PR debug/82630

	* target.def (const_not_ok_for_debug_p): Default to
	default_const_not_ok_for_debug_p instead of hook_bool_rtx_false.
	* targhooks.h (default_const_not_ok_for_debug_p): New declaration.
	* targhooks.c (default_const_not_ok_for_debug_p): New function.
	* dwarf2out.c (const_ok_for_output_1): Only reject UNSPECs for
	which targetm.const_not_ok_for_debug_p returned true.
	* config/arm/arm.c (arm_const_not_ok_for_debug_p): Return true
	for UNSPECs.
	* config/powerpcspe/powerpcspe.c (rs6000_const_not_ok_for_debug_p):
	Likewise.
	* config/rs6000/rs6000.c (rs6000_const_not_ok_for_debug_p): Likewise.
	* config/i386/i386.c (ix86_delegitimize_address_1): Don't delegitimize
	UNSPEC_GOTOFF with addend into addend - _GLOBAL_OFFSET_TABLE_ + symbol
	if !base_term_p.
	(ix86_const_not_ok_for_debug_p): New function.
	(i386_asm_output_addr_const_extra): Handle UNSPEC_GOTOFF.
	(TARGET_CONST_NOT_OK_FOR_DEBUG_P): Redefine.

	* g++.dg/guality/pr82630.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254025 138bc75d-0d04-0410-961f-82ee72b054a4

11 files changed, 142 insertions, 12 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8aa652dfd11..b9be7254ff7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,24 @@
+2017-10-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/82630
+	* target.def (const_not_ok_for_debug_p): Default to
+	default_const_not_ok_for_debug_p instead of hook_bool_rtx_false.
+	* targhooks.h (default_const_not_ok_for_debug_p): New declaration.
+	* targhooks.c (default_const_not_ok_for_debug_p): New function.
+	* dwarf2out.c (const_ok_for_output_1): Only reject UNSPECs for
+	which targetm.const_not_ok_for_debug_p returned true.
+	* config/arm/arm.c (arm_const_not_ok_for_debug_p): Return true
+	for UNSPECs.
+	* config/powerpcspe/powerpcspe.c (rs6000_const_not_ok_for_debug_p):
+	Likewise.
+	* config/rs6000/rs6000.c (rs6000_const_not_ok_for_debug_p): Likewise.
+	* config/i386/i386.c (ix86_delegitimize_address_1): Don't delegitimize
+	UNSPEC_GOTOFF with addend into addend - _GLOBAL_OFFSET_TABLE_ + symbol
+	if !base_term_p.
+	(ix86_const_not_ok_for_debug_p): New function.
+	(i386_asm_output_addr_const_extra): Handle UNSPEC_GOTOFF.
+	(TARGET_CONST_NOT_OK_FOR_DEBUG_P): Redefine.
+
 2017-10-23  David Malcolm  <dmalcolm@redhat.com>
 
 	PR bootstrap/82610
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 6f01021a351..22e169318ad 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -30391,6 +30391,8 @@ arm_const_not_ok_for_debug_p (rtx p)
   tree decl_op0 = NULL;
   tree decl_op1 = NULL;
 
+  if (GET_CODE (p) == UNSPEC)
+    return true;
   if (GET_CODE (p) == MINUS)
     {
       if (GET_CODE (XEXP (p, 1)) == SYMBOL_REF)
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 3fafcfe9613..72caf62bbf8 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -16840,13 +16840,17 @@ ix86_delegitimize_address_1 (rtx x, bool base_term_p)
 	 movl foo@GOTOFF(%ecx), %edx
 	 in which case we return (%ecx - %ebx) + foo
 	 or (%ecx - _GLOBAL_OFFSET_TABLE_) + foo if pseudo_pic_reg
-	 and reload has completed.  */
+	 and reload has completed.  Don't do the latter for debug,
+	 as _GLOBAL_OFFSET_TABLE_ can't be expressed in the assembly.  */
       if (pic_offset_table_rtx
 	  && (!reload_completed || !ix86_use_pseudo_pic_reg ()))
         result = gen_rtx_PLUS (Pmode, gen_rtx_MINUS (Pmode, copy_rtx (addend),
 						     pic_offset_table_rtx),
 			       result);
-      else if (pic_offset_table_rtx && !TARGET_MACHO && !TARGET_VXWORKS_RTP)
+      else if (base_term_p
+	       && pic_offset_table_rtx
+	       && !TARGET_MACHO
+	       && !TARGET_VXWORKS_RTP)
 	{
 	  rtx tmp = gen_rtx_SYMBOL_REF (Pmode, GOT_SYMBOL_NAME);
 	  tmp = gen_rtx_MINUS (Pmode, copy_rtx (addend), tmp);
@@ -16899,6 +16903,25 @@ ix86_find_base_term (rtx x)
 
   return ix86_delegitimize_address_1 (x, true);
 }
+
+/* Return true if X shouldn't be emitted into the debug info.
+   Disallow UNSPECs other than @gotoff - we can't emit _GLOBAL_OFFSET_TABLE_
+   symbol easily into the .debug_info section, so we need not to
+   delegitimize, but instead assemble as @gotoff.
+   Disallow _GLOBAL_OFFSET_TABLE_ SYMBOL_REF - the assembler magically
+   assembles that as _GLOBAL_OFFSET_TABLE_-. expression.  */
+
+static bool
+ix86_const_not_ok_for_debug_p (rtx x)
+{
+  if (GET_CODE (x) == UNSPEC && XINT (x, 1) != UNSPEC_GOTOFF)
+    return true;
+
+  if (SYMBOL_REF_P (x) && strcmp (XSTR (x, 0), GOT_SYMBOL_NAME) == 0)
+    return true;
+
+  return false;
+}
 
 static void
 put_condition_code (enum rtx_code code, machine_mode mode, bool reverse,
@@ -18217,6 +18240,10 @@ i386_asm_output_addr_const_extra (FILE *file, rtx x)
   op = XVECEXP (x, 0, 0);
   switch (XINT (x, 1))
     {
+    case UNSPEC_GOTOFF:
+      output_addr_const (file, op);
+      fputs ("@gotoff", file);
+      break;
     case UNSPEC_GOTTPOFF:
       output_addr_const (file, op);
       /* FIXME: This might be @TPOFF in Sun ld.  */
@@ -49827,6 +49854,9 @@ ix86_run_selftests (void)
 #undef TARGET_DELEGITIMIZE_ADDRESS
 #define TARGET_DELEGITIMIZE_ADDRESS ix86_delegitimize_address
 
+#undef TARGET_CONST_NOT_OK_FOR_DEBUG_P
+#define TARGET_CONST_NOT_OK_FOR_DEBUG_P ix86_const_not_ok_for_debug_p
+
 #undef TARGET_MS_BITFIELD_LAYOUT_P
 #define TARGET_MS_BITFIELD_LAYOUT_P ix86_ms_bitfield_layout_p
 
diff --git a/gcc/config/powerpcspe/powerpcspe.c b/gcc/config/powerpcspe/powerpcspe.c
index b39a8f8559f..b5fc656a8f1 100644
--- a/gcc/config/powerpcspe/powerpcspe.c
+++ b/gcc/config/powerpcspe/powerpcspe.c
@@ -9539,6 +9539,8 @@ rs6000_delegitimize_address (rtx orig_x)
 static bool
 rs6000_const_not_ok_for_debug_p (rtx x)
 {
+  if (GET_CODE (x) == UNSPEC)
+    return true;
   if (GET_CODE (x) == SYMBOL_REF
       && CONSTANT_POOL_ADDRESS_P (x))
     {
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 06713ad2b32..309541933cd 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -8988,6 +8988,8 @@ rs6000_delegitimize_address (rtx orig_x)
 static bool
 rs6000_const_not_ok_for_debug_p (rtx x)
 {
+  if (GET_CODE (x) == UNSPEC)
+    return true;
   if (GET_CODE (x) == SYMBOL_REF
       && CONSTANT_POOL_ADDRESS_P (x))
     {
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 81c95ece095..dcc624e6fe0 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -13740,9 +13740,17 @@ expansion_failed (tree expr, rtx rtl, char const *reason)
 static bool
 const_ok_for_output_1 (rtx rtl)
 {
-  if (GET_CODE (rtl) == UNSPEC)
+  if (targetm.const_not_ok_for_debug_p (rtl))
     {
-      /* If delegitimize_address couldn't do anything with the UNSPEC, assume
+      if (GET_CODE (rtl) != UNSPEC)
+	{
+	  expansion_failed (NULL_TREE, rtl,
+			    "Expression rejected for debug by the backend.\n");
+	  return false;
+	}
+
+      /* If delegitimize_address couldn't do anything with the UNSPEC, and
+	 the target hook doesn't explicitly allow it in debug info, assume
 	 we can't express it in the debug info.  */
       /* Don't complain about TLS UNSPECs, those are just too hard to
 	 delegitimize.  Note this could be a non-decl SYMBOL_REF such as
@@ -13769,13 +13777,6 @@ const_ok_for_output_1 (rtx rtl)
       return false;
     }
 
-  if (targetm.const_not_ok_for_debug_p (rtl))
-    {
-      expansion_failed (NULL_TREE, rtl,
-			"Expression rejected for debug by the backend.\n");
-      return false;
-    }
-
   /* FIXME: Refer to PR60655. It is possible for simplification
      of rtl expressions in var tracking to produce such expressions.
      We should really identify / validate expressions
diff --git a/gcc/target.def b/gcc/target.def
index b7dda5b5f2e..435849c3d35 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -2822,7 +2822,7 @@ DEFHOOK
  "This hook should return true if @var{x} should not be emitted into\n\
 debug sections.",
  bool, (rtx x),
- hook_bool_rtx_false)
+ default_const_not_ok_for_debug_p)
 
 /* Given an address RTX, say whether it is valid.  */
 DEFHOOK
diff --git a/gcc/targhooks.c b/gcc/targhooks.c
index ae2595113f8..41cab3825df 100644
--- a/gcc/targhooks.c
+++ b/gcc/targhooks.c
@@ -177,6 +177,14 @@ default_legitimize_address_displacement (rtx *disp ATTRIBUTE_UNUSED,
   return false;
 }
 
+bool
+default_const_not_ok_for_debug_p (rtx x)
+{
+  if (GET_CODE (x) == UNSPEC)
+    return true;
+  return false;
+}
+
 rtx
 default_expand_builtin_saveregs (void)
 {
diff --git a/gcc/targhooks.h b/gcc/targhooks.h
index db1a087942a..1510bb97a9c 100644
--- a/gcc/targhooks.h
+++ b/gcc/targhooks.h
@@ -26,6 +26,7 @@ extern void default_external_libcall (rtx);
 extern rtx default_legitimize_address (rtx, rtx, machine_mode);
 extern bool default_legitimize_address_displacement (rtx *, rtx *,
 						     machine_mode);
+extern bool default_const_not_ok_for_debug_p (rtx);
 
 extern int default_unspec_may_trap_p (const_rtx, unsigned);
 extern machine_mode default_promote_function_mode (const_tree, machine_mode,
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0e3a0e3867d..f6fd200329a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/82630
+	* g++.dg/guality/pr82630.C: New test.
+
 2017-10-23  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/82662
diff --git a/gcc/testsuite/g++.dg/guality/pr82630.C b/gcc/testsuite/g++.dg/guality/pr82630.C
new file mode 100644
index 00000000000..71d11acf5e2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/guality/pr82630.C
@@ -0,0 +1,58 @@
+// PR debug/82630
+// { dg-do run }
+// { dg-additional-options "-fPIC" { target fpic } }
+
+struct C
+{
+  int &c;
+  long d;
+  __attribute__((always_inline)) C (int &x) : c(x), d() {}
+};
+int v;
+
+__attribute__((noipa)) void
+fn1 (const void *x)
+{
+  asm volatile ("" : : "g" (x) : "memory");
+}
+
+__attribute__((noipa)) void
+fn2 (C x)
+{
+  int a = x.c + x.d;
+  asm volatile ("" : : "g" (a) : "memory");
+}
+
+__attribute__((noipa)) void
+fn3 (void)
+{
+  asm volatile ("" : : : "memory");
+}
+
+__attribute__((noipa))
+#ifdef __i386__
+__attribute__((regparm (2)))
+#endif
+static void
+fn4 (int *x, const char *y, C z)
+{
+  fn2 (C (*x));
+  fn1 ("baz");
+  fn2 (z);	// { dg-final { gdb-test 41 "y\[0\]" "'f'" } }
+  fn1 ("baz");	// { dg-final { gdb-test 41 "y\[1\]" "'o'" } }
+}
+
+__attribute__((noipa)) void
+fn5 (int *x)
+{
+  fn4 (x, "foo", C (*x));
+  fn3 ();
+}
+
+int
+main ()
+{
+  int a = 10;
+  fn5 (&a);
+  return 0;
+}