https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107851
Bug ID: 107851
Summary: Issues with -Wanalyzer-allocation-size messages
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: dmalcolm at gcc dot gnu.org
Target Milestone: ---
Taken from gcc.dg/analyzer/allocation-size-2.c
#include <stdlib.h>
#include <stdint.h>
void test_2 (int32_t n)
{
int32_t *ptr = malloc (n * sizeof (int16_t));
free (ptr);
}
With "-fanalyzer" (https://godbolt.org/z/fKcdrrh3z) we get:
<source>: In function 'test_2':
<source>:6:18: warning: allocated buffer size is not a multiple of the
pointee's size [CWE-131] [-Wanalyzer-allocation-size]
6 | int32_t *ptr = malloc (n * sizeof (int16_t));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'test_2': event 1
|
| 6 | int32_t *ptr = malloc (n * sizeof (int16_t));
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (1) allocated '(long unsigned int)n * 2' bytes
and assigned to 'int32_t *' {aka 'int *'} here; 'sizeof (int32_t {aka int})' is
'4'
|
<source>:6:18: warning: allocated buffer size is not a multiple of the
pointee's size [CWE-131] [-Wanalyzer-allocation-size]
'test_2': events 1-3
|
| 6 | int32_t *ptr = malloc (n * sizeof (int16_t));
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (1) allocated '(long unsigned int)n * 2' bytes
here
| | (2) allocated '(long unsigned int)n * 2' bytes
here
| | (3) assigned to 'int32_t *' {aka 'int *'} here;
'sizeof (int32_t {aka int})' is '4'
|
Compiler returned: 0
With "-fanalyzer -fanalyzer-fine-grained" ( https://godbolt.org/z/3fbvofPje )
we get:
<source>: In function 'test_2':
<source>:6:18: warning: allocated buffer size is not a multiple of the
pointee's size [CWE-131] [-Wanalyzer-allocation-size]
6 | int32_t *ptr = malloc (n * sizeof (int16_t));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'test_2': events 1-3
|
| 6 | int32_t *ptr = malloc (n * sizeof (int16_t));
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (1) allocated '(long unsigned int)n * 2' bytes
here
| | (2) allocated '(long unsigned int)n * 2' bytes
here
| | (3) assigned to 'int32_t *' {aka 'int *'} here;
'sizeof (int32_t {aka int})' is '4'
|
Compiler returned: 0
Issues:
* note how the "allocated '(long unsigned int)n * 2' bytes here" message is
repeated
* note how we get a duplicate diagnostic, which goes away with
-fanalyzer-fine-grained
