[xray] [tests] Detect and handle missing LLVMTestingSupport gracefully

Add a code to properly test for presence of LLVMTestingSupport library
when performing a stand-alone build, and skip tests requiring it when
it is not present.  Since the library is not installed, llvm-config
reported empty --libs for it and the tests failed to link with undefined
references.  Skipping the two fdr_* test files is better than failing to
build, and should be good enough until we find a better solution.

NB: both installing LLVMTestingSupport and building it automatically
from within compiler-rt sources are non-trivial.  The former due to
dependency on gtest, the latter due to tight integration with LLVM
source tree.

Differential Revision: https://reviews.llvm.org/D55891

llvm-svn: 349899

1 files changed, 21 insertions, 1 deletions

diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
index c4500328e5c..518a16a9679 100644
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -239,7 +239,7 @@ macro(load_llvm_config)
     # Detect if we have the LLVMXRay and TestingSupport library installed and
     # available from llvm-config.
     execute_process(
-      COMMAND ${LLVM_CONFIG_PATH} "--ldflags" "--libs" "xray" "testingsupport"
+      COMMAND ${LLVM_CONFIG_PATH} "--ldflags" "--libs" "xray"
       RESULT_VARIABLE HAD_ERROR
       OUTPUT_VARIABLE CONFIG_OUTPUT)
     if (HAD_ERROR)
@@ -254,6 +254,26 @@ macro(load_llvm_config)
       set(COMPILER_RT_HAS_LLVMXRAY TRUE)
     endif()
 
+    set(COMPILER_RT_HAS_LLVMTESTINGSUPPORT FALSE)
+    execute_process(
+      COMMAND ${LLVM_CONFIG_PATH} "--ldflags" "--libs" "testingsupport"
+      RESULT_VARIABLE HAD_ERROR
+      OUTPUT_VARIABLE CONFIG_OUTPUT)
+    if (HAD_ERROR)
+      message(WARNING "llvm-config finding testingsupport failed with status ${HAD_ERROR}")
+    else()
+      string(REGEX REPLACE "[ \t]*[\r\n]+[ \t]*" ";" CONFIG_OUTPUT ${CONFIG_OUTPUT})
+      list(GET CONFIG_OUTPUT 0 LDFLAGS)
+      list(GET CONFIG_OUTPUT 1 LIBLIST)
+      if (LIBLIST STREQUAL "")
+        message(WARNING "testingsupport library not installed, some tests will be skipped")
+      else()
+        set(LLVM_TESTINGSUPPORT_LDFLAGS ${LDFLAGS} CACHE STRING "Linker flags for LLVMTestingSupport library")
+        set(LLVM_TESTINGSUPPORT_LIBLIST ${LIBLIST} CACHE STRING "Library list for LLVMTestingSupport")
+        set(COMPILER_RT_HAS_LLVMTESTINGSUPPORT TRUE)
+      endif()
+    endif()
+
     # Make use of LLVM CMake modules.
     # --cmakedir is supported since llvm r291218 (4.0 release)
     execute_process(