Fortran: Add infrastructure to detect compiler version (#15372)

Fortran does not offer syntax to compose a string literal at
preprocessing time from numeric compuations.  Instead encode each digit
of each component as a separate INFO string and compose them in CMake
code after extraction.  Support MAJOR, MINOR, PATCH, and TWEAK
components with up to 8 digits each.

Modules/CMakeDetermineCompilerId.cmake

@@ -409,12 +409,28 @@ function(CMAKE_DETERMINE_COMPILER_ID_CHECK lang file)
     # Read the compiler identification string from the executable file.
     set(COMPILER_ID)
     set(COMPILER_VERSION)
+    set(COMPILER_VERSION_MAJOR 0)
+    set(COMPILER_VERSION_MINOR 0)
+    set(COMPILER_VERSION_PATCH 0)
+    set(COMPILER_VERSION_TWEAK 0)
+    set(HAVE_COMPILER_VERSION_MAJOR 0)
+    set(HAVE_COMPILER_VERSION_MINOR 0)
+    set(HAVE_COMPILER_VERSION_PATCH 0)
+    set(HAVE_COMPILER_VERSION_TWEAK 0)
+    set(DIGIT_VALUE_1 1)
+    set(DIGIT_VALUE_2 10)
+    set(DIGIT_VALUE_3 100)
+    set(DIGIT_VALUE_4 1000)
+    set(DIGIT_VALUE_5 10000)
+    set(DIGIT_VALUE_6 100000)
+    set(DIGIT_VALUE_7 1000000)
+    set(DIGIT_VALUE_8 10000000)
     set(PLATFORM_ID)
     set(ARCHITECTURE_ID)
     set(SIMULATE_ID)
     set(SIMULATE_VERSION)
     file(STRINGS ${file}
-      CMAKE_${lang}_COMPILER_ID_STRINGS LIMIT_COUNT 6 REGEX "INFO:[A-Za-z0-9_]+\\[[^]]*\\]")
+      CMAKE_${lang}_COMPILER_ID_STRINGS LIMIT_COUNT 38 REGEX "INFO:[A-Za-z0-9_]+\\[[^]]*\\]")
     set(COMPILER_ID_TWICE)
     foreach(info ${CMAKE_${lang}_COMPILER_ID_STRINGS})
       if("${info}" MATCHES "INFO:compiler\\[([^]\"]*)\\]")
@@ -433,6 +449,15 @@ function(CMAKE_DETERMINE_COMPILER_ID_CHECK lang file)
         string(REGEX REPLACE "^0+([0-9])" "\\1" COMPILER_VERSION "${CMAKE_MATCH_1}")
         string(REGEX REPLACE "\\.0+([0-9])" ".\\1" COMPILER_VERSION "${COMPILER_VERSION}")
       endif()
+      foreach(comp MAJOR MINOR PATCH TWEAK)
+        foreach(digit 1 2 3 4 5 6 7 8 9)
+          if("${info}" MATCHES "INFO:compiler_version_${comp}_digit_${digit}\\[([0-9])\\]")
+            set(value ${CMAKE_MATCH_1})
+            math(EXPR COMPILER_VERSION_${comp} "${COMPILER_VERSION_${comp}} + ${value} * ${DIGIT_VALUE_${digit}}")
+            set(HAVE_COMPILER_VERSION_${comp} 1)
+          endif()
+        endforeach()
+      endforeach()
       if("${info}" MATCHES "INFO:simulate\\[([^]\"]*)\\]")
         set(SIMULATE_ID "${CMAKE_MATCH_1}")
       endif()
@@ -445,6 +470,20 @@ function(CMAKE_DETERMINE_COMPILER_ID_CHECK lang file)
       endif()
     endforeach()
 
+    # Construct compiler version from components if needed.
+    if(NOT DEFINED COMPILER_VERSION AND HAVE_COMPILER_VERSION_MAJOR)
+      set(COMPILER_VERSION "${COMPILER_VERSION_MAJOR}")
+      if(HAVE_COMPILER_VERSION_MINOR)
+        set(COMPILER_VERSION "${COMPILER_VERSION}.${COMPILER_VERSION_MINOR}")
+        if(HAVE_COMPILER_VERSION_PATCH)
+          set(COMPILER_VERSION "${COMPILER_VERSION}.${COMPILER_VERSION_PATCH}")
+          if(HAVE_COMPILER_VERSION_TWEAK)
+            set(COMPILER_VERSION "${COMPILER_VERSION}.${COMPILER_VERSION_TWEAK}")
+          endif()
+        endif()
+      endif()
+    endif()
+
     # Detect the exact architecture from the PE header.
     if(WIN32)
       # The offset to the PE signature is stored at 0x3c.

Modules/CMakeDetermineFortranCompiler.cmake

@@ -119,6 +119,47 @@ if(NOT CMAKE_Fortran_COMPILER_ID_RUN)
   set(CMAKE_Fortran_COMPILER_ID_VENDOR_FLAGS_NAG "-V")
   set(CMAKE_Fortran_COMPILER_ID_VENDOR_REGEX_NAG "NAG Fortran Compiler")
 
+  set(_version_info "")
+  foreach(m MAJOR MINOR PATCH TWEAK)
+    set(_COMP "_${m}")
+    set(_version_info "${_version_info}
+#if defined(COMPILER_VERSION${_COMP})")
+    foreach(d 1 2 3 4 5 6 7 8)
+      set(_version_info "${_version_info}
+# undef DEC
+# undef HEX
+# define DEC(n) DEC_${d}(n)
+# define HEX(n) HEX_${d}(n)
+# if COMPILER_VERSION${_COMP} == 0
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[0]'
+# elif COMPILER_VERSION${_COMP} == 1
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[1]'
+# elif COMPILER_VERSION${_COMP} == 2
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[2]'
+# elif COMPILER_VERSION${_COMP} == 3
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[3]'
+# elif COMPILER_VERSION${_COMP} == 4
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[4]'
+# elif COMPILER_VERSION${_COMP} == 5
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[5]'
+# elif COMPILER_VERSION${_COMP} == 6
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[6]'
+# elif COMPILER_VERSION${_COMP} == 7
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[7]'
+# elif COMPILER_VERSION${_COMP} == 8
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[8]'
+# elif COMPILER_VERSION${_COMP} == 9
+        PRINT *, 'INFO:compiler_version${_COMP}_digit_${d}[9]'
+# endif
+")
+    endforeach()
+    set(_version_info "${_version_info}
+#endif")
+  endforeach()
+  set(CMAKE_Fortran_COMPILER_ID_VERSION_INFO "${_version_info}")
+  unset(_version_info)
+  unset(_COMP)
+
   # Try to identify the compiler.
   set(CMAKE_Fortran_COMPILER_ID)
   include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)

Modules/CMakeFortranCompilerId.F.in

@@ -134,4 +134,26 @@
         PRINT *, 'INFO:arch[X86]'
 # endif
 #endif
+
+#if 0
+! Encode compiler version digits
+#endif
+#define DEC_8(n) (((n) / 10000000) % 10)
+#define DEC_7(n) (((n) / 1000000)  % 10)
+#define DEC_6(n) (((n) / 100000)   % 10)
+#define DEC_5(n) (((n) / 10000)    % 10)
+#define DEC_4(n) (((n) / 1000)     % 10)
+#define DEC_3(n) (((n) / 100)      % 10)
+#define DEC_2(n) (((n) / 10)       % 10)
+#define DEC_1(n) (((n)    )        % 10)
+#define HEX_8(n) ((n)>>28 & 0xF)
+#define HEX_7(n) ((n)>>24 & 0xF)
+#define HEX_6(n) ((n)>>20 & 0xF)
+#define HEX_5(n) ((n)>>16 & 0xF)
+#define HEX_4(n) ((n)>>12 & 0xF)
+#define HEX_3(n) ((n)>>8  & 0xF)
+#define HEX_2(n) ((n)>>4  & 0xF)
+#define HEX_1(n) ((n)     & 0xF)
+@CMAKE_Fortran_COMPILER_ID_VERSION_INFO@
+
       END