Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libasm/disasm_cb.c b/libasm/disasm_cb.c
new file mode 100644
index 0000000..cf278c7
--- /dev/null
+++ b/libasm/disasm_cb.c
@@ -0,0 +1,179 @@
+/* Copyright (C) 2005, 2007, 2008 Red Hat, Inc.
+   This file is part of elfutils.
+   Written by Ulrich Drepper <drepper@redhat.com>, 2005.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <string.h>
+
+#include "libasmP.h"
+#include "../libebl/libeblP.h"
+
+
+struct symtoken
+{
+  DisasmCtx_t *ctx;
+  void *symcbarg;
+};
+
+
+static int
+default_elf_getsym (GElf_Addr addr, Elf32_Word scnndx, GElf_Addr value,
+		    char **buf, size_t *buflen, void *arg)
+{
+  struct symtoken *symtoken = (struct symtoken *) arg;
+
+  /* First try the user provided function.  */
+  if (symtoken->ctx->symcb != NULL)
+    {
+      int res = symtoken->ctx->symcb (addr, scnndx, value, buf, buflen,
+				      symtoken->symcbarg);
+      if (res >= 0)
+	return res;
+    }
+
+  // XXX Look up in ELF file.
+
+  return -1;
+}
+
+
+struct symaddrpair
+{
+  GElf_Addr addr;
+  const char *name;
+};
+
+
+static void
+read_symtab_exec (DisasmCtx_t *ctx)
+{
+  /* We simply use all we can get our hands on.  This will produce
+     some duplicate information but this is no problem, we simply
+     ignore the latter definitions.  */
+  Elf_Scn *scn= NULL;
+  while ((scn = elf_nextscn (ctx->elf, scn)) != NULL)
+    {
+      GElf_Shdr shdr_mem;
+      GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+      Elf_Data *data;
+      if (shdr == NULL || shdr->sh_type != SHT_SYMTAB
+	  || (data = elf_getdata (scn, NULL)) == NULL)
+	continue;
+
+      int xndxscnidx = elf_scnshndx (scn);
+      Elf_Data *xndxdata = NULL;
+      if (xndxscnidx > 0)
+	xndxdata = elf_getdata (elf_getscn (ctx->elf, xndxscnidx), NULL);
+
+      /* Iterate over all symbols.  Add all defined symbols.  */
+      int nsyms = shdr->sh_size / shdr->sh_entsize;
+      for (int cnt = 1; cnt < nsyms; ++cnt)
+	{
+	  Elf32_Word xshndx;
+	  GElf_Sym sym_mem;
+	  GElf_Sym *sym = gelf_getsymshndx (data, xndxdata, cnt, &sym_mem,
+					    &xshndx);
+	  if (sym == NULL)
+	    continue;
+
+	  /* Undefined symbols are useless here.  */
+	  if (sym->st_shndx == SHN_UNDEF)
+	    continue;
+
+
+	}
+    }
+}
+
+
+static void
+read_symtab (DisasmCtx_t *ctx)
+{
+  /* Find the symbol table(s).  */
+  GElf_Ehdr ehdr_mem;
+  GElf_Ehdr *ehdr = gelf_getehdr (ctx->elf, &ehdr_mem);
+  if (ehdr == NULL)
+    return;
+
+  switch (ehdr->e_type)
+    {
+    case ET_EXEC:
+    case ET_DYN:
+      read_symtab_exec (ctx);
+      break;
+
+    case ET_REL:
+      // XXX  Handle
+      break;
+
+    default:
+      break;
+    }
+}
+
+
+static int
+null_elf_getsym (GElf_Addr addr __attribute__ ((unused)),
+		 Elf32_Word scnndx __attribute__ ((unused)),
+		 GElf_Addr value __attribute__ ((unused)),
+		 char **buf __attribute__ ((unused)),
+		 size_t *buflen __attribute__ ((unused)),
+		 void *arg __attribute__ ((unused)))
+{
+  return -1;
+}
+
+
+int
+disasm_cb (DisasmCtx_t *ctx, const uint8_t **startp, const uint8_t *end,
+	   GElf_Addr addr, const char *fmt, DisasmOutputCB_t outcb,
+	   void *outcbarg, void *symcbarg)
+{
+  struct symtoken symtoken;
+  DisasmGetSymCB_t getsym = ctx->symcb ?: null_elf_getsym;
+
+  if (ctx->elf != NULL)
+    {
+      /* Read all symbols of the ELF file and stuff them into a hash
+	 table.  The key is the address and the section index.  */
+      read_symtab (ctx);
+
+      symtoken.ctx = ctx;
+      symtoken.symcbarg = symcbarg;
+
+      symcbarg = &symtoken;
+
+      getsym = default_elf_getsym;
+    }
+
+  return ctx->ebl->disasm (ctx->ebl, startp, end, addr, fmt, outcb,
+			   getsym, outcbarg, symcbarg);
+}
+INTDEF (disasm_cb)