Merge branch 'master' into master

BackwardConfig.cmake

@@ -72,7 +72,7 @@ if (${STACK_DETAILS_AUTO_DETECT})
 		LIBDL_INCLUDE_DIR LIBDL_LIBRARY)
 
 	# find libdwarf
-	find_path(LIBDWARF_INCLUDE_DIR NAMES "libdwarf.h")
+	find_path(LIBDWARF_INCLUDE_DIR NAMES "libdwarf.h" PATH_SUFFIXES libdwarf)
 	find_path(LIBELF_INCLUDE_DIR NAMES "libelf.h")
 	find_path(LIBDL_INCLUDE_DIR NAMES "dlfcn.h")
 	find_library(LIBDWARF_LIBRARY dwarf)
@@ -133,7 +133,7 @@ else()
 	endif()
 
 	if (STACK_DETAILS_DWARF)
-		LIST(APPEND BACKWARD_LIBRARIES dwarf elf)
+		LIST(APPEND _BACKWARD_LIBRARIES dwarf elf)
 	endif()
 endif()
 
@@ -169,10 +169,8 @@ list(APPEND _BACKWARD_INCLUDE_DIRS ${BACKWARD_INCLUDE_DIR})
 
 macro(add_backward target)
 	target_include_directories(${target} PRIVATE ${BACKWARD_INCLUDE_DIRS})
-	set_property(TARGET ${target} APPEND PROPERTY COMPILE_DEFINITIONS ${_BACKWARD_DEFINITIONS})
-	if(BACKWARD_HAS_EXTERNAL_LIBRARIES)
-		set_property(TARGET ${target} APPEND PROPERTY LINK_LIBRARIES ${_BACKWARD_LIBRARIES})
-	endif()
+	set_property(TARGET ${target} APPEND PROPERTY COMPILE_DEFINITIONS ${BACKWARD_DEFINITIONS})
+	set_property(TARGET ${target} APPEND PROPERTY LINK_LIBRARIES ${BACKWARD_LIBRARIES})
 endmacro()
 
 set(BACKWARD_INCLUDE_DIRS ${_BACKWARD_INCLUDE_DIRS} CACHE INTERNAL "_BACKWARD_INCLUDE_DIRS")
@@ -180,6 +178,16 @@ set(BACKWARD_DEFINITIONS ${_BACKWARD_DEFINITIONS} CACHE INTERNAL "BACKWARD_DEFIN
 set(BACKWARD_LIBRARIES ${_BACKWARD_LIBRARIES} CACHE INTERNAL "BACKWARD_LIBRARIES")
 mark_as_advanced(BACKWARD_INCLUDE_DIRS BACKWARD_DEFINITIONS BACKWARD_LIBRARIES)
 
+# Expand each definition in BACKWARD_DEFINITIONS to its own cmake var and export
+# to outer scope
+foreach(var ${BACKWARD_DEFINITIONS})
+  string(REPLACE "=" ";" var_as_list ${var})
+  list(GET var_as_list 0 var_name)
+  list(GET var_as_list 1 var_value)
+  set(${var_name} ${var_value})
+  mark_as_advanced(${var_name})
+endforeach()
+
 if (NOT TARGET Backward::Backward)
 	add_library(Backward::Backward INTERFACE IMPORTED)
 	set_target_properties(Backward::Backward PROPERTIES

README.md

@@ -149,7 +149,29 @@ Of course you can simply add the define (`-DBACKWARD_HAS_...=1`) and the
 linkage details in your build system and even auto-detect which library is
 installed, it's up to you.
 
-That'ss it, you are all set, you should be getting nice stack traces like the
+#### [libdwarf](https://sourceforge.net/projects/libdwarf/) and [libelf](http://www.mr511.de/software/english.html)
+
+	apt-get install libdwarf-dev (or equivalent)
+
+And do not forget to link with the lib and inform Backward to use it:
+
+	#define BACKWARD_HAS_DWARF 1
+
+There are several alternative implementations of libdwarf and libelf that
+are API compatible so it's possible, although it hasn't been tested, to
+replace the ones used when developing backward (in bold, below):
+
+* **_libelf_** by [Michael "Tired" Riepe](http://www.mr511.de/software/english.html)
+* **_libdwarf_** by [David Anderson](https://www.prevanders.net/dwarf.html)
+* libelf from [elfutils](https://fedorahosted.org/elfutils/)
+* libelf and libdwarf from FreeBSD's [ELF Tool Chain](https://sourceforge.net/p/elftoolchain/wiki/Home/) project
+
+
+Of course you can simply add the define (`-DBACKWARD_HAS_...=1`) and the
+linkage details in your build system and even auto-detect which library is
+installed, it's up to you.
+
+That's it, you are all set, you should be getting nice stack traces like the
 one at the beginning of this document.
 
 ## API

backward.hpp

@@ -719,7 +719,7 @@ private:
 			} else {
 				ip -= 1; // else just normally decrement it (no overflow/underflow will happen)
 			}
-		}
+    }
 
 		if (_index >= 0) { // ignore first frame.
 			(*_f)(static_cast<size_t>(_index), reinterpret_cast<void*>(ip));