Windows Support --------------- +- clang-cl now defaults to ``/Zc:twoPhase`` if targeting MSVC2017 update 3 or + later (``_MSC_VER`` >= 1911). This matches MSVC's behavior. Explicitly pass + ``/Zc:twoPhase-`` to restore the old behavior. - ... C Language Changes in Clang diff --git a/include/clang/Driver/CLCompatOptions.td b/include/clang/Driver/CLCompatOptions.td index bb51c3aa11..bf5addb854 100644 --- a/include/clang/Driver/CLCompatOptions.td +++ b/include/clang/Driver/CLCompatOptions.td @@ -235,10 +235,10 @@ def _SLASH_Zc_trigraphs : CLFlag<"Zc:trigraphs">, def _SLASH_Zc_trigraphs_off : CLFlag<"Zc:trigraphs-">, HelpText<"Disable trigraphs (default)">, Alias; def _SLASH_Zc_twoPhase : CLFlag<"Zc:twoPhase">, - HelpText<"Enable two-phase name lookup in templates">, + HelpText<"Enable two-phase name lookup in templates (default)">, Alias; def _SLASH_Zc_twoPhase_ : CLFlag<"Zc:twoPhase-">, - HelpText<"Disable two-phase name lookup in templates (default)">, + HelpText<"Disable two-phase name lookup in templates">, Alias; def _SLASH_Z7 : CLFlag<"Z7">, HelpText<"Enable CodeView debug information in object files">; diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp index 690d4fa3fa..c0f914bf98 100644 --- a/lib/Driver/ToolChains/Clang.cpp +++ b/lib/Driver/ToolChains/Clang.cpp @@ -4883,12 +4883,14 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, !IsWindowsMSVC || IsMSVC2015Compatible)) CmdArgs.push_back("-fno-threadsafe-statics"); - // -fno-delayed-template-parsing is default, except when targeting MSVC. - // Many old Windows SDK versions require this to parse. - // FIXME: MSVC introduced /Zc:twoPhase- to disable this behavior in their - // compiler. We should be able to disable this by default at some point. + // -fno-delayed-template-parsing is default, except when targeting MSVC + // earlier than MSVC 2017 15.3 (_MSC_VER 1911). Windows SDK versions + // 10.0.15063.0 (Creators Update or Redstone 2) and earlier require this to + // parse. + bool IsMSVCBefore2017Update3 = !MSVT.empty() && MSVT < VersionTuple(19, 11); if (Args.hasFlag(options::OPT_fdelayed_template_parsing, - options::OPT_fno_delayed_template_parsing, IsWindowsMSVC)) + options::OPT_fno_delayed_template_parsing, + IsMSVCBefore2017Update3)) CmdArgs.push_back("-fdelayed-template-parsing"); // -fgnu-keywords default varies depending on language; only pass if diff --git a/test/Driver/cl-options.c b/test/Driver/cl-options.c index 68f08b0c18..cb3be9ad7e 100644 --- a/test/Driver/cl-options.c +++ b/test/Driver/cl-options.c @@ -316,13 +316,19 @@ // We recognize -f[no-]delayed-template-parsing. // /Zc:twoPhase[-] has the opposite meaning. -// RUN: %clang_cl -c -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDDEFAULT %s -// DELAYEDDEFAULT: "-fdelayed-template-parsing" -// RUN: %clang_cl -c -fdelayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s -// RUN: %clang_cl -c /Zc:twoPhase- -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s +// RUN: %clang_cl -c -fmsc-version=1910 -### -- %s 2>&1 | FileCheck -check-prefix=OLDDELAYEDDEFAULT %s +// OLDDELAYEDDEFAULT: "-fdelayed-template-parsing" +// RUN: %clang_cl -fmsc-version=1911 -c -### -- %s 2>&1 | FileCheck -check-prefix=NEWDELAYEDDEFAULT %s +// NEWDELAYEDDEFAULT-NOT: "-fdelayed-template-parsing" +// RUN: %clang_cl -c -fmsc-version=1910 -fdelayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s +// RUN: %clang_cl -c -fmsc-version=1911 -fdelayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s +// RUN: %clang_cl -c -fmsc-version=1910 /Zc:twoPhase- -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s +// RUN: %clang_cl -c -fmsc-version=1911 /Zc:twoPhase- -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s // DELAYEDON: "-fdelayed-template-parsing" -// RUN: %clang_cl -c -fno-delayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s -// RUN: %clang_cl -c /Zc:twoPhase -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s +// RUN: %clang_cl -c -fmsc-version=1910 -fno-delayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s +// RUN: %clang_cl -c -fmsc-version=1911 -fno-delayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s +// RUN: %clang_cl -c -fmsc-version=1910 /Zc:twoPhase -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s +// RUN: %clang_cl -c -fmsc-version=1911 /Zc:twoPhase -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s // DELAYEDOFF-NOT: "-fdelayed-template-parsing" // RUN: %clang_cl -c -### /std:c++latest -- %s 2>&1 | FileCheck -check-prefix CHECK-LATEST-CHAR8_T %s -- 2.40.0