Detect dladdr() presence in CMake script

* CMakeLists.txt (CheckCSourceCompiles): Include module.
* CMakeLists.txt: Check if C test code which calls dladdr() can be
compiled and linked successfully; set HAVE_DLADDR variable accordingly.
* CMakeLists.txt [HAVE_DLADDR] (HAVE_DLADDR): Define macro.

1 files changed, 12 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 67ced5a0..c7ac9ced 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,6 +31,7 @@ else()
 endif()
 
 include(CheckCCompilerFlag)
+include(CheckCSourceCompiles)
 include(CheckFunctionExists)
 include(CheckIncludeFile)
 include(CheckSymbolExists)
@@ -339,6 +340,17 @@ if (NOT HAVE_SIGSETJMP)
   add_definitions("-DGC_NO_SIGSETJMP")
 endif()
 
+# Check for dladdr (used for debugging).
+check_c_source_compiles("
+#define _GNU_SOURCE 1\n
+#include <dlfcn.h>\n
+int main(void) { Dl_info info; (void)dladdr(\"\", &info); return 0; }"
+  HAVE_DLADDR)
+if (HAVE_DLADDR)
+  # Define to use 'dladdr' function.
+  add_definitions("-DHAVE_DLADDR")
+endif()
+
 add_library(gc ${SRC})
 if (enable_threads)
   target_link_libraries(gc PRIVATE ${THREADDLLIBS})