From 8afafb65322a3fec01206720a1d8be4083e9c0d6 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Wed, 27 May 2009 02:21:45 +0100 Subject: [build] Add -fno-dwarf2-cfi-asm to CFLAGS if supported by the gcc in use gcc 4.4 defaults to using .cfi assembler directives for debugging information, which causes unneeded .eh_frame sections to be generated. These sections are already stripped out by our linker script, so don't affect the final build, but do distort the output of "size" when run on individual .o files; the .eh_frame size is included within the size reported for .text. This makes it difficult to accurately judge the effects of source code changes upon object code size. Fix by adding -fno-dwarf2-cfi-asm to CFLAGS if we detect that this option is supported by the gcc that we are compiling with. Tested-by: Daniel Verkamp --- src/Makefile.housekeeping | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'src/Makefile.housekeeping') diff --git a/src/Makefile.housekeeping b/src/Makefile.housekeeping index e886c4b2..cf7a9c78 100644 --- a/src/Makefile.housekeeping +++ b/src/Makefile.housekeeping @@ -134,6 +134,16 @@ SP_FLAGS := $(shell $(SP_TEST) && $(ECHO) '-fno-stack-protector') CFLAGS += $(SP_FLAGS) endif +# gcc 4.4 generates .eh_frame sections by default, which distort the +# output of "size". Inhibit this. +# +ifeq ($(CCTYPE),gcc) +CFI_TEST = $(CC) -fno-dwarf2-cfi-asm -x c -c /dev/null \ + -o /dev/null >/dev/null 2>&1 +CFI_FLAGS := $(shell $(CFI_TEST) && $(ECHO) '-fno-dwarf2-cfi-asm') +CFLAGS += $(CFI_FLAGS) +endif + # Some versions of gas choke on division operators, treating them as # comment markers. Specifying --divide will work around this problem, # but isn't available on older gas versions. -- cgit v1.2.3-55-g7522