Save strings we're expanding in case an embedded eval causes them

to be freed (if they're the value of a variable that's reset for example).
See Savannah patch #7534
This commit is contained in:
Paul Smith 2011-08-29 16:20:19 +00:00
parent b06b8c64a2
commit e4d5d43424
4 changed files with 42 additions and 34 deletions

View file

@ -1,3 +1,11 @@
2011-08-29 Paul Smith <psmith@gnu.org>
* expand.c (variable_expand_string): Always allocate a new buffer
for a string we're expanding. The string we're working on can get
freed while we work on it (for example if it's the value of a
variable which modifies itself using an eval operation).
See Savannah patch #7534 for the original report by Lubomir Rintel.
2011-06-12 Paul Smith <psmith@gnu.org>
* read.c (parse_file_seq): Move the check for empty members out of

View file

@ -197,7 +197,7 @@ variable_expand_string (char *line, const char *string, long length)
{
struct variable *v;
const char *p, *p1;
char *abuf = NULL;
char *save;
char *o;
unsigned int line_offset;
@ -212,16 +212,11 @@ variable_expand_string (char *line, const char *string, long length)
return (variable_buffer);
}
/* If we want a subset of the string, allocate a temporary buffer for it.
Most of the functions we use here don't work with length limits. */
if (length > 0 && string[length] != '\0')
{
abuf = xmalloc(length+1);
memcpy(abuf, string, length);
abuf[length] = '\0';
string = abuf;
}
p = string;
/* We need a copy of STRING: due to eval, it's possible that it will get
freed as we process it (it might be the value of a variable that's reset
for example). Also having a nil-terminated string is handy. */
save = length < 0 ? xstrdup (string) : xstrndup (string, length);
p = save;
while (1)
{
@ -411,8 +406,7 @@ variable_expand_string (char *line, const char *string, long length)
++p;
}
if (abuf)
free (abuf);
free (save);
variable_buffer_output (o, "", 1);
return (variable_buffer + line_offset);

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@ -1,3 +1,8 @@
2011-08-29 Paul Smith <psmith@gnu.org>
* scripts/features/varnesting: Test resetting of variables while
expanding them. See Savannah patch #7534
2011-06-12 Paul Smith <psmith@gnu.org>
* scripts/features/archives: Check archives with whitespace at the

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@ -1,29 +1,30 @@
$description = "The following test creates a makefile to ...";
# -*-perl-*-
$description = "Test recursive variables";
$details = "";
open(MAKEFILE,"> $makefile");
run_make_test('
x = variable1
variable2 := Hello
y = $(subst 1,2,$(x))
z = y
a := $($($(z)))
all:
@echo $(a)
',
'', "Hello\n");
# The Contents of the MAKEFILE ...
# This tests resetting the value of a variable while expanding it.
# You may only see problems with this if you're using valgrind or
# some other memory checker that poisons freed memory.
# See Savannah patch #7534
print MAKEFILE "x = variable1\n"
."variable2 := Hello\n"
."y = \$(subst 1,2,\$(x))\n"
."z = y\n"
."a := \$(\$(\$(z)))\n"
."all: \n"
."\t\@echo \$(a)\n";
# END of Contents of MAKEFILE
close(MAKEFILE);
&run_make_with_options($makefile,"",&get_logfile);
# Create the answer to what should be produced by this Makefile
$answer = "Hello\n";
&compare_output($answer,&get_logfile(1));
run_make_test('
VARIABLE = $(eval VARIABLE := echo hi)$(VARIABLE)
wololo:
@$(VARIABLE)
',
'', "hi\n");
1;