Makefile: Handle '#' in COMPILE_OPTIONS (#15070)

Teach the Makefile generators to escape '#' characters on the right hand
side of variable assignments in flags.make.  This is needed for flags
like '-Wno-error=#warnings'.  Otherwise the make tool treats them as
comments and leaves them out of the _FLAGS variable value.

Add a case to the CompileOptions test covering '#' in a COMPILE_OPTIONS
value, at least on compilers where it is known to be supported.

1 files changed, 7 insertions, 3 deletions

diff --git a/Source/cmMakefileTargetGenerator.cxx b/Source/cmMakefileTargetGenerator.cxx
index 758c8e4..7849d12 100644
--- a/Source/cmMakefileTargetGenerator.cxx
+++ b/Source/cmMakefileTargetGenerator.cxx
@@ -361,9 +361,13 @@ void cmMakefileTargetGenerator::WriteTargetLanguageFlags()
   for(std::set<std::string>::const_iterator l = languages.begin();
       l != languages.end(); ++l)
     {
-    *this->FlagFileStream << *l << "_FLAGS = " << this->GetFlags(*l) << "\n\n";
-    *this->FlagFileStream << *l << "_DEFINES = " << this->GetDefines(*l) <<
-      "\n\n";
+    std::string flags = this->GetFlags(*l);
+    std::string defines = this->GetDefines(*l);
+    // Escape comment characters so they do not terminate assignment.
+    cmSystemTools::ReplaceString(flags, "#", "\\#");
+    cmSystemTools::ReplaceString(defines, "#", "\\#");
+    *this->FlagFileStream << *l << "_FLAGS = " << flags << "\n\n";
+    *this->FlagFileStream << *l << "_DEFINES = " << defines << "\n\n";
     }
 }