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From: "christian.prochaska@genode-labs.com" <sourceware-bugzilla@sourceware.org> To: gdb-prs@sourceware.org Subject: [Bug breakpoints/13247] Wrong breakpoint address for ARM binary built with -O2 Date: Wed, 05 Oct 2011 16:09:00 -0000 [thread overview] Message-ID: <bug-13247-4717-m2CS29ZOKA@http.sourceware.org/bugzilla/> (raw) In-Reply-To: <bug-13247-4717@http.sourceware.org/bugzilla/> http://sourceware.org/bugzilla/show_bug.cgi?id=13247 --- Comment #1 from Christian Prochaska <christian.prochaska@genode-labs.com> 2011-10-05 16:09:15 UTC --- I'm still quite new to DWARF, but noted a difference in the line number information for the two binaries: -O0 binary ---------- The File Name Table: Entry Dir Time Size Name 1 0 0 0 func1.c 2 0 0 0 func1.h Line Number Statements: Extended opcode 2: set Address to 0x83a4 Special opcode 8: advance Address by 0 to 0x83a4 and Line by 3 to 4 Special opcode 146: advance Address by 20 to 0x83b8 and Line by 1 to 5 Advance PC by 16 to 0x83c8 Extended opcode 1: End of Sequence -O2 binary ---------- The File Name Table: Entry Dir Time Size Name 1 0 0 0 func1.c 2 0 0 0 func1.h Line Number Statements: Extended opcode 2: set Address to 0x838c Special opcode 8: advance Address by 0 to 0x838c and Line by 3 to 4 Special opcode 33: advance Address by 4 to 0x8390 and Line by 0 to 4 Special opcode 62: advance Address by 8 to 0x8398 and Line by 1 to 5 Advance PC by 8 to 0x83a0 Extended opcode 1: End of Sequence ------------- I wonder about the line with opcode 33 in the output for the -O2 binary, it seems superfluous to me? Also, the next line with opcode 62 contains the correct breakpoint address 0x8398 which was not chosen by GDB. After looking at the assembly files, I guess the line number statements are related to the ".loc" statements? In func1.s for the -O2 build there appears two times ".loc 1 4 0", which is not the case for the -O0 build. func1: .LFB0: .file 1 "func1.c" .loc 1 4 0 .cfi_startproc @ args = 20, pretend = 16, frame = 0 @ frame_needed = 0, uses_anonymous_args = 0 @ link register save eliminated. sub sp, sp, #16 .LCFI0: .cfi_def_cfa_offset 16 .loc 1 4 0 sub ip, sp, #4 stmib ip, {r0, r1, r2, r3} .loc 1 5 0 add sp, sp, #16 bx lr .cfi_endproc -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
next prev parent reply other threads:[~2011-10-05 16:09 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-10-02 11:39 [Bug breakpoints/13247] New: " christian.prochaska@genode-labs.com 2011-10-05 16:09 ` christian.prochaska@genode-labs.com [this message] 2011-10-06 15:29 ` [Bug breakpoints/13247] " christian.prochaska@genode-labs.com
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