launcher: support setting a compiler launcher through the environment

This makes it much easier to use a launcher for all CMake projects in an
environment rather than having to remember to pass the setting to every
CMake build.

Help/envvar/CMAKE_LANG_COMPILER_LAUNCHER.rst

@@ -0,0 +1,10 @@
+CMAKE_<LANG>_COMPILER_LAUNCHER
+------------------------------
+
+.. include:: ENV_VAR.txt
+
+Default compiler launcher to use for the specified language. Will only be used
+by CMake to initialize the variable on the first configuration. Afterwards, it
+is available through the cache setting of the variable of the same name. For
+any configuration run (including the first), the environment variable will be
+ignored if the :variable:`CMAKE_<LANG>_COMPILER_LAUNCHER` variable is defined.

Help/manual/cmake-env-variables.7.rst

@@ -28,6 +28,7 @@ Environment Variables that Control the Build
    /envvar/CMAKE_GENERATOR_INSTANCE
    /envvar/CMAKE_GENERATOR_PLATFORM
    /envvar/CMAKE_GENERATOR_TOOLSET
+   /envvar/CMAKE_LANG_COMPILER_LAUNCHER
    /envvar/CMAKE_MSVCIDE_RUN_PATH
    /envvar/CMAKE_NO_VERBOSE
    /envvar/CMAKE_OSX_ARCHITECTURES

Help/release/dev/compiler-launcher-env.rst

@@ -0,0 +1,5 @@
+compiler-launcher-env
+---------------------
+
+* The :envvar:`CMAKE_<LANG>_COMPILER_LAUNCHER` environment variable may now be
+  used to initialize the :variable:`CMAKE_<LANG>_COMPILER_LAUNCHER` variable.

Help/variable/CMAKE_LANG_COMPILER_LAUNCHER.rst

@@ -5,3 +5,6 @@ Default value for :prop_tgt:`<LANG>_COMPILER_LAUNCHER` target property.
 This variable is used to initialize the property on each target as it is
 created.  This is done only when ``<LANG>`` is ``C``, ``CXX``, ``Fortran``,
 or ``CUDA``.
+
+This variable is initialized to the :envvar:`CMAKE_<LANG>_COMPILER_LAUNCHER`
+environment variable if it is set.

Modules/CMakeCInformation.cmake

@@ -110,6 +110,11 @@ if(CMAKE_C_STANDARD_LIBRARIES_INIT)
   mark_as_advanced(CMAKE_C_STANDARD_LIBRARIES)
 endif()
 
+if(NOT CMAKE_C_COMPILER_LAUNCHER AND DEFINED ENV{CMAKE_C_COMPILER_LAUNCHER})
+  set(CMAKE_C_COMPILER_LAUNCHER "$ENV{CMAKE_C_COMPILER_LAUNCHER}"
+    CACHE STRING "Compiler launcher for C.")
+endif()
+
 include(CMakeCommonLanguageInclude)
 
 # now define the following rule variables

Modules/CMakeCUDAInformation.cmake

@@ -82,6 +82,11 @@ if(CMAKE_CUDA_STANDARD_LIBRARIES_INIT)
   mark_as_advanced(CMAKE_CUDA_STANDARD_LIBRARIES)
 endif()
 
+if(NOT CMAKE_CUDA_COMPILER_LAUNCHER AND DEFINED ENV{CMAKE_CUDA_COMPILER_LAUNCHER})
+  set(CMAKE_CUDA_COMPILER_LAUNCHER "$ENV{CMAKE_CUDA_COMPILER_LAUNCHER}"
+    CACHE STRING "Compiler launcher for CUDA.")
+endif()
+
 include(CMakeCommonLanguageInclude)
 
 # now define the following rules:

Modules/CMakeCXXInformation.cmake

@@ -207,6 +207,11 @@ if(CMAKE_CXX_STANDARD_LIBRARIES_INIT)
   mark_as_advanced(CMAKE_CXX_STANDARD_LIBRARIES)
 endif()
 
+if(NOT CMAKE_CXX_COMPILER_LAUNCHER AND DEFINED ENV{CMAKE_CXX_COMPILER_LAUNCHER})
+  set(CMAKE_CXX_COMPILER_LAUNCHER "$ENV{CMAKE_CXX_COMPILER_LAUNCHER}"
+    CACHE STRING "Compiler launcher for CXX.")
+endif()
+
 include(CMakeCommonLanguageInclude)
 
 # now define the following rules:

Modules/CMakeFortranInformation.cmake

@@ -163,6 +163,11 @@ set(CMAKE_Fortran_FLAGS_INIT "$ENV{FFLAGS} ${CMAKE_Fortran_FLAGS_INIT}")
 
 cmake_initialize_per_config_variable(CMAKE_Fortran_FLAGS "Flags used by the Fortran compiler")
 
+if(NOT CMAKE_Fortran_COMPILER_LAUNCHER AND DEFINED ENV{CMAKE_Fortran_COMPILER_LAUNCHER})
+  set(CMAKE_Fortran_COMPILER_LAUNCHER "$ENV{CMAKE_Fortran_COMPILER_LAUNCHER}"
+    CACHE STRING "Compiler launcher for Fortran.")
+endif()
+
 include(CMakeCommonLanguageInclude)
 
 # now define the following rule variables

Tests/RunCMake/CompilerLauncher/C-common.cmake

@@ -0,0 +1,3 @@
+enable_language(C)
+set(CMAKE_VERBOSE_MAKEFILE TRUE)
+add_executable(main main.c)

Tests/RunCMake/CompilerLauncher/C-env-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/C-env-launch-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/C-env.cmake

@@ -0,0 +1 @@
+include(C-common.cmake)

Tests/RunCMake/CompilerLauncher/C-launch-env.cmake

@@ -0,0 +1,3 @@
+set(CTEST_USE_LAUNCHERS 1)
+include(CTestUseLaunchers)
+include(C-env.cmake)

Tests/RunCMake/CompilerLauncher/C.cmake

@@ -1,4 +1,2 @@
-enable_language(C)
 set(CMAKE_C_COMPILER_LAUNCHER "${CMAKE_COMMAND};-E;env;USED_LAUNCHER=1")
-set(CMAKE_VERBOSE_MAKEFILE TRUE)
-add_executable(main main.c)
+include(C-common.cmake)

Tests/RunCMake/CompilerLauncher/CUDA-common.cmake

@@ -0,0 +1,3 @@
+enable_language(CUDA)
+set(CMAKE_VERBOSE_MAKEFILE TRUE)
+add_executable(main main.cu)

Tests/RunCMake/CompilerLauncher/CUDA-env-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/CUDA-env-launch-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/CUDA-env.cmake

@@ -0,0 +1 @@
+include(CUDA-common.cmake)

Tests/RunCMake/CompilerLauncher/CUDA-launch-env.cmake

@@ -0,0 +1,3 @@
+set(CTEST_USE_LAUNCHERS 1)
+include(CTestUseLaunchers)
+include(CUDA-env.cmake)

Tests/RunCMake/CompilerLauncher/CUDA.cmake

@@ -1,4 +1,2 @@
-enable_language(CUDA)
 set(CMAKE_CUDA_COMPILER_LAUNCHER "${CMAKE_COMMAND};-E;env;USED_LAUNCHER=1")
-set(CMAKE_VERBOSE_MAKEFILE TRUE)
-add_executable(main main.cu)
+include(CUDA-common.cmake)

Tests/RunCMake/CompilerLauncher/CXX-common.cmake

@@ -0,0 +1,3 @@
+enable_language(CXX)
+set(CMAKE_VERBOSE_MAKEFILE TRUE)
+add_executable(main main.cxx)

Tests/RunCMake/CompilerLauncher/CXX-env-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/CXX-env-launch-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/CXX-env.cmake

@@ -0,0 +1 @@
+include(CXX-common.cmake)

Tests/RunCMake/CompilerLauncher/CXX-launch-env.cmake

@@ -0,0 +1,3 @@
+set(CTEST_USE_LAUNCHERS 1)
+include(CTestUseLaunchers)
+include(CXX-env.cmake)

Tests/RunCMake/CompilerLauncher/CXX.cmake

@@ -1,4 +1,2 @@
-enable_language(CXX)
 set(CMAKE_CXX_COMPILER_LAUNCHER "${CMAKE_COMMAND};-E;env;USED_LAUNCHER=1")
-set(CMAKE_VERBOSE_MAKEFILE TRUE)
-add_executable(main main.cxx)
+include(CXX-common.cmake)

Tests/RunCMake/CompilerLauncher/Fortran-common.cmake

@@ -0,0 +1,3 @@
+enable_language(Fortran)
+set(CMAKE_VERBOSE_MAKEFILE TRUE)
+add_executable(main main.F)

Tests/RunCMake/CompilerLauncher/Fortran-env-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/Fortran-env-launch-Build-stdout.txt

@@ -0,0 +1 @@
+.*-E env USED_LAUNCHER=1.*

Tests/RunCMake/CompilerLauncher/Fortran-env.cmake

@@ -0,0 +1 @@
+include(Fortran-common.cmake)

Tests/RunCMake/CompilerLauncher/Fortran-launch-env.cmake

@@ -0,0 +1,3 @@
+set(CTEST_USE_LAUNCHERS 1)
+include(CTestUseLaunchers)
+include(Fortran-env.cmake)

Tests/RunCMake/CompilerLauncher/Fortran.cmake

@@ -1,4 +1,2 @@
-enable_language(Fortran)
 set(CMAKE_Fortran_COMPILER_LAUNCHER "${CMAKE_COMMAND};-E;env;USED_LAUNCHER=1")
-set(CMAKE_VERBOSE_MAKEFILE TRUE)
-add_executable(main main.F)
+include(Fortran-common.cmake)

Tests/RunCMake/CompilerLauncher/RunCMakeTest.cmake

@@ -15,6 +15,13 @@ function(run_compiler_launcher lang)
   run_cmake_command(${lang}-Build ${CMAKE_COMMAND} --build . ${verbose_args})
 endfunction()
 
+function(run_compiler_launcher_env lang)
+  string(REGEX REPLACE "-.*" "" core_lang "${lang}")
+  set(ENV{CMAKE_${core_lang}_COMPILER_LAUNCHER} "${CMAKE_COMMAND};-E;env;USED_LAUNCHER=1")
+  run_compiler_launcher(${lang})
+  unset(ENV{CMAKE_${core_lang}_COMPILER_LAUNCHER})
+endfunction()
+
 set(langs C CXX)
 if(CMake_TEST_CUDA)
   list(APPEND langs CUDA)
@@ -25,7 +32,9 @@ endif()
 
 foreach(lang ${langs})
   run_compiler_launcher(${lang})
+  run_compiler_launcher_env(${lang}-env)
   if (NOT RunCMake_GENERATOR STREQUAL "Watcom WMake")
     run_compiler_launcher(${lang}-launch)
+    run_compiler_launcher_env(${lang}-launch-env)
   endif()
 endforeach()