This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[PATCH][2/n] Change dw2_asm_output_offset to allow assembling extra offset


This is needed so that we can output references to $early-debug-symbol + 
constant offset where $early-debug-symbol is the beginning of a 
.debug_info section containing early debug info from the compile-stage.
Constant offsets are always fine for any object formats I know, I
tested ia64-linux apart from x86_64-linux.  I have access to darwin at
home (x86_64), so can try there as well.

The question is whether we want to assemble "+" HOST_WIDE_INT_PRINT_DEC
directly for the non-ASM_OUTPUT_DWARF_OFFSET case as well as opposed
to building a PLUS (we do build a SYMBOL_REF already).

I've also refrained from changing all existing callers to
dw2_asm_output_offset to pass a 0 offset argument to avoid the
overloading - please tell me if you prefer that.  The LTO support
adds a single call here:

@@ -9064,8 +9248,12 @@ output_die (dw_die_ref die)
                    size = DWARF2_ADDR_SIZE;
                  else
                    size = DWARF_OFFSET_SIZE;
-                 dw2_asm_output_offset (size, sym, debug_info_section, 
"%s",
-                                        name);
+                 if (AT_ref (a)->with_offset)
+                   dw2_asm_output_offset (size, sym, AT_ref 
(a)->die_offset,
+                                          debug_info_section, "%s", 
name);
+                 else
+                   dw2_asm_output_offset (size, sym, debug_info_section, 
"%s",
+                                          name);
                }

(ignore that ->with_offset, it can hopefully go if die_offset is zero
for other cases - just checking with an assert right now).

Bootstrap & regtest pending on x86_64-unknown-linux-gnu.  The patch
is an effective no-op currently (the offset != 0 condition is always
false for now).

Ok?

CCing affected target maintainers - I've verified this on ia64
by just generating assembly for a simple testcase with -g and
changing one of the generated section-relative offsets in the
suggested way (adding "+4"), passing through the assembler and
inspecting the resulting relocations.

Thanks,
Richard.

2015-08-19  Richard Biener  <rguenther@suse.de>

	* dwarf2asm.h (dw2_asm_output_offset): Add overload with
	extra offset argument.
	* dwarf2asm.c (dw2_asm_output_offset): Implement that.
	* doc/tm.texi.in (ASM_OUTPUT_DWARF_OFFSET): Adjust documentation
	to reflect new offset parameter.
	* doc/tm.texi: Regenerate.
	* config/darwin.h (ASM_OUTPUT_DWARF_OFFSET): Adjust.
	* config/darwin-protos.h (darwin_asm_output_dwarf_delta): Add
	offset argument.
	(darwin_asm_output_dwarf_offset): Likewise.
	* config/darwin.c (darwin_asm_output_dwarf_delta): Add offset
	argument.
	(darwin_asm_output_dwarf_offset): Pass offset argument through.
	* config/ia64/ia64.h (ASM_OUTPUT_DWARF_OFFSET): Adjust.
	* config/i386/cygmin.h (ASM_OUTPUT_DWARF_OFFSET): Likewise.

Index: gcc/dwarf2asm.c
===================================================================
--- gcc/dwarf2asm.c	(revision 226856)
+++ gcc/dwarf2asm.c	(working copy)
@@ -33,6 +33,8 @@ along with GCC; see the file COPYING3.
 #include "dwarf2asm.h"
 #include "dwarf2.h"
 #include "tm_p.h"
+#include "function.h"
+#include "emit-rtl.h"
 
 
 /* Output an unaligned integer with the given value and size.  Prefer not
@@ -190,12 +192,39 @@ dw2_asm_output_offset (int size, const c
   va_start (ap, comment);
 
 #ifdef ASM_OUTPUT_DWARF_OFFSET
-  ASM_OUTPUT_DWARF_OFFSET (asm_out_file, size, label, base);
+  ASM_OUTPUT_DWARF_OFFSET (asm_out_file, size, label, 0, base);
 #else
   dw2_assemble_integer (size, gen_rtx_SYMBOL_REF (Pmode, label));
 #endif
 
   if (flag_debug_asm && comment)
+    {
+      fprintf (asm_out_file, "\t%s ", ASM_COMMENT_START);
+      vfprintf (asm_out_file, comment, ap);
+    }
+  fputc ('\n', asm_out_file);
+
+  va_end (ap);
+}
+
+void
+dw2_asm_output_offset (int size, const char *label, HOST_WIDE_INT offset,
+		       section *base ATTRIBUTE_UNUSED,
+		       const char *comment, ...)
+{
+  va_list ap;
+
+  va_start (ap, comment);
+
+#ifdef ASM_OUTPUT_DWARF_OFFSET
+  ASM_OUTPUT_DWARF_OFFSET (asm_out_file, size, label, offset, base);
+#else
+  dw2_assemble_integer (size, gen_rtx_PLUS (Pmode,
+					    gen_rtx_SYMBOL_REF (Pmode, label),
+					    gen_int_mode (offset, Pmode)));
+#endif
+
+  if (flag_debug_asm && comment)
     {
       fprintf (asm_out_file, "\t%s ", ASM_COMMENT_START);
       vfprintf (asm_out_file, comment, ap);
Index: gcc/dwarf2asm.h
===================================================================
--- gcc/dwarf2asm.h	(revision 226856)
+++ gcc/dwarf2asm.h	(working copy)
@@ -40,6 +40,10 @@ extern void dw2_asm_output_offset (int,
 				   const char *, ...)
      ATTRIBUTE_NULL_PRINTF_4;
 
+extern void dw2_asm_output_offset (int, const char *, HOST_WIDE_INT,
+				   section *, const char *, ...)
+     ATTRIBUTE_NULL_PRINTF_5;
+
 extern void dw2_asm_output_addr (int, const char *, const char *, ...)
      ATTRIBUTE_NULL_PRINTF_3;
 
Index: gcc/doc/tm.texi.in
===================================================================
--- gcc/doc/tm.texi.in	(revision 226856)
+++ gcc/doc/tm.texi.in	(working copy)
@@ -7020,10 +7020,11 @@ between the two given labels in system d
 slots on IA64 VMS, using an integer of the given size.
 @end defmac
 
-@defmac ASM_OUTPUT_DWARF_OFFSET (@var{stream}, @var{size}, @var{label}, @var{section})
+@defmac ASM_OUTPUT_DWARF_OFFSET (@var{stream}, @var{size}, @var{label}, @var{offset}, @var{section})
 A C statement to issue assembly directives that create a
-section-relative reference to the given @var{label}, using an integer of the
-given @var{size}.  The label is known to be defined in the given @var{section}.
+section-relative reference to the given @var{label} plus @var{offset}, using
+an integer of the given @var{size}.  The label is known to be defined in the
+given @var{section}.
 @end defmac
 
 @defmac ASM_OUTPUT_DWARF_PCREL (@var{stream}, @var{size}, @var{label})
Index: gcc/config/darwin-protos.h
===================================================================
--- gcc/config/darwin-protos.h	(revision 226856)
+++ gcc/config/darwin-protos.h	(working copy)
@@ -91,9 +91,9 @@ extern void darwin_globalize_label (FILE
 extern void darwin_assemble_visibility (tree, int);
 
 extern void darwin_asm_output_dwarf_delta (FILE *, int, const char *,
-					   const char *);
+					   const char *, HOST_WIDE_INT);
 extern void darwin_asm_output_dwarf_offset (FILE *, int, const char *,
-					    section *);
+					    HOST_WIDE_INT, section *);
 
 extern void darwin_asm_declare_object_name (FILE *, const char *, tree);
 extern void darwin_asm_declare_constant_name (FILE *, const char *,
Index: gcc/config/darwin.c
===================================================================
--- gcc/config/darwin.c	(revision 226856)
+++ gcc/config/darwin.c	(working copy)
@@ -2814,7 +2814,8 @@ static int darwin_dwarf_label_counter;
 
 void
 darwin_asm_output_dwarf_delta (FILE *file, int size,
-			       const char *lab1, const char *lab2)
+			       const char *lab1, const char *lab2,
+			       HOST_WIDE_INT offset)
 {
   int islocaldiff = (lab1[0] == '*' && lab1[1] == 'L'
 		     && lab2[0] == '*' && lab2[1] == 'L');
@@ -2828,6 +2829,8 @@ darwin_asm_output_dwarf_delta (FILE *fil
   assemble_name_raw (file, lab1);
   fprintf (file, "-");
   assemble_name_raw (file, lab2);
+  if (offset != 0)
+    fprintf (file, "+" HOST_WIDE_INT_PRINT_DEC, offset);
   if (islocaldiff)
     fprintf (file, "\n\t%s L$set$%d", directive, darwin_dwarf_label_counter++);
 }
@@ -2839,7 +2842,7 @@ darwin_asm_output_dwarf_delta (FILE *fil
 
 void
 darwin_asm_output_dwarf_offset (FILE *file, int size, const char * lab,
-				section *base)
+				HOST_WIDE_INT offset, section *base)
 {
   char sname[64];
   int namelen;
@@ -2850,7 +2853,7 @@ darwin_asm_output_dwarf_offset (FILE *fi
 
   namelen = strchr (base->named.name + 8, ',') - (base->named.name + 8);
   sprintf (sname, "*Lsection%.*s", namelen, base->named.name + 8);
-  darwin_asm_output_dwarf_delta (file, size, lab, sname);
+  darwin_asm_output_dwarf_delta (file, size, lab, sname, offset);
 }
 
 /* Called from the within the TARGET_ASM_FILE_START for each target.  */
Index: gcc/config/darwin.h
===================================================================
--- gcc/config/darwin.h	(revision 226856)
+++ gcc/config/darwin.h	(working copy)
@@ -826,10 +826,10 @@ enum machopic_addr_class {
      ((CODE) == 1 || (GLOBAL) == 0) ? DW_EH_PE_pcrel : DW_EH_PE_absptr)
 
 #define ASM_OUTPUT_DWARF_DELTA(FILE,SIZE,LABEL1,LABEL2)  \
-  darwin_asm_output_dwarf_delta (FILE, SIZE, LABEL1, LABEL2)
+  darwin_asm_output_dwarf_delta (FILE, SIZE, LABEL1, LABEL2, 0)
 
-#define ASM_OUTPUT_DWARF_OFFSET(FILE,SIZE,LABEL,BASE)  \
-  darwin_asm_output_dwarf_offset (FILE, SIZE, LABEL, BASE)
+#define ASM_OUTPUT_DWARF_OFFSET(FILE,SIZE,LABEL,OFFSET,BASE)  \
+  darwin_asm_output_dwarf_offset (FILE, SIZE, LABEL, OFFSET, BASE)
 
 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(ASM_OUT_FILE, ENCODING, SIZE, ADDR, DONE)	\
       if (ENCODING == ASM_PREFERRED_EH_DATA_FORMAT (2, 1)) {				\
Index: gcc/config/ia64/ia64.h
===================================================================
--- gcc/config/ia64/ia64.h	(revision 226856)
+++ gcc/config/ia64/ia64.h	(working copy)
@@ -1583,11 +1583,13 @@ do {									\
 /* Use section-relative relocations for debugging offsets.  Unlike other
    targets that fake this by putting the section VMA at 0, IA-64 has
    proper relocations for them.  */
-#define ASM_OUTPUT_DWARF_OFFSET(FILE, SIZE, LABEL, SECTION)	\
+#define ASM_OUTPUT_DWARF_OFFSET(FILE, SIZE, LABEL, OFFSET, SECTION) \
   do {								\
     fputs (integer_asm_op (SIZE, FALSE), FILE);			\
     fputs ("@secrel(", FILE);					\
     assemble_name (FILE, LABEL);				\
+    if (offset != 0)						\
+      fprintf (FILE, "+" HOST_WIDE_INT_PRINT_DEC, OFFSET);	\
     fputc (')', FILE);						\
   } while (0)
 
Index: gcc/config/i386/cygming.h
===================================================================
--- gcc/config/i386/cygming.h	(revision 226856)
+++ gcc/config/i386/cygming.h	(working copy)
@@ -97,13 +97,15 @@ along with GCC; see the file COPYING3.
 /* Use section relative relocations for debugging offsets.  Unlike
    other targets that fake this by putting the section VMA at 0, PE
    won't allow it.  */
-#define ASM_OUTPUT_DWARF_OFFSET(FILE, SIZE, LABEL, SECTION)	\
+#define ASM_OUTPUT_DWARF_OFFSET(FILE, SIZE, LABEL, OFFSET, SECTION) \
   do {								\
     switch (SIZE)						\
       {								\
       case 4:							\
 	fputs ("\t.secrel32\t", FILE);				\
 	assemble_name (FILE, LABEL);				\
+	if (offset != 0)					\
+	  fprintf (FILE, "+" HOST_WIDE_INT_PRINT_DEC, offset)	\
 	break;							\
       case 8:							\
 	/* This is a hack.  There is no 64-bit section relative	\
@@ -113,6 +115,8 @@ along with GCC; see the file COPYING3.
 	   Fake the 64-bit offset by zero-extending it.  */	\
 	fputs ("\t.secrel32\t", FILE);				\
 	assemble_name (FILE, LABEL);				\
+	if (offset != 0)					\
+	  fprintf (FILE, "+" HOST_WIDE_INT_PRINT_DEC, offset)	\
 	fputs ("\n\t.long\t0", FILE);				\
 	break;							\
       default:							\


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]