c: GNU extension allowing compound literals of variable sizeHEADtrunkmaster

This patch implements a GNU extension by allowing compound literals
to be VLAs which then can be initialized with an empty initializer.
This addresses a use case where one would now need to use alloca, but
this also has limitations (e.g. allocated memory accumulates in a loop).
The error for a compound literal with variable size is changed to a
pedwarn, and a new error for static and constexpr is added.

gcc/c/ChangeLog:
	* c-decl.cc (build_compound_literal): Add error.
	* c-parser.cc (c_parser_braced_init): Take bool argument for
	variable size instead of DECL.
	(c_parser_initializer,c_parser_initval): Adapt.
	(c_parser_postfix_expression_after_paren_type): Change
	error to pedwarn.
	* c-typeck.cc (process_init_element): Add error for
	variable-size compound literal with static or constexpr.

gcc/ChangeLog:
	* doc/extend.texi: Document new extension.

gcc/testsuite/ChangeLog:
	* gcc.dg/gnu-compoundlit-1.c: New test.
	* gcc.dg/gnu-compoundlit-2.c: New test.
	* gcc.dg/pr68090.c: Adapt.
	* gcc.dg/vla-init-4.c: Adapt.
	* gcc.dg/vla-init-5.c: Adapt.

0 files changed, 0 insertions, 0 deletions