freebsd-dev/lib/csu/amd64/Makefile
Dimitry Andric 9ef4e3afcb Apply a workaround for a binutils issue with the .note.ABI-tag section
generated from lib/csu/common/crtbrand.c (which ultimately ends up in
executables and shared libraries, via crt1.o, gcrt1.o or Scrt1.o).

For all arches except sparc, gcc emits the section directive for the
abitag struct in crtbrand.c with a PROGBITS type.  However, newer
versions of binutils (after 2.16.90) require the section to be of NOTE
type, to guarantee that the .note.ABI-tag section correctly ends up in
the first page of the final executable.

Unfortunately, there is no clean way to tell gcc to use another section
type, so crtbrand.c (or the C files that include it) must be compiled in
multiple steps:

- Compile the .c file to a .s file.
- Edit the .s file to change the 'progbits' type to 'note', for the section
  directive that defines the .note.ABI-tag section.
- Compile the .s file to an object file.

These steps are done in the invididual Makefiles for each applicable arch.

Reviewed by:	kib
2011-01-13 20:44:31 +00:00

46 lines
1.1 KiB
Makefile

# $FreeBSD$
.PATH: ${.CURDIR}/../common
SRCS= crt1.c crti.S crtn.S
OBJS= ${SRCS:N*.h:R:S/$/.o/g}
OBJS+= Scrt1.o gcrt1.o
CFLAGS+= -I${.CURDIR}/../common \
-I${.CURDIR}/../../libc/include
CFLAGS+= -fno-omit-frame-pointer
all: ${OBJS}
CLEANFILES= ${OBJS}
CLEANFILES+= crt1.s gcrt1.s Scrt1.s
# See the comment in lib/csu/common/crtbrand.c for the reason crt1.c is not
# directly compiled to .o files.
crt1.s: crt1.c
${CC} ${CFLAGS} -S -o ${.TARGET} ${.CURDIR}/crt1.c
sed -i "" -e '/\.note\.ABI-tag/s/progbits/note/' ${.TARGET}
crt1.o: crt1.s
${CC} ${CFLAGS} -c -o ${.TARGET} crt1.s
gcrt1.s: crt1.c
${CC} ${CFLAGS} -DGCRT -S -o ${.TARGET} ${.CURDIR}/crt1.c
sed -i "" -e '/\.note\.ABI-tag/s/progbits/note/' ${.TARGET}
gcrt1.o: gcrt1.s
${CC} ${CFLAGS} -c -o ${.TARGET} gcrt1.s
Scrt1.s: crt1.c
${CC} ${CFLAGS} -fPIC -DPIC -S -o ${.TARGET} ${.CURDIR}/crt1.c
sed -i "" -e '/\.note\.ABI-tag/s/progbits/note/' ${.TARGET}
Scrt1.o: Scrt1.s
${CC} ${CFLAGS} -c -o ${.TARGET} Scrt1.s
realinstall:
${INSTALL} -o ${LIBOWN} -g ${LIBGRP} -m ${LIBMODE} \
${OBJS} ${DESTDIR}${LIBDIR}
.include <bsd.lib.mk>