Implement -s and -S options which strip symbols.

7 files changed, 138 insertions, 38 deletions

diff --git a/gold/layout.cc b/gold/layout.cc
index af91d41..f7e1365 100644
--- a/gold/layout.cc
+++ b/gold/layout.cc
@@ -86,11 +86,19 @@ Layout::Hash_key::operator()(const Layout::Key& k) const
  return k.first + k.second.first + k.second.second;
 }
 
+// Return whether PREFIX is a prefix of STR.
+
+static inline bool
+is_prefix_of(const char* prefix, const char* str)
+{
+  return strncmp(prefix, str, strlen(prefix)) == 0;
+}
+
 // Whether to include this section in the link.
 
 template<int size, bool big_endian>
 bool
-Layout::include_section(Object*, const char*,
+Layout::include_section(Object*, const char* name,
 			const elfcpp::Shdr<size, big_endian>& shdr)
 {
   // Some section types are never linked.  Some are only linked when
@@ -111,8 +119,20 @@ Layout::include_section(Object*, const char*,
     case elfcpp::SHT_GROUP:
       return parameters->output_is_object();
 
+    case elfcpp::SHT_PROGBITS:
+      if (parameters->strip_debug()
+	  && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+	{
+	  // Debugging sections can only be recognized by name.
+	  if (is_prefix_of(".debug", name)
+	      || is_prefix_of(".gnu.linkonce.wi.", name)
+	      || is_prefix_of(".line", name)
+	      || is_prefix_of(".stab", name))
+	    return false;
+	}
+      return true;
+
     default:
-      // FIXME: Handle stripping debug sections here.
       return true;
     }
 }
@@ -973,32 +993,35 @@ Layout::create_symtab_sections(const Input_objects* input_objects,
   off = symtab->finalize(local_symcount, off, dynoff, dyn_global_index,
 			 dyncount, &this->sympool_);
 
-  this->sympool_.set_string_offsets();
+  if (!parameters->strip_all())
+    {
+      this->sympool_.set_string_offsets();
 
-  const char* symtab_name = this->namepool_.add(".symtab", NULL);
-  Output_section* osymtab = this->make_output_section(symtab_name,
-						      elfcpp::SHT_SYMTAB,
-						      0);
-  this->symtab_section_ = osymtab;
+      const char* symtab_name = this->namepool_.add(".symtab", NULL);
+      Output_section* osymtab = this->make_output_section(symtab_name,
+							  elfcpp::SHT_SYMTAB,
+							  0);
+      this->symtab_section_ = osymtab;
 
-  Output_section_data* pos = new Output_data_space(off - startoff,
-						   align);
-  osymtab->add_output_section_data(pos);
+      Output_section_data* pos = new Output_data_space(off - startoff,
+						       align);
+      osymtab->add_output_section_data(pos);
 
-  const char* strtab_name = this->namepool_.add(".strtab", NULL);
-  Output_section* ostrtab = this->make_output_section(strtab_name,
-						      elfcpp::SHT_STRTAB,
-						      0);
+      const char* strtab_name = this->namepool_.add(".strtab", NULL);
+      Output_section* ostrtab = this->make_output_section(strtab_name,
+							  elfcpp::SHT_STRTAB,
+							  0);
 
-  Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
-  ostrtab->add_output_section_data(pstr);
+      Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
+      ostrtab->add_output_section_data(pstr);
 
-  osymtab->set_address(0, startoff);
-  osymtab->set_link_section(ostrtab);
-  osymtab->set_info(local_symcount);
-  osymtab->set_entsize(symsize);
+      osymtab->set_address(0, startoff);
+      osymtab->set_link_section(ostrtab);
+      osymtab->set_info(local_symcount);
+      osymtab->set_entsize(symsize);
 
-  *poff = off;
+      *poff = off;
+    }
 }
 
 // Create the .shstrtab section, which holds the names of the
@@ -1555,19 +1578,22 @@ Layout::add_comdat(const char* signature, bool group)
 void
 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
 {
-  const Output_section* symtab_section = this->symtab_section_;
-  for (Section_list::const_iterator p = this->section_list_.begin();
-       p != this->section_list_.end();
-       ++p)
+  if (!parameters->strip_all())
     {
-      if ((*p)->needs_symtab_index())
+      const Output_section* symtab_section = this->symtab_section_;
+      for (Section_list::const_iterator p = this->section_list_.begin();
+	   p != this->section_list_.end();
+	   ++p)
 	{
-	  gold_assert(symtab_section != NULL);
-	  unsigned int index = (*p)->symtab_index();
-	  gold_assert(index > 0 && index != -1U);
-	  off_t off = (symtab_section->offset()
-		       + index * symtab_section->entsize());
-	  symtab->write_section_symbol(*p, of, off);
+	  if ((*p)->needs_symtab_index())
+	    {
+	      gold_assert(symtab_section != NULL);
+	      unsigned int index = (*p)->symtab_index();
+	      gold_assert(index > 0 && index != -1U);
+	      off_t off = (symtab_section->offset()
+			   + index * symtab_section->entsize());
+	      symtab->write_section_symbol(*p, of, off);
+	    }
 	}
     }
 
diff --git a/gold/object.cc b/gold/object.cc
index cfdb17c..b8843e9 100644
--- a/gold/object.cc
+++ b/gold/object.cc
@@ -715,6 +715,9 @@ void
 Sized_relobj<size, big_endian>::write_local_symbols(Output_file* of,
 						    const Stringpool* sympool)
 {
+  if (parameters->strip_all())
+    return;
+
   gold_assert(this->symtab_shndx_ != -1U);
   if (this->symtab_shndx_ == 0)
     {
diff --git a/gold/options.cc b/gold/options.cc
index 4ddb1ac..bd9f797 100644
--- a/gold/options.cc
+++ b/gold/options.cc
@@ -334,6 +334,10 @@ options::Command_line_options::options[] =
   GENERAL_ARG('R', "rpath", N_("Add DIR to runtime search path"),
               N_("-R DIR, -rpath DIR"), ONE_DASH,
               &General_options::add_to_rpath),
+  GENERAL_NOARG('s', "strip-all", N_("Strip all symbols"), NULL,
+		TWO_DASHES, &General_options::set_strip_all),
+  GENERAL_NOARG('S', "strip-debug", N_("Strip debugging information"), NULL,
+		TWO_DASHES, &General_options::set_strip_debug),
   GENERAL_NOARG('\0', "eh-frame-hdr", N_("Create exception frame header"),
                 NULL, TWO_DASHES, &General_options::set_create_eh_frame_hdr),
   GENERAL_ARG('\0', "rpath-link",
@@ -378,6 +382,7 @@ General_options::General_options()
     optimization_level_(0),
     output_file_name_("a.out"),
     is_relocatable_(false),
+    strip_(STRIP_NONE),
     create_eh_frame_hdr_(false),
     rpath_(),
     rpath_link_(),
diff --git a/gold/options.h b/gold/options.h
index 159e7b2..1e850cf 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -134,6 +134,16 @@ class General_options
   is_relocatable() const
   { return this->is_relocatable_; }
 
+  // -s: Strip all symbols.
+  bool
+  strip_all() const
+  { return this->strip_ == STRIP_ALL; }
+
+  // -S: Strip debugging information.
+  bool
+  strip_debug() const
+  { return this->strip_ == STRIP_ALL || this->strip_ == STRIP_DEBUG; }
+
   // --eh-frame-hdr: Whether to generate an exception frame header.
   bool
   create_eh_frame_hdr() const
@@ -172,6 +182,17 @@ class General_options
   friend class Command_line;
   friend class options::Command_line_options;
 
+  // Which symbols to strip.
+  enum Strip
+  {
+    // Don't strip any symbols.
+    STRIP_NONE,
+    // Strip all symbols.
+    STRIP_ALL,
+    // Strip debugging information.
+    STRIP_DEBUG
+  };
+
   void
   set_export_dynamic()
   { this->export_dynamic_ = true; }
@@ -201,6 +222,14 @@ class General_options
   { this->is_relocatable_ = true; }
 
   void
+  set_strip_all()
+  { this->strip_ = STRIP_ALL; }
+
+  void
+  set_strip_debug()
+  { this->strip_ = STRIP_DEBUG; }
+
+  void
   set_create_eh_frame_hdr()
   { this->create_eh_frame_hdr_ = true; }
 
@@ -238,6 +267,7 @@ class General_options
   int optimization_level_;
   const char* output_file_name_;
   bool is_relocatable_;
+  Strip strip_;
   bool create_eh_frame_hdr_;
   Dir_list rpath_;
   Dir_list rpath_link_;
diff --git a/gold/parameters.cc b/gold/parameters.cc
index 3c7cf28..337469a 100644
--- a/gold/parameters.cc
+++ b/gold/parameters.cc
@@ -42,6 +42,13 @@ Parameters::Parameters(const General_options* options)
     this->output_file_type_ = OUTPUT_OBJECT;
   else
     this->output_file_type_ = OUTPUT_EXECUTABLE;
+
+  if (options->strip_all())
+    this->strip_ = STRIP_ALL;
+  else if (options->strip_debug())
+    this->strip_ = STRIP_DEBUG;
+  else
+    this->strip_ = STRIP_NONE;
 }
 
 // Set whether we are doing a static link.
diff --git a/gold/parameters.h b/gold/parameters.h
index a150981..8d8ef36 100644
--- a/gold/parameters.h
+++ b/gold/parameters.h
@@ -62,6 +62,16 @@ class Parameters
   sysroot() const
   { return this->sysroot_; }
 
+  // Whether to strip all symbols.
+  bool
+  strip_all() const
+  { return this->strip_ == STRIP_ALL; }
+
+  // Whether to strip debugging information.
+  bool
+  strip_debug() const
+  { return this->strip_ == STRIP_ALL || this->strip_ == STRIP_DEBUG; }
+
   // Whether we are doing a static link--a link in which none of the
   // input files are shared libraries.  This is only known after we
   // have seen all the input files.
@@ -114,11 +124,24 @@ class Parameters
       OUTPUT_OBJECT
     };
 
+  // Which symbols to strip.
+  enum Strip
+  {
+    // Don't strip any symbols.
+    STRIP_NONE,
+    // Strip all symbols.
+    STRIP_ALL,
+    // Strip debugging information.
+    STRIP_DEBUG
+  };
+
   // The type of the output file.
   Output_file_type output_file_type_;
   // The target system root directory.
   std::string sysroot_;
-  
+  // Which symbols to strip.
+  Strip strip_;
+
   // Whether the doing_static_link_ field is valid.
   bool is_doing_static_link_valid_;
   // Whether we are doing a static link.
diff --git a/gold/symtab.cc b/gold/symtab.cc
index c9ac1c9..5237b8c 100644
--- a/gold/symtab.cc
+++ b/gold/symtab.cc
@@ -1316,10 +1316,16 @@ Symbol_table::sized_finalize(unsigned index, off_t off, Stringpool* pool)
 	}
 
       sym->set_value(value);
-      sym->set_symtab_index(index);
-      pool->add(sym->name(), NULL);
-      ++index;
-      off += sym_size;
+
+      if (parameters->strip_all())
+	sym->set_symtab_index(-1U);
+      else
+	{
+	  sym->set_symtab_index(index);
+	  pool->add(sym->name(), NULL);
+	  ++index;
+	  off += sym_size;
+	}
     }
 
   this->output_count_ = index - orig_index;