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-rw-r--r--tools/jprof/elf.cpp133
1 files changed, 133 insertions, 0 deletions
diff --git a/tools/jprof/elf.cpp b/tools/jprof/elf.cpp
new file mode 100644
index 000000000..1de1d2dcc
--- /dev/null
+++ b/tools/jprof/elf.cpp
@@ -0,0 +1,133 @@
+/* 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 */