From 26fc730dd2b04a718f12ea5ba0aa7a8737cc513e Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 19 Jan 2018 23:36:04 +0100
Subject: re PR debug/81570 (create_pseudo_cfg assumes that
 INCOMING_FRAME_SP_OFFSET is a constant)

	PR debug/81570
	PR debug/83728
	* dwarf2cfi.c (DEFAULT_INCOMING_FRAME_SP_OFFSET): Define to
	INCOMING_FRAME_SP_OFFSET if not defined.
	(scan_trace): Add ENTRY argument.  If true and
	DEFAULT_INCOMING_FRAME_SP_OFFSET != INCOMING_FRAME_SP_OFFSET,
	emit a note to adjust the CFA offset.
	(create_cfi_notes): Adjust scan_trace callers.
	(create_cie_data): Use DEFAULT_INCOMING_FRAME_SP_OFFSET rather than
	INCOMING_FRAME_SP_OFFSET in the CIE.
	* config/i386/i386.h (DEFAULT_INCOMING_FRAME_SP_OFFSET): Define.
	* config/stormy16/stormy16.h (DEFAULT_INCOMING_FRAME_SP_OFFSET):
	Likewise.
	* doc/tm.texi.in (DEFAULT_INCOMING_FRAME_SP_OFFSET): Document.
	* doc/tm.texi: Regenerated.

From-SVN: r256904
---
 gcc/dwarf2cfi.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

(limited to 'gcc/dwarf2cfi.c')

diff --git a/gcc/dwarf2cfi.c b/gcc/dwarf2cfi.c
index 3ae5b8e..07e6a5a 100644
--- a/gcc/dwarf2cfi.c
+++ b/gcc/dwarf2cfi.c
@@ -52,6 +52,10 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef INCOMING_RETURN_ADDR_RTX
 #define INCOMING_RETURN_ADDR_RTX  (gcc_unreachable (), NULL_RTX)
 #endif
+
+#ifndef DEFAULT_INCOMING_FRAME_SP_OFFSET
+#define DEFAULT_INCOMING_FRAME_SP_OFFSET INCOMING_FRAME_SP_OFFSET
+#endif
 
 /* A collected description of an entire row of the abstract CFI table.  */
 struct GTY(()) dw_cfi_row
@@ -2484,7 +2488,7 @@ scan_insn_after (rtx_insn *insn)
    instructions therein.  */
 
 static void
-scan_trace (dw_trace_info *trace)
+scan_trace (dw_trace_info *trace, bool entry)
 {
   rtx_insn *prev, *insn = trace->head;
   dw_cfa_location this_cfa;
@@ -2503,6 +2507,17 @@ scan_trace (dw_trace_info *trace)
   this_cfa = cur_row->cfa;
   cur_cfa = &this_cfa;
 
+  /* If the current function starts with a non-standard incoming frame
+     sp offset, emit a note before the first instruction.  */
+  if (entry
+      && DEFAULT_INCOMING_FRAME_SP_OFFSET != INCOMING_FRAME_SP_OFFSET)
+    {
+      add_cfi_insn = insn;
+      gcc_assert (NOTE_P (insn) && NOTE_KIND (insn) == NOTE_INSN_DELETED);
+      this_cfa.offset = INCOMING_FRAME_SP_OFFSET;
+      def_cfa_1 (&this_cfa);
+    }
+
   for (prev = insn, insn = NEXT_INSN (insn);
        insn;
        prev = insn, insn = NEXT_INSN (insn))
@@ -2671,12 +2686,12 @@ create_cfi_notes (void)
 
   /* Always begin at the entry trace.  */
   ti = &trace_info[0];
-  scan_trace (ti);
+  scan_trace (ti, true);
 
   while (!trace_work_list.is_empty ())
     {
       ti = trace_work_list.pop ();
-      scan_trace (ti);
+      scan_trace (ti, false);
     }
 
   queued_reg_saves.release ();
@@ -2980,7 +2995,12 @@ create_cie_data (void)
   /* On entry, the Canonical Frame Address is at SP.  */
   memset (&loc, 0, sizeof (loc));
   loc.reg = dw_stack_pointer_regnum;
-  loc.offset = INCOMING_FRAME_SP_OFFSET;
+  /* create_cie_data is called just once per TU, and when using .cfi_startproc
+     is even done by the assembler rather than the compiler.  If the target
+     has different incoming frame sp offsets depending on what kind of
+     function it is, use a single constant offset for the target and
+     if needed, adjust before the first instruction in insn stream.  */
+  loc.offset = DEFAULT_INCOMING_FRAME_SP_OFFSET;
   def_cfa_1 (&loc);
 
   if (targetm.debug_unwind_info () == UI_DWARF2
-- 
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