[PATCH] ARM: asm/unified.h: guard the IT macros against redefinition when using LTO

[Nicolas Pitre]

With LTO, the intermediate representation for each .c file contains those
global assembly macro definitions. When the lot is merged together during
the final link, we get duplicate definition errors:

[...]
/tmp/cc48fUMp.s:42352: Error: Macro `it' was already defined
/tmp/cc48fUMp.s:42354: Error: Macro `itt' was already defined
/tmp/cc48fUMp.s:42356: Error: Macro `ite' was already defined
[...]

Guard those against redefinitions.

Signed-off-by: Nicolas Pitre <nico at linaro.org>

diff --git a/arch/arm/include/asm/unified.h b/arch/arm/include/asm/unified.h
index a91ae49961..ee257a3de7 100644
--- a/arch/arm/include/asm/unified.h
+++ b/arch/arm/include/asm/unified.h
@@ -103,6 +103,8 @@
 	.endm
 #else	/* !__ASSEMBLY__ */
 __asm__(
+/* the .L_it_macros_defined guards against redefinition in the LTO case */
+"	.ifndef	.L_it_macros_defined\n"
 "	.macro	it, cond\n"
 "	.endm\n"
 "	.macro	itt, cond\n"
@@ -132,7 +134,9 @@ __asm__(
 "	.macro	iteet, cond\n"
 "	.endm\n"
 "	.macro	iteee, cond\n"
-"	.endm\n");
+"	.endm\n"
+"	.set	.L_it_macros_defined,1\n"
+"	.endif");
 #endif	/* __ASSEMBLY__ */
 
 #endif	/* CONFIG_ARM_ASM_UNIFIED */