Add push/pop_function_decl

For the aarch64 simd clones patches, it would be useful to be able to
push a function declaration onto the cfun stack, even though it has no
function body associated with it.  That is, we want cfun to be null,
current_function_decl to be the decl itself, and the target and
optimisation flags to reflect the declaration.

This patch adds a push/pop_function_decl pair to do that.

I think the more direct way of doing what I want to do under the
existing interface would have been:

  push_cfun (nullptr);
  invoke_set_current_function_hook (fndecl);
  pop_cfun ();

where invoke_set_current_function_hook would need to become public.
But it seemed safer to use the higher-level routines, since it makes
sure that the target/optimisation changes are synchronised with the
function changes.  In particular, if cfun was null before the
sequence above, the pop_cfun would leave the flags unchanged,
rather than restore them to the state before the push_cfun.

gcc/
	* function.h (push_function_decl, pop_function_decl): Declare.
	* function.cc (set_function_decl): New function, extracted from...
	(set_cfun): ...here.
	(push_function_decl): New function, extracted from...
	(push_cfun): ...here.
	(pop_cfun_1): New function, extracted from...
	(pop_cfun): ...here.
	(pop_function_decl): New function.

0 files changed, 0 insertions, 0 deletions