9 files changed, 51 insertions, 4 deletions
diff --git a/Modules/CMakeDetermineASMCompiler.cmake b/Modules/CMakeDetermineASMCompiler.cmake
index a56020fb67..7da6ac04aa 100644
--- a/Modules/CMakeDetermineASMCompiler.cmake
+++ b/Modules/CMakeDetermineASMCompiler.cmake
@@ -33,8 +33,9 @@ IF(NOT CMAKE_ASM${ASM_DIALECT}_COMPILER)
         SET(CMAKE_ASM_COMPILER_ID "${CMAKE_CXX_COMPILER_ID}")
       ELSE()
         # List all default C and CXX compilers
-        SET(CMAKE_ASM${ASM_DIALECT}_COMPILER_LIST ${_CMAKE_TOOLCHAIN_PREFIX}gcc ${_CMAKE_TOOLCHAIN_PREFIX}cc cl bcc xlc
-                                                  ${_CMAKE_TOOLCHAIN_PREFIX}c++ ${_CMAKE_TOOLCHAIN_PREFIX}g++ CC aCC cl bcc xlC)
+        SET(CMAKE_ASM${ASM_DIALECT}_COMPILER_LIST
+             ${_CMAKE_TOOLCHAIN_PREFIX}cc  ${_CMAKE_TOOLCHAIN_PREFIX}gcc cl bcc xlc
+          CC ${_CMAKE_TOOLCHAIN_PREFIX}c++ ${_CMAKE_TOOLCHAIN_PREFIX}g++ aCC cl bcc xlC)
       ENDIF()
     ENDIF()
   ELSE() # some specific assembler "dialect"
diff --git a/Modules/CMakeDetermineCCompiler.cmake b/Modules/CMakeDetermineCCompiler.cmake
index 9ebf0b3957..3ce968c02d 100644
--- a/Modules/CMakeDetermineCCompiler.cmake
+++ b/Modules/CMakeDetermineCCompiler.cmake
@@ -33,6 +33,12 @@
 
 INCLUDE(${CMAKE_ROOT}/Modules/CMakeDetermineCompiler.cmake)
 
+# Load system-specific compiler preferences for this language.
+INCLUDE(Platform/${CMAKE_SYSTEM_NAME}-C OPTIONAL)
+IF(NOT CMAKE_C_COMPILER_NAMES)
+  SET(CMAKE_C_COMPILER_NAMES cc)
+ENDIF()
+
 IF(NOT CMAKE_C_COMPILER)
   SET(CMAKE_C_COMPILER_INIT NOTFOUND)
 
@@ -56,7 +62,7 @@ IF(NOT CMAKE_C_COMPILER)
 
   # finally list compilers to try
   IF(NOT CMAKE_C_COMPILER_INIT)
-    SET(CMAKE_C_COMPILER_LIST ${_CMAKE_TOOLCHAIN_PREFIX}gcc ${_CMAKE_TOOLCHAIN_PREFIX}cc cl bcc xlc clang)
+    SET(CMAKE_C_COMPILER_LIST ${_CMAKE_TOOLCHAIN_PREFIX}cc ${_CMAKE_TOOLCHAIN_PREFIX}gcc cl bcc xlc clang)
   ENDIF()
 
   _cmake_find_compiler(C)
diff --git a/Modules/CMakeDetermineCXXCompiler.cmake b/Modules/CMakeDetermineCXXCompiler.cmake
index 43b44acd92..0116d341ab 100644
--- a/Modules/CMakeDetermineCXXCompiler.cmake
+++ b/Modules/CMakeDetermineCXXCompiler.cmake
@@ -32,6 +32,12 @@
 
 INCLUDE(${CMAKE_ROOT}/Modules/CMakeDetermineCompiler.cmake)
 
+# Load system-specific compiler preferences for this language.
+INCLUDE(Platform/${CMAKE_SYSTEM_NAME}-CXX OPTIONAL)
+IF(NOT CMAKE_CXX_COMPILER_NAMES)
+  SET(CMAKE_CXX_COMPILER_NAMES CC)
+ENDIF()
+
 IF(NOT CMAKE_CXX_COMPILER)
   SET(CMAKE_CXX_COMPILER_INIT NOTFOUND)
 
@@ -55,7 +61,7 @@ IF(NOT CMAKE_CXX_COMPILER)
 
   # finally list compilers to try
   IF(NOT CMAKE_CXX_COMPILER_INIT)
-    SET(CMAKE_CXX_COMPILER_LIST ${_CMAKE_TOOLCHAIN_PREFIX}c++ ${_CMAKE_TOOLCHAIN_PREFIX}g++ CC aCC cl bcc xlC clang++)
+    SET(CMAKE_CXX_COMPILER_LIST CC ${_CMAKE_TOOLCHAIN_PREFIX}c++ ${_CMAKE_TOOLCHAIN_PREFIX}g++ aCC cl bcc xlC clang++)
   ENDIF()
 
   _cmake_find_compiler(CXX)
diff --git a/Modules/CMakeDetermineCompiler.cmake b/Modules/CMakeDetermineCompiler.cmake
index 55d554bdcf..2d12c07578 100644
--- a/Modules/CMakeDetermineCompiler.cmake
+++ b/Modules/CMakeDetermineCompiler.cmake
@@ -29,10 +29,16 @@ macro(_cmake_find_compiler lang)
       list(APPEND CMAKE_${lang}_COMPILER_LIST
         ${_${lang}_COMPILER_NAMES_${CMAKE_${l}_COMPILER_ID}})
     endforeach()
+    # Prefer vendors based on the platform.
+    list(APPEND CMAKE_${lang}_COMPILER_LIST ${CMAKE_${lang}_COMPILER_NAMES})
     # Append the rest of the list and remove duplicates.
     list(APPEND CMAKE_${lang}_COMPILER_LIST ${_${lang}_COMPILER_LIST})
     unset(_${lang}_COMPILER_LIST)
     list(REMOVE_DUPLICATES CMAKE_${lang}_COMPILER_LIST)
+    if(CMAKE_${lang}_COMPILER_EXCLUDE)
+      list(REMOVE_ITEM CMAKE_${lang}_COMPILER_LIST
+        ${CMAKE_${lang}_COMPILER_EXCLUDE})
+    endif()
   endif()
 
   # Look for directories containing compilers of reference languages.
diff --git a/Modules/CMakeDetermineFortranCompiler.cmake b/Modules/CMakeDetermineFortranCompiler.cmake
index 6d6990e6f4..45033c2a39 100644
--- a/Modules/CMakeDetermineFortranCompiler.cmake
+++ b/Modules/CMakeDetermineFortranCompiler.cmake
@@ -20,6 +20,10 @@
 # as a default compiler
 
 INCLUDE(${CMAKE_ROOT}/Modules/CMakeDetermineCompiler.cmake)
+INCLUDE(Platform/${CMAKE_SYSTEM_NAME}-Fortran OPTIONAL)
+IF(NOT CMAKE_Fortran_COMPILER_NAMES)
+  SET(CMAKE_Fortran_COMPILER_NAMES f95)
+ENDIF()
 
 IF(NOT CMAKE_Fortran_COMPILER)
   # prefer the environment variable CC
diff --git a/Modules/Platform/CYGWIN-CXX.cmake b/Modules/Platform/CYGWIN-CXX.cmake
new file mode 100644
index 0000000000..bf37f79030
--- /dev/null
+++ b/Modules/Platform/CYGWIN-CXX.cmake
@@ -0,0 +1,7 @@
+if(NOT CMAKE_CXX_COMPILER_NAMES)
+  set(CMAKE_CXX_COMPILER_NAMES c++)
+endif()
+
+# Exclude C++ compilers differing from C compiler only by case
+# because this platform may have a case-insensitive filesystem.
+set(CMAKE_CXX_COMPILER_EXCLUDE CC aCC xlC)
diff --git a/Modules/Platform/Darwin-CXX.cmake b/Modules/Platform/Darwin-CXX.cmake
new file mode 100644
index 0000000000..bf37f79030
--- /dev/null
+++ b/Modules/Platform/Darwin-CXX.cmake
@@ -0,0 +1,7 @@
+if(NOT CMAKE_CXX_COMPILER_NAMES)
+  set(CMAKE_CXX_COMPILER_NAMES c++)
+endif()
+
+# Exclude C++ compilers differing from C compiler only by case
+# because this platform may have a case-insensitive filesystem.
+set(CMAKE_CXX_COMPILER_EXCLUDE CC aCC xlC)
diff --git a/Modules/Platform/Linux-CXX.cmake b/Modules/Platform/Linux-CXX.cmake
new file mode 100644
index 0000000000..b594daeb0b
--- /dev/null
+++ b/Modules/Platform/Linux-CXX.cmake
@@ -0,0 +1,3 @@
+if(NOT CMAKE_CXX_COMPILER_NAMES)
+  set(CMAKE_CXX_COMPILER_NAMES c++)
+endif()
diff --git a/Modules/Platform/Windows-CXX.cmake b/Modules/Platform/Windows-CXX.cmake
new file mode 100644
index 0000000000..bf37f79030
--- /dev/null
+++ b/Modules/Platform/Windows-CXX.cmake
@@ -0,0 +1,7 @@
+if(NOT CMAKE_CXX_COMPILER_NAMES)
+  set(CMAKE_CXX_COMPILER_NAMES c++)
+endif()
+
+# Exclude C++ compilers differing from C compiler only by case
+# because this platform may have a case-insensitive filesystem.
+set(CMAKE_CXX_COMPILER_EXCLUDE CC aCC xlC)