https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109990
Bug ID: 109990
Summary: [12 Regression] Bogus -Wuse-after-free warning after
realloc
Product: gcc
Version: 13.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: bruno at clisp dot org
Target Milestone: ---
Created attachment 55168
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55168&action=edit
test case bar.c
Compiling the attached file produces a warning that is not justified:
$ gcc -Wall -O2 -S bar.c
bar.c: In function ‘read_alias_file’:
bar.c:122:52: warning: pointer may be used after ‘realloc’ [-Wuse-after-free]
122 | map[i].alias += new_pool - string_space;
| ~~~~~~~~~^~~~~~~~~~~~~~
bar.c:114:45: note: call to ‘realloc’ here
114 | char *new_pool = (char *) realloc (string_space,
new_size);
|
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The warning is not justified because only the pointer 'string_space' is used
here; it is not being dereferenced.
Seen with gcc 12.3.0 and 13.1.0.
