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fixed #498 - avoid potential leak in simplecpp::Macro::parseDefine() #527

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fixed #498 - avoid potential leak in simplecpp::Macro::parseDefine() #527

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6 changes: 4 additions & 2 deletions simplecpp.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1693,7 +1693,9 @@ namespace simplecpp {
nameTokDef = nametoken;
variadic = false;
variadicOpt = false;
delete optExpandValue;
optExpandValue = nullptr;
delete optNoExpandValue;
optNoExpandValue = nullptr;
if (!nameTokDef) {
valueToken = endToken = nullptr;
Expand Down Expand Up @@ -2367,8 +2369,8 @@ namespace simplecpp {
bool variadicOpt;

/** Expansion value for varadic macros with __VA_OPT__ expanded and discarded respectively */
const TokenList *optExpandValue;
const TokenList *optNoExpandValue;
const TokenList *optExpandValue{};
const TokenList *optNoExpandValue{};

/** was the value of this macro actually defined in the code? */
bool valueDefinedInCode_;
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13 changes: 13 additions & 0 deletions test.cpp
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Expand Up @@ -3217,6 +3217,7 @@ static void safe_api()
#endif
}

// crashes detected by fuzzer
static void fuzz_crash()
{
{
Expand All @@ -3231,6 +3232,16 @@ static void fuzz_crash()
}
}

// memory leaks detected by LSAN/valgrind
static void leak()
{
{ // #498
const char code[] = "#define e(...)__VA_OPT__()\n"
"#define e\n";
(void)preprocess(code, simplecpp::DUI());
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I assume this has to be executed by some valgrind or sanitizer to detect the issue? i.e. if I just compile and run then this test does not ensure there is no leak?
It feels a bit misplaced somehow but maybe writing a separate test for it is overkill.. but well a comment would be nice?

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Yes, obviously you need to run a leak checker.

I assumed the test name leak was enough. I can add a comment.

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I added some comments.

}
}

int main(int argc, char **argv)
{
TEST_CASE(backslash);
Expand Down Expand Up @@ -3487,5 +3498,7 @@ int main(int argc, char **argv)

TEST_CASE(fuzz_crash);

TEST_CASE(leak);

return numberOfFailedAssertions > 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}