re PR debug/88635 (Assembler error when building with "-g -O2 -m32")

	PR debug/88635
	* dwarf2out.c (const_ok_for_output_1): Reject MINUS that contains
	SYMBOL_REF, CODE_LABEL or UNSPEC in subexpressions of second argument.
	Reject PLUS that contains SYMBOL_REF, CODE_LABEL or UNSPEC in
	subexpressions of both operands.
	(mem_loc_descriptor): Handle UNSPEC if target hook acks it and all the
	subrtxes are CONSTANT_P.
	* config/i386/i386.c (ix86_const_not_ok_for_debug_p): Revert
	2018-11-09 changes.

	* gcc.dg/debug/dwarf2/pr88635.c: New test.

From-SVN: r267594

5 files changed, 100 insertions, 19 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 87be8ae..e6992b0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2019-01-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/88635
+	* dwarf2out.c (const_ok_for_output_1): Reject MINUS that contains
+	SYMBOL_REF, CODE_LABEL or UNSPEC in subexpressions of second argument.
+	Reject PLUS that contains SYMBOL_REF, CODE_LABEL or UNSPEC in
+	subexpressions of both operands.
+	(mem_loc_descriptor): Handle UNSPEC if target hook acks it and all the
+	subrtxes are CONSTANT_P.
+	* config/i386/i386.c (ix86_const_not_ok_for_debug_p): Revert
+	2018-11-09 changes.
+
 2019-01-04  Jan Hubicka  <hubicka@ucw.cz>
 
 	* params.def (hot-bb-count-ws-permille): Set to 990.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 016d6e3..5cf876a 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -17240,18 +17240,6 @@ ix86_const_not_ok_for_debug_p (rtx x)
   if (SYMBOL_REF_P (x) && strcmp (XSTR (x, 0), GOT_SYMBOL_NAME) == 0)
     return true;
 
-  /* Reject UNSPECs within expressions.  We could accept symbol@gotoff
-     + literal_constant, but that would hardly come up in practice,
-     and it's not worth the trouble of having to reject that as an
-     operand to pretty much anything else.  */
-  if (UNARY_P (x)
-      && GET_CODE (XEXP (x, 0)) == UNSPEC)
-    return true;
-  if (BINARY_P (x)
-      && (GET_CODE (XEXP (x, 0)) == UNSPEC
-	  || GET_CODE (XEXP (x, 1)) == UNSPEC))
-    return true;
-
   return false;
 }
 
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 8d9a384..0d643dd 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -14464,6 +14464,41 @@ const_ok_for_output_1 (rtx rtl)
     case NOT:
     case NEG:
       return false;
+    case PLUS:
+      {
+	/* Make sure SYMBOL_REFs/UNSPECs are at most in one of the
+	   operands.  */
+	subrtx_var_iterator::array_type array;
+	bool first = false;
+	FOR_EACH_SUBRTX_VAR (iter, array, XEXP (rtl, 0), ALL)
+	  if (SYMBOL_REF_P (*iter)
+	      || LABEL_P (*iter)
+	      || GET_CODE (*iter) == UNSPEC)
+	    {
+	      first = true;
+	      break;
+	    }
+	if (!first)
+	  return true;
+	FOR_EACH_SUBRTX_VAR (iter, array, XEXP (rtl, 1), ALL)
+	  if (SYMBOL_REF_P (*iter)
+	      || LABEL_P (*iter)
+	      || GET_CODE (*iter) == UNSPEC)
+	    return false;
+	return true;
+      }
+    case MINUS:
+      {
+	/* Disallow negation of SYMBOL_REFs or UNSPECs when they
+	   appear in the second operand of MINUS.  */
+	subrtx_var_iterator::array_type array;
+	FOR_EACH_SUBRTX_VAR (iter, array, XEXP (rtl, 1), ALL)
+	  if (SYMBOL_REF_P (*iter)
+	      || LABEL_P (*iter)
+	      || GET_CODE (*iter) == UNSPEC)
+	    return false;
+	return true;
+      }
     default:
       return true;
     }
@@ -15607,6 +15642,7 @@ mem_loc_descriptor (rtx rtl, machine_mode mode,
 	 pool.  */
     case CONST:
     case SYMBOL_REF:
+    case UNSPEC:
       if (!is_a <scalar_int_mode> (mode, &int_mode)
 	  || (GET_MODE_SIZE (int_mode) > DWARF2_ADDR_SIZE
 #ifdef POINTERS_EXTEND_UNSIGNED
@@ -15614,6 +15650,30 @@ mem_loc_descriptor (rtx rtl, machine_mode mode,
 #endif
 	      ))
 	break;
+
+      if (GET_CODE (rtl) == UNSPEC)
+	{
+	  /* If delegitimize_address couldn't do anything with the UNSPEC, we
+	     can't express it in the debug info.  This can happen e.g. with some
+	     TLS UNSPECs.  Allow UNSPECs formerly from CONST that the backend
+	     approves.  */
+	  bool not_ok = false;
+	  subrtx_var_iterator::array_type array;
+	  FOR_EACH_SUBRTX_VAR (iter, array, rtl, ALL)
+	    if ((*iter != rtl && !CONSTANT_P (*iter))
+		|| !const_ok_for_output_1 (*iter))
+	      {
+		not_ok = true;
+		break;
+	      }
+
+	  if (not_ok)
+	    break;
+
+	  rtl = gen_rtx_CONST (GET_MODE (rtl), rtl);
+	  goto symref;
+	}
+
       if (GET_CODE (rtl) == SYMBOL_REF
 	  && SYMBOL_REF_TLS_MODEL (rtl) != TLS_MODEL_NONE)
 	{
@@ -16282,7 +16342,6 @@ mem_loc_descriptor (rtx rtl, machine_mode mode,
     case VEC_CONCAT:
     case VEC_DUPLICATE:
     case VEC_SERIES:
-    case UNSPEC:
     case HIGH:
     case FMA:
     case STRICT_LOW_PART:
@@ -16291,9 +16350,6 @@ mem_loc_descriptor (rtx rtl, machine_mode mode,
     case CLRSB:
     case CLOBBER:
     case CLOBBER_HIGH:
-      /* If delegitimize_address couldn't do anything with the UNSPEC, we
-	 can't express it in the debug info.  This can happen e.g. with some
-	 TLS UNSPECs.  */
       break;
 
     case CONST_STRING:
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 814d846..af59095 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,10 +1,11 @@
-2019-01-05  Dominique d'Humieres  <dominiq@gcc.gnu.org>
+2019-01-05  Jakub Jelinek  <jakub@redhat.com>
 
-	PR target/60563
-	Missing PR entry in the previous commit.
+	PR debug/88635
+	* gcc.dg/debug/dwarf2/pr88635.c: New test.
 
 2019-01-05  Dominique d'Humieres  <dominiq@gcc.gnu.org>
 
+	PR target/60563
 	* g++.dg/ext/sync-4.C: Add dg-xfail-run-if for darwin.
 
 2019-01-04  Martin Sebor  <msebor@redhat.com>
diff --git a/gcc/testsuite/gcc.dg/debug/dwarf2/pr88635.c b/gcc/testsuite/gcc.dg/debug/dwarf2/pr88635.c
new file mode 100644
index 0000000..02c53d1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/debug/dwarf2/pr88635.c
@@ -0,0 +1,24 @@
+/* PR debug/88635 */
+/* { dg-do assemble } */
+/* { dg-options "-g -O2" } */
+/* { dg-additional-options "-fpie" { target pie } } */
+
+static void
+foo (char *b)
+{
+  unsigned c = 0;
+  --c;
+  do
+    if (++*b++ == 0)
+      break;
+  while (--c);
+  if (c == 0)
+    while (*b++)
+      ;
+}
+
+void
+bar (void)
+{
+  foo ("");
+}