From e5db213db23d45650b7769226b1c27f07a36d6d5 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Mon, 13 Sep 1999 23:55:22 +0000 Subject: [PATCH] 1999-09-13 Donn Terry * coffcode.h (styp_to_sec_flags): Further refinement of COMDAT handling to support both GNU and MS objects. --- bfd/ChangeLog | 3 + bfd/coffcode.h | 268 ++++++++++++++++++++++++++++++++----------------- 2 files changed, 179 insertions(+), 92 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 5c1a366d265..95657f67dac 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,5 +1,8 @@ 1999-09-13 Donn Terry + * coffcode.h (styp_to_sec_flags): Further refinement of COMDAT + handling to support both GNU and MS objects. + * coffcode.h (coff_write_object_contents): Don't check reloc_count when determining whether to set F_RELFLG. diff --git a/bfd/coffcode.h b/bfd/coffcode.h index 1c52be596c4..cd236973d51 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$, where + 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 (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: } } -- 2.30.2