Merge topic 'implicit-link-lib-exclude'

805a40b668 Optionally exclude implicit link libraries via environment
b10a2bf63a Tests/RunCMake/ParseImplicitLinkInfo: Fix ExcludeDirs test case

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !10745

Help/envvar/CMAKE_LANG_IMPLICIT_LINK_DIRECTORIES_EXCLUDE.rst

@@ -11,3 +11,6 @@ variable when it is automatically detected from the ``<LANG>`` compiler.
 
 This may be used to work around misconfigured compiler drivers that pass
 extraneous implicit link directories to their linker.
+
+See also the :envvar:`CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES_EXCLUDE`
+environment variable.

Help/envvar/CMAKE_LANG_IMPLICIT_LINK_LIBRARIES_EXCLUDE.rst

@@ -0,0 +1,17 @@
+CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES_EXCLUDE
+--------------------------------------------
+
+.. versionadded:: 4.1
+
+.. include:: include/ENV_VAR.rst
+
+A :ref:`semicolon-separated list <CMake Language Lists>` of libraries
+to exclude from the :variable:`CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES`
+variable when it is automatically detected from the ``<LANG>`` compiler.
+
+This may be used to work around detection limitations that result in
+extraneous implicit link libraries, e.g., when using compiler driver
+flags that affect the set of implicitly linked libraries.
+
+See also the :envvar:`CMAKE_<LANG>_IMPLICIT_LINK_DIRECTORIES_EXCLUDE`
+environment variable.

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

@@ -61,6 +61,7 @@ Environment Variables that Control the Build
    /envvar/CMAKE_INSTALL_PREFIX
    /envvar/CMAKE_LANG_COMPILER_LAUNCHER
    /envvar/CMAKE_LANG_IMPLICIT_LINK_DIRECTORIES_EXCLUDE
+   /envvar/CMAKE_LANG_IMPLICIT_LINK_LIBRARIES_EXCLUDE
    /envvar/CMAKE_LANG_LINKER_LAUNCHER
    /envvar/CMAKE_MSVCIDE_RUN_PATH
    /envvar/CMAKE_NO_VERBOSE

Help/release/dev/implicit-link-lib-exclude.rst

@@ -0,0 +1,6 @@
+implicit-link-lib-exclude
+-------------------------
+
+* The :envvar:`CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES_EXCLUDE` environment
+  variable was added to optionally exclude specific libraries from the
+  detected set of :variable:`CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES`.

Help/variable/CMAKE_LANG_IMPLICIT_LINK_LIBRARIES.rst

@@ -5,10 +5,14 @@ Implicit link libraries and flags detected for language ``<LANG>``.
 
 Compilers typically pass language runtime library names and other
 flags when they invoke a linker.  These flags are implicit link
-options for the compiler's language.  For each language enabled
-by the :command:`project` or :command:`enable_language` command,
-CMake automatically detects these libraries and flags and reports
-the results in this variable.
+options for the compiler's language.
+
+For each language enabled by the :command:`project` or
+:command:`enable_language` command, CMake automatically detects these
+libraries and flags and reports the results in this variable.
+The :envvar:`CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES_EXCLUDE` environment
+variable may be set to exclude specific libraries from the automatically
+detected results.
 
 When linking to a static library, CMake adds the implicit link libraries and
 flags from this variable for each language used in the static library (except

Modules/CMakeDetermineCompilerABI.cmake

@@ -287,7 +287,10 @@ function(CMAKE_DETERMINE_COMPILER_ABI lang src)
         list(REMOVE_ITEM implicit_dirs ${CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES_EXCLUDE})
       endif()
 
-      # Filter out implicit link directories excluded by the environment.
+      # Filter out implicit link information excluded by the environment.
+      if(DEFINED ENV{CMAKE_${lang}_IMPLICIT_LINK_LIBRARIES_EXCLUDE})
+        list(REMOVE_ITEM implicit_libs $ENV{CMAKE_${lang}_IMPLICIT_LINK_LIBRARIES_EXCLUDE})
+      endif()
       if(DEFINED ENV{CMAKE_${lang}_IMPLICIT_LINK_DIRECTORIES_EXCLUDE})
         list(REMOVE_ITEM implicit_dirs $ENV{CMAKE_${lang}_IMPLICIT_LINK_DIRECTORIES_EXCLUDE})
       endif()

Tests/RunCMake/ParseImplicitLinkInfo/ExcludeDirs.cmake

@@ -1,4 +1,7 @@
-include("${info}")
+block()
+  include("${info}")
+  set(INFO_CMAKE_C_IMPLICIT_LINK_DIRECTORIES "${CMAKE_C_IMPLICIT_LINK_DIRECTORIES}" PARENT_SCOPE)
+endblock()
 list(GET INFO_CMAKE_C_IMPLICIT_LINK_DIRECTORIES -1 last_dir)
 set(ENV{CMAKE_C_IMPLICIT_LINK_DIRECTORIES_EXCLUDE} "${last_dir}")
 enable_language(C)

Tests/RunCMake/ParseImplicitLinkInfo/ExcludeLibs.cmake

@@ -0,0 +1,13 @@
+block()
+  include("${info}")
+  set(INFO_CMAKE_C_IMPLICIT_LINK_LIBRARIES "${CMAKE_C_IMPLICIT_LINK_LIBRARIES}" PARENT_SCOPE)
+endblock()
+list(GET INFO_CMAKE_C_IMPLICIT_LINK_LIBRARIES -1 last_lib)
+set(ENV{CMAKE_C_IMPLICIT_LINK_LIBRARIES_EXCLUDE} "${last_lib}")
+enable_language(C)
+message(STATUS "INFO_CMAKE_C_IMPLICIT_LINK_LIBRARIES=[${INFO_CMAKE_C_IMPLICIT_LINK_LIBRARIES}]")
+message(STATUS "ENV{CMAKE_C_IMPLICIT_LINK_LIBRARIES_EXCLUDE}=[$ENV{CMAKE_C_IMPLICIT_LINK_LIBRARIES_EXCLUDE}]")
+message(STATUS "CMAKE_C_IMPLICIT_LINK_LIBRARIES=[${CMAKE_C_IMPLICIT_LINK_LIBRARIES}]")
+if("${last_lib}" IN_LIST CMAKE_C_IMPLICIT_LINK_LIBRARIES)
+  message(FATAL_ERROR "${last_lib} was not excluded!")
+endif()

Tests/RunCMake/ParseImplicitLinkInfo/Inspect.cmake

@@ -9,6 +9,7 @@ foreach(var
     CMAKE_C_COMPILER_LINKER
     CMAKE_C_COMPILER_LINKER_ID
     CMAKE_C_COMPILER_LINKER_VERSION
+    CMAKE_C_IMPLICIT_LINK_LIBRARIES
     CMAKE_C_IMPLICIT_LINK_DIRECTORIES
     )
   if(DEFINED ${var})

Tests/RunCMake/ParseImplicitLinkInfo/RunCMakeTest.cmake

@@ -10,6 +10,7 @@ run_cmake(ParseImplicitLinkInfo)
 # - CMAKE_C_COMPILER_LINKER
 # - CMAKE_C_COMPILER_LINKER_ID
 # - CMAKE_C_COMPILER_LINKER_VERSION
+# - CMAKE_C_IMPLICIT_LINK_LIBRARIES
 # - CMAKE_C_IMPLICIT_LINK_DIRECTORIES
 run_cmake(Inspect)
 set(info "${RunCMake_BINARY_DIR}/Inspect-build/info.cmake")
@@ -19,6 +20,9 @@ if(CMAKE_HOST_UNIX)
   run_cmake_script(DetermineLinkerId)
 endif()
 
+if(CMAKE_C_IMPLICIT_LINK_LIBRARIES MATCHES ";")
+  run_cmake_with_options(ExcludeLibs "-Dinfo=${RunCMake_BINARY_DIR}/Inspect-build/info.cmake")
+endif()
 if(CMAKE_C_IMPLICIT_LINK_DIRECTORIES MATCHES ";")
   run_cmake_with_options(ExcludeDirs "-Dinfo=${RunCMake_BINARY_DIR}/Inspect-build/info.cmake")
 endif()