Commit 42f29a25 authored Sep 20, 2009 by Tim Abbott Committed by Sam Ravnborg Sep 21, 2009

kbuild: Don't define ALIGN and ENTRY when preprocessing linker scripts.



Adding a reference to <linux/linkage.h> to x86's <asm/cache.h> causes
the x86 linker script to have syntax errors, because the ALIGN and
ENTRY keywords get redefined to the assembly implementations of those.
One could fix this by adjusting the include structure, but I think any
solution based on that approach would be fragile.

Currently, it is impossible when writing a header to do something
different for assembly files and linker scripts, even though there are
clearly cases where one wants them to define macros differently for
the two (ENTRY being an excellent example).
So I think the right solution here is to introduce a new preprocessor
definition, called LINKER_SCRIPT that is set along with __ASSEMBLY__
for linker scripts, and to use that to not define ALIGN and ENTRY in
linker scripts.
I suspect we'll find other uses for this mechanism in
the future.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

parent 51b563fc

include/linux/linkage.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -57,6 +57,7 @@

		#ifdef __ASSEMBLY__

		#ifndef LINKER_SCRIPT
		#define ALIGN __ALIGN
		#define ALIGN_STR __ALIGN_STR

		@@ -66,6 +67,7 @@
		ALIGN; \
		name:
		#endif
		#endif /* LINKER_SCRIPT */

		#ifndef WEAK
		#define WEAK(name) \

scripts/Makefile.build

+1 −1

Original line number	Diff line number	Diff line
		@@ -271,7 +271,7 @@ targets += $(extra-y) $(MAKECMDGOALS) $(always)
		# ---------------------------------------------------------------------------
		quiet_cmd_cpp_lds_S = LDS $@
		cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
		-D__ASSEMBLY__ -o $@ $<
		-D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<

		$(obj)/%.lds: $(src)/%.lds.S FORCE
		$(call if_changed_dep,cpp_lds_S)

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