[libomptarget] Introduce LIBOMPTARGET_ENABLE_DEBUG cmake option.

At the moment, support for runtime debug output using the
OMPTARGET_DEBUG=1 environment variable is only available with
CMAKE_BUILD_TYPE=Debug builds. The patch allows setting it independently
using the LIBOMPTARGET_ENABLE_DEBUG option, which is enabled by default
depending on CMAKE_BUILD_TYPE. That is, unless this option is set
explicitly, nothing changes. This is the same mechanism used by LLVM for
LLVM_ENABLE_ASSERTIONS.

This patch also removes adding -g -O0 in debug builds, it should be
handled by cmake's CMAKE_{C|CXX}_FLAGS_DEBUG configuration option.

Idea by Hal Finkel

Differential Revision: https://reviews.llvm.org/D55952

llvm-svn: 356998

2 files changed, 9 insertions, 5 deletions

diff --git a/openmp/libomptarget/CMakeLists.txt b/openmp/libomptarget/CMakeLists.txt
index 9bbb5e6342e..a953662bf8b 100644
--- a/openmp/libomptarget/CMakeLists.txt
+++ b/openmp/libomptarget/CMakeLists.txt
@@ -40,13 +40,17 @@ set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} nvptx64-nvidia-cuda")
 # the list of supported targets in the current system.
 set (LIBOMPTARGET_SYSTEM_TARGETS "")
 
-# If building this library in debug mode, we define a macro to enable
-# dumping progress messages at runtime.
+# Check whether using debug mode. In debug mode, allow dumping progress
+# messages at runtime by default. Otherwise, it can be enabled
+# independently using the LIBOMPTARGET_ENABLE_DEBUG option.
 string( TOLOWER "${CMAKE_BUILD_TYPE}" LIBOMPTARGET_CMAKE_BUILD_TYPE)
 if(LIBOMPTARGET_CMAKE_BUILD_TYPE MATCHES debug)
+  option(LIBOMPTARGET_ENABLE_DEBUG "Allow debug output with the environment variable LIBOMPTARGET_DEBUG=1" ON)
+else()
+  option(LIBOMPTARGET_ENABLE_DEBUG "Allow debug output with the environment variable LIBOMPTARGET_DEBUG=1" OFF)
+endif()
+if(LIBOMPTARGET_ENABLE_DEBUG)
   add_definitions(-DOMPTARGET_DEBUG)
-  add_definitions(-g)
-  add_definitions(-O0)
 endif()
 
 include_directories(include)
diff --git a/openmp/libomptarget/test/CMakeLists.txt b/openmp/libomptarget/test/CMakeLists.txt
index 5950c773285..607801e50e5 100644
--- a/openmp/libomptarget/test/CMakeLists.txt
+++ b/openmp/libomptarget/test/CMakeLists.txt
@@ -6,7 +6,7 @@ if(NOT OPENMP_TEST_COMPILER_ID STREQUAL "Clang" OR
   return()
 endif()
 
-if(LIBOMPTARGET_CMAKE_BUILD_TYPE MATCHES debug)
+if(LIBOMPTARGET_ENABLE_DEBUG)
   set(LIBOMPTARGET_DEBUG True)
 else()
   set(LIBOMPTARGET_DEBUG False)