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Re: [patch] Privatize gimplify_ctx structure.

On 11/20/2013 10:51 AM, Richard Biener wrote:
On Wed, Nov 20, 2013 at 4:06 PM, Trevor Saunders <> wrote:
On Wed, Nov 20, 2013 at 03:18:07PM +0100, Richard Biener wrote:
On Wed, Nov 20, 2013 at 3:16 PM, Jakub Jelinek <> wrote:
On Wed, Nov 20, 2013 at 03:12:34PM +0100, Richard Biener wrote:
The limit looks reasonable, but you could have used a simple linked
list (and never free).  Also being able to pop a random context
looks fragile ...  that is, pop_gimplify_context shouldn't have an argument.
Can't we use stack_vec<gimplify_context, 30> for that?  Though that would
mean a global var constructor and destructor, so alternatively just use
a normal vec and .create(30) it somewhere during initialization?
only with gimplify_context *, otherwise things will break during re-allocation.
hm? it seems like the only member of gimplify_ctx that can't just be
memcpyd is the prev pointer which presumably could go away if you have a
vec of all the contexts.
Callers have a pointer to gimplify_context AFAIK.

No one except gimplify.c can have a pointer to the gimplify_context, so its contained to within gimplify.c. Pretty much everything is based off the current context pointer (gimplify_ctxp). There are places where the address of a field within that context structure is passed to another routine. If that routine then eventually triggered another push/pop_context call, the address underneath could be changed... and chaos ensues.

I don't know if that does happen, but it is a possibility and I dont see the need to find out. So a simple allocation scheme has the minimal impact on the code, and my preference is leave it as it is, or otherwise do the simple linked list malloc-ing only as necessary....

Want me to change it, or leave it as is?


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