Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!tut.cis.ohio-state.edu!sysrap.ks.fujitsu.junet!seki
From: seki@sysrap.ks.fujitsu.junet (Masahiro SEKIGUCHI)
Newsgroups: gnu.gcc.bug
Subject: gcc 1.36 SDB info bug
Message-ID: <8911150600.AA00573@seki.sysrap.ks.fujitsu.co.jp>
Date: 15 Nov 89 06:00:48 GMT
Sender: daemon@tut.cis.ohio-state.edu
Distribution: gnu
Organization: Architecture Dept., R&P Div., Fujitsu Limited
Lines: 83

OUTLINE

Gcc generates negative line numbers in SDB debugging
informations, when an inline function defined in an
include file is called.

DETAILS

The compiler was built with ``config.gcc i386v'' from
unmodified sources of gcc 1.36.

Compiling the following file ``test.c'' causes the
following file ``test.s'' as an output.  Used command
line is:
	gcc -v -S -g test.c

``test.s'' includes two wrong directive ``.line -1''
between lines ``.L3:'' and ``.L4:''.

My assembler reported errors for ``.line -1''.  I don't
know whether it is a common feature of System V or it is
a bug of my assembler.  Please ignore this report if
negative line numbers should be accepted, and so, it is
not a bug of gcc.

--- test.c
	#include "test.h"
	main ()
	{ int n;
	  n = test();
	}
--- test.h
	static int inline test () { return 1; }
--- test.s
	.file	"test.c"
gcc_compiled.:
.text
	.align 4
	.def	main;	.val	main;	.scl	2;	.type	044;	.endef
.globl main
main:
	.ln	1
	pushl %ebp
	movl %esp,%ebp
	subl $4,%esp
	.def	.bf;	.val	.;	.scl	101;	.line	3;	.endef
	.def	.bb;	.val	.;	.scl	100;	.line	1;	.endef
	.def	n;	.val	-4;	.scl	1;	.type	04;	.endef
	.ln	2
	.def	.bb;	.val	.;	.scl	100;	.line	2;	.endef
	leal -4(%ebp),%eax
	movl $1,%eax
	jmp .L4
.L4:
	.def	.eb;.val	.;	.scl	100;	.line	-1;	.endef
	movl %eax,-4(%ebp)
	.def	.eb;.val	.;	.scl	100;	.line	-1;	.endef
	.ln	3
.L3:
	.def	.ef;	.val	.;	.scl	101;	.line	3;	.endef
	leave
	ret
	.def	main;	.val	.;	.scl	-1;	.endef

GUESS

I think this error is a result of relative line number
culculation.  Gcc subtracts a line number in test.h from
a line number in test.c to get a ``relative'' line number.
In this case, a statement is in an inline function defined
in test.h, while the top of the current function is in
test.c

My suggestion is to change some codes in sdbout.c to use
``dummy'' line numbers if an inline function defined in
an include file is used.  I found similar fix in the file
final.c, which is just before the call to
ASM_OUTPUT_SOUECE_LINE, while the fix was erased out.

-- 
	Masahiro Sekiguchi
	Architecture Dept., R&P Div., Fujitsu Limited
	seki@sysrap.ks.fujitsu.co.jp (JUNET) -or- PDB01144 (NIFTY-Serve)