- if(CMAKE_COMPILER_IS_GNUCC AND (NOT enable_model-checking))
- set(optCFLAGS "${optCFLAGS} -finline-functions ")
- if(WIN32)
- if (COMPILER_C_VERSION_MAJOR_MINOR STRGREATER "4.8")
- # On windows, we need 4.8 or higher to enable lto because of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50293
- #
- # We are experiencing assertion failures even with 4.8 on MinGW.
- # Push the support forward: will see if 4.9 works when we test it.
- set(optCFLAGS "${optCFLAGS} -flto ")
- endif()
- else()
- # On non-windows, 4.6 is enough for that
- if(LINKER_VERSION STRGREATER "2.22")
- set(optCFLAGS "${optCFLAGS} -flto ")
+else()
+ set(optCFLAGS "-O0 ")
+endif()
+if(enable_compile_optimizations AND CMAKE_COMPILER_IS_GNUCC
+ AND (NOT enable_model-checking))
+ # This is redundant (already in -03):
+ set(optCFLAGS "${optCFLAGS} -finline-functions ")
+endif()
+
+# Do not leak the current directory into the binaries
+if(CMAKE_COMPILER_IS_GNUCC)
+ execute_process(COMMAND realpath --relative-to=${CMAKE_BINARY_DIR} ${CMAKE_SOURCE_DIR}
+ RESULT_VARIABLE RESULT OUTPUT_VARIABLE RELATIVE_SOURCE_DIR ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+ if(RESULT EQUAL 0)
+ message(STATUS "Relative source directory is \"${RELATIVE_SOURCE_DIR}\".")
+ else()
+ message(WARNING "Failed to find relative source directory. Using \".\".")
+ set(RELATIVE_SOURCE_DIR ".")
+ endif()
+ set(optCFLAGS "${optCFLAGS} -fdebug-prefix-map=${CMAKE_SOURCE_DIR}=${RELATIVE_SOURCE_DIR}")
+endif()
+
+# Configure LTO
+# NOTE, cmake 3.0 has a INTERPROCEDURAL_OPTIMIZATION target
+# property for this (http://www.cmake.org/cmake/help/v3.0/prop_tgt/INTERPROCEDURAL_OPTIMIZATION.html)
+if(enable_lto) # User wants LTO. Try if we can do that
+ set(enable_lto OFF)
+ if(enable_compile_optimizations
+ AND CMAKE_COMPILER_IS_GNUCC
+ AND (NOT enable_model-checking))
+ # On windows, we need 4.8 or higher to enable lto because of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50293
+ # We are experiencing assertion failures even with 4.8 on MinGW.
+ # Push the support forward: will see if 4.9 works when we test it.
+ #
+ # On Linux, we got the following with GCC 4.8.4 on Centos and Ubuntu
+ # lto1: internal compiler error: in output_die, at dwarf2out.c:8478
+ # Please submit a full bug report, with preprocessed source if appropriate.
+ # So instead, we push the support forward
+
+ if ( (CMAKE_C_COMPILER_VERSION VERSION_GREATER "4.8.5")
+ AND (LINKER_VERSION VERSION_GREATER "2.22"))
+ set(enable_lto ON)
+ endif()
+ endif()
+ if(enable_lto)
+ message(STATUS "LTO seems usable.")
+ else()
+ if(NOT enable_compile_optimizations)
+ message(STATUS "LTO disabled: Compile-time optimizations turned off.")
+ else()
+ if(enable_model-checking)
+ message(STATUS "LTO disabled when compiling with model-checking.")
+ else()
+ message(STATUS "LTO does not seem usable -- try updating your build chain.")