Revert "specify language flag when source LANGUAGE property is set"
Revert commit 74b1c9fc8e (Explicitly specify language flag when source
LANGUAGE property is set, 2020-06-01, v3.19.0-rc1~722^2) and the lookup
tables from its two immediate ancestors. The purpose of that change was
to convert an explicit `LANGUAGE` source file property into an explicit
language specification compiler flag like `-x c`. This seems reasonable
since the property is documented as meaning "indicate what programming
language the source file is". It is also needed to help compilers deal
with non-standard source file extensions they don't recognize.
However, some projects have been setting `LANGUAGE C` on `.S` assembler
source files to mean "use the C compiler". Passing `-x c` for them
breaks the build because the `.S` sources are not written in C. These
projects should be updated to use `enable_language(ASM)`, for which
CMake often chooses the C compiler as the assembler when using
toolchains that support it (which would have to be the case for projects
using the approach).
Revert the change for now to preserve the old behavior for such projects.
We can re-introduce it with a policy in a future version of CMake.
Fixes: #21469
Issue: #14516, #20716
diff --git a/Help/release/3.19.rst b/Help/release/3.19.rst
index be63e9d..961d6c0 100644
--- a/Help/release/3.19.rst
+++ b/Help/release/3.19.rst
@@ -330,3 +330,19 @@
* If ``CUDA`` compiler detection fails with user-specified
:variable:`CMAKE_CUDA_ARCHITECTURES` or
:variable:`CMAKE_CUDA_HOST_COMPILER`, an error is raised.
+
+Updates
+=======
+
+Changes made since CMake 3.19.0 include the following.
+
+3.19.1
+------
+
+* CMake 3.19.0 compiles source files with the :prop_sf:`LANGUAGE`
+ property by passing an explicit language flag such as ``-x c``.
+ This is consistent with the property's documented meaning that
+ the source file is written in the specified language. However,
+ it can break projects that were using the property only to
+ cause the specified language's compiler to be used. This has
+ been reverted to restore behavior from CMake 3.18 and below.
diff --git a/Modules/Compiler/AppleClang-C.cmake b/Modules/Compiler/AppleClang-C.cmake
index 26a4bbd..2794f52 100644
--- a/Modules/Compiler/AppleClang-C.cmake
+++ b/Modules/Compiler/AppleClang-C.cmake
@@ -1,8 +1,6 @@
include(Compiler/Clang)
__compiler_clang(C)
-set(CMAKE_C_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c)
-
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.0)
set(CMAKE_C90_STANDARD_COMPILE_OPTION "-std=c90")
set(CMAKE_C90_EXTENSION_COMPILE_OPTION "-std=gnu90")
diff --git a/Modules/Compiler/AppleClang-CXX.cmake b/Modules/Compiler/AppleClang-CXX.cmake
index 611c674..15edc21 100644
--- a/Modules/Compiler/AppleClang-CXX.cmake
+++ b/Modules/Compiler/AppleClang-CXX.cmake
@@ -1,8 +1,6 @@
include(Compiler/Clang)
__compiler_clang(CXX)
-set(CMAKE_CXX_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c++)
-
if(NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
set(CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN "-fvisibility-inlines-hidden")
endif()
diff --git a/Modules/Compiler/Clang-C.cmake b/Modules/Compiler/Clang-C.cmake
index fb6ffa7..7c4a263 100644
--- a/Modules/Compiler/Clang-C.cmake
+++ b/Modules/Compiler/Clang-C.cmake
@@ -8,8 +8,6 @@
if("x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC")
set(CMAKE_C_CLANG_TIDY_DRIVER_MODE "cl")
-elseif("x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xGNU")
- set(CMAKE_C_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.4)
diff --git a/Modules/Compiler/Clang-CXX.cmake b/Modules/Compiler/Clang-CXX.cmake
index 311d2b0..789e991 100644
--- a/Modules/Compiler/Clang-CXX.cmake
+++ b/Modules/Compiler/Clang-CXX.cmake
@@ -2,9 +2,7 @@
__compiler_clang(CXX)
__compiler_clang_cxx_standards(CXX)
-
if("x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xGNU")
- set(CMAKE_CXX_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c++)
set(CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN "-fvisibility-inlines-hidden")
endif()
diff --git a/Modules/Compiler/GNU-C.cmake b/Modules/Compiler/GNU-C.cmake
index 8105a77..ca286b3 100644
--- a/Modules/Compiler/GNU-C.cmake
+++ b/Modules/Compiler/GNU-C.cmake
@@ -1,8 +1,6 @@
include(Compiler/GNU)
__compiler_gnu(C)
-set(CMAKE_C_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c)
-
if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5)
set(CMAKE_C90_STANDARD_COMPILE_OPTION "-std=c90")
set(CMAKE_C90_EXTENSION_COMPILE_OPTION "-std=gnu90")
diff --git a/Modules/Compiler/GNU-CXX.cmake b/Modules/Compiler/GNU-CXX.cmake
index 59ec056..fcaaeab 100644
--- a/Modules/Compiler/GNU-CXX.cmake
+++ b/Modules/Compiler/GNU-CXX.cmake
@@ -1,8 +1,6 @@
include(Compiler/GNU)
__compiler_gnu(CXX)
-set(CMAKE_CXX_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c++)
-
if (WIN32)
if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.6)
set(CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN "-fno-keep-inline-dllexport")
diff --git a/Modules/Compiler/Intel-C.cmake b/Modules/Compiler/Intel-C.cmake
index 322f63d..ec3bfd8 100644
--- a/Modules/Compiler/Intel-C.cmake
+++ b/Modules/Compiler/Intel-C.cmake
@@ -28,8 +28,6 @@
else()
- set(CMAKE_C_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c)
-
if (NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 15.0.0)
set(CMAKE_C11_STANDARD_COMPILE_OPTION "-std=c11")
set(CMAKE_C11_EXTENSION_COMPILE_OPTION "-std=gnu11")
diff --git a/Modules/Compiler/Intel-CXX.cmake b/Modules/Compiler/Intel-CXX.cmake
index 42adfd1..b71b946 100644
--- a/Modules/Compiler/Intel-CXX.cmake
+++ b/Modules/Compiler/Intel-CXX.cmake
@@ -42,8 +42,6 @@
else()
- set(CMAKE_CXX_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c++)
-
if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0.0)
set(CMAKE_CXX20_STANDARD_COMPILE_OPTION "-std=c++20")
set(CMAKE_CXX20_EXTENSION_COMPILE_OPTION "-std=gnu++20")
diff --git a/Modules/Compiler/XL-C.cmake b/Modules/Compiler/XL-C.cmake
index 78c44d5..2077bda 100644
--- a/Modules/Compiler/XL-C.cmake
+++ b/Modules/Compiler/XL-C.cmake
@@ -6,8 +6,6 @@
# -qthreaded = Ensures that all optimizations will be thread-safe
string(APPEND CMAKE_C_FLAGS_INIT " -qthreaded")
-set(CMAKE_C_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -qsourcetype=c)
-
if (CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10.1)
set(CMAKE_C90_STANDARD_COMPILE_OPTION "-qlanglvl=stdc89")
set(CMAKE_C90_EXTENSION_COMPILE_OPTION "-qlanglvl=extc89")
diff --git a/Modules/Compiler/XL-CXX.cmake b/Modules/Compiler/XL-CXX.cmake
index 3b911f3..41e3e11 100644
--- a/Modules/Compiler/XL-CXX.cmake
+++ b/Modules/Compiler/XL-CXX.cmake
@@ -6,8 +6,6 @@
# -qthreaded = Ensures that all optimizations will be thread-safe
string(APPEND CMAKE_CXX_FLAGS_INIT " -qthreaded")
-set(CMAKE_CXX_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -+)
-
if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 10.1)
if(CMAKE_SYSTEM MATCHES "Linux")
set(CMAKE_CXX98_STANDARD_COMPILE_OPTION "")
@@ -34,3 +32,6 @@
endif ()
__compiler_check_default_language_standard(CXX 10.1 98)
+
+set(CMAKE_CXX_COMPILE_OBJECT
+ "<CMAKE_CXX_COMPILER> -+ <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> -c <SOURCE>")
diff --git a/Modules/Compiler/XLClang-C.cmake b/Modules/Compiler/XLClang-C.cmake
index 1668a4d..54c18a6 100644
--- a/Modules/Compiler/XLClang-C.cmake
+++ b/Modules/Compiler/XLClang-C.cmake
@@ -1,8 +1,6 @@
include(Compiler/XLClang)
__compiler_xlclang(C)
-set(CMAKE_C_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c)
-
if (CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 13.1.1)
set(CMAKE_C90_STANDARD_COMPILE_OPTION "-std=c89")
set(CMAKE_C90_EXTENSION_COMPILE_OPTION "-std=gnu89")
diff --git a/Modules/Compiler/XLClang-CXX.cmake b/Modules/Compiler/XLClang-CXX.cmake
index 02638c7..9ea3d7c 100644
--- a/Modules/Compiler/XLClang-CXX.cmake
+++ b/Modules/Compiler/XLClang-CXX.cmake
@@ -1,8 +1,6 @@
include(Compiler/XLClang)
__compiler_xlclang(CXX)
-set(CMAKE_CXX_COMPILE_OPTIONS_EXPLICIT_LANGUAGE -x c++)
-
if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 13.1.1)
set(CMAKE_CXX98_STANDARD_COMPILE_OPTION "")
set(CMAKE_CXX98_EXTENSION_COMPILE_OPTION "")
diff --git a/Source/cmExtraSublimeTextGenerator.cxx b/Source/cmExtraSublimeTextGenerator.cxx
index 1c7e4b1..7c36144 100644
--- a/Source/cmExtraSublimeTextGenerator.cxx
+++ b/Source/cmExtraSublimeTextGenerator.cxx
@@ -349,13 +349,6 @@
if (language.empty()) {
language = "C";
}
-
- // explicitly add the explicit language flag before any other flag
- // this way backwards compatibility with user flags is maintained
- if (source->GetProperty("LANGUAGE")) {
- lg->AppendFeatureOptions(flags, language, "EXPLICIT_LANGUAGE");
- }
-
std::string const& config =
lg->GetMakefile()->GetSafeDefinition("CMAKE_BUILD_TYPE");
diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index 766ae72..b40d8ea 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -937,14 +937,6 @@
default:
break;
}
-
- // explicitly add the explicit language flag before any other flag
- // this way backwards compatibility with user flags is maintained
- if (sf->GetProperty("LANGUAGE")) {
- this->CurrentLocalGenerator->AppendFeatureOptions(flags, lang,
- "EXPLICIT_LANGUAGE");
- }
-
const std::string COMPILE_FLAGS("COMPILE_FLAGS");
if (cmProp cflags = sf->GetProperty(COMPILE_FLAGS)) {
lg->AppendFlags(flags, genexInterpreter.Evaluate(*cflags, COMPILE_FLAGS));
diff --git a/Source/cmMakefileTargetGenerator.cxx b/Source/cmMakefileTargetGenerator.cxx
index 5f97d86..3c4f68c 100644
--- a/Source/cmMakefileTargetGenerator.cxx
+++ b/Source/cmMakefileTargetGenerator.cxx
@@ -573,13 +573,6 @@
// Build the set of compiler flags.
std::string flags;
- // explicitly add the explicit language flag before any other flag
- // this way backwards compatibility with user flags is maintained
- if (source.GetProperty("LANGUAGE")) {
- this->LocalGenerator->AppendFeatureOptions(flags, lang,
- "EXPLICIT_LANGUAGE");
- }
-
// Add language-specific flags.
std::string langFlags = cmStrCat("$(", lang, "_FLAGS", filterArch, ")");
this->LocalGenerator->AppendFlags(flags, langFlags);
diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index 04d84a0..76df9f2 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -190,16 +190,7 @@
}
}
- std::string flags;
- // explicitly add the explicit language flag before any other flag
- // this way backwards compatibility with user flags is maintained
- if (source->GetProperty("LANGUAGE")) {
- this->LocalGenerator->AppendFeatureOptions(flags, language,
- "EXPLICIT_LANGUAGE");
- flags += " ";
- }
-
- flags += this->GetFlags(language, config, filterArch);
+ std::string flags = this->GetFlags(language, config, filterArch);
// Add Fortran format flags.
if (language == "Fortran") {
diff --git a/Tests/SetLang/CMakeLists.txt b/Tests/SetLang/CMakeLists.txt
index 616421e..9de4fc6 100644
--- a/Tests/SetLang/CMakeLists.txt
+++ b/Tests/SetLang/CMakeLists.txt
@@ -15,10 +15,3 @@
add_library(stay stay_c.c stay_cxx.cxx)
set_property(TARGET stay PROPERTY COMPILE_OPTIONS "-TP")
endif()
-
-if((CMAKE_C_COMPILER_ID MATCHES "(GNU|Clang|MSVC|Borland|Embarcadero|Intel|TI|XL)"))
- add_library(zoom zoom.zzz)
- set_source_files_properties(zoom.zzz PROPERTIES LANGUAGE CXX)
- target_link_libraries(SetLang zoom)
- target_compile_definitions(SetLang PRIVATE WITH_ZOOM)
-endif()
diff --git a/Tests/SetLang/bar.c b/Tests/SetLang/bar.c
index 515e8c2..b934356 100644
--- a/Tests/SetLang/bar.c
+++ b/Tests/SetLang/bar.c
@@ -1,22 +1,10 @@
#include <stdio.h>
int foo();
-
-#ifdef WITH_ZOOM
-int zoom();
-#endif
-
class A
{
public:
- A()
- {
- this->i = foo();
-#ifdef WITH_ZOOM
- i += zoom();
- i -= zoom();
-#endif
- }
+ A() { this->i = foo(); }
int i;
};
diff --git a/Tests/SetLang/zoom.zzz b/Tests/SetLang/zoom.zzz
deleted file mode 100644
index a0c8899..0000000
--- a/Tests/SetLang/zoom.zzz
+++ /dev/null
@@ -1,7 +0,0 @@
-int zoom()
-{
- int r = 10;
- r++;
- int ret = r + 10;
- return ret;
-}
