fixup! cmake: Add TryAppendLinkerFlag module

hebasto · Oct 26, 2023 · e3a378b · e3a378b
1 parent 40973d6
commit e3a378b
Showing 1 changed file with 41 additions and 33 deletions.
diff --git a/cmake/module/TryAppendLinkerFlag.cmake b/cmake/module/TryAppendLinkerFlag.cmake
@@ -8,7 +8,7 @@ include(CheckCXXSourceCompiles)
 #[=[
 Usage example:
 
-  try_append_linker_flag(core "-Wl,--major-subsystem-version,6")
+  try_append_linker_flag("-Wl,--major-subsystem-version,6" TARGET core)
 
 
 In configuration output, this function prints a string by the following pattern:
@@ -17,61 +17,69 @@ In configuration output, this function prints a string by the following pattern:
   -- Performing Test LINKER_SUPPORTS_[flag] - Success
 
 ]=]
-function(try_append_linker_flag target flag)
-  cmake_parse_arguments(PARSE_ARGV 2
+function(try_append_linker_flag flag)
+  cmake_parse_arguments(PARSE_ARGV 1
     TALF                              # prefix
     ""                                # options
-    "SOURCE;RESULT_VAR"               # one_value_keywords
+    "TARGET;VAR;SOURCE;RESULT_VAR"    # one_value_keywords
     "IF_CHECK_PASSED;IF_CHECK_FAILED" # multi_value_keywords
   )
 
   string(MAKE_C_IDENTIFIER "${flag}" result)
   string(TOUPPER "${result}" result)
-  set(result "LINKER_SUPPORTS_${result}")
-
-  # Every subsequent check_cxx_source_compiles((<code> <resultVar>) run will re-use
-  # the cached result rather than performing the check again, even if the <code> changes.
-  # Removing the cached result in order to force the check to be re-evaluated.
-  unset(${result} CACHE)
-
-  if(NOT DEFINED TALF_SOURCE)
-    set(TALF_SOURCE "int main() { return 0; }")
+  string(PREPEND result LINKER_SUPPORTS_)
+
+  set(source "int main() { return 0; }")
+  if(DEFINED TALF_SOURCE AND NOT TALF_SOURCE STREQUAL source)
+    set(source "${TALF_SOURCE}")
+    string(SHA256 source_hash "${source}")
+    string(SUBSTRING ${source_hash} 0 4 source_hash_head)
+    string(APPEND result _${source_hash_head})
   endif()
 
   # This forces running a linker.
   set(CMAKE_TRY_COMPILE_TARGET_TYPE EXECUTABLE)
-
-  get_target_property(working_linker_werror_flag internal_werror INTERFACE_LINK_OPTIONS)
-  if(NOT working_linker_werror_flag)
-    set(working_linker_werror_flag)
-  endif()
-
   set(CMAKE_REQUIRED_LINK_OPTIONS ${flag} ${working_linker_werror_flag})
-
-  check_cxx_source_compiles("${TALF_SOURCE}" ${result})
+  check_cxx_source_compiles("${source}" ${result})
 
   if(${result})
     if(DEFINED TALF_IF_CHECK_PASSED)
-      target_link_options(${target} INTERFACE ${TALF_IF_CHECK_PASSED})
+      if(DEFINED TALF_TARGET)
+        target_link_options(${TALF_TARGET} INTERFACE ${TALF_IF_CHECK_PASSED})
+      endif()
+      if(DEFINED TALF_VAR)
+        string(STRIP "${${TALF_VAR}} ${TALF_IF_CHECK_PASSED}" ${TALF_VAR})
+      endif()
     else()
-      target_link_options(${target} INTERFACE ${flag})
+      if(DEFINED TALF_TARGET)
+        target_link_options(${TALF_TARGET} INTERFACE ${flag})
+      endif()
+      if(DEFINED TALF_VAR)
+        string(STRIP "${${TALF_VAR}} ${flag}" ${TALF_VAR})
+      endif()
     endif()
   elseif(DEFINED TALF_IF_CHECK_FAILED)
-    target_link_options(${target} INTERFACE ${TALF_IF_CHECK_FAILED})
+    if(DEFINED TALF_TARGET)
+      target_link_options(${TALF_TARGET} INTERFACE ${TACXXF_IF_CHECK_FAILED})
+    endif()
+    if(DEFINED TALF_VAR)
+      string(STRIP "${${TALF_VAR}} ${TACXXF_IF_CHECK_FAILED}" ${TALF_VAR})
+    endif()
+  endif()
+
+  if(DEFINED TALF_VAR)
+    set(${TALF_VAR} "${${TALF_VAR}}" PARENT_SCOPE)
   endif()
 
-  set(${TALF_RESULT_VAR} "${${result}}" PARENT_SCOPE)
+  if(DEFINED TALF_RESULT_VAR)
+    set(${TALF_RESULT_VAR} "${${result}}" PARENT_SCOPE)
+  endif()
 endfunction()
 
-if(NOT TARGET internal_werror)
-  add_library(internal_werror INTERFACE)
-endif()
 if(MSVC)
-  set(warning_as_error_flag /WX)
+  try_append_linker_flag("/WX" VAR working_linker_werror_flag)
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
-  set(warning_as_error_flag -Wl,-fatal_warnings)
+  try_append_linker_flag("-Wl,-fatal_warnings" VAR working_linker_werror_flag)
 else()
-  set(warning_as_error_flag -Wl,--fatal-warnings)
+  try_append_linker_flag("-Wl,--fatal-warnings" VAR working_linker_werror_flag)
 endif()
-try_append_linker_flag(internal_werror "${warning_as_error_flag}")
-unset(warning_as_error_flag)