[IEPM] Introduce inline entry point markers

[IEPM] Introduce inline entry point markers

Output DW_AT_entry_pc based on markers.

Introduce DW_AT_GNU_entry_view as a DWARF extension.

If views are enabled are we're not in strict compliance mode, output
DW_AT_GNU_entry_view if it might be nonzero.

This patch depends on SFN and LVU patchsets, and on the IEPM patch that
introduces the inline_entry debug hook.

for  include/ChangeLog

	* dwarf2.def (DW_AT_GNU_entry_view): New.

for  gcc/ChangeLog

	* cfgexpand.c (expand_gimple_basic_block): Handle inline entry
	markers.
	* dwarf2out.c (dwarf2_debug_hooks): Enable inline_entry hook.
	(BLOCK_INLINE_ENTRY_LABEL): New.
	(dwarf2out_var_location): Disregard inline entry markers.
	(inline_entry_data): New struct.
	(inline_entry_data_hasher): New hashtable type.
	(inline_entry_data_hasher::hash): New.
	(inline_entry_data_hasher::equal): New.
	(inline_entry_data_table): New variable.
	(add_high_low_attributes): Add DW_AT_entry_pc and
	DW_AT_GNU_entry_view attributes if a pending entry is found
	in inline_entry_data_table.  Add old entry_pc attribute only
	if debug nonbinding markers are disabled.
	(gen_inlined_subroutine_die): Set BLOCK_DIE if nonbinding
	markers are enabled.
	(block_within_block_p, dwarf2out_inline_entry): New.
	(dwarf2out_finish): Check that no entries remained in
	inline_entry_data_table.
	* final.c (reemit_insn_block_notes): Handle inline entry notes.
	(final_scan_insn, notice_source_line): Likewise.
	(rest_of_clean_state): Skip inline entry markers.
	* gimple-pretty-print.c (dump_gimple_debug): Handle inline entry
	markers.
	* gimple.c (gimple_build_debug_inline_entry): New.
	* gimple.h (enum gimple_debug_subcode): Add
	GIMPLE_DEBUG_INLINE_ENTRY.
	(gimple_build_debug_inline_entry): Declare.
	(gimple_debug_inline_entry_p): New.
	(gimple_debug_nonbind_marker_p): Adjust.
	* insn-notes.def (INLINE_ENTRY): New.
	* print-rtl.c (rtx_writer::print_rtx_operand_code_0): Handle
	inline entry marker notes.
	(print_insn): Likewise.
	* rtl.h	(NOTE_MARKER_P): Add INLINE_ENTRY support.
	(INSN_DEBUG_MARKER_KIND): Likewise.
	(GEN_RTX_DEBUG_MARKER_INLINE_ENTRY_PAT): New.
	* tree-inline.c	(expand_call_inline): Build and insert
	debug_inline_entry stmt.
	* tree-ssa-live.c (remove_unused_scope_block_p): Preserve
	inline entry blocks early, if nonbind markers are enabled.
	(dump_scope_block): Dump fragment info.
	* var-tracking.c (reemit_marker_as_note): Handle inline entry note.
	* doc/gimple.texi (gimple_debug_inline_entry_p): New.
	(gimple_build_debug_inline_entry): New.
	* doc/invoke.texi (gstatement-frontiers, gno-statement-frontiers):
	Enable/disable inline entry points too.
	* doc/rtl.texi (NOTE_INSN_INLINE_ENTRY): New.
	(DEBUG_INSN): Describe inline entry markers.

From-SVN: r257511