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[clang] Don't spuriously pass -stdlib=libc++ to CC1 on Darwin

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Previously, we would be passing down -stdlib=libc++ from the Driver
to CC1 whenever the default standard library on the platform was libc++,
even if -stdlib= had not been passed to the Driver. This meant that we
would pass -stdlib=libc++ in nonsensical circumstances, such as when
compiling C code.

This logic had been added in b534ce46bd to make sure that header
search paths were set up properly. However, since libc++ is now the
default Standard Library on Darwin, passing this explicitly is not
required anymore. Indeed, if no -stdlib= is specified, CC1 will end
up using libc++ if it queries which standard library to use, without
having to be told.

Not passing -stdlib= at all to CC1 on Darwin should become possible
once CC1 stops relying on it to set up framework search paths.

Furthermore, this commit also removes a diagnostic checking whether the
deployment target is too old to support libc++. Nowadays, all supported
deployment targets use libc++ and compiling with libstdc++ is not
supported anymore. The Driver was the wrong place to issue this
diagnostic since it doesn't know whether libc++ will actually be linked
against (e.g. C vs C++), which would lead to spurious diagnostics.
Given that these targets are not supported anymore, we simply drop
the diagnostic instead of trying to refactor it into CC1.

rdar://103198514

Differential Revision: https://reviews.llvm.org/D139938
This commit is contained in:
Louis Dionne
2022-12-13 10:10:35 -05:00
parent 4b2cf982cc
commit 6540f32db0
5 changed files with 48 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
clang/include/clang/Basic/DiagnosticDriverKinds.td
View File

@@ -203,8 +203,6 @@ def warn_drv_missing_plugin_name : Warning<
def warn_drv_missing_plugin_arg : Warning<
"missing plugin argument for plugin %0 in %1">,
InGroup<InvalidCommandLineArgument>;
def err_drv_invalid_libcxx_deployment : Error<
"invalid deployment target for -stdlib=libc++ (requires %0 or later)">;
def err_drv_invalid_argument_to_option : Error<
"invalid argument '%0' to -%1">;
def err_drv_missing_sanitizer_ignorelist : Error<

21
clang/lib/Driver/ToolChains/Darwin.cpp
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@@ -2869,7 +2869,6 @@ Darwin::TranslateArgs(const DerivedArgList &Args, StringRef BoundArch,
// First get the generic Apple args, before moving onto Darwin-specific ones.
DerivedArgList *DAL =
MachO::TranslateArgs(Args, BoundArch, DeviceOffloadKind);
const OptTable &Opts = getDriver().getOpts();
// If no architecture is bound, none of the translations here are relevant.
if (BoundArch.empty())
@@ -2901,26 +2900,6 @@ Darwin::TranslateArgs(const DerivedArgList &Args, StringRef BoundArch,
}
}
if (!Args.getLastArg(options::OPT_stdlib_EQ) &&
GetCXXStdlibType(Args) == ToolChain::CST_Libcxx)
DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_stdlib_EQ),
"libc++");
// Validate the C++ standard library choice.
CXXStdlibType Type = GetCXXStdlibType(*DAL);
if (Type == ToolChain::CST_Libcxx) {
// Check whether the target provides libc++.
StringRef where;
// Complain about targeting iOS < 5.0 in any way.
if (isTargetIOSBased() && isIPhoneOSVersionLT(5, 0))
where = "iOS 5.0";
if (where != StringRef()) {
getDriver().Diag(clang::diag::err_drv_invalid_libcxx_deployment) << where;
}
}
auto Arch = tools::darwin::getArchTypeForMachOArchName(BoundArch);
if ((Arch == llvm::Triple::arm || Arch == llvm::Triple::thumb)) {
if (Args.hasFlag(options::OPT_fomit_frame_pointer,

13
clang/test/Driver/darwin-header-search-libcxx.cpp
View File

@@ -159,3 +159,16 @@
// RUN: --check-prefix=CHECK-LIBCXX-MISSING-BOTH %s
// CHECK-LIBCXX-MISSING-BOTH: ignoring nonexistent directory "[[TOOLCHAIN]]/usr/bin/../include/c++/v1"
// CHECK-LIBCXX-MISSING-BOTH: ignoring nonexistent directory "[[SYSROOT]]/usr/include/c++/v1"
// Make sure that on Darwin, we use libc++ header search paths by default even when
// -stdlib= isn't passed.
//
// RUN: %clang -### %s -fsyntax-only 2>&1 \
// RUN: --target=x86_64-apple-darwin \
// RUN: -ccc-install-dir %S/Inputs/basic_darwin_toolchain_no_libcxx/usr/bin \
// RUN: -isysroot %S/Inputs/basic_darwin_sdk_usr_cxx_v1 \
// RUN: | FileCheck -DSYSROOT=%S/Inputs/basic_darwin_sdk_usr_cxx_v1 \
// RUN: -DTOOLCHAIN=%S/Inputs/basic_darwin_toolchain_no_libcxx \
// RUN: --check-prefix=CHECK-LIBCXX-STDLIB-UNSPECIFIED %s
// CHECK-LIBCXX-STDLIB-UNSPECIFIED: "-cc1"
// CHECK-LIBCXX-STDLIB-UNSPECIFIED: "-internal-isystem" "[[SYSROOT]]/usr/include/c++/v1"

8
clang/test/Driver/darwin-stdlib-dont-pass-in-c.c Normal file
View File

@@ -0,0 +1,8 @@
// This test ensures that the Driver doesn't pass -stdlib= down to CC1 when compiling C code.
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch arm64 -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.9 %s -### 2>&1 | FileCheck %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7k %s -### 2>&1 | FileCheck %s
// CHECK-NOT: "-stdlib="

35
clang/test/Driver/darwin-stdlib.cpp
View File

@@ -1,10 +1,29 @@
// This test will fail if CLANG_DEFAULT_CXX_STDLIB is set to libstdc++.
// XFAIL: default-cxx-stdlib=libstdc++
// Make sure that the Driver passes down -stdlib=libc++ to CC1 when specified explicitly.
//
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch arm64 -miphoneos-version-min=7.0 -stdlib=libc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBCXX %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.9 -stdlib=libc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBCXX %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=7.0 -stdlib=libc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBCXX %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7k -stdlib=libc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBCXX %s
// CHECK-LIBCXX: "-stdlib=libc++"
// CHECK-LIBCXX-NOT: "-stdlib=libstdc++"
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch arm64 -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.9 %s -### 2>&1 | FileCheck %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7k %s -### 2>&1 | FileCheck %s
// Make sure that the Driver passes down -stdlib=libstdc++ to CC1 when specified explicitly. Note that this
// shouldn't really be used on Darwin because libstdc++ is not supported anymore, but we still pin down the
// Driver behavior for now.
//
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch arm64 -miphoneos-version-min=7.0 -stdlib=libstdc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBSTDCXX %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.9 -stdlib=libstdc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBSTDCXX %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=7.0 -stdlib=libstdc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBSTDCXX %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7k -stdlib=libstdc++ %s -### 2>&1 | FileCheck --check-prefix=CHECK-LIBSTDCXX %s
// CHECK-LIBSTDCXX: "-stdlib=libstdc++"
// CHECK-LIBSTDCXX-NOT: "-stdlib=libc++"
// CHECK: "-stdlib=libc++"
// CHECK-NOT: "-stdlib=libstdc++"
// Make sure that the Driver does not spuriously pass down any -stdlib=<...> option to CC1 if none is
// specified on the command-line. In that case, CC1 should use the default standard library, which is
// going to be libc++.
//
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch arm64 -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck --check-prefix=CHECK-NONE %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -mmacosx-version-min=10.9 %s -### 2>&1 | FileCheck --check-prefix=CHECK-NONE %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7s -miphoneos-version-min=7.0 %s -### 2>&1 | FileCheck --check-prefix=CHECK-NONE %s
// RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %S/Inputs/darwin_toolchain_tree/bin/ -arch armv7k %s -### 2>&1 | FileCheck --check-prefix=CHECK-NONE %s
// CHECK-NONE-NOT: "-stdlib="