From: Philippe Waroquiers <philippe.waroquiers@skynet.be>
Date: Sat, 9 Feb 2019 14:02:25 +0000 (+0100)
Subject: Fix type_stack leaks in c expression parsing.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ab759ca8db37ffd3e32df5226e0b4ea16a81c849;p=binutils-gdb.git

Fix type_stack leaks in c expression parsing.

Valgrind detects a bunch of leaks in several tests, such as:

==22905== 40 (24 direct, 16 indirect) bytes in 1 blocks are definitely lost in loss record 531 of 3,268
==22905==    at 0x4C2C4CC: operator new(unsigned long) (vg_replace_malloc.c:344)
==22905==    by 0x5893AD: get_type_stack() (parse.c:1509)
==22905==    by 0x3F4EAD: c_yyparse() (c-exp.y:1223)
==22905==    by 0x3F71BC: c_parse(parser_state*) (c-exp.y:3308)
==22905==    by 0x588CEA: parse_exp_in_context_1(char const**, unsigned long, block const*, int, int, int*) [clone .constprop.89] (parse.c:1205)
==22905==    by 0x588FA1: parse_exp_in_context (parse.c:1108)
==22905==    by 0x588FA1: parse_exp_1 (parse.c:1099)
==22905==    by 0x588FA1: parse_expression(char const*) (parse.c:1247)
...

==22395== 456 (168 direct, 288 indirect) bytes in 7 blocks are definitely lost in loss record 2,658 of 2,978
==22395==    at 0x4C2C4CC: operator new(unsigned long) (vg_replace_malloc.c:344)
==22395==    by 0x5893AD: get_type_stack() (parse.c:1509)
==22395==    by 0x3F4ECF: c_yyparse() (c-exp.y:1230)
==22395==    by 0x3F71BC: c_parse(parser_state*) (c-exp.y:3308)
==22395==    by 0x588CEA: parse_exp_in_context_1(char const**, unsigned long, block const*, int, int, int*) [clone .constprop.89] (parse.c:1205)
==22395==    by 0x588FA1: parse_exp_in_context (parse.c:1108)
==22395==    by 0x588FA1: parse_exp_1 (parse.c:1099)
==22395==    by 0x588FA1: parse_expression(char const*) (parse.c:1247)
==22395==    by 0x67BB9D: whatis_exp(char const*, int) (typeprint.c:515)
...

==22395== VALGRIND_GDB_ERROR_BEGIN
==22395== 144 (24 direct, 120 indirect) bytes in 1 blocks are definitely lost in loss record 1,016 of 2,978
==22395==    at 0x4C2C4CC: operator new(unsigned long) (vg_replace_malloc.c:344)
==22395==    by 0x5893AD: get_type_stack() (parse.c:1509)
==22395==    by 0x3F4E8A: c_yyparse() (c-exp.y:1217)
==22395==    by 0x3F71BC: c_parse(parser_state*) (c-exp.y:3308)
==22395==    by 0x588CEA: parse_exp_in_context_1(char const**, unsigned long, block const*, int, int, int*) [clone .constprop.89] (parse.c:1205)
==22395==    by 0x588FA1: parse_exp_in_context (parse.c:1108)
==22395==    by 0x588FA1: parse_exp_1 (parse.c:1099)
==22395==    by 0x588FA1: parse_expression(char const*) (parse.c:1247)
==22395==    by 0x67BB9D: whatis_exp(char const*, int) (typeprint.c:515)
...

Fix these by storing the allocated type_stack in the cpstate->type_stacks
vector.

Tested on debian/amd64, natively and under valgrind.

gdb/ChangeLog
2019-02-10  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* c-exp.y (direct_abs_decl): Use emplace_back to record the
	type_stack.
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3deb474bf55..f4f0c0c9396 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2019-02-10  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
+
+	* c-exp.y (direct_abs_decl): Use emplace_back to record the
+	type_stack.
+
 2019-02-10  Joel Brobecker  <brobecker@adacore.com>
 
 	* ada-varobj.c (ada_value_is_changeable_p): Add handling of
diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index f3ef23c75a7..508e9ef28dd 100644
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -1215,12 +1215,14 @@ direct_abs_decl: '(' abs_decl ')'
 			  push_type_int ($2);
 			  push_type (tp_array);
 			  $$ = get_type_stack ();
+			  cpstate->type_stacks.emplace_back ($$);
 			}
 	|	array_mod
 			{
 			  push_type_int ($1);
 			  push_type (tp_array);
 			  $$ = get_type_stack ();
+			  cpstate->type_stacks.emplace_back ($$);
 			}
 
 	| 	direct_abs_decl func_mod
@@ -1228,11 +1230,13 @@ direct_abs_decl: '(' abs_decl ')'
 			  push_type_stack ($1);
 			  push_typelist ($2);
 			  $$ = get_type_stack ();
+			  cpstate->type_stacks.emplace_back ($$);
 			}
 	|	func_mod
 			{
 			  push_typelist ($1);
 			  $$ = get_type_stack ();
+			  cpstate->type_stacks.emplace_back ($$);
 			}
 	;