[CMake] Remove CLANG_DEFAULT_STD_C/CLANG_DEFAULT_STD_CXX

When Clang is used as a cross compiler, it should respect the target
platform default. Defaulting to a configure-time CLANG_DEFAULT_STD_C/CLANG_DEFAULT_STD_CXX
does not make much sense.

When Clang is used as a single-platform compiler, we should use Clang
configuration file (https://discourse.llvm.org/t/configuration-files/42529
https://clang.llvm.org/docs/UsersManual.html#configuration-files).

The Gentoo needs from D34365 has been satisfied by a configuration file.

Reviewed By: mgorny

Differential Revision: https://reviews.llvm.org/D133375
This commit is contained in:
Fangrui Song 2022-10-16 13:15:44 -07:00
parent dc884f0f43
commit 3baadff896
9 changed files with 2 additions and 60 deletions

View File

@ -189,12 +189,6 @@ set(CLANG_SPAWN_CC1 OFF CACHE BOOL
option(CLANG_DEFAULT_PIE_ON_LINUX "Default to -fPIE and -pie on linux-gnu" ON)
# TODO: verify the values against LangStandards.def?
set(CLANG_DEFAULT_STD_C "" CACHE STRING
"Default standard to use for C/ObjC code (IDENT from LangStandards.def, empty for platform default)")
set(CLANG_DEFAULT_STD_CXX "" CACHE STRING
"Default standard to use for C++/ObjC++ code (IDENT from LangStandards.def, empty for platform default)")
set(CLANG_DEFAULT_LINKER "" CACHE STRING
"Default linker to use (linker name or absolute path, empty for platform default)")

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@ -14,24 +14,6 @@
/* Default linker to use. */
#define CLANG_DEFAULT_LINKER "${CLANG_DEFAULT_LINKER}"
/* Default C/ObjC standard to use. */
#cmakedefine CLANG_DEFAULT_STD_C LangStandard::lang_${CLANG_DEFAULT_STD_C}
/* Always #define something so that missing the config.h #include at use sites
* becomes a compile error.
*/
#ifndef CLANG_DEFAULT_STD_C
#define CLANG_DEFAULT_STD_C LangStandard::lang_unspecified
#endif
/* Default C++/ObjC++ standard to use. */
#cmakedefine CLANG_DEFAULT_STD_CXX LangStandard::lang_${CLANG_DEFAULT_STD_CXX}
/* Always #define something so that missing the config.h #include at use sites
* becomes a compile error.
*/
#ifndef CLANG_DEFAULT_STD_CXX
#define CLANG_DEFAULT_STD_CXX LangStandard::lang_unspecified
#endif
/* Default C++ stdlib to use. */
#define CLANG_DEFAULT_CXX_STDLIB "${CLANG_DEFAULT_CXX_STDLIB}"

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@ -58,23 +58,14 @@ LangStandard::Kind clang::getDefaultLanguageStandard(clang::Language Lang,
return LangStandard::lang_cuda;
case Language::Asm:
case Language::C:
if (CLANG_DEFAULT_STD_C != LangStandard::lang_unspecified)
return CLANG_DEFAULT_STD_C;
// The PS4 uses C99 as the default C standard.
if (T.isPS4())
return LangStandard::lang_gnu99;
return LangStandard::lang_gnu17;
case Language::ObjC:
if (CLANG_DEFAULT_STD_C != LangStandard::lang_unspecified)
return CLANG_DEFAULT_STD_C;
return LangStandard::lang_gnu11;
case Language::CXX:
case Language::ObjCXX:
if (CLANG_DEFAULT_STD_CXX != LangStandard::lang_unspecified)
return CLANG_DEFAULT_STD_CXX;
if (T.isPS())
return LangStandard::lang_gnucxx14;
return LangStandard::lang_gnucxx17;

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@ -1,5 +1,5 @@
// UNSUPPORTED: default-std-cxx, ps4, ps5
/// Test default standards when CLANG_DEFAULT_STD_CXX is unspecified.
// UNSUPPORTED: ps4, ps5
/// Test default standards.
/// PS4/PS5 default to gnu++14.
// RUN: %clang_cc1 -dM -E %s | FileCheck --check-prefix=CXX17 %s

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@ -126,9 +126,6 @@ if config.has_plugins and config.llvm_plugin_ext:
if config.clang_default_pie_on_linux:
config.available_features.add('default-pie-on-linux')
if config.clang_default_std_cxx != '':
config.available_features.add('default-std-cxx')
# Set available features we allow tests to conditionalize on.
#
if config.clang_default_cxx_stdlib != '':

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@ -24,7 +24,6 @@ config.have_zlib = @LLVM_ENABLE_ZLIB@
config.have_zstd = @LLVM_ENABLE_ZSTD@
config.clang_arcmt = @CLANG_ENABLE_ARCMT@
config.clang_default_pie_on_linux = @CLANG_DEFAULT_PIE_ON_LINUX@
config.clang_default_std_cxx = "@CLANG_DEFAULT_STD_CXX@"
config.clang_default_cxx_stdlib = "@CLANG_DEFAULT_CXX_STDLIB@"
config.clang_staticanalyzer = @CLANG_ENABLE_STATIC_ANALYZER@
config.clang_staticanalyzer_z3 = @LLVM_WITH_Z3@

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@ -11,8 +11,6 @@ write_cmake_config("Config") {
"BUG_REPORT_URL=https://github.com/llvm/llvm-project/issues/",
"CLANG_DEFAULT_PIE_ON_LINUX=1",
"CLANG_DEFAULT_LINKER=",
"CLANG_DEFAULT_STD_C=",
"CLANG_DEFAULT_STD_CXX=",
"CLANG_DEFAULT_CXX_STDLIB=",
"CLANG_DEFAULT_RTLIB=",
"CLANG_DEFAULT_OBJCOPY=objcopy",

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@ -46,7 +46,6 @@ write_lit_config("lit_site_cfg") {
"LLVM_WITH_Z3=0",
"CLANG_BUILD_EXAMPLES=0",
"CLANG_BUILT_STANDALONE=0",
"CLANG_DEFAULT_STD_CXX=",
"CLANG_DEFAULT_CXX_STDLIB=", # Empty string means "default value" here.
"CLANG_DEFAULT_PIE_ON_LINUX=0",
"CLANG_PLUGIN_SUPPORT=0", # FIXME: Analysis/plugins need global -fPIC

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@ -28,24 +28,6 @@
/* Default linker to use. */
#define CLANG_DEFAULT_LINKER ""
/* Default C/ObjC standard to use. */
/* #undef CLANG_DEFAULT_STD_C */
/* Always #define something so that missing the config.h #include at use sites
* becomes a compile error.
*/
#ifndef CLANG_DEFAULT_STD_C
#define CLANG_DEFAULT_STD_C LangStandard::lang_unspecified
#endif
/* Default C++/ObjC++ standard to use. */
/* #undef CLANG_DEFAULT_STD_CXX */
/* Always #define something so that missing the config.h #include at use sites
* becomes a compile error.
*/
#ifndef CLANG_DEFAULT_STD_CXX
#define CLANG_DEFAULT_STD_CXX LangStandard::lang_unspecified
#endif
/* Default C++ stdlib to use. */
#define CLANG_DEFAULT_CXX_STDLIB ""