On Wed, Aug 19, 2015 at 4:25 PM, Richard Biener <rguent...@suse.de> wrote:
>
> 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.
Given no further comments and my plan to go ahead with the early LTO debug
merge I am currently re-testing this nicely split out part and plan to commit it
once that succeeded. This makes life a lot easier when testing the remains
as the tm.texi dance vanishes.
Richard.
> Thanks,
> Richard.
>
> 2015-08-19 Richard Biener <rguent...@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: \
