[Compiler-rt] Emit error if builtins library cannot be found
authorYi Kong <yikong@google.com>
Sat, 16 May 2020 03:59:21 +0000 (11:59 +0800)
committerYi Kong <yikong@google.com>
Sun, 17 May 2020 02:54:53 +0000 (10:54 +0800)
commit2fe66bdb2e5fb556e15d4a07158e89ec007c587b
tree757c2482fbb64155894a6a306977c3fc25283ac6
parent3735505e4ffd0117de93d344fc0549151a205d11
[Compiler-rt] Emit error if builtins library cannot be found

Since setting COMPILER_RT_USE_BUILTINS_LIBRARY would remove -z,defs
flag, missing builtins library would continue to build unnoticed.
Explicitly emit an error in such case.

Differential Revision: https://reviews.llvm.org/D79470
compiler-rt/cmake/Modules/AddCompilerRT.cmake