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authorIan Lance Taylor <ian@airs.com>1999-09-13 23:55:22 +0000
committerIan Lance Taylor <ian@airs.com>1999-09-13 23:55:22 +0000
commite5db213db23d45650b7769226b1c27f07a36d6d5 (patch)
treec10a8967fa16e0485d3ea7a63b246002489471eb /bfd/coffcode.h
parent361d94e76821d32498bb1e3d3848b5bae0654ae3 (diff)
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1999-09-13 Donn Terry <donn@interix.com>
* coffcode.h (styp_to_sec_flags): Further refinement of COMDAT handling to support both GNU and MS objects.
Diffstat (limited to 'bfd/coffcode.h')
-rw-r--r--bfd/coffcode.h268
1 files changed, 176 insertions, 92 deletions
diff --git a/bfd/coffcode.h b/bfd/coffcode.h
index 1c52be5..cd23697 100644
--- a/bfd/coffcode.h
+++ b/bfd/coffcode.h
@@ -759,6 +759,8 @@ styp_to_sec_flags (abfd, hdr, name, section)
if (_bfd_coff_get_external_symbols (abfd))
{
bfd_byte *esymstart, *esym, *esymend;
+ int seen_state = 0;
+ char *target_name;
esymstart = esym = (bfd_byte *) obj_coff_external_syms (abfd);
esymend = esym + obj_raw_syment_count (abfd) * SYMESZ;
@@ -778,122 +780,204 @@ styp_to_sec_flags (abfd, hdr, name, section)
abort ();
}
- /* The MS documentation is vague, but it appears to
- require that n_sclass be C_STAT for both entries;
- However, the Alpha compiler uses C_EXT for the one
- with the "real" name, at least for string-pooled
- constants. */
- if (isym.n_scnum == section->target_index
- && (isym.n_sclass == C_STAT || isym.n_sclass == C_EXT)
- && isym.n_type == T_NULL
- && isym.n_value == 0)
+ if (isym.n_scnum == section->target_index)
{
- /* The first TWO entries with the section # are both
- of interest to us. The first one is the "section
+ /* According to the MSVC documentation, the first
+ TWO entries with the section # are both of
+ interest to us. The first one is the "section
symbol" (section name). The second is the comdat
- symbol name. 'value' must be zero for it to
- apply. Here, we've found a qualifying entry; we
- distinguish the first from the second by numaux
- (which should be 0 for the second). FIXME: We
- should use the first one first rather than
- counting on numaux. */
- if (isym.n_numaux == 1)
- {
- union internal_auxent aux;
+ symbol name. Here, we've found the first
+ qualifying entry; we distinguish it from the
+ second with a state flag.
- symname = _bfd_coff_internal_syment_name (abfd, &isym,
- buf);
- if (symname == NULL)
- abort ();
+ In the case of gas-generated (at least until that
+ is fixed) .o files, it isn't necessarily the
+ second one. It may be some other later symbol.
- if (strcmp (name, symname) != 0)
- abort ();
+ Since gas also doesn't follow MS conventions and
+ emits the section similar to .text$<name>, where
+ <something> is the name we're looking for, we
+ distinguish the two as follows:
- /* This is the section symbol. */
+ If the section name is simply a section name (no
+ $) we presume it's MS-generated, and look at
+ precisely the second symbol for the comdat name.
+ If the section name has a $, we assume it's
+ gas-generated, and look for <something> (whatever
+ follows the $) as the comdat symbol. */
- bfd_coff_swap_aux_in (abfd, (PTR) (esym + SYMESZ),
- isym.n_type, isym.n_sclass,
- 0, isym.n_numaux, (PTR) &aux);
+ /* All 3 branches use this */
+ symname = _bfd_coff_internal_syment_name (abfd, &isym, buf);
- /* FIXME: Microsoft uses NODUPLICATES and
- ASSOCIATIVE, but gnu uses ANY and SAME_SIZE.
- Unfortunately, gnu doesn't do the comdat
- symbols right. So, until we can fix it to do
- the right thing, we are temporarily disabling
- comdats for the MS types (they're used in
- DLLs and C++, but we don't support *their*
- C++ libraries anyway - DJ. */
+ if (symname == NULL)
+ abort ();
- switch (aux.x_scn.x_comdat)
- {
- case IMAGE_COMDAT_SELECT_NODUPLICATES:
-#ifdef STRICT_PE_FORMAT
- sec_flags |= SEC_LINK_DUPLICATES_ONE_ONLY;
+ switch (seen_state)
+ {
+ case 0:
+ {
+ /* The first time we've seen the symbol. */
+ union internal_auxent aux;
+
+ seen_state = 1;
+
+ /* If it isn't the stuff we're expecting, die;
+ The MS documentation is vague, but it
+ appears that the second entry serves BOTH
+ as the comdat symbol and the defining
+ symbol record (either C_STAT or C_EXT,
+ possibly with an aux entry with debug
+ information if it's a function.) It
+ appears the only way to find the second one
+ is to count. (On Intel, they appear to be
+ adjacent, but on Alpha, they have been
+ found separated.)
+
+ Here, we think we've found the first one,
+ but there's some checking we can do to be
+ sure. */
+
+ if (! (isym.n_sclass == C_STAT
+ && isym.n_type == T_NULL
+ && isym.n_value == 0))
+ abort ();
+
+ /* FIXME LATER: MSVC generates section names
+ like .text for comdats. Gas generates
+ names like .text$foo__Fv (in the case of a
+ function). See comment above for more. */
+
+ if (strcmp (name, symname) != 0)
+ abort ();
+
+ /* This is the section symbol. */
+
+ bfd_coff_swap_aux_in (abfd, (PTR) (esym + SYMESZ),
+ isym.n_type, isym.n_sclass,
+ 0, isym.n_numaux, (PTR) &aux);
+
+ target_name = strchr (name, '$');
+ if (target_name != NULL)
+ {
+ /* Gas mode. */
+ seen_state = 2;
+ /* Skip the `$'. */
+ target_name += 1;
+ }
+
+ /* FIXME: Microsoft uses NODUPLICATES and
+ ASSOCIATIVE, but gnu uses ANY and
+ SAME_SIZE. Unfortunately, gnu doesn't do
+ the comdat symbols right. So, until we can
+ fix it to do the right thing, we are
+ temporarily disabling comdats for the MS
+ types (they're used in DLLs and C++, but we
+ don't support *their* C++ libraries anyway
+ - DJ. */
+
+ /* Cygwin does not follow the MS style, and
+ uses ANY and SAME_SIZE where NODUPLICATES
+ and ASSOCIATIVE should be used. For
+ Interix, we just do the right thing up
+ front. */
+
+ switch (aux.x_scn.x_comdat)
+ {
+ case IMAGE_COMDAT_SELECT_NODUPLICATES:
+#ifdef STRICT_PE_FORMAT
+ sec_flags |= SEC_LINK_DUPLICATES_ONE_ONLY;
#else
- sec_flags &= ~SEC_LINK_ONCE;
+ sec_flags &= ~SEC_LINK_ONCE;
#endif
- break;
+ break;
+
+ case IMAGE_COMDAT_SELECT_ANY:
+ sec_flags |= SEC_LINK_DUPLICATES_DISCARD;
+ break;
- case IMAGE_COMDAT_SELECT_ANY:
- sec_flags |= SEC_LINK_DUPLICATES_DISCARD;
- break;
+ case IMAGE_COMDAT_SELECT_SAME_SIZE:
+ sec_flags |= SEC_LINK_DUPLICATES_SAME_SIZE;
+ break;
- case IMAGE_COMDAT_SELECT_SAME_SIZE:
- sec_flags |= SEC_LINK_DUPLICATES_SAME_SIZE;
- break;
+ case IMAGE_COMDAT_SELECT_EXACT_MATCH:
+ /* Not yet fully implemented ??? */
+ sec_flags |= SEC_LINK_DUPLICATES_SAME_CONTENTS;
+ break;
- case IMAGE_COMDAT_SELECT_EXACT_MATCH:
- /* Not yet fully implemented in the linker. */
- sec_flags |= SEC_LINK_DUPLICATES_SAME_CONTENTS;
- break;
+ /* debug$S gets this case; other
+ implications ??? */
- case IMAGE_COMDAT_SELECT_ASSOCIATIVE:
+ /* There may be no symbol... we'll search
+ the whole table... Is this the right
+ place to play this game? Or should we do
+ it when reading it in. */
+ case IMAGE_COMDAT_SELECT_ASSOCIATIVE:
#ifdef STRICT_PE_FORMAT
- /* FIXME: This is not currently implemented. */
- sec_flags |= SEC_LINK_DUPLICATES_DISCARD;
+ /* FIXME: This is not currently implemented. */
+ sec_flags |= SEC_LINK_DUPLICATES_DISCARD;
#else
- sec_flags &= ~SEC_LINK_ONCE;
+ sec_flags &= ~SEC_LINK_ONCE;
#endif
- break;
-
- default:
- /* FIXME: Shouldn't this be at least a
- warning? */
- sec_flags |= SEC_LINK_DUPLICATES_DISCARD;
- break;
- }
- }
- else
- {
- char *newname;
-
- /* This should be the the second symbol with the
- section #. It is the actual symbol name.
- Intel puts the two adjacent, but Alpha (at
- least) spreads them out. */
-
- section->comdat =
- bfd_alloc (abfd, sizeof (struct bfd_comdat_info));
- if (section->comdat == NULL)
- abort ();
- section->comdat->symbol = (esym - esymstart) / SYMESZ;
- symname = _bfd_coff_internal_syment_name (abfd, &isym,
- buf);
- if (symname == NULL)
- abort ();
-
- newname = bfd_alloc (abfd, strlen (symname) + 1);
- if (newname == NULL)
- abort ();
- strcpy (newname, symname);
- section->comdat->name = newname;
+ break;
+ default: /* 0 means "no symbol" */
+ /* debug$F gets this case; other
+ implications ??? */
+ sec_flags |= SEC_LINK_DUPLICATES_DISCARD;
+ break;
+ }
+ }
break;
+
+ case 2:
+ /* Gas mode: the first matching on partial name. */
+
+#ifndef TARGET_UNDERSCORE
+#define TARGET_UNDERSCORE 0
+#endif
+ /* Is this the name we're looking for? */
+ if (strcmp (target_name,
+ symname + (TARGET_UNDERSCORE ? 1 : 0)) != 0)
+ {
+ /* Not the name we're looking for */
+ esym += (isym.n_numaux + 1) * SYMESZ;
+ continue;
+ }
+ /* Fall through. */
+ case 1:
+ /* MSVC mode: the lexically second symbol (or
+ drop through from the above). */
+ {
+ char *newname;
+
+ /* This must the the second symbol with the
+ section #. It is the actual symbol name.
+ Intel puts the two adjacent, but Alpha (at
+ least) spreads them out. */
+
+ section->comdat =
+ bfd_alloc (abfd, sizeof (struct bfd_comdat_info));
+ if (section->comdat == NULL)
+ abort ();
+ section->comdat->symbol =
+ (esym - esymstart) / SYMESZ;
+
+ newname = bfd_alloc (abfd, strlen (symname) + 1);
+ if (newname == NULL)
+ abort ();
+
+ strcpy (newname, symname);
+ section->comdat->name = newname;
+
+ }
+
+ goto breakloop;
}
}
esym += (isym.n_numaux + 1) * SYMESZ;
}
+ breakloop:
}
}