https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97069
Bug ID: 97069
Summary: Zero valued #line directive results in excessively
large blocks of memory being allocated
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: martin.ogden at arm dot com
CC: marxin at gcc dot gnu.org
Target Milestone: ---
Created attachment 49225
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49225&action=edit
Associated main.i file
Adding a #line directive with a line number of 0 causes gcov to attempt to
allocate large (~2G) blocks of memory. To reproduce, consider main.c:
int main()
{
}
#line 0 "main.c"
void zero_line_directive()
{
}
Compile and attempt to run gcov:
$ gcc main.c -Wall -Werror --coverage
$ ./a.out
$ gcov main.c # gcov a-main.c for gcc-11
terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc
The bad allocation is made in gcc/gcc/gcov.c at line 1346:
s->lines.resize(last_line + 1);
A line number of 0 causes `last_line` to be large (often 0x100000, sometimes
larger ~10^8).
System details
--------------
Fault occurs on Ubuntu 16.04.6 with with gcc-{5,7,8,9,11} and gcov-{5,7,8,9,11}
(not tested with v{<=4,6,10}).
$ lsb_release -a
...
Distributor ID: Ubuntu
Description: Ubuntu 16.04.6 LTS
Release: 16.04
Codename: xenial
$ gcc -v
gcc version 11.0.0 20200902 (experimental) (GCC)
$ gcc-9 -v
gcc-9 (Ubuntu 9.3.0-10ubuntu2~16.04) 9.3.0
$ gcc-8
gcc-8 (Ubuntu 8.1.0-9ubuntu1~16.04.york1) 8.1.0
$ gcc-7 -v
gcc-7 (Ubuntu 7.3.0-23ubuntu2~16.04.york0) 7.3.0
$ gcc-5 -v
gcc-5 (Ubuntu 5.5.0-12ubuntu1~16.04) 5.5.0 20171010
It also occurs on macOS 10.15.6 with gcc-{7,8,9} (not tested with
v{<=5,6,10,11}).
