On Thu, 2 Jun 2005, Ulrich Weigand wrote:
Hello, I'm seeing compiler crashes during garbage collection when using mudflap.
The problem appears to be that some basic_block_def structures point to edge_prediction structures which point to edge_def structures that have already been ggc_free()'d.
I keep hitting this problem on my darwin machine with my "rename exit and entry blocks to block 0 and 1" patch.
At first i thought it was something in the patch, but it's not. It's the exact problem you describe.
Now, looking at remove_edge (cfg.c) is does indeed appear that it is possible for edges to get deleted without the corresponding prediction structure being removed as well ...