DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (409f3966645a)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "leaky.h"

#ifdef USE_ELF

#include "leaky.h"
#include <stdio.h>
#include <malloc.h>
#include <libelf/libelf.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>

void leaky::readSymbols(const char *fileName)
{
    int fd = ::open(fileName, O_RDONLY);
    if (fd < 0) {
	fprintf(stderr, "%s: unable to open \"%s\"\n", applicationName,
		fileName);
	exit(-1);
    }

    elf_version(EV_CURRENT);
    Elf *elf = elf_begin(fd, ELF_C_READ, 0);
    if (!elf) {
	fprintf(stderr, "%s: \"%s\": has no symbol table\n", applicationName,
		fileName);
	exit(-1);
    }

    long alloced = 10000;
    Symbol* syms = (Symbol*) malloc(sizeof(Symbol) * 10000);
    Symbol* sp = syms;
    Symbol* last = syms + alloced;

    // Get each of the relevant sections and add them to the list of
    // symbols.
    Elf32_Ehdr *ehdr = elf32_getehdr(elf);
    if (!ehdr) {
	fprintf(stderr, "%s: elf library lossage\n", applicationName);
	exit(-1);
    }
#if 0
    Elf32_Half ndx = ehdr->e_shstrndx;
#endif

    Elf_Scn *scn = 0;
    int strtabndx = -1;
    for (int i = 1; (scn = elf_nextscn(elf, scn)) != 0; i++) {
	Elf32_Shdr *shdr = elf32_getshdr(scn);
#if 0
	char *name = elf_strptr(elf, ndx, (size_t) shdr->sh_name);
	printf("Section %s (%d 0x%x)\n", name ? name : "(null)",
	       shdr->sh_type, shdr->sh_type);
#endif
	if (shdr->sh_type == SHT_STRTAB) {
	    /* We assume here that string tables preceed symbol tables... */
	    strtabndx = i;
	    continue;
	}
#if 0
	if (shdr->sh_type == SHT_DYNAMIC) {
	    /* Dynamic */
	    Elf_Data *data = elf_getdata(scn, 0);
	    if (!data || !data->d_size) {
		printf("No data...");
		continue;
	    }

	    Elf32_Dyn *dyn = (Elf32_Dyn*) data->d_buf;
	    Elf32_Dyn *lastdyn =
		(Elf32_Dyn*) ((char*) data->d_buf + data->d_size);
	    for (; dyn < lastdyn; dyn++) {
		printf("tag=%d value=0x%x\n", dyn->d_tag, dyn->d_un.d_val);
	    }
	} else
#endif
	if ((shdr->sh_type == SHT_SYMTAB) ||
	    (shdr->sh_type == SHT_DYNSYM)) {
	    /* Symbol table */
	    Elf_Data *data = elf_getdata(scn, 0);
	    if (!data || !data->d_size) {
		printf("No data...");
		continue;
	    }

	    /* In theory we now have the symbols... */
	    Elf32_Sym *esym = (Elf32_Sym*) data->d_buf;
	    Elf32_Sym *lastsym =
		(Elf32_Sym*) ((char*) data->d_buf + data->d_size);
	    for (; esym < lastsym; esym++) {
#if 0
		char *nm = elf_strptr(elf, strtabndx, (size_t)esym->st_name);
		printf("%20s 0x%08x %02x %02x\n",
		       nm, esym->st_value, ELF32_ST_BIND(esym->st_info),
		       ELF32_ST_TYPE(esym->st_info));
#endif
		if ((esym->st_value == 0) ||
		    (ELF32_ST_BIND(esym->st_info) == STB_WEAK) ||
		    (ELF32_ST_BIND(esym->st_info) == STB_NUM) ||
		    (ELF32_ST_TYPE(esym->st_info) != STT_FUNC)) {
		    continue;
		}
#if 1
		char *nm = elf_strptr(elf, strtabndx, (size_t)esym->st_name);
#endif
		sp->name = nm ? strdup(nm) : "(no name)";
		sp->address = esym->st_value;
		sp++;
		if (sp >= last) {
		    long n = alloced + 10000;
		    syms = (Symbol*)
			realloc(syms, (size_t) (sizeof(Symbol) * n));
		    last = syms + n;
		    sp = syms + alloced;
		    alloced = n;
		}
	    }
	}
    }

    int interesting = sp - syms;
    if (!quiet) {
	printf("Total of %d symbols\n", interesting);
    }
    usefulSymbols = interesting;
    externalSymbols = syms;
}

#endif /* USE_ELF */