ARC: dw2 unwind: add infrastructure for adding cfi pseudo ops to asm

1. detect whether binutils supports the cfi pseudo ops
2. define conditional macros to generate the ops
3. define new ENTRY_CFI/END_CFI to annotate hand asm code.
   - Needed because we don't want to emit dwarf info in general ENTRY/END
     used by lowest level trap/exception/interrutp handlers as unwinder
     gets confused trying to unwind out of them. We want unwinder to
     instead stop when it hits onfo those routines
   - These provide minimal start/end cfi ops assuming routine doesn't
     touch stack memory/regs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2016-09-16 17:23:26 -07:00
parent 2dad1122d9
commit 5a205a32ff
3 changed files with 52 additions and 1 deletions

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@ -65,7 +65,8 @@ endif
endif
cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables
cfi := $(call as-instr,.cfi_startproc\n.cfi_endproc,-DARC_DW2_UNWIND_AS_CFI)
cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables $(cfi)
ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
# Generic build system uses -O2, we want -O3

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@ -0,0 +1,38 @@
/*
* Copyright (C) 2016-17 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef _ASM_ARC_DWARF_H
#define _ASM_ARC_DWARF_H
#ifdef __ASSEMBLY__
#ifdef ARC_DW2_UNWIND_AS_CFI
#define CFI_STARTPROC .cfi_startproc
#define CFI_ENDPROC .cfi_endproc
#define CFI_DEF_CFA .cfi_def_cfa
#define CFI_REGISTER .cfi_register
#define CFI_REL_OFFSET .cfi_rel_offset
#define CFI_UNDEFINED .cfi_undefined
#else
#define CFI_IGNORE #
#define CFI_STARTPROC CFI_IGNORE
#define CFI_ENDPROC CFI_IGNORE
#define CFI_DEF_CFA CFI_IGNORE
#define CFI_REGISTER CFI_IGNORE
#define CFI_REL_OFFSET CFI_IGNORE
#define CFI_UNDEFINED CFI_IGNORE
#endif /* !ARC_DW2_UNWIND_AS_CFI */
#endif /* __ASSEMBLY__ */
#endif /* _ASM_ARC_DWARF_H */

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@ -9,6 +9,8 @@
#ifndef __ASM_LINKAGE_H
#define __ASM_LINKAGE_H
#include <asm/dwarf.h>
#ifdef __ASSEMBLY__
#define ASM_NL ` /* use '`' to mark new line in macro */
@ -32,6 +34,16 @@
#endif
.endm
#define ENTRY_CFI(name) \
.globl name ASM_NL \
ALIGN ASM_NL \
name: ASM_NL \
CFI_STARTPROC ASM_NL
#define END_CFI(name) \
CFI_ENDPROC ASM_NL \
.size name, .-name
#else /* !__ASSEMBLY__ */
#ifdef CONFIG_ARC_HAS_ICCM