Add alternate per-vendor compiler id detection

At least one Fortran compiler does not provide a preprocessor symbol to
identify itself.  Instead we try running unknown compilers with version
query flags known for each vendor and look for known output.  Future
commits will add vendor-specific flags/output table entries.

2 files changed, 32 insertions, 0 deletions

diff --git a/Tests/CMakeTests/CMakeLists.txt b/Tests/CMakeTests/CMakeLists.txt
index 161ca44..6df026e 100644
--- a/Tests/CMakeTests/CMakeLists.txt
+++ b/Tests/CMakeTests/CMakeLists.txt
@@ -26,6 +26,7 @@ AddCMakeTest(If "")
 AddCMakeTest(String "")
 AddCMakeTest(Math "")
 AddCMakeTest(CMakeMinimumRequired "")
+AddCMakeTest(CompilerIdVendor "")
 
 if(HAVE_ELF_H)
   AddCMakeTest(ELF "")
diff --git a/Tests/CMakeTests/CompilerIdVendorTest.cmake.in b/Tests/CMakeTests/CompilerIdVendorTest.cmake.in
new file mode 100644
index 0000000..68f6462
--- /dev/null
+++ b/Tests/CMakeTests/CompilerIdVendorTest.cmake.in
@@ -0,0 +1,31 @@
+# This is not supposed to be included by user code, but we need to
+# test it.
+include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
+
+set(MY_BINARY_DIR "@CMAKE_CURRENT_BINARY_DIR@/CompilerIdVendor")
+file(REMOVE_RECURSE ${MY_BINARY_DIR})
+file(MAKE_DIRECTORY ${MY_BINARY_DIR})
+
+set(CMAKE_MyLang_COMPILER ${CMAKE_COMMAND})
+set(CMAKE_MyLang_COMPILER_ID_ARG1)
+set(CMAKE_MyLang_COMPILER_ID_FLAGS_LIST)
+set(CMAKE_MyLang_COMPILER_ID_DIR ${MY_BINARY_DIR})
+
+file(WRITE "${MY_BINARY_DIR}/BogusVendor.cmake" "message(\"This is a BogusVendor compiler\")")
+list(APPEND CMAKE_MyLang_COMPILER_ID_VENDORS BogusVendor)
+set(CMAKE_MyLang_COMPILER_ID_VENDOR_FLAGS_BogusVendor -P BogusVendor.cmake)
+set(CMAKE_MyLang_COMPILER_ID_VENDOR_REGEX_BogusVendor ThisDoesNotMatch_BogusVendor)
+
+file(WRITE "${MY_BINARY_DIR}/MyVendor.cmake" "message(\"This is a MyVendor compiler\")")
+list(APPEND CMAKE_MyLang_COMPILER_ID_VENDORS MyVendor)
+set(CMAKE_MyLang_COMPILER_ID_VENDOR_FLAGS_MyVendor -P MyVendor.cmake)
+set(CMAKE_MyLang_COMPILER_ID_VENDOR_REGEX_MyVendor MyVendor)
+
+set(CMAKE_BINARY_DIR ${MY_BINARY_DIR})
+cmake_determine_compiler_id_vendor(MyLang)
+
+if("${CMAKE_MyLang_COMPILER_ID}" STREQUAL "MyVendor")
+  message(STATUS "Found MyVendor compiler id!")
+else()
+  message(FATAL_ERROR "Did not find MyVendor compiler id: [${CMAKE_MyLang_COMPILER_ID}]")
+endif()