Consider the following test case:
#include <vector>
using namespace std;
int main ()
{
vector<int> V(10);
V[10] = 1;
}
Compile it like:
g++ -O2 -ggdb -o t t.cc
Run gdb and examine the first few instructions in main:
(gdb) x/10i main
0x8048880 <main>: push %ebp
0x8048881 <main+1>: mov %esp,%ebp
0x8048883 <main+3>: push %ebx
0x8048884 <main+4>: sub $0x34,%esp
0x8048887 <main+7>: and $0xfffffff0,%esp
0x804888a <main+10>: sub $0x10,%esp
0x804888d <main+13>: cmpb $0x0,0x804a7c0
0x8048894 <main+20>: je 0x8048964 <main+228>
0x804889a <main+26>: xor %eax,%eax
0x804889c <main+28>: lea 0xffffffe8(%ebp),%ebx
Run addr2line on the address where the cmpb instruction is and you
get (if you use the latest versions of gcc and binutils):
$ addr2line -s -f -e t 0804888d
_S_get_pool
mt_allocator.h:450
The patch (which I'll attach separately) allows addr2line to print
additional information about how we arrived at that address via several
levels of inlining:
$ addr2line -i -s -f -e t 0804888d
_S_get_pool
mt_allocator.h:450
__mt_alloc
mt_allocator.h:656
allocator
allocator.h:97
vector
stl_vector.h:217
main
t.cc:7
One possible use of this is in environments which trap various
exceptions and want to print a traceback for the user, by calling
addr2line on the current PC and each saved PC in the stack. In the
case of functions that inline other functions, that traceback is
incomplete because it misses all the inlined functions and the caller
of inlined functions. I.E. for the current example, where the caller
of main is probably _start(), it would appear that the current
function (_S_get_pool) was called directly by _start, skipping main
and all the other intermediate inlined functions.
The patch is somewhat large because it adds another function to the
BFD target structure, which currently returns FALSE for all non-DWARF2
environments. The meat of the changes is actually in bfd/dwarf2.c and
binutils/addr2line.c.
--
Summary: Extension to BFD and addr2line to print inlining chain
Product: binutils
Version: 2.17 (HEAD)
Status: NEW
Severity: normal
Priority: P2
Component: binutils
AssignedTo: unassigned at sources dot redhat dot com
ReportedBy: fnf at specifixinc dot com
CC: bug-binutils at gnu dot org,fnf at specifixinc dot com
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://sources.redhat.com/bugzilla/show_bug.cgi?id=947
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