[PATCH] D23030: [CMake] Don't trust compiler error code, also check for errors

[Reid Kleckner via llvm-commits]

rnk added inline comments.

================
Comment at: cmake/Modules/BuiltinTests.cmake:1
@@ -1,1 +1,2 @@
+include(CMakeCheckCompilerFlagCommonPatterns)
 
----------------
That was also my first thought, but the file has this comment:
```
# Do NOT include this module directly into any of your code. It is meant as
# a library for Check*CompilerFlag.cmake modules. It's content may change in
# any way between releases.
```

Think we should do it anyway?

================
Comment at: cmake/Modules/BuiltinTests.cmake:44
@@ +43,3 @@
+  foreach(var ${_CheckCCompilerFlag_COMMON_PATTERNS})
+    if("${TEST_OUTPUT}" STREQUAL "FAIL_REGEX")
+      continue()
----------------
I think you meant `if ("${var}" STREQUAL "FAIL_REGEX")`


https://reviews.llvm.org/D23030