michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "leaky.h"
michael@0: 
michael@0: #ifdef USE_ELF
michael@0: 
michael@0: #include "leaky.h"
michael@0: #include <stdio.h>
michael@0: #include <malloc.h>
michael@0: #include <libelf/libelf.h>
michael@0: #include <unistd.h>
michael@0: #include <fcntl.h>
michael@0: #include <string.h>
michael@0: 
michael@0: void leaky::readSymbols(const char *fileName)
michael@0: {
michael@0:     int fd = ::open(fileName, O_RDONLY);
michael@0:     if (fd < 0) {
michael@0: 	fprintf(stderr, "%s: unable to open \"%s\"\n", applicationName,
michael@0: 		fileName);
michael@0: 	exit(-1);
michael@0:     }
michael@0: 
michael@0:     elf_version(EV_CURRENT);
michael@0:     Elf *elf = elf_begin(fd, ELF_C_READ, 0);
michael@0:     if (!elf) {
michael@0: 	fprintf(stderr, "%s: \"%s\": has no symbol table\n", applicationName,
michael@0: 		fileName);
michael@0: 	exit(-1);
michael@0:     }
michael@0: 
michael@0:     long alloced = 10000;
michael@0:     Symbol* syms = (Symbol*) malloc(sizeof(Symbol) * 10000);
michael@0:     Symbol* sp = syms;
michael@0:     Symbol* last = syms + alloced;
michael@0: 
michael@0:     // Get each of the relevant sections and add them to the list of
michael@0:     // symbols.
michael@0:     Elf32_Ehdr *ehdr = elf32_getehdr(elf);
michael@0:     if (!ehdr) {
michael@0: 	fprintf(stderr, "%s: elf library lossage\n", applicationName);
michael@0: 	exit(-1);
michael@0:     }
michael@0: #if 0
michael@0:     Elf32_Half ndx = ehdr->e_shstrndx;
michael@0: #endif
michael@0: 
michael@0:     Elf_Scn *scn = 0;
michael@0:     int strtabndx = -1;
michael@0:     for (int i = 1; (scn = elf_nextscn(elf, scn)) != 0; i++) {
michael@0: 	Elf32_Shdr *shdr = elf32_getshdr(scn);
michael@0: #if 0
michael@0: 	char *name = elf_strptr(elf, ndx, (size_t) shdr->sh_name);
michael@0: 	printf("Section %s (%d 0x%x)\n", name ? name : "(null)",
michael@0: 	       shdr->sh_type, shdr->sh_type);
michael@0: #endif
michael@0: 	if (shdr->sh_type == SHT_STRTAB) {
michael@0: 	    /* We assume here that string tables preceed symbol tables... */
michael@0: 	    strtabndx = i;
michael@0: 	    continue;
michael@0: 	}
michael@0: #if 0
michael@0: 	if (shdr->sh_type == SHT_DYNAMIC) {
michael@0: 	    /* Dynamic */
michael@0: 	    Elf_Data *data = elf_getdata(scn, 0);
michael@0: 	    if (!data || !data->d_size) {
michael@0: 		printf("No data...");
michael@0: 		continue;
michael@0: 	    }
michael@0: 
michael@0: 	    Elf32_Dyn *dyn = (Elf32_Dyn*) data->d_buf;
michael@0: 	    Elf32_Dyn *lastdyn =
michael@0: 		(Elf32_Dyn*) ((char*) data->d_buf + data->d_size);
michael@0: 	    for (; dyn < lastdyn; dyn++) {
michael@0: 		printf("tag=%d value=0x%x\n", dyn->d_tag, dyn->d_un.d_val);
michael@0: 	    }
michael@0: 	} else
michael@0: #endif
michael@0: 	if ((shdr->sh_type == SHT_SYMTAB) ||
michael@0: 	    (shdr->sh_type == SHT_DYNSYM)) {
michael@0: 	    /* Symbol table */
michael@0: 	    Elf_Data *data = elf_getdata(scn, 0);
michael@0: 	    if (!data || !data->d_size) {
michael@0: 		printf("No data...");
michael@0: 		continue;
michael@0: 	    }
michael@0: 
michael@0: 	    /* In theory we now have the symbols... */
michael@0: 	    Elf32_Sym *esym = (Elf32_Sym*) data->d_buf;
michael@0: 	    Elf32_Sym *lastsym =
michael@0: 		(Elf32_Sym*) ((char*) data->d_buf + data->d_size);
michael@0: 	    for (; esym < lastsym; esym++) {
michael@0: #if 0
michael@0: 		char *nm = elf_strptr(elf, strtabndx, (size_t)esym->st_name);
michael@0: 		printf("%20s 0x%08x %02x %02x\n",
michael@0: 		       nm, esym->st_value, ELF32_ST_BIND(esym->st_info),
michael@0: 		       ELF32_ST_TYPE(esym->st_info));
michael@0: #endif
michael@0: 		if ((esym->st_value == 0) ||
michael@0: 		    (ELF32_ST_BIND(esym->st_info) == STB_WEAK) ||
michael@0: 		    (ELF32_ST_BIND(esym->st_info) == STB_NUM) ||
michael@0: 		    (ELF32_ST_TYPE(esym->st_info) != STT_FUNC)) {
michael@0: 		    continue;
michael@0: 		}
michael@0: #if 1
michael@0: 		char *nm = elf_strptr(elf, strtabndx, (size_t)esym->st_name);
michael@0: #endif
michael@0: 		sp->name = nm ? strdup(nm) : "(no name)";
michael@0: 		sp->address = esym->st_value;
michael@0: 		sp++;
michael@0: 		if (sp >= last) {
michael@0: 		    long n = alloced + 10000;
michael@0: 		    syms = (Symbol*)
michael@0: 			realloc(syms, (size_t) (sizeof(Symbol) * n));
michael@0: 		    last = syms + n;
michael@0: 		    sp = syms + alloced;
michael@0: 		    alloced = n;
michael@0: 		}
michael@0: 	    }
michael@0: 	}
michael@0:     }
michael@0: 
michael@0:     int interesting = sp - syms;
michael@0:     if (!quiet) {
michael@0: 	printf("Total of %d symbols\n", interesting);
michael@0:     }
michael@0:     usefulSymbols = interesting;
michael@0:     externalSymbols = syms;
michael@0: }
michael@0: 
michael@0: #endif /* USE_ELF */