CMakeDetermineCompilerId: Add notion of "simulated" id/version

Some compilers try to simulate other compilers as a drop-in replacement
supporting all the same command-line options and predefined preprocessor
macros.  In such cases it will be useful to have CMake load the compiler
information files for the simulated compiler instead of duplicating the
information.  Teach CMakeDetermineCompilerId to extract the simulated
compiler id and version when the compiler id detection provides it.

1 files changed, 18 insertions, 0 deletions

diff --git a/Modules/CMakePlatformId.h.in b/Modules/CMakePlatformId.h.in
index 69171c2a3c..1e41fec6bd 100644
--- a/Modules/CMakePlatformId.h.in
+++ b/Modules/CMakePlatformId.h.in
@@ -151,6 +151,24 @@ char const info_version[] = {
   ']','\0'};
 #endif
 
+/* Construct a string literal encoding the version number components. */
+#ifdef SIMULATE_VERSION_MAJOR
+char const info_simulate_version[] = {
+  'I', 'N', 'F', 'O', ':',
+  's','i','m','u','l','a','t','e','_','v','e','r','s','i','o','n','[',
+  SIMULATE_VERSION_MAJOR,
+# ifdef SIMULATE_VERSION_MINOR
+  '.', SIMULATE_VERSION_MINOR,
+#  ifdef SIMULATE_VERSION_PATCH
+   '.', SIMULATE_VERSION_PATCH,
+#   ifdef SIMULATE_VERSION_TWEAK
+    '.', SIMULATE_VERSION_TWEAK,
+#   endif
+#  endif
+# endif
+  ']','\0'};
+#endif
+
 /* Construct the string literal in pieces to prevent the source from
    getting matched.  Store it in a pointer rather than an array
    because some compilers will just produce instructions to fill the