try_compile: Escape CMAKE_<lang>_FLAGS in test projects (#14268)

If CMAKE_<lang>_FLAGS contains quotes or other CMake language characters
they must be escaped when written into the generated CMakeLists.txt file
so that the test project parses them properly.

Teach the TryCompile test to cover this case by adding a flag with
quotes into CMAKE_C_FLAGS during a C language try_compile.

3 files changed, 30 insertions, 8 deletions

diff --git a/Source/cmCoreTryCompile.cxx b/Source/cmCoreTryCompile.cxx
index 860417f..e312806 100644
--- a/Source/cmCoreTryCompile.cxx
+++ b/Source/cmCoreTryCompile.cxx
@@ -12,6 +12,7 @@
 #include "cmCoreTryCompile.h"
 #include "cmake.h"
 #include "cmCacheManager.h"
+#include "cmLocalGenerator.h"
 #include "cmGlobalGenerator.h"
 #include "cmExportTryCompileFileGenerator.h"
 #include <cmsys/Directory.hxx>
@@ -214,8 +215,8 @@ int cmCoreTryCompile::TryCompileCode(std::vector<std::string> const& argv)
       }
 
     // Detect languages to enable.
-    cmGlobalGenerator* gg =
-      this->Makefile->GetCMakeInstance()->GetGlobalGenerator();
+    cmLocalGenerator* lg = this->Makefile->GetLocalGenerator();
+    cmGlobalGenerator* gg = lg->GetGlobalGenerator();
     std::set<std::string> testLangs;
     for(std::vector<std::string>::iterator si = sources.begin();
         si != sources.end(); ++si)
@@ -295,13 +296,12 @@ int cmCoreTryCompile::TryCompileCode(std::vector<std::string> const& argv)
     for(std::set<std::string>::iterator li = testLangs.begin();
         li != testLangs.end(); ++li)
       {
-      fprintf(fout, "SET(CMAKE_%s_FLAGS \"", li->c_str());
       std::string langFlags = "CMAKE_" + *li + "_FLAGS";
-      if(const char* flags = this->Makefile->GetDefinition(langFlags.c_str()))
-        {
-        fprintf(fout, " %s ", flags);
-        }
-      fprintf(fout, " ${COMPILE_DEFINITIONS}\")\n");
+      const char* flags = this->Makefile->GetDefinition(langFlags.c_str());
+      fprintf(fout, "SET(CMAKE_%s_FLAGS %s)\n", li->c_str(),
+              lg->EscapeForCMake(flags?flags:"").c_str());
+      fprintf(fout, "SET(CMAKE_%s_FLAGS \"${CMAKE_%s_FLAGS}"
+              " ${COMPILE_DEFINITIONS}\")\n", li->c_str(), li->c_str());
       }
     fprintf(fout, "INCLUDE_DIRECTORIES(${INCLUDE_DIRECTORIES})\n");
     fprintf(fout, "SET(CMAKE_SUPPRESS_REGENERATION 1)\n");
diff --git a/Tests/TryCompile/CMakeLists.txt b/Tests/TryCompile/CMakeLists.txt
index 4540fd0..7b25e84 100644
--- a/Tests/TryCompile/CMakeLists.txt
+++ b/Tests/TryCompile/CMakeLists.txt
@@ -89,6 +89,24 @@ if(SHOULD_FAIL)
    message(SEND_ERROR "Should fail passed ${TRY_OUT}")
 endif()
 
+# try to compile a file that should compile
+set(_c_flags "${CMAKE_C_FLAGS}")
+if(CMAKE_GENERATOR STREQUAL "Visual Studio 6")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D \"TESTDEF\"")
+elseif(WATCOM)
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -dTESTDEF")
+else()
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} \"-DTESTDEF\"")
+endif()
+try_compile(SHOULD_PASS
+    ${TryCompile_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp
+    ${TryCompile_SOURCE_DIR}/testdef.c
+    OUTPUT_VARIABLE TRY_OUT)
+if(NOT SHOULD_PASS)
+  message(SEND_ERROR "should pass failed ${TRY_OUT}")
+endif()
+set(CMAKE_C_FLAGS "${_c_flags}")
+
 if(NOT SHOULD_FAIL)
   if(SHOULD_PASS)
     message("All Tests passed, ignore all previous output.")
diff --git a/Tests/TryCompile/testdef.c b/Tests/TryCompile/testdef.c
new file mode 100644
index 0000000..5401e71
--- /dev/null
+++ b/Tests/TryCompile/testdef.c
@@ -0,0 +1,4 @@
+#ifndef TESTDEF
+# error "TESTDEF should be defined!"
+#endif
+int main(void) { return 0; }