diff options
Diffstat (limited to 'tools/lsd/lsd.c')
| -rw-r--r-- | tools/lsd/lsd.c | 777 |
1 files changed, 777 insertions, 0 deletions
diff --git a/tools/lsd/lsd.c b/tools/lsd/lsd.c new file mode 100644 index 0000000..03c235b --- /dev/null +++ b/tools/lsd/lsd.c @@ -0,0 +1,777 @@ +#include <stdio.h> +#include <common.h> +#include <debug.h> +#include <libelf.h> +#include <libebl.h> +#include <elf.h> +#include <gelf.h> +#include <string.h> +#include <errno.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <hash.h> +#include <lsd.h> + +extern int verbose_flag; + +typedef struct source_t source_t; + +typedef struct { + Elf_Scn *scn; + GElf_Shdr shdr; + Elf_Data *data; +} section_info_t; + +typedef struct next_export_t { + source_t *source; + int next_idx; +} next_export_t; + +struct source_t { + source_t *next; + int visited; + + char *name; /* full path name of this executable file */ + /* ELF-related information: */ + Elf *elf; + int elf_fd; + GElf_Ehdr elf_hdr; + size_t shstrndx; + int shnum; /* number of sections */ + + section_info_t symtab; + section_info_t strtab; + section_info_t dynamic; + section_info_t hash; + + section_info_t *relocations; + int num_relocations; /* number of relocs (<= relocations_size) */ + int relocations_size; /* sice of array -- NOT number of relocs! */ + + /* satisfied_execs: array containing pointers to the libraries or + executables that this executable satisfies symbol references for. */ + source_t **satisfied_execs; + int num_satisfied_execs; + int satisfied_execs_size; + + /* satisfied: array is parallel to symbol table; for each undefined symbol + in that array, we maintain a flag stating whether that symbol has been + satisfied, and if so, by which library. This applies both to executable + files and libraries. + */ + source_t **satisfied; + + /* exports: array is parallel to symbol table; for each global symbol + in that array, we maintain a flag stating whether that symbol satisfies + a dependency in some other file. num_syms is the length of the exports + array, as well as the satisfied array. This applied to libraries only. + + next_exports: this is a bit tricky. We use this field to maintain a + linked list of source_t for each global symbol of a shared library. + For a shared library's global symbol at index N has the property that + exports[N] is the head of a linked list (threaded through next_export) + of all source_t that this symbol resolves a reference to. For example, + if symbol printf has index 1000 in libc.so, and an executable A and + library L use printf, then the source_t entry corresponding to libc.so + will have exports[1000] be a linked list that contains the nodes for + application A and library L. + */ + + next_export_t *exports; + /* num_exported is the number of symbols in this file actually used by + somebody else; it's not the size of the exports array. */ + int num_exported; + next_export_t *next_export; + int num_next_export; + int next_export_size; + + int num_syms; /* number of symbols in symbol table. This is the length of + both exports[] and satisfied[] arrays. */ + + /* This is an array that contains one element for each library dependency + listed in the executable or shared library. */ + source_t **lib_deps; /* list of library dependencies */ + int num_lib_deps; /* actual number of library dependencies */ + int lib_deps_size; /* size of lib_deps array--NOT actual number of deps! */ + +}; + +static source_t *sources = NULL; + +static char * find_file(const char *libname, + char **lib_lookup_dirs, + int num_lib_lookup_dirs); + +static inline source_t* find_source(const char *name, + char **lib_lookup_dirs, + int num_lib_lookup_dirs) { + source_t *trav = sources; + char *full = find_file(name, lib_lookup_dirs, num_lib_lookup_dirs); + FAILIF(full == NULL, "Cannot construct full path for file [%s]!\n", name); + while (trav) { + if (!strcmp(trav->name, full)) + break; + trav = trav->next; + } + free(full); + return trav; +} + +static inline void add_to_sources(source_t *src) { + src->next = sources; + sources = src; +} + +static source_t* init_source(char *full_path) { + source_t *source = (source_t *)CALLOC(1, sizeof(source_t)); + + ASSERT(full_path); + source->name = full_path; + source->elf_fd = -1; + + INFO("Opening %s...\n", full_path); + source->elf_fd = open(full_path, O_RDONLY); + FAILIF(source->elf_fd < 0, "open(%s): %s (%d)\n", + full_path, + strerror(errno), + errno); + INFO("Calling elf_begin(%s)...\n", full_path); + source->elf = elf_begin(source->elf_fd, ELF_C_READ, NULL); + FAILIF_LIBELF(source->elf == NULL, elf_begin); + + /* libelf can recognize COFF and A.OUT formats, but we handle only ELF. */ + if (elf_kind(source->elf) != ELF_K_ELF) { + ERROR("Input file %s is not in ELF format!\n", full_path); + return NULL; + } + + /* Make sure this is a shared library or an executable. */ + { + INFO("Making sure %s is a shared library or an executable...\n", + full_path); + FAILIF_LIBELF(0 == gelf_getehdr(source->elf, &source->elf_hdr), gelf_getehdr); + FAILIF(source->elf_hdr.e_type != ET_DYN && + source->elf_hdr.e_type != ET_EXEC, + "%s must be a shared library (elf type is %d, expecting %d).\n", + full_path, + source->elf_hdr.e_type, + ET_DYN); + } + + /* Get the index of the section-header-strings-table section. */ + FAILIF_LIBELF(elf_getshstrndx (source->elf, &source->shstrndx) < 0, + elf_getshstrndx); + + FAILIF_LIBELF(elf_getshnum (source->elf, &source->shnum) < 0, elf_getshnum); + + /* Find various sections. */ + size_t scnidx; + Elf_Scn *scn; + GElf_Shdr *shdr, shdr_mem; + INFO("Locating %d sections in %s...\n", source->shnum, full_path); + for (scnidx = 1; scnidx < source->shnum; scnidx++) { + scn = elf_getscn(source->elf, scnidx); + FAILIF_LIBELF(NULL == scn, elf_getscn); + shdr = gelf_getshdr(scn, &shdr_mem); + FAILIF_LIBELF(NULL == shdr, gelf_getshdr); + INFO("\tfound section [%s]...\n", elf_strptr(source->elf, source->shstrndx, shdr->sh_name)); + if (shdr->sh_type == SHT_DYNSYM) { + source->symtab.scn = scn; + source->symtab.data = elf_getdata(scn, NULL); + FAILIF_LIBELF(NULL == source->symtab.data, elf_getdata); + memcpy(&source->symtab.shdr, shdr, sizeof(GElf_Shdr)); + + /* The sh_link field of the section header of the symbol table + contains the index of the associated strings table. */ + source->strtab.scn = elf_getscn(source->elf, + source->symtab.shdr.sh_link); + FAILIF_LIBELF(NULL == source->strtab.scn, elf_getscn); + FAILIF_LIBELF(NULL == gelf_getshdr(scn, &source->strtab.shdr), + gelf_getshdr); + source->strtab.data = elf_getdata(source->strtab.scn, NULL); + FAILIF_LIBELF(NULL == source->strtab.data, elf_getdata); + } + else if (shdr->sh_type == SHT_DYNAMIC) { + source->dynamic.scn = scn; + source->dynamic.data = elf_getdata(scn, NULL); + FAILIF_LIBELF(NULL == source->symtab.data, elf_getdata); + memcpy(&source->dynamic.shdr, shdr, sizeof(GElf_Shdr)); + } + else if (shdr->sh_type == SHT_HASH) { + source->hash.scn = scn; + source->hash.data = elf_getdata(scn, NULL); + FAILIF_LIBELF(NULL == source->hash.data, elf_getdata); + memcpy(&source->hash.shdr, shdr, sizeof(GElf_Shdr)); + } + else if (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA) { + if (source->num_relocations == source->relocations_size) { + source->relocations_size += 5; + source->relocations = + (section_info_t *)REALLOC(source->relocations, + source->relocations_size * + sizeof(section_info_t)); + } + section_info_t *reloc = + source->relocations + source->num_relocations; + reloc->scn = scn; + reloc->data = elf_getdata(scn, NULL); + FAILIF_LIBELF(NULL == reloc->data, elf_getdata); + memcpy(&reloc->shdr, shdr, sizeof(GElf_Shdr)); + source->num_relocations++; + } + } + + if (source->dynamic.scn == NULL) { + INFO("File [%s] does not have a dynamic section!\n", full_path); + return 0; + } + + FAILIF(source->symtab.scn == NULL, + "File [%s] does not have a dynamic symbol table!\n", + full_path); + + FAILIF(source->hash.scn == NULL, + "File [%s] does not have a hash table!\n", + full_path); + FAILIF(source->hash.shdr.sh_link != elf_ndxscn(source->symtab.scn), + "Hash points to section %d, not to %d as expected!\n", + source->hash.shdr.sh_link, + elf_ndxscn(scn)); + + /* Now, find out how many symbols we have and allocate the array of + satisfied symbols. + + NOTE: We don't count the number of undefined symbols here; we will + iterate over the symbol table later, and count them then, when it is + more convenient. + */ + size_t symsize = gelf_fsize (source->elf, + ELF_T_SYM, + 1, source->elf_hdr.e_version); + ASSERT(symsize); + + source->num_syms = source->symtab.data->d_size / symsize; + source->satisfied = (source_t **)CALLOC(source->num_syms, + sizeof(source_t *)); + source->exports = (source_t **)CALLOC(source->num_syms, + sizeof(next_export_t)); + + source->num_exported = 0; + source->satisfied_execs = NULL; + source->num_satisfied_execs = 0; + source->satisfied_execs_size = 0; + + add_to_sources(source); + return source; +} + +static void destroy_source(source_t *source) { + FREE(source->satisfied_execs); + FREE(source->satisfied); + FREE(source->exports); + FREE(source->next_export); + FREE(source->lib_deps); /* list of library dependencies */ + FAILIF_LIBELF(elf_end(source->elf), elf_end); + FAILIF(close(source->elf_fd) < 0, "Could not close file %s: %s (%d)!\n", + source->name, strerror(errno), errno); + FREE(source->name); + FREE(source); +} + +static void print_needed_libs(source_t *source) +{ + size_t idx; + for (idx = 0; idx < source->num_lib_deps; idx++) { + PRINT("%s:%s\n", + source->name, + source->lib_deps[idx]->name); + } +} + +static int is_symbol_imported(source_t *source, + GElf_Sym *sym, + size_t symidx) +{ + const char *symname = elf_strptr(source->elf, + elf_ndxscn(source->strtab.scn), + sym->st_name); + + /* A symbol is imported by an executable or a library if it is undefined + and is either global or weak. There is an additional case for + executables that we will check below. */ + if (sym->st_shndx == SHN_UNDEF && + (GELF_ST_BIND(sym->st_info) == STB_GLOBAL || + GELF_ST_BIND(sym->st_info) == STB_WEAK)) { + INFO("*** symbol [%s:%s] is imported (UNDEFIEND).\n", + source->name, + symname); + return 1; + } + +#ifdef ARM_SPECIFIC_HACKS + /* A symbol is imported by an executable if is marked as an undefined + symbol--this is standard to all ELF formats. Alternatively, according + to the ARM specifications, a symbol in a BSS section that is also marked + by an R_ARM_COPY relocation is also imported. */ + + if (source->elf_hdr.e_type != ET_EXEC) { + INFO("is_symbol_imported(): [%s] is a library, " + "no further checks.\n", source->name); + return 0; + } + + /* Is the symbol in the BSS section, and is there a COPY relocation on + that symbol? */ + INFO("*** [%s:%s] checking further to see if symbol is imported.\n", + source->name, symname); + if (sym->st_shndx < source->shnum) { + /* Is it the .bss section? */ + Elf_Scn *scn = elf_getscn(source->elf, sym->st_shndx); + FAILIF_LIBELF(NULL == scn, elf_getscn); + GElf_Shdr *shdr, shdr_mem; + shdr = gelf_getshdr(scn, &shdr_mem); + FAILIF_LIBELF(NULL == shdr, gelf_getshdr); + if (!strcmp(".bss", elf_strptr(source->elf, + source->shstrndx, + shdr->sh_name))) + { + /* Is there an R_ARM_COPY relocation on this symbol? Iterate + over the list of relocation sections and scan each section for + an entry that matches the symbol. */ + size_t idx; + for (idx = 0; idx < source->num_relocations; idx++) { + section_info_t *reloc = source->relocations + idx; + /* Does the relocation section refer to the symbol table in + which this symbol resides, and does it relocate the .bss + section? */ + if (reloc->shdr.sh_link == elf_ndxscn(source->symtab.scn) && + reloc->shdr.sh_info == sym->st_shndx) + { + /* Go over the relocations and see if any of them matches + our symbol. */ + size_t nrels = reloc->shdr.sh_size / reloc->shdr.sh_entsize; + size_t relidx, newidx; + if (reloc->shdr.sh_type == SHT_REL) { + for (newidx = relidx = 0; relidx < nrels; ++relidx) { + GElf_Rel rel_mem; + FAILIF_LIBELF(gelf_getrel (reloc->data, + relidx, + &rel_mem) == NULL, + gelf_getrel); + if (GELF_R_TYPE(rel_mem.r_info) == R_ARM_COPY && + GELF_R_SYM (rel_mem.r_info) == symidx) + { + INFO("*** symbol [%s:%s] is imported " + "(DEFINED, REL-COPY-RELOCATED).\n", + source->name, + symname); + return 1; + } + } /* for each rel entry... */ + } else { + for (newidx = relidx = 0; relidx < nrels; ++relidx) { + GElf_Rela rel_mem; + FAILIF_LIBELF(gelf_getrela (reloc->data, + relidx, + &rel_mem) == NULL, + gelf_getrela); + if (GELF_R_TYPE(rel_mem.r_info) == R_ARM_COPY && + GELF_R_SYM (rel_mem.r_info) == symidx) + { + INFO("*** symbol [%s:%s] is imported " + "(DEFINED, RELA-COPY-RELOCATED).\n", + source->name, + symname); + return 1; + } + } /* for each rela entry... */ + } /* if rel else rela */ + } + } + } + } +#endif/*ARM_SPECIFIC_HACKS*/ + + return 0; +} + +static void resolve(source_t *source) { + /* Iterate the symbol table. For each undefined symbol, scan the + list of dependencies till we find a global symbol in one of them that + satisfies the undefined reference. At this point, we update both the + satisfied[] array of the sources entry, as well as the exports array of + the dependency where we found the match. + */ + + GElf_Sym *sym, sym_mem; + size_t symidx; + for (symidx = 0; symidx < source->num_syms; symidx++) { + sym = gelf_getsymshndx(source->symtab.data, + NULL, + symidx, + &sym_mem, + NULL); + FAILIF_LIBELF(NULL == sym, gelf_getsymshndx); + if (is_symbol_imported(source, sym, symidx)) + { + /* This is an undefined symbol. Go over the list of libraries + and look it up. */ + size_t libidx; + int found = 0; + source_t *last_found = NULL; + const char *symname = elf_strptr(source->elf, + elf_ndxscn(source->strtab.scn), + sym->st_name); + for (libidx = 0; libidx < source->num_lib_deps; libidx++) { + source_t *lib = source->lib_deps[libidx]; + int lib_symidx = hash_lookup(lib->elf, + lib->hash.data, + lib->symtab.data, + lib->strtab.data, + symname); + if (STN_UNDEF != lib_symidx) + { + /* We found the symbol--now check to see if it is global + or weak. If this is the case, then the symbol satisfies + the dependency. */ + GElf_Sym *lib_sym, lib_sym_mem; + lib_sym = gelf_getsymshndx(lib->symtab.data, + NULL, + lib_symidx, + &lib_sym_mem, + NULL); + FAILIF_LIBELF(NULL == lib_sym, gelf_getsymshndx); + + if(lib_sym->st_shndx != STN_UNDEF && + (GELF_ST_BIND(lib_sym->st_info) == STB_GLOBAL || + GELF_ST_BIND(lib_sym->st_info) == STB_WEAK)) + { + /* We found the symbol! Update the satisfied array at this + index location. */ + source->satisfied[symidx] = lib; + /* Now, link this structure into the linked list + corresponding to the found symbol in the library's + global array. */ + if (source->num_next_export == source->next_export_size) { + source->next_export_size += 30; + source->next_export = + (source_t **)REALLOC(source->next_export, + source->next_export_size * + sizeof(struct next_export_t)); + } + source->next_export[source->num_next_export] = lib->exports[lib_symidx]; + lib->exports[lib_symidx].source = source; + lib->exports[lib_symidx].next_idx = source->num_next_export; + + source->num_next_export++; + lib->num_exported++; + + INFO("[%s:%s (index %d)] satisfied by [%s] (index %d)\n", + source->name, + symname, + symidx, + lib->name, + lib_symidx); + if (found) { + if (found == 1) { + found++; + ERROR("ERROR: multiple definitions found for [%s:%s]!\n", + source->name, symname); + ERROR("\tthis definition [%s]\n", lib->name); + } + ERROR("\tprevious definition [%s]\n", last_found->name); + } + + last_found = lib; + if (!found) found = 1; + } + } + } + if(found == 0) { + ERROR("ERROR: could not find match for %s:%s.\n", + source->name, + symname); + } + } /* if we found the symbol... */ + } /* for each symbol... */ +} /* resolve() */ + +static void print_used_symbols(source_t *source) { + + int name_len = strlen(source->name); + static const char ext[] = ".syms"; + char *filter = (char *)MALLOC(name_len + sizeof(ext)); + strcpy(filter, source->name); + strcpy(filter + name_len, ext); + + FILE *fp = fopen(filter, "w+"); + FAILIF(NULL == fp, + "Can't open %s: %s (%d)\n", + filter, + strerror(errno), errno); + + /* Is anybody using the symbols defined in source? */ + + if (source->num_exported > 0) { + INFO("[%s] exports %d symbols to %d libraries and executables.\n", + source->name, + source->num_exported, + source->num_satisfied_execs); + size_t symidx; + for (symidx = 0; symidx < source->num_syms; symidx++) { + if (source->exports[symidx].source != NULL) { + GElf_Sym *sym, sym_mem; + sym = gelf_getsymshndx(source->symtab.data, + NULL, + symidx, + &sym_mem, + NULL); + FAILIF_LIBELF(NULL == sym, gelf_getsymshndx); + fprintf(fp, "%s\n", elf_strptr(source->elf, + elf_ndxscn(source->strtab.scn), + sym->st_name)); + } + } + } + else if (source->num_satisfied_execs > 0) { + + /* Is the source listed as a depenency on anyone? If so, then the source exports no symbols + to anyone, but someone lists it as a dependency, which is unnecessary, so we print a warning. + */ + + ERROR("WARNING: [%s] is listed as a dependency in: ", source->name); + int i; + for (i = 0; i < source->num_satisfied_execs; i++) { + ERROR(" [%s],", source->satisfied_execs[i]->name); + } + ERROR(" but none of its symbols are used!.\n"); + } +#if 0 /* This is not really an error--a library's symbols may not be used anyone as specified in the ELF file, + but someone may still open a library via dlopen(). + */ + else { + ERROR("WARNING: None of [%s]'s symbols are used by any library or executable!\n", source->name); + } +#endif + + fclose(fp); + FREE(filter); +} + +static void print_symbol_references(source_t *source) { + + int name_len = strlen(source->name); + static const char ext[] = ".info"; + char *filter = (char *)MALLOC(name_len + sizeof(ext)); + strcpy(filter, source->name); + strcpy(filter + name_len, ext); + + FILE *fp = fopen(filter, "w+"); + FAILIF(NULL == fp, + "Can't open %s: %s (%d)\n", + filter, + strerror(errno), errno); + + if (source->num_exported > 0) { + size_t symidx; + for (symidx = 0; symidx < source->num_syms; symidx++) { + if (source->exports[symidx].source != NULL) { + const char *symname; + GElf_Sym *sym, sym_mem; + sym = gelf_getsymshndx(source->symtab.data, + NULL, + symidx, + &sym_mem, + NULL); + FAILIF_LIBELF(NULL == sym, gelf_getsymshndx); + symname = elf_strptr(source->elf, + elf_ndxscn(source->strtab.scn), + sym->st_name); + fprintf(fp, "%s\n", symname); + next_export_t *export = &source->exports[symidx]; + while (export->source != NULL) { + //fprintf(stderr, "%s:%s\n", symname, export->source->name); + fprintf(fp, "\t%s\n", export->source->name); + export = &export->source->next_export[export->next_idx]; + } + } + } + } + + fclose(fp); + FREE(filter); +} + +static char * find_file(const char *libname, + char **lib_lookup_dirs, + int num_lib_lookup_dirs) { + if (libname[0] == '/') { + /* This is an absolute path name--just return it. */ + INFO("ABSOLUTE PATH: [%s].\n", libname); + return strdup(libname); + } else { + /* First try the working directory. */ + int fd; + if ((fd = open(libname, O_RDONLY)) > 0) { + close(fd); + INFO("FOUND IN CURRENT DIR: [%s].\n", libname); + return strdup(libname); + } else { + /* Iterate over all library paths. For each path, append the file + name and see if there is a file at that place. If that fails, + bail out. */ + + char *name; + while (num_lib_lookup_dirs--) { + size_t lib_len = strlen(*lib_lookup_dirs); + /* one extra character for the slash, and another for the + terminating NULL. */ + name = (char *)MALLOC(lib_len + strlen(libname) + 2); + strcpy(name, *lib_lookup_dirs); + name[lib_len] = '/'; + strcpy(name + lib_len + 1, libname); + if ((fd = open(name, O_RDONLY)) > 0) { + close(fd); + INFO("FOUND: [%s] in [%s].\n", libname, name); + return name; + } + INFO("NOT FOUND: [%s] in [%s].\n", libname, name); + free(name); + } + } + } + return NULL; +} + +static source_t* process_library(const char *libname, + char **lib_lookup_dirs, + int num_lib_lookup_dirs) { + source_t *source = find_source(libname, lib_lookup_dirs, num_lib_lookup_dirs); + if (NULL == source) { + INFO("Processing [%s].\n", libname); + char *full = find_file(libname, lib_lookup_dirs, num_lib_lookup_dirs); + FAILIF(NULL == full, + "Could not find [%s] in the current directory or in any of " + "the search paths!\n", libname); + source = init_source(full); + if (source) { + GElf_Dyn *dyn, dyn_mem; + size_t dynidx; + size_t numdyn = + source->dynamic.shdr.sh_size / + source->dynamic.shdr.sh_entsize; + + for (dynidx = 0; dynidx < numdyn; dynidx++) { + dyn = gelf_getdyn (source->dynamic.data, + dynidx, + &dyn_mem); + FAILIF_LIBELF(NULL == dyn, gelf_getdyn); + if (dyn->d_tag == DT_NEEDED) { + /* Process the needed library recursively. */ + const char *dep_lib = + elf_strptr (source->elf, + source->dynamic.shdr.sh_link, + dyn->d_un.d_val); + INFO("[%s] depends on [%s].\n", libname, dep_lib); + source_t *dep = process_library(dep_lib, + lib_lookup_dirs, + num_lib_lookup_dirs); + + /* Tell dep that source depends on it. */ + if (dep->num_satisfied_execs == dep->satisfied_execs_size) { + dep->satisfied_execs_size += 10; + dep->satisfied_execs = + REALLOC(dep->satisfied_execs, + dep->satisfied_execs_size * + sizeof(source_t *)); + } + dep->satisfied_execs[dep->num_satisfied_execs++] = source; + + /* Add the library to the dependency list. */ + if (source->num_lib_deps == source->lib_deps_size) { + source->lib_deps_size += 10; + source->lib_deps = REALLOC(source->lib_deps, + source->lib_deps_size * + sizeof(source_t *)); + } + source->lib_deps[source->num_lib_deps++] = dep; + } + } /* for each dynamic entry... */ + } + } else INFO("[%s] has been processed already.\n", libname); + + return source; +} + +void lsd(char **execs, int num_execs, + int list_needed_libs, + int print_info, + char **lib_lookup_dirs, int num_lib_lookup_dirs) { + + source_t *source; /* for general usage */ + int input_idx; + + for (input_idx = 0; input_idx < num_execs; input_idx++) { + INFO("executable: [%s]\n", execs[input_idx]); + /* Here process library is actually processing the top-level executable + files. */ + process_library(execs[input_idx], lib_lookup_dirs, num_lib_lookup_dirs); + /* if source is NULL, then the respective executable is static */ + /* Mark the source as an executable */ + } /* for each input executable... */ + + if (list_needed_libs) { + source = sources; + while (source) { + print_needed_libs(source); + source = source->next; + } + } + + /* Now, for each entry in the sources array, iterate its symbol table. For + each undefined symbol, scan the list of dependencies till we find a + global symbol in one of them that satisfies the undefined reference. + At this point, we update both the satisfied[] array of the sources entry, + as well as the exports array of the dependency where we found the match. + */ + + source = sources; + while (source) { + resolve(source); + source = source->next; + } + + /* We are done! Since the end result of our calculations is a set of + symbols for each library that other libraries or executables link + against, we iterate over the set of libraries one last time, and for + each symbol that is marked as satisfying some dependence, we emit + a line with the symbol's name to a text file derived from the library's + name by appending the suffix .syms to it. */ + + source = sources; + while (source) { + /* If it's a library, print the results. */ + if (source->elf_hdr.e_type == ET_DYN) { + print_used_symbols(source); + if (print_info) + print_symbol_references(source); + } + source = source->next; + } + + /* Free the resources--you can't do it in the loop above because function + print_symbol_references() accesses nodes other than the one being + iterated over. + */ + source = sources; + while (source) { + source_t *old = source; + source = source->next; + /* Destroy the evidence. */ + destroy_source(old); + } +} + |