diff options
Diffstat (limited to 'bfd/linker.c')
| -rw-r--r-- | bfd/linker.c | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/bfd/linker.c b/bfd/linker.c index 76bc70a..fc52b51 100644 --- a/bfd/linker.c +++ b/bfd/linker.c @@ -223,7 +223,10 @@ SUBSUBSECTION archive and decide which elements of the archive should be included in the link. For each such element it must call the <<add_archive_element>> linker callback, and it must add the - symbols from the object file to the linker hash table. + symbols from the object file to the linker hash table. (The + callback may in fact indicate that a replacement BFD should be + used, in which case the symbols from that BFD should be added + to the linker hash table instead.) @findex _bfd_generic_link_add_archive_symbols In most cases the work of looking through the symbols in the @@ -243,9 +246,13 @@ SUBSUBSECTION element should be included in the link. If the element is to be included, the <<add_archive_element>> linker callback routine must be called with the element as an argument, and - the elements symbols must be added to the linker hash table + the element's symbols must be added to the linker hash table just as though the element had itself been passed to the - <<_bfd_link_add_symbols>> function. + <<_bfd_link_add_symbols>> function. The <<add_archive_element>> + callback has the option to indicate that it would like to + replace the element archive with a substitute BFD, in which + case it is the symbols of that substitute BFD that must be + added to the linker hash table instead. When the a.out <<_bfd_link_add_symbols>> function receives an archive, it calls <<_bfd_generic_link_add_archive_symbols>> @@ -257,7 +264,8 @@ SUBSUBSECTION symbol) it calls the <<add_archive_element>> callback and then <<aout_link_check_archive_element>> calls <<aout_link_add_symbols>> to actually add the symbols to the - linker hash table. + linker hash table - possibly those of a substitute BFD, if the + <<add_archive_element>> callback avails itself of that option. The ECOFF back end is unusual in that it does not normally call <<_bfd_generic_link_add_archive_symbols>>, because ECOFF @@ -957,8 +965,10 @@ archive_hash_table_init included. CHECKFN should set *PNEEDED to TRUE if the object file should be included, and must also call the bfd_link_info add_archive_element callback function and handle adding the symbols - to the global hash table. CHECKFN should only return FALSE if some - sort of error occurs. + to the global hash table. CHECKFN must notice if the callback + indicates a substitute BFD, and arrange to add those symbols instead + if it does so. CHECKFN should only return FALSE if some sort of + error occurs. For some formats, such as a.out, it is possible to look through an object file but not actually include it in the link. The @@ -1213,11 +1223,20 @@ generic_link_check_archive_element (bfd *abfd, { bfd_size_type symcount; asymbol **symbols; + bfd *subsbfd = NULL; /* This object file defines this symbol, so pull it in. */ - if (! (*info->callbacks->add_archive_element) (info, abfd, - bfd_asymbol_name (p))) + if (! (*info->callbacks->add_archive_element) + (info, abfd, bfd_asymbol_name (p), &subsbfd)) return FALSE; + /* Potentially, the add_archive_element hook may have set a + substitute BFD for us. */ + if (subsbfd) + { + abfd = subsbfd; + if (!bfd_generic_link_read_symbols (abfd)) + return FALSE; + } symcount = _bfd_generic_link_get_symcount (abfd); symbols = _bfd_generic_link_get_symbols (abfd); if (! generic_link_add_symbol_list (abfd, info, symcount, @@ -1238,12 +1257,16 @@ generic_link_check_archive_element (bfd *abfd, symbfd = h->u.undef.abfd; if (symbfd == NULL) { + bfd *subsbfd = NULL; /* This symbol was created as undefined from outside BFD. We assume that we should link in the object file. This is for the -u option in the linker. */ if (! (*info->callbacks->add_archive_element) - (info, abfd, bfd_asymbol_name (p))) + (info, abfd, bfd_asymbol_name (p), &subsbfd)) return FALSE; + /* Potentially, the add_archive_element hook may have set a + substitute BFD for us. But no symbols are going to get + registered by anything we're returning to from here. */ *pneeded = TRUE; return TRUE; } |