Escape target flags taken from COMPILE_OPTIONS

Factor appending of individual flags out into an AppendFlagEscape method
in cmLocalGenerator and teach it to use EscapeForShell.  Update all
COMPILE_OPTIONS handling to use AppendFlagEscape.

Override the method in the Xcode generator to use its custom escape
implementation.

Teach the CompileOptions test to add an option that requires escaping
everywhere instead of just with the GNU tools.

2 files changed, 19 insertions, 6 deletions

diff --git a/Tests/CompileOptions/CMakeLists.txt b/Tests/CompileOptions/CMakeLists.txt
index 6d8a96a..52c3759 100644
--- a/Tests/CompileOptions/CMakeLists.txt
+++ b/Tests/CompileOptions/CMakeLists.txt
@@ -5,7 +5,11 @@ project(CompileOptions)
 add_library(testlib other.cpp)
 
 add_executable(CompileOptions main.cpp)
-set_property(TARGET CompileOptions PROPERTY COMPILE_OPTIONS "$<$<CXX_COMPILER_ID:GNU>:-DTEST_DEFINE>")
+set_property(TARGET CompileOptions PROPERTY COMPILE_OPTIONS
+  "-DTEST_DEFINE"
+  "-DNEEDS_ESCAPE=\"E$CAPE\""
+  "$<$<CXX_COMPILER_ID:GNU>:-DTEST_DEFINE_GNU>"
+  )
 target_link_libraries(CompileOptions testlib)
 
 if(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
diff --git a/Tests/CompileOptions/main.cpp b/Tests/CompileOptions/main.cpp
index 0d39050..90740f1 100644
--- a/Tests/CompileOptions/main.cpp
+++ b/Tests/CompileOptions/main.cpp
@@ -1,11 +1,20 @@
+#ifndef TEST_DEFINE
+# error Expected definition TEST_DEFINE
+#endif
+
+#ifndef NEEDS_ESCAPE
+# error Expected definition NEEDS_ESCAPE
+#endif
 
 #ifdef DO_GNU_TESTS
-#  ifndef TEST_DEFINE
-#    error Expected TEST_DEFINE
-#  endif
+# ifndef TEST_DEFINE_GNU
+#  error Expected definition TEST_DEFINE_GNU
+# endif
 #endif
 
-int main(int argc, char **argv)
+#include <string.h>
+
+int main()
 {
-  return 0;
+  return strcmp(NEEDS_ESCAPE, "E$CAPE") == 0 ? 0 : 1;
 }