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* x86-64-tdep.c (x86_64_skip_prologue): Rewritten from scratch.

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Michal Ludvig 2002-03-25 07:59:16 +00:00
parent 23c7880c01
commit e76e1718eb
2 changed files with 51 additions and 1 deletions
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4
gdb/ChangeLog
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@ -1,3 +1,7 @@
2002-03-25 Michal Ludvig <mludvig@suse.cz>
* x86-64-tdep.c (x86_64_skip_prologue): Rewritten from scratch.
2002-03-23 Andrew Cagney <ac131313@redhat.com>
* command.h: Update copyright.

48
gdb/x86-64-tdep.c
View file

@ -759,10 +759,56 @@ x86_64_frameless_function_invocation (struct frame_info *frame)
return 0;
}
/* On x86_64 there are no reasonable prologs. */
/* If a function with debugging information and known beginning
is detected, we will return pc of the next line in the source
code. With this approach we effectively skip the prolog. */
#define PROLOG_BUFSIZE 4
CORE_ADDR
x86_64_skip_prologue (CORE_ADDR pc)
{
int i, firstline, currline;
struct symtab_and_line v_sal;
struct symbol *v_function;
CORE_ADDR salendaddr = 0, endaddr = 0;
/* We will handle only functions beginning with:
55 pushq %rbp
48 89 e5 movq %rsp,%rbp
*/
unsigned char prolog_expect[PROLOG_BUFSIZE] = { 0x55, 0x48, 0x89, 0xe5 },
prolog_buf[PROLOG_BUFSIZE];
read_memory (pc, (char *) prolog_buf, PROLOG_BUFSIZE);
/* First check, whether pc points to pushq %rbp, movq %rsp,%rbp. */
for (i = 0; i < PROLOG_BUFSIZE; i++)
if (prolog_expect[i] != prolog_buf[i])
return pc;
v_function = find_pc_function (pc);
v_sal = find_pc_line (pc, 0);
/* If pc doesn't point to a function with debuginfo,
some of the following may be NULL. */
if (!v_function || !v_function->ginfo.value.block || !v_sal.symtab)
return pc;
firstline = v_sal.line;
currline = firstline;
salendaddr = v_sal.end;
endaddr = v_function->ginfo.value.block->endaddr;
for (i = 0; i < v_sal.symtab->linetable->nitems; i++)
if (v_sal.symtab->linetable->item[i].line > firstline
&& v_sal.symtab->linetable->item[i].pc >= salendaddr
&& v_sal.symtab->linetable->item[i].pc < endaddr)
{
pc = v_sal.symtab->linetable->item[i].pc;
currline = v_sal.symtab->linetable->item[i].line;
break;
}
return pc;
}