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/ChangeLog

+2018-01-19  Jakub Jelinek  <jakub@redhat.com>
+
+	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.
+
 2018-01-19  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	PR rtl-optimization/83147

gcc/config/i386/i386.h

@@ -2110,6 +2110,10 @@ extern int const svr4_dbx_register_map[FIRST_PSEUDO_REGISTER];
   (cfun->machine->func_type == TYPE_EXCEPTION \
    ? 2 * UNITS_PER_WORD : UNITS_PER_WORD)
 
+/* The value of INCOMING_FRAME_SP_OFFSET the assembler assumes in
+   .cfi_startproc.  */
+#define DEFAULT_INCOMING_FRAME_SP_OFFSET UNITS_PER_WORD
+
 /* Describe how we implement __builtin_eh_return.  */
 #define EH_RETURN_DATA_REGNO(N)	((N) <= DX_REG ? (N) : INVALID_REGNUM)
 #define EH_RETURN_STACKADJ_RTX	gen_rtx_REG (Pmode, CX_REG)

gcc/config/stormy16/stormy16.h

@@ -228,6 +228,7 @@ enum reg_class
 
 #define INCOMING_FRAME_SP_OFFSET (xstormy16_interrupt_function_p () ? -6 : -4)
 
+#define DEFAULT_INCOMING_FRAME_SP_OFFSET -4
 
 /* Register That Address the Stack Frame.  */
 

gcc/doc/tm.texi

@@ -3168,6 +3168,15 @@ You only need to define this macro if you want to support call frame
 debugging information like that provided by DWARF 2.
 @end defmac
 
+@defmac DEFAULT_INCOMING_FRAME_SP_OFFSET
+Like @code{INCOMING_FRAME_SP_OFFSET}, but must be the same for all
+functions of the same ABI, and when using GAS @code{.cfi_*} directives
+must also agree with the default CFI GAS emits.  Define this macro
+only if @code{INCOMING_FRAME_SP_OFFSET} can have different values
+between different functions of the same ABI or when
+@code{INCOMING_FRAME_SP_OFFSET} does not agree with GAS default CFI.
+@end defmac
+
 @defmac ARG_POINTER_CFA_OFFSET (@var{fundecl})
 A C expression whose value is an integer giving the offset, in bytes,
 from the argument pointer to the canonical frame address (cfa).  The

gcc/doc/tm.texi.in

@@ -2559,6 +2559,15 @@ You only need to define this macro if you want to support call frame
 debugging information like that provided by DWARF 2.
 @end defmac
 
+@defmac DEFAULT_INCOMING_FRAME_SP_OFFSET
+Like @code{INCOMING_FRAME_SP_OFFSET}, but must be the same for all
+functions of the same ABI, and when using GAS @code{.cfi_*} directives
+must also agree with the default CFI GAS emits.  Define this macro
+only if @code{INCOMING_FRAME_SP_OFFSET} can have different values
+between different functions of the same ABI or when
+@code{INCOMING_FRAME_SP_OFFSET} does not agree with GAS default CFI.
+@end defmac
+
 @defmac ARG_POINTER_CFA_OFFSET (@var{fundecl})
 A C expression whose value is an integer giving the offset, in bytes,
 from the argument pointer to the canonical frame address (cfa).  The

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