I'm writing a compiler that produces C code. The programs produced consist only of the main function, and they use a lot of memory, that is allocated with malloc(). Most of the memory allocated is used only in a small part of the program, and I thought it would be a good idea to free() it after use, since it's not going to be used again. I would be glad, then, if valgrind would report to me about memory not free()d in the end of the program, that is, still reachable memory. I'm using valgrind with --error-exitcode=1 inside a Makefile, to check for this kind of problem automatically.
The question is: is there a way to make valgrind exit with 1 in case there are still reachable allocs?
An alternative to grepping through Valgrind output: modify your compiler so it emits:
int main() { return foo_main(); }
int foo_main() { /* whatever you've emitted before */ }
Assuming you are not assigning allocated blocks to global variables (which would make no sense since you only have one function), you've just transformed "still reachable" into "definitely leaked".
Possibly even better transformation: don't call exit(0) in your main; change it to return 0; instead. The net effect should be same as above -- __libc_main will now call exit for you, and all local variables in main will be out of scope by that time.