From e76e1718ebd4ce4083be216b8dd1ee8c849dd956 Mon Sep 17 00:00:00 2001 From: Michal Ludvig Date: Mon, 25 Mar 2002 07:59:16 +0000 Subject: [PATCH] * x86-64-tdep.c (x86_64_skip_prologue): Rewritten from scratch. --- gdb/ChangeLog | 4 ++++ gdb/x86-64-tdep.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 51 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c48794f4609..948ecc99d47 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,7 @@ +2002-03-25 Michal Ludvig + + * x86-64-tdep.c (x86_64_skip_prologue): Rewritten from scratch. + 2002-03-23 Andrew Cagney * command.h: Update copyright. diff --git a/gdb/x86-64-tdep.c b/gdb/x86-64-tdep.c index b7751cc4463..a876d26ddc3 100644 --- a/gdb/x86-64-tdep.c +++ b/gdb/x86-64-tdep.c @@ -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; } -- 2.30.2