[GOLD] reporting local symbol names

get_symbol_name currently returns "" for the usual STT_SECTION symbols
generated by gas.  That's not very helpful, return the section name.
Demangle local symbols too, fixing an inconsistency in
issue_discarded_error where global symbols are demangled.

	* object.cc (Sized_relobj_file::get_symbol_name): Return a
	std::string.  Return section name for STT_SECTION symbols with
	zero st_name.  Sanity check st_name, and don't run off the end
	of an improperly terminated .strtab.  Demangle sym names.
	* object.h (Sized_relobj_file::get_symbol_name): Update decl.
	* target-reloc.h (issue_discarded_error): Adjust.
	* powerpc.cc (Target_powerpc::Relocate::relocate): Report reloc
	type and symbol for relocation overflows.

1 files changed, 37 insertions, 8 deletions

diff --git a/gold/object.cc b/gold/object.cc
index 77b2690..acd7c94 100644
--- a/gold/object.cc
+++ b/gold/object.cc
@@ -3054,7 +3054,7 @@ Sized_relobj_file<size, big_endian>::find_kept_section_object(
 // Return the name of symbol SYMNDX.
 
 template<int size, bool big_endian>
-const char*
+std::string
 Sized_relobj_file<size, big_endian>::get_symbol_name(unsigned int symndx)
 {
   if (this->symtab_shndx_ == 0)
@@ -3065,6 +3065,24 @@ Sized_relobj_file<size, big_endian>::get_symbol_name(unsigned int symndx)
 							&symbols_size,
 							false);
 
+  const unsigned char* p = symbols + symndx * This::sym_size;
+  if (p >= symbols + symbols_size)
+    return NULL;
+
+  elfcpp::Sym<size, big_endian> sym(p);
+
+  if (sym.get_st_name() == 0 && sym.get_st_type() == elfcpp::STT_SECTION)
+    {
+      bool is_ordinary;
+      unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
+						      sym.get_st_shndx(),
+						      &is_ordinary);
+      if (!is_ordinary || sym_shndx >= this->shnum())
+	return NULL;
+
+      return this->section_name(sym_shndx);
+    }
+
   unsigned int symbol_names_shndx =
     this->adjust_shndx(this->section_link(this->symtab_shndx_));
   section_size_type names_size;
@@ -3072,14 +3090,25 @@ Sized_relobj_file<size, big_endian>::get_symbol_name(unsigned int symndx)
     this->section_contents(symbol_names_shndx, &names_size, false);
   const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
 
-  const unsigned char* p = symbols + symndx * This::sym_size;
-
-  if (p >= symbols + symbols_size)
+  unsigned int sym_name = sym.get_st_name();
+  if (sym_name >= names_size)
     return NULL;
-
-  elfcpp::Sym<size, big_endian> sym(p);
-
-  return symbol_names + sym.get_st_name();
+  const char* namep = symbol_names + sym_name;
+  const void* endp = memchr(namep, 0, names_size - sym_name);
+  if (!endp)
+    endp = symbol_names + names_size;
+  std::string name = std::string(namep, static_cast<const char*>(endp) - namep);
+
+  if (!parameters->options().do_demangle())
+    return name;
+
+  char* demangled_name = cplus_demangle(name.c_str(), DMGL_ANSI | DMGL_PARAMS);
+  if (!demangled_name)
+    return name;
+
+  name = demangled_name;
+  free(demangled_name);
+  return name;
 }
 
 // Get symbol counts.