CMake is funky on detecting Intel 17 as GCC compatible.

[vchuravy]

Summary

This adds a fallback in case that the Intel compiler is failed to be detected correctly.

[chapuni]

Looks good. I cannot check it since I don't have Intel compiler, though.

[chapuni]

btw, would it work with icl.exe on windows?

@vchuravy, please do things in the next time when you create a differential,

1. Add *-commits to subscribers
2. Create diff to let contain whole the file, with "diff -U999999"

[vchuravy]

In D27610#618151, @chapuni wrote:

btw, would it work with icl.exe on windows?

As far as I know Intel on Windows is capable off handling gnu-style options, but I don't have a test system.

@vchuravy, please do things in the next time when you create a differential,

1. Add *-commits to subscribers
2. Create diff to let contain whole the file, with "diff -U999999"

I am still new to submitting patches to llvm so thanks for pointing that out to me.

[chapuni]

I think this would affect just to Intel compilers.

llvm/trunk/cmake/modules/DetermineGCCCompatible.cmake

 # Determine if the compiler has GCC-compatible command-line syntax.
 
 if(NOT DEFINED LLVM_COMPILER_IS_GCC_COMPATIBLE)
   if(CMAKE_COMPILER_IS_GNUCXX)
     set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
   elseif( MSVC )
     set(LLVM_COMPILER_IS_GCC_COMPATIBLE OFF)
   elseif( "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" )
     set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
+  elseif( "${CMAKE_CXX_COMPILER_ID}" MATCHES "Intel" )
+    set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
   endif()
 endif()