2012-01-23  Jakub Jelinek  <jakub@redhat.com>

	PR target/51957

	* target.def (const_not_ok_for_debug_p): New hook.

	* doc/tm.texi.in (TARGET_CONST_NOT_OK_FOR_DEBUG_P): New hook

	documentation.

	* doc/tm.texi: Regenerated.

	* dwarf2out.c (const_ok_for_output_1): If

	targetm.const_not_ok_for_debug_p returns true, fail.

	* config/rs6000/rs6000.c (rs6000_const_not_ok_for_debug_p): New

	function.

	(TARGET_CONST_NOT_OK_FOR_DEBUG_P): Redefine.

	* gcc.dg/pr51957-1.c: New test.

	* gcc.dg/pr51957-1.h: New file.

	* gcc.dg/pr51957-2.c: New test.

--- gcc/target.def.jj	2012-01-20 12:35:16.000000000 +0100

+++ gcc/target.def	2012-01-23 13:14:52.601638343 +0100

@@ -1382,6 +1382,14 @@ DEFHOOK

  rtx, (rtx x),

  delegitimize_mem_from_attrs)

+/* Given an RTX, return true if it is not ok to emit it into debug info

+   section.  */

+DEFHOOK

+(const_not_ok_for_debug_p,

+ "",

+ bool, (rtx x),

+ hook_bool_rtx_false)

+

 /* Given an address RTX, say whether it is valid.  */

 DEFHOOK

 (legitimate_address_p,

--- gcc/doc/tm.texi.in.jj	2012-01-20 12:35:10.000000000 +0100

+++ gcc/doc/tm.texi.in	2012-01-23 13:27:19.544241676 +0100

@@ -5567,6 +5567,11 @@ the semantics of these opaque @code{UNSP

 into their original form.

 @end deftypefn

+@hook TARGET_CONST_NOT_OK_FOR_DEBUG_P

+This hook should return true if @var{x} should not be emitted into

+debug sections.

+@end deftypefn

+

 @hook TARGET_CANNOT_FORCE_CONST_MEM

 This hook should return true if @var{x} is of a form that cannot (or

 should not) be spilled to the constant pool.  @var{mode} is the mode

--- gcc/doc/tm.texi.jj	2012-01-20 12:35:10.000000000 +0100

+++ gcc/doc/tm.texi	2012-01-23 13:27:33.000000000 +0100

@@ -5631,6 +5631,11 @@ the semantics of these opaque @code{UNSP

 into their original form.

 @end deftypefn

+@deftypefn {Target Hook} bool TARGET_CONST_NOT_OK_FOR_DEBUG_P (rtx @var{x})

+This hook should return true if @var{x} should not be emitted into

+debug sections.

+@end deftypefn

+

 @deftypefn {Target Hook} bool TARGET_CANNOT_FORCE_CONST_MEM (enum machine_mode @var{mode}, rtx @var{x})

 This hook should return true if @var{x} is of a form that cannot (or

 should not) be spilled to the constant pool.  @var{mode} is the mode

--- gcc/dwarf2out.c.jj	2012-01-22 16:02:10.000000000 +0100

+++ gcc/dwarf2out.c	2012-01-23 13:58:09.887380014 +0100

@@ -10683,6 +10683,13 @@ const_ok_for_output_1 (rtx *rtlp, void *

       return 1;

     }

+  if (targetm.const_not_ok_for_debug_p (rtl))

+    {

+      expansion_failed (NULL_TREE, rtl,

+			"Expression rejected for debug by the backend.\n");

+      return 1;

+    }

+

   if (GET_CODE (rtl) != SYMBOL_REF)

     return 0;

--- gcc/config/rs6000/rs6000.c.jj	2012-01-22 16:02:10.000000000 +0100

+++ gcc/config/rs6000/rs6000.c	2012-01-23 13:25:05.092031129 +0100

@@ -1106,6 +1106,7 @@ static rtx rs6000_debug_legitimize_addre

 static rtx rs6000_legitimize_tls_address (rtx, enum tls_model);

 static void rs6000_output_dwarf_dtprel (FILE *, int, rtx) ATTRIBUTE_UNUSED;

 static rtx rs6000_delegitimize_address (rtx);

+static bool rs6000_const_not_ok_for_debug_p (rtx);

 static rtx rs6000_tls_get_addr (void);

 static rtx rs6000_got_sym (void);

 static int rs6000_tls_symbol_ref_1 (rtx *, void *);

@@ -1405,6 +1406,9 @@ static const struct attribute_spec rs600

 #undef TARGET_DELEGITIMIZE_ADDRESS

 #define TARGET_DELEGITIMIZE_ADDRESS rs6000_delegitimize_address

+#undef TARGET_CONST_NOT_OK_FOR_DEBUG_P

+#define TARGET_CONST_NOT_OK_FOR_DEBUG_P rs6000_const_not_ok_for_debug_p

+

 #undef TARGET_ASM_FUNCTION_PROLOGUE

 #define TARGET_ASM_FUNCTION_PROLOGUE rs6000_output_function_prologue

 #undef TARGET_ASM_FUNCTION_EPILOGUE

@@ -5815,6 +5819,25 @@ rs6000_delegitimize_address (rtx orig_x)

   return orig_x;

 }

+/* Return true if X shouldn't be emitted into the debug info.

+   The linker doesn't like .toc section references from

+   .debug_* sections, so reject .toc section symbols.  */

+

+static bool

+rs6000_const_not_ok_for_debug_p (rtx x)

+{

+  if (GET_CODE (x) == SYMBOL_REF

+      && CONSTANT_POOL_ADDRESS_P (x))

+    {

+      rtx c = get_pool_constant (x);

+      enum machine_mode cmode = get_pool_mode (x);

+      if (ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (c, cmode))

+	return true;

+    }

+

+  return false;

+}

+

 /* Construct the SYMBOL_REF for the tls_get_addr function.  */

 static GTY(()) rtx rs6000_tls_symbol;

--- gcc/testsuite/gcc.dg/pr51957-1.c.jj	2012-01-23 14:06:45.024357678 +0100

+++ gcc/testsuite/gcc.dg/pr51957-1.c	2012-01-23 14:12:02.895492825 +0100

@@ -0,0 +1,29 @@

+/* PR target/51957 */

+/* { dg-do link } */

+/* { dg-options "-O2 -g -fprofile-use" } */

+/* { dg-additional-sources "pr51957-2.c" } */

+

+int v[128];

+#include "pr51957-1.h"

+

+void

+foo (U *x)

+{

+  T *a = x->u;

+  while (1)

+    {

+      union R *b;

+      b = fn1 ();

+      if (b != w[0] && !(v[b->p->c] == 1))

+	{

+	  fn2 (a->t, "foobar", b->p);

+	  b = w[0];

+	}

+      if (b != w[0])

+	fn3 ();

+      if (w[0] && b != w[0])

+	fn4 (b->p);

+      if (b != w[0] && (v[b->p->c] == 1) && fn4 (b->p))

+	break;

+    }

+}

--- gcc/testsuite/gcc.dg/pr51957-1.h.jj	2012-01-23 14:06:56.491290757 +0100

+++ gcc/testsuite/gcc.dg/pr51957-1.h	2012-01-23 14:07:35.243060438 +0100

@@ -0,0 +1,9 @@

+union R { int c; union R *p; };

+extern union R *w[];

+typedef struct { int t; } T;

+typedef struct { void *u; } U;

+union R *fn1 (void);

+void fn2 (int, const char *, union R *);

+void fn3 (void);

+int fn4 (union R *);

+void foo (U *x);

--- gcc/testsuite/gcc.dg/pr51957-2.c.jj	2012-01-23 14:10:59.840862700 +0100

+++ gcc/testsuite/gcc.dg/pr51957-2.c	2012-01-23 14:10:52.870904033 +0100

@@ -0,0 +1,35 @@

+/* PR target/51957 */

+/* { dg-do compile } */

+/* { dg-options "-O0" } */

+

+#include "pr51957-1.h"

+

+union R *w[10];

+

+union R *

+fn1 (void)

+{

+  return (union R *) 0;

+}

+

+void

+fn2 (int x, const char *y, union R *z)

+{

+}

+

+void

+fn3 (void)

+{

+}

+

+int

+fn4 (union R *x)

+{

+  return 0;

+}

+

+int

+main ()

+{

+  return 0;

+}