Merge topic 'try_compile-config-flags'

bd581a37 try_compile: Honor CMAKE_<LANG>_FLAGS_<CONFIG> changes (#16054)
82ef90fc cmCoreTryCompile: Factor out config lookup for re-use

Help/release/dev/try_compile-config-flags.rst

@@ -0,0 +1,7 @@
+try_compile-config-flags
+------------------------
+
+* The :command:`try_compile` command source file signature now honors
+  configuration-specific flags (e.g. :variable:`CMAKE_<LANG>_FLAGS_DEBUG`)
+  in the generated test project.  Previously only the default such flags
+  for the current toolchain were used.

Source/cmCoreTryCompile.cxx

@@ -294,6 +294,9 @@ int cmCoreTryCompile::TryCompileCode(std::vector<std::string> const& argv,
         }
       }
 
+    std::string const tcConfig =
+      this->Makefile->GetSafeDefinition("CMAKE_TRY_COMPILE_CONFIGURATION");
+
     // we need to create a directory and CMakeLists file etc...
     // first create the directories
     sourceDirectory = this->BinaryDirectory.c_str();
@@ -350,6 +353,13 @@ int cmCoreTryCompile::TryCompileCode(std::vector<std::string> const& argv,
               cmOutputConverter::EscapeForCMake(flags?flags:"").c_str());
       fprintf(fout, "set(CMAKE_%s_FLAGS \"${CMAKE_%s_FLAGS}"
               " ${COMPILE_DEFINITIONS}\")\n", li->c_str(), li->c_str());
+      static std::string const cfgDefault = "DEBUG";
+      std::string const cfg = !tcConfig.empty()?
+        cmSystemTools::UpperCase(tcConfig) : cfgDefault;
+      std::string const langFlagsCfg = "CMAKE_" + *li + "_FLAGS_" + cfg;
+      const char* flagsCfg = this->Makefile->GetDefinition(langFlagsCfg);
+      fprintf(fout, "set(%s %s)\n", langFlagsCfg.c_str(),
+              cmOutputConverter::EscapeForCMake(flagsCfg?flagsCfg:"").c_str());
       }
     switch(this->Makefile->GetPolicyStatus(cmPolicies::CMP0056))
       {
@@ -406,8 +416,7 @@ int cmCoreTryCompile::TryCompileCode(std::vector<std::string> const& argv,
       std::string fname = "/" + std::string(targetName) + "Targets.cmake";
       cmExportTryCompileFileGenerator tcfg(gg, targets, this->Makefile);
       tcfg.SetExportFile((this->BinaryDirectory + fname).c_str());
-      tcfg.SetConfig(this->Makefile->GetSafeDefinition(
-                                          "CMAKE_TRY_COMPILE_CONFIGURATION"));
+      tcfg.SetConfig(tcConfig);
 
       if(!tcfg.GenerateImportFile())
         {

Tests/RunCMake/try_compile/CompileFlags.cmake

@@ -0,0 +1,17 @@
+enable_language(C)
+set(CMAKE_C_FLAGS_RELEASE "-DPP_ERROR ${CMAKE_C_FLAGS_DEBUG}")
+
+#-----------------------------------------------------------------------------
+set(CMAKE_TRY_COMPILE_CONFIGURATION Release)
+try_compile(RESULT ${CMAKE_CURRENT_BINARY_DIR}
+  ${CMAKE_CURRENT_SOURCE_DIR}/src.c
+  OUTPUT_VARIABLE out
+  )
+string(REPLACE "\n" "\n  " out "  ${out}")
+if(RESULT)
+  message(FATAL_ERROR "try_compile passed but should have failed:\n${out}")
+elseif(NOT "x${out}" MATCHES "PP_ERROR is defined")
+  message(FATAL_ERROR "try_compile did not fail with PP_ERROR:\n${out}")
+else()
+  message(STATUS "try_compile with per-config flag worked as expected")
+endif()

Tests/RunCMake/try_compile/RunCMakeTest.cmake

@@ -21,6 +21,7 @@ run_cmake(TargetTypeInvalid)
 run_cmake(TargetTypeStatic)
 
 run_cmake(CMP0056)
+run_cmake(CompileFlags)
 
 if(RunCMake_GENERATOR MATCHES "Make|Ninja")
   # Use a single build tree for a few tests without cleaning.

Tests/RunCMake/try_compile/src.c

@@ -1 +1,4 @@
 int main(void) { return 0; }
+#ifdef PP_ERROR
+# error PP_ERROR is defined
+#endif