ENH: Merging CompilerId implementation from branch CMake-Modules-CompilerId to the main tree. Changes between CMake-Modules-CompilerId-bp and CMake-Modules-CompilerId-mp1 are included.

Modules/CMakeCXXCompilerId.cpp

@@ -0,0 +1,49 @@
+#ifndef __cplusplus
+# error "A C compiler has been selected for C++."
+#endif
+
+static char const info_compiler[] = "INFO:compiler["
+#if defined(__COMO__)
+"Comeau"
+#elif defined(__INTEL_COMPILER) || defined(__ICC)
+"Intel"
+#elif defined(__BORLANDC__)
+"Borland"
+#elif defined(__WATCOMC__)
+"Watcom"
+#elif defined(__SUNPRO_CC)
+"SunPro"
+#elif defined(__HP_aCC)
+"HP"
+#elif defined(__DECCXX)
+"Compaq"
+#elif defined(__IBMCPP__)
+"VisualAge"
+#elif defined(__GNUC__)
+"GNUC"
+#elif defined(_MSC_VER)
+"MSVC"
+#elif defined(_COMPILER_VERSION)
+"MIPSpro"
+
+/* This compiler is either not known or is too old to define an
+   identification macro.  Try to identify the platform and guess that
+   it is the native compiler.  */
+#elif defined(__sgi)
+"MIPSpro"
+#elif defined(__hpux) || defined(__hpua)
+"HP"
+
+#else /* unknown compiler */
+""
+#endif
+"]";
+
+/* Include the platform identification source.  */
+#include "CMakePlatformId.h"
+
+/* Make sure the information strings are referenced.  */
+int main()
+{
+  return ((int)&info_compiler) + ((int)&info_platform);
+}