diff options
Diffstat (limited to 'gdb/mipsread.c')
| -rw-r--r-- | gdb/mipsread.c | 311 |
1 files changed, 308 insertions, 3 deletions
diff --git a/gdb/mipsread.c b/gdb/mipsread.c index e47b251..9a90dd1 100644 --- a/gdb/mipsread.c +++ b/gdb/mipsread.c @@ -1,6 +1,6 @@ /* Read a symbol table in MIPS' format (Third-Eye). - Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993 Free Software - Foundation, Inc. + Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994 + Free Software Foundation, Inc. Contributed by Alessandro Forin (af@cs.cmu.edu) at CMU. Major work by Per Bothner, John Gilmore and Ian Lance Taylor at Cygnus Support. @@ -24,6 +24,8 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ mdebugread.c. */ #include "defs.h" +#include <string.h> +#include "bfd.h" #include "symtab.h" #include "symfile.h" #include "objfiles.h" @@ -31,10 +33,13 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "stabsread.h" #include "gdb-stabs.h" +#include "coff/sym.h" #include "coff/internal.h" #include "coff/ecoff.h" #include "libcoff.h" /* Private BFD COFF information. */ #include "libecoff.h" /* Private BFD ECOFF information. */ +#include "elf/common.h" +#include "elf/mips.h" static void mipscoff_new_init PARAMS ((struct objfile *)); @@ -52,6 +57,10 @@ mipscoff_symfile_finish PARAMS ((struct objfile *)); static struct section_offsets * mipscoff_symfile_offsets PARAMS ((struct objfile *, CORE_ADDR)); +static void +read_alphacoff_dynamic_symtab PARAMS ((struct section_offsets *, + struct objfile *objfile)); + /* Initialize anything that needs initializing when a completely new symbol file is specified (not just adding some symbols from another file, e.g. a shared library). */ @@ -93,11 +102,23 @@ mipscoff_symfile_read (objfile, section_offsets, mainline) process it and define symbols accordingly. */ if (ecoff_slurp_symbolic_info (abfd) == false) - error ("Error reading symbol table: %s", bfd_errmsg (bfd_error)); + error ("Error reading symbol table: %s", bfd_errmsg (bfd_get_error ())); mdebug_build_psymtabs (objfile, &ecoff_backend (abfd)->debug_swap, &ecoff_data (abfd)->debug_info, section_offsets); + /* Add the dynamic symbols if we are reading the main symbol table. */ + + if (mainline) + read_alphacoff_dynamic_symtab (section_offsets, objfile); + + if (!have_partial_symbols ()) + { + wrap_here (""); + printf_filtered ("(no debugging symbols found)..."); + wrap_here (""); + } + /* Install any minimal symbols that have been collected as the current minimal symbols for this objfile. */ @@ -138,6 +159,290 @@ mipscoff_symfile_offsets (objfile, addr) return section_offsets; } +/* Alpha OSF/1 encapsulates the dynamic symbols in ELF format in a + standard coff section. The ELF format for the symbols differs from + the format defined in elf/external.h. It seems that a normal ELF 32 bit + format is used, and the representation only changes because longs are + 64 bit on the alpha. In addition, the handling of text/data section + indices for symbols is different from the ELF ABI. + As the BFD linker currently does not support dynamic linking on the alpha, + there seems to be no reason to pollute BFD with another mixture of object + file formats for now. */ + +/* Format of an alpha external ELF symbol. */ + +typedef struct { + unsigned char st_name[4]; /* Symbol name, index in string tbl */ + unsigned char st_pad[4]; /* Pad to long word boundary */ + unsigned char st_value[8]; /* Value of the symbol */ + unsigned char st_size[4]; /* Associated symbol size */ + unsigned char st_info[1]; /* Type and binding attributes */ + unsigned char st_other[1]; /* No defined meaning, 0 */ + unsigned char st_shndx[2]; /* Associated section index */ +} Elfalpha_External_Sym; + +/* Format of an alpha external ELF dynamic info structure. */ + +typedef struct { + unsigned char d_tag[4]; /* Tag */ + unsigned char d_pad[4]; /* Pad to long word boundary */ + union { + unsigned char d_ptr[8]; /* Pointer value */ + unsigned char d_val[4]; /* Integer value */ + } d_un; +} Elfalpha_External_Dyn; + +/* Struct to obtain the section pointers for alpha dynamic symbol info. */ + +struct alphacoff_dynsecinfo { + asection *sym_sect; /* Section pointer for .dynsym section */ + asection *str_sect; /* Section pointer for .dynstr section */ + asection *dyninfo_sect; /* Section pointer for .dynamic section */ + asection *got_sect; /* Section pointer for .got section */ +}; + +static void +alphacoff_locate_sections PARAMS ((bfd *, asection *, void *)); + +/* We are called once per section from read_alphacoff_dynamic_symtab. + We need to examine each section we are passed, check to see + if it is something we are interested in processing, and + if so, stash away some access information for the section. */ + +static void +alphacoff_locate_sections (ignore_abfd, sectp, sip) + bfd *ignore_abfd; + asection *sectp; + PTR sip; +{ + register struct alphacoff_dynsecinfo *si; + + si = (struct alphacoff_dynsecinfo *) sip; + + if (STREQ (sectp->name, ".dynsym")) + { + si->sym_sect = sectp; + } + else if (STREQ (sectp->name, ".dynstr")) + { + si->str_sect = sectp; + } + else if (STREQ (sectp->name, ".dynamic")) + { + si->dyninfo_sect = sectp; + } + else if (STREQ (sectp->name, ".got")) + { + si->got_sect = sectp; + } +} + +/* Scan an alpha dynamic symbol table for symbols of interest and + add them to the minimal symbol table. */ + +static void +read_alphacoff_dynamic_symtab (section_offsets, objfile) + struct section_offsets *section_offsets; + struct objfile *objfile; +{ + bfd *abfd = objfile->obfd; + struct alphacoff_dynsecinfo si; + char *sym_secptr; + char *str_secptr; + char *dyninfo_secptr; + char *got_secptr; + bfd_size_type sym_secsize; + bfd_size_type str_secsize; + bfd_size_type dyninfo_secsize; + bfd_size_type got_secsize; + int sym_count; + int i; + int stripped; + Elfalpha_External_Sym *x_symp; + char *dyninfo_p; + char *dyninfo_end; + int got_entry_size = 8; + int dt_mips_local_gotno = -1; + int dt_mips_gotsym = -1; + + + /* We currently only know how to handle alpha dynamic symbols. */ + if (bfd_get_arch (abfd) != bfd_arch_alpha) + return; + + /* Locate the dynamic symbols sections and read them in. */ + memset ((char *) &si, 0, sizeof (si)); + bfd_map_over_sections (abfd, alphacoff_locate_sections, (PTR) &si); + if (si.sym_sect == NULL + || si.str_sect == NULL + || si.dyninfo_sect == NULL + || si.got_sect == NULL) + return; + + sym_secsize = bfd_get_section_size_before_reloc (si.sym_sect); + str_secsize = bfd_get_section_size_before_reloc (si.str_sect); + dyninfo_secsize = bfd_get_section_size_before_reloc (si.dyninfo_sect); + got_secsize = bfd_get_section_size_before_reloc (si.got_sect); + sym_secptr = alloca (sym_secsize); + str_secptr = alloca (str_secsize); + dyninfo_secptr = alloca (dyninfo_secsize); + got_secptr = alloca (got_secsize); + + if (!bfd_get_section_contents (abfd, si.sym_sect, sym_secptr, + (file_ptr)0, sym_secsize)) + return; + if (!bfd_get_section_contents (abfd, si.str_sect, str_secptr, + (file_ptr)0, str_secsize)) + return; + if (!bfd_get_section_contents (abfd, si.dyninfo_sect, dyninfo_secptr, + (file_ptr)0, dyninfo_secsize)) + return; + if (!bfd_get_section_contents (abfd, si.got_sect, got_secptr, + (file_ptr)0, got_secsize)) + return; + + /* Find the number of local GOT entries and the index for the + the first dynamic symbol in the GOT. */ + for (dyninfo_p = dyninfo_secptr, dyninfo_end = dyninfo_p + dyninfo_secsize; + dyninfo_p < dyninfo_end; + dyninfo_p += sizeof (Elfalpha_External_Dyn)) + { + Elfalpha_External_Dyn *x_dynp = (Elfalpha_External_Dyn *)dyninfo_p; + long dyn_tag; + + dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_tag); + if (dyn_tag == DT_NULL) + break; + else if (dyn_tag == DT_MIPS_LOCAL_GOTNO) + { + dt_mips_local_gotno = bfd_h_get_32 (abfd, + (bfd_byte *) x_dynp->d_un.d_val); + } + else if (dyn_tag == DT_MIPS_GOTSYM) + { + dt_mips_gotsym = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_un.d_val); + } + } + if (dt_mips_local_gotno < 0 || dt_mips_gotsym < 0) + return; + + /* Scan all dynamic symbols and enter them into the minimal symbol table + if appropriate. */ + sym_count = sym_secsize / sizeof (Elfalpha_External_Sym); + stripped = (bfd_get_symcount (abfd) == 0); + + /* Skip first symbol, which is a null dummy. */ + for (i = 1, x_symp = (Elfalpha_External_Sym *) sym_secptr + 1; + i < sym_count; + i++, x_symp++) + { + unsigned long strx; + char *name; + bfd_vma sym_value; + unsigned char sym_info; + unsigned int sym_shndx; + int isglobal; + enum minimal_symbol_type ms_type; + + strx = bfd_h_get_32 (abfd, (bfd_byte *) x_symp->st_name); + if (strx >= str_secsize) + continue; + name = str_secptr + strx; + if (*name == '\0' || *name == '.') + continue; + + sym_value = bfd_h_get_64 (abfd, (bfd_byte *) x_symp->st_value); + sym_info = bfd_h_get_8 (abfd, (bfd_byte *) x_symp->st_info); + sym_shndx = bfd_h_get_16 (abfd, (bfd_byte *) x_symp->st_shndx); + isglobal = (ELF_ST_BIND (sym_info) == STB_GLOBAL); + + if (sym_shndx == SHN_UNDEF) + { + /* Handle undefined functions which are defined in a shared + library. */ + if (ELF_ST_TYPE (sym_info) != STT_FUNC + || ELF_ST_BIND (sym_info) != STB_GLOBAL) + continue; + + ms_type = mst_solib_trampoline; + + /* If sym_value is nonzero, it points to the shared library + trampoline entry, which is what we are looking for. + + If sym_value is zero, then we have to get the GOT entry + for the symbol. + If the GOT entry is nonzero, it represents the quickstart + address of the function and we use that as the symbol value. + + If the GOT entry is zero, the function address has to be resolved + by the runtime loader before the executable is started. + We are unable to find any meaningful address for these + functions in the executable file, so we skip them. */ + if (sym_value == 0) + { + int got_entry_offset = + (i - dt_mips_gotsym + dt_mips_local_gotno) * got_entry_size; + + if (got_entry_offset < 0 || got_entry_offset >= got_secsize) + continue; + sym_value = + bfd_h_get_64 (abfd, + (bfd_byte *) (got_secptr + got_entry_offset)); + if (sym_value == 0) + continue; + } + } + else + { + /* Symbols defined in the executable itself. We only care about + them if this is a stripped executable, otherwise they have + been retrieved from the normal symbol table already. */ + if (!stripped) + continue; + + if (sym_shndx == SHN_MIPS_TEXT) + { + if (isglobal) + ms_type = mst_text; + else + ms_type = mst_file_text; + sym_value += ANOFFSET (section_offsets, SECT_OFF_TEXT); + } + else if (sym_shndx == SHN_MIPS_DATA) + { + if (isglobal) + ms_type = mst_data; + else + ms_type = mst_file_data; + sym_value += ANOFFSET (section_offsets, SECT_OFF_DATA); + } + else if (sym_shndx == SHN_MIPS_ACOMMON) + { + if (isglobal) + ms_type = mst_bss; + else + ms_type = mst_file_bss; + sym_value += ANOFFSET (section_offsets, SECT_OFF_BSS); + } + else if (sym_shndx == SHN_ABS) + { + ms_type = mst_abs; + } + else + { + continue; + } + } + + prim_record_minimal_symbol (obsavestring (name, + strlen (name), + &objfile -> symbol_obstack), + sym_value, + ms_type, + objfile); + } +} + /* Initialization */ static struct sym_fns ecoff_sym_fns = |