Watcom: Introduce OpenWatcom compiler id and fix compiler version

Distinguish "Open Watcom" from old "Watcom" by introducing a new
"OpenWatcom" compiler id.  The __WATCOMC__ format is "VVRP" for Watcom
and "VVRP + 1100" for Open Watcom.

Modules/CMakeCCompilerId.c.in

@@ -68,10 +68,19 @@
 # define COMPILER_VERSION_MINOR HEX(__BORLANDC__ & 0xFF)
 
 #elif defined(__WATCOMC__)
-# define COMPILER_ID "Watcom"
-  /* __WATCOMC__ = VVRR */
-# define COMPILER_VERSION_MAJOR DEC(__WATCOMC__ / 100)
-# define COMPILER_VERSION_MINOR DEC(__WATCOMC__ % 100)
+# if __WATCOMC__ < 1200
+#  define COMPILER_ID "Watcom"
+   /* __WATCOMC__ = VVRP */
+#  define COMPILER_VERSION_MAJOR DEC(__WATCOMC__ / 100)
+# else
+#  define COMPILER_ID "OpenWatcom"
+   /* __WATCOMC__ = VVRP + 1100 */
+#  define COMPILER_VERSION_MAJOR DEC((__WATCOMC__ - 1100) / 100)
+# endif
+# define COMPILER_VERSION_MINOR  DEC((__WATCOMC__ / 10) % 10)
+# if (__WATCOMC__ % 10) > 0
+#  define COMPILER_VERSION_PATCH DEC(__WATCOMC__ % 10)
+# endif
 
 #elif defined(__SUNPRO_C)
 # define COMPILER_ID "SunPro"

Modules/CMakeCXXCompilerId.cpp.in

@@ -73,10 +73,19 @@
 # define COMPILER_VERSION_MINOR HEX(__BORLANDC__ & 0xFF)
 
 #elif defined(__WATCOMC__)
-# define COMPILER_ID "Watcom"
-  /* __WATCOMC__ = VVRR */
-# define COMPILER_VERSION_MAJOR DEC(__WATCOMC__ / 100)
-# define COMPILER_VERSION_MINOR DEC(__WATCOMC__ % 100)
+# if __WATCOMC__ < 1200
+#  define COMPILER_ID "Watcom"
+   /* __WATCOMC__ = VVRP */
+#  define COMPILER_VERSION_MAJOR DEC(__WATCOMC__ / 100)
+# else
+#  define COMPILER_ID "OpenWatcom"
+   /* __WATCOMC__ = VVRP + 1100 */
+#  define COMPILER_VERSION_MAJOR DEC((__WATCOMC__ - 1100) / 100)
+# endif
+# define COMPILER_VERSION_MINOR  DEC((__WATCOMC__ / 10) % 10)
+# if (__WATCOMC__ % 10) > 0
+#  define COMPILER_VERSION_PATCH DEC(__WATCOMC__ % 10)
+# endif
 
 #elif defined(__SUNPRO_CC)
 # define COMPILER_ID "SunPro"

Modules/InstallRequiredSystemLibraries.cmake

@@ -374,10 +374,6 @@ if(WATCOM)
   string(REGEX MATCHALL "[0-9]+" _watcom_version_list "${_compiler_version}")
   list(GET _watcom_version_list 0 _watcom_major)
   list(GET _watcom_version_list 1 _watcom_minor)
-  if(${_watcom_major} GREATER 11)
-    math(EXPR _watcom_major "${_watcom_major} - 11")
-  endif()
-  math(EXPR _watcom_minor "${_watcom_minor} / 10")
   set( __install__libs
     ${CompilerPath}/clbr${_watcom_major}${_watcom_minor}.dll
     ${CompilerPath}/mt7r${_watcom_major}${_watcom_minor}.dll

Modules/Platform/Windows-wcl386.cmake

@@ -93,16 +93,18 @@ if(NOT _CMAKE_WATCOM_VERSION)
   set(WATCOM17)
   set(WATCOM18)
   set(WATCOM19)
-  if("${_compiler_version}" LESS 12.70)
-    set(WATCOM16 1)
-  endif()
-  if("${_compiler_version}" EQUAL 12.70)
-    set(WATCOM17 1)
-  endif()
-  if("${_compiler_version}" EQUAL 12.80)
-    set(WATCOM18 1)
-  endif()
-  if("${_compiler_version}" EQUAL 12.90)
-    set(WATCOM19 1)
+  if("${_compiler_id}" STREQUAL "OpenWatcom")
+    if("${_compiler_version}" VERSION_LESS 1.7)
+      set(WATCOM16 1)
+    endif()
+    if("${_compiler_version}" VERSION_EQUAL 1.7)
+      set(WATCOM17 1)
+    endif()
+    if("${_compiler_version}" VERSION_EQUAL 1.8)
+      set(WATCOM18 1)
+    endif()
+    if("${_compiler_version}" VERSION_EQUAL 1.9)
+      set(WATCOM19 1)
+    endif()
   endif()
 endif()

Source/cmExtraCodeBlocksGenerator.cxx

@@ -715,7 +715,7 @@ std::string cmExtraCodeBlocksGenerator::GetCBCompilerId(const cmMakefile* mf)
     {
     compiler = "icc";
     }
-  else if (compilerId == "Watcom")
+  else if (compilerId == "Watcom" || compilerId == "OpenWatcom")
     {
     compiler = "ow";
     }