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 */