More dynamic object support, initial scripting support.

1 files changed, 670 insertions, 0 deletions

diff --git a/gold/dynobj.cc b/gold/dynobj.cc
new file mode 100644
index 0000000..ba1fb15
--- /dev/null
+++ b/gold/dynobj.cc
@@ -0,0 +1,670 @@
+// dynobj.cc -- dynamic object support for gold
+
+#include "gold.h"
+
+#include <vector>
+#include <cstring>
+
+#include "symtab.h"
+#include "dynobj.h"
+
+namespace gold
+{
+
+// Class Sized_dynobj.
+
+template<int size, bool big_endian>
+Sized_dynobj<size, big_endian>::Sized_dynobj(
+    const std::string& name,
+    Input_file* input_file,
+    off_t offset,
+    const elfcpp::Ehdr<size, big_endian>& ehdr)
+  : Dynobj(name, input_file, offset),
+    elf_file_(this, ehdr),
+    soname_()
+{
+}
+
+// Set up the object.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::setup(
+    const elfcpp::Ehdr<size, big_endian>& ehdr)
+{
+  this->set_target(ehdr.get_e_machine(), size, big_endian,
+		   ehdr.get_e_ident()[elfcpp::EI_OSABI],
+		   ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
+
+  const unsigned int shnum = this->elf_file_.shnum();
+  this->set_shnum(shnum);
+}
+
+// Find the SHT_DYNSYM section and the various version sections, and
+// the dynamic section, given the section headers.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::find_dynsym_sections(
+    const unsigned char* pshdrs,
+    unsigned int* pdynsym_shndx,
+    unsigned int* pversym_shndx,
+    unsigned int* pverdef_shndx,
+    unsigned int* pverneed_shndx,
+    unsigned int* pdynamic_shndx)
+{
+  *pdynsym_shndx = -1U;
+  *pversym_shndx = -1U;
+  *pverdef_shndx = -1U;
+  *pverneed_shndx = -1U;
+  *pdynamic_shndx = -1U;
+
+  const unsigned int shnum = this->shnum();
+  const unsigned char* p = pshdrs;
+  for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size)
+    {
+      typename This::Shdr shdr(p);
+
+      unsigned int* pi;
+      switch (shdr.get_sh_type())
+	{
+	case elfcpp::SHT_DYNSYM:
+	  pi = pdynsym_shndx;
+	  break;
+	case elfcpp::SHT_GNU_versym:
+	  pi = pversym_shndx;
+	  break;
+	case elfcpp::SHT_GNU_verdef:
+	  pi = pverdef_shndx;
+	  break;
+	case elfcpp::SHT_GNU_verneed:
+	  pi = pverneed_shndx;
+	  break;
+	case elfcpp::SHT_DYNAMIC:
+	  pi = pdynamic_shndx;
+	  break;
+	default:
+	  pi = NULL;
+	  break;
+	}
+
+      if (pi == NULL)
+	continue;
+
+      if (*pi != -1U)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: unexpected duplicate type %u section: %u, %u\n"),
+		  program_name, this->name().c_str(), shdr.get_sh_type(),
+		  *pi, i);
+	  gold_exit(false);
+	}
+
+      *pi = i;
+    }
+}
+
+// Read the contents of section SHNDX.  PSHDRS points to the section
+// headers.  TYPE is the expected section type.  LINK is the expected
+// section link.  Store the data in *VIEW and *VIEW_SIZE.  The
+// section's sh_info field is stored in *VIEW_INFO.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::read_dynsym_section(
+    const unsigned char* pshdrs,
+    unsigned int shndx,
+    elfcpp::SHT type,
+    unsigned int link,
+    File_view** view,
+    off_t* view_size,
+    unsigned int* view_info)
+{
+  if (shndx == -1U)
+    {
+      *view = NULL;
+      *view_size = 0;
+      *view_info = 0;
+      return;
+    }
+
+  typename This::Shdr shdr(pshdrs + shndx * This::shdr_size);
+
+  assert(shdr.get_sh_type() == type);
+
+  if (shdr.get_sh_link() != link)
+    {
+      fprintf(stderr,
+	      _("%s: %s: unexpected link in section %u header: %u != %u\n"),
+	      program_name, this->name().c_str(), shndx,
+	      shdr.get_sh_link(), link);
+      gold_exit(false);
+    }
+
+  *view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size());
+  *view_size = shdr.get_sh_size();
+  *view_info = shdr.get_sh_info();
+}
+
+// Set soname_ if this shared object has a DT_SONAME tag.  PSHDRS
+// points to the section headers.  DYNAMIC_SHNDX is the section index
+// of the SHT_DYNAMIC section.  STRTAB_SHNDX, STRTAB, and STRTAB_SIZE
+// are the section index and contents of a string table which may be
+// the one associated with the SHT_DYNAMIC section.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::set_soname(const unsigned char* pshdrs,
+					   unsigned int dynamic_shndx,
+					   unsigned int strtab_shndx,
+					   const unsigned char* strtabu,
+					   off_t strtab_size)
+{
+  typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size);
+  assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
+
+  const off_t dynamic_size = dynamicshdr.get_sh_size();
+  const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(),
+						 dynamic_size);
+
+  const unsigned int link = dynamicshdr.get_sh_link();
+  if (link != strtab_shndx)
+    {
+      if (link >= this->shnum())
+	{
+	  fprintf(stderr,
+		  _("%s: %s: DYNAMIC section %u link out of range: %u\n"),
+		  program_name, this->name().c_str(),
+		  dynamic_shndx, link);
+	  gold_exit(false);
+	}
+
+      typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size);
+      if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: DYNAMIC section %u link %u is not a strtab\n"),
+		  program_name, this->name().c_str(),
+		  dynamic_shndx, link);
+	  gold_exit(false);
+	}
+
+      strtab_size = strtabshdr.get_sh_size();
+      strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size);
+    }
+
+  for (const unsigned char* p = pdynamic;
+       p < pdynamic + dynamic_size;
+       p += This::dyn_size)
+    {
+      typename This::Dyn dyn(p);
+
+      if (dyn.get_d_tag() == elfcpp::DT_SONAME)
+	{
+	  off_t val = dyn.get_d_val();
+	  if (val >= strtab_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: DT_SONAME value out of range: "
+			"%lld >= %lld\n"),
+		      program_name, this->name().c_str(),
+		      static_cast<long long>(val),
+		      static_cast<long long>(strtab_size));
+	      gold_exit(false);
+	    }
+
+	  const char* strtab = reinterpret_cast<const char*>(strtabu);
+	  this->soname_ = std::string(strtab + val);
+	  return;
+	}
+
+      if (dyn.get_d_tag() == elfcpp::DT_NULL)
+	return;
+    }
+
+  fprintf(stderr, _("%s: %s: missing DT_NULL in dynamic segment\n"),
+	  program_name, this->name().c_str());
+  gold_exit(false);
+}
+
+// Read the symbols and sections from a dynamic object.  We read the
+// dynamic symbols, not the normal symbols.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
+{
+  this->read_section_data(&this->elf_file_, sd);
+
+  const unsigned char* const pshdrs = sd->section_headers->data();
+
+  unsigned int dynsym_shndx;
+  unsigned int versym_shndx;
+  unsigned int verdef_shndx;
+  unsigned int verneed_shndx;
+  unsigned int dynamic_shndx;
+  this->find_dynsym_sections(pshdrs, &dynsym_shndx, &versym_shndx,
+			     &verdef_shndx, &verneed_shndx, &dynamic_shndx);
+
+  unsigned int strtab_shndx = -1U;
+
+  if (dynsym_shndx == -1U)
+    {
+      sd->symbols = NULL;
+      sd->symbols_size = 0;
+      sd->symbol_names = NULL;
+      sd->symbol_names_size = 0;
+    }
+  else
+    {
+      // Get the dynamic symbols.
+      typename This::Shdr dynsymshdr(pshdrs + dynsym_shndx * This::shdr_size);
+      assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM);
+
+      sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(),
+					   dynsymshdr.get_sh_size());
+      sd->symbols_size = dynsymshdr.get_sh_size();
+
+      // Get the symbol names.
+      strtab_shndx = dynsymshdr.get_sh_link();
+      if (strtab_shndx >= this->shnum())
+	{
+	  fprintf(stderr,
+		  _("%s: %s: invalid dynamic symbol table name index: %u\n"),
+		  program_name, this->name().c_str(), strtab_shndx);
+	  gold_exit(false);
+	}
+      typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
+      if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: dynamic symbol table name section "
+		    "has wrong type: %u\n"),
+		  program_name, this->name().c_str(),
+		  static_cast<unsigned int>(strtabshdr.get_sh_type()));
+	  gold_exit(false);
+	}
+
+      sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(),
+						strtabshdr.get_sh_size());
+      sd->symbol_names_size = strtabshdr.get_sh_size();
+
+      // Get the version information.
+
+      unsigned int dummy;
+      this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym,
+				dynsym_shndx, &sd->versym, &sd->versym_size,
+				&dummy);
+
+      // We require that the version definition and need section link
+      // to the same string table as the dynamic symbol table.  This
+      // is not a technical requirement, but it always happens in
+      // practice.  We could change this if necessary.
+
+      this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef,
+				strtab_shndx, &sd->verdef, &sd->verdef_size,
+				&sd->verdef_info);
+
+      this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed,
+				strtab_shndx, &sd->verneed, &sd->verneed_size,
+				&sd->verneed_info);
+    }
+
+  // Read the SHT_DYNAMIC section to find whether this shared object
+  // has a DT_SONAME tag.  This doesn't really have anything to do
+  // with reading the symbols, but this is a convenient place to do
+  // it.
+  if (dynamic_shndx != -1U)
+    this->set_soname(pshdrs, dynamic_shndx, strtab_shndx,
+		     (sd->symbol_names == NULL
+		      ? NULL
+		      : sd->symbol_names->data()),
+		     sd->symbol_names_size);
+}
+
+// Lay out the input sections for a dynamic object.  We don't want to
+// include sections from a dynamic object, so all that we actually do
+// here is check for .gnu.warning sections.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_layout(const General_options&,
+					  Symbol_table* symtab,
+					  Layout*,
+					  Read_symbols_data* sd)
+{
+  const unsigned int shnum = this->shnum();
+  if (shnum == 0)
+    return;
+
+  // Get the section headers.
+  const unsigned char* pshdrs = sd->section_headers->data();
+
+  // Get the section names.
+  const unsigned char* pnamesu = sd->section_names->data();
+  const char* pnames = reinterpret_cast<const char*>(pnamesu);
+
+  // Skip the first, dummy, section.
+  pshdrs += This::shdr_size;
+  for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
+    {
+      typename This::Shdr shdr(pshdrs);
+
+      if (shdr.get_sh_name() >= sd->section_names_size)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: bad section name offset for section %u: %lu\n"),
+		  program_name, this->name().c_str(), i,
+		  static_cast<unsigned long>(shdr.get_sh_name()));
+	  gold_exit(false);
+	}
+
+      const char* name = pnames + shdr.get_sh_name();
+
+      this->handle_gnu_warning_section(name, i, symtab);
+    }
+
+  delete sd->section_headers;
+  sd->section_headers = NULL;
+  delete sd->section_names;
+  sd->section_names = NULL;
+}
+
+// Add an entry to the vector mapping version numbers to version
+// strings.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::set_version_map(
+    Version_map* version_map,
+    unsigned int ndx,
+    const char* name) const
+{
+  assert(ndx < version_map->size());
+  if ((*version_map)[ndx] != NULL)
+    {
+      fprintf(stderr, _("%s: %s: duplicate definition for version %u\n"),
+	      program_name, this->name().c_str(), ndx);
+      gold_exit(false);
+    }
+  (*version_map)[ndx] = name;
+}
+
+// Create a vector mapping version numbers to version strings.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::make_version_map(
+    Read_symbols_data* sd,
+    Version_map* version_map) const
+{
+  if (sd->verdef == NULL && sd->verneed == NULL)
+    return;
+
+  // First find the largest version index.
+  unsigned int maxver = 0;
+
+  if (sd->verdef != NULL)
+    {
+      const unsigned char* pverdef = sd->verdef->data();
+      off_t verdef_size = sd->verdef_size;
+      const unsigned int count = sd->verdef_info;
+
+      const unsigned char* p = pverdef;
+      for (unsigned int i = 0; i < count; ++i)
+	{
+	  elfcpp::Verdef<size, big_endian> verdef(p);
+
+	  const unsigned int vd_ndx = verdef.get_vd_ndx();
+
+	  // The GNU linker clears the VERSYM_HIDDEN bit.  I'm not
+	  // sure why.
+
+	  if (vd_ndx > maxver)
+	    maxver = vd_ndx;
+
+	  const unsigned int vd_next = verdef.get_vd_next();
+	  if ((p - pverdef) + vd_next >= verdef_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: verdef vd_next field out of range: %u\n"),
+		      program_name, this->name().c_str(), vd_next);
+	      gold_exit(false);
+	    }
+
+	  p += vd_next;
+	}
+    }
+
+  if (sd->verneed != NULL)
+    {
+      const unsigned char* pverneed = sd->verneed->data();
+      off_t verneed_size = sd->verneed_size;
+      const unsigned int count = sd->verneed_info;
+
+      const unsigned char* p = pverneed;
+      for (unsigned int i = 0; i < count; ++i)
+	{
+	  elfcpp::Verneed<size, big_endian> verneed(p);
+
+	  const unsigned int vn_aux = verneed.get_vn_aux();
+	  if ((p - pverneed) + vn_aux >= verneed_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: verneed vn_aux field out of range: %u\n"),
+		      program_name, this->name().c_str(), vn_aux);
+	      gold_exit(false);
+	    }
+
+	  const unsigned int vn_cnt = verneed.get_vn_cnt();
+	  const unsigned char* pvna = p + vn_aux;
+	  for (unsigned int j = 0; j < vn_cnt; ++j)
+	    {
+	      elfcpp::Vernaux<size, big_endian> vernaux(pvna);
+
+	      const unsigned int vna_other = vernaux.get_vna_other();
+	      if (vna_other > maxver)
+		maxver = vna_other;
+
+	      const unsigned int vna_next = vernaux.get_vna_next();
+	      if ((pvna - pverneed) + vna_next >= verneed_size)
+		{
+		  fprintf(stderr,
+			  _("%s: %s: verneed vna_next field "
+			    "out of range: %u\n"),
+			  program_name, this->name().c_str(), vna_next);
+		  gold_exit(false);
+		}
+
+	      pvna += vna_next;
+	    }
+
+	  const unsigned int vn_next = verneed.get_vn_next();
+	  if ((p - pverneed) + vn_next >= verneed_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: verneed vn_next field out of range: %u\n"),
+		      program_name, this->name().c_str(), vn_next);
+	      gold_exit(false);
+	    }
+
+	  p += vn_next;
+	}
+    }
+
+  // Now MAXVER is the largest version index we have seen.
+
+  version_map->resize(maxver + 1);
+
+  const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
+  off_t names_size = sd->symbol_names_size;
+
+  if (sd->verdef != NULL)
+    {
+      const unsigned char* pverdef = sd->verdef->data();
+      off_t verdef_size = sd->verdef_size;
+      const unsigned int count = sd->verdef_info;
+
+      const unsigned char* p = pverdef;
+      for (unsigned int i = 0; i < count; ++i)
+	{
+	  elfcpp::Verdef<size, big_endian> verdef(p);
+
+	  const unsigned int vd_cnt = verdef.get_vd_cnt();
+	  if (vd_cnt < 1)
+	    {
+	      fprintf(stderr, _("%s: %s: verdef vd_cnt field too small: %u\n"),
+		      program_name, this->name().c_str(), vd_cnt);
+	      gold_exit(false);
+	    }
+
+	  const unsigned int vd_aux = verdef.get_vd_aux();
+	  if ((p - pverdef) + vd_aux >= verdef_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: verdef vd_aux field out of range: %u\n"),
+		      program_name, this->name().c_str(), vd_aux);
+	      gold_exit(false);
+	    }
+
+	  const unsigned char* pvda = p + vd_aux;
+	  elfcpp::Verdaux<size, big_endian> verdaux(pvda);
+
+	  const unsigned int vda_name = verdaux.get_vda_name();
+	  if (vda_name >= names_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: verdaux vda_name field out of range: %u\n"),
+		      program_name, this->name().c_str(), vda_name);
+	      gold_exit(false);
+	    }
+
+	  this->set_version_map(version_map, verdef.get_vd_ndx(),
+				names + vda_name);
+
+	  const unsigned int vd_next = verdef.get_vd_next();
+	  if ((p - pverdef) + vd_next >= verdef_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: verdef vd_next field out of range: %u\n"),
+		      program_name, this->name().c_str(), vd_next);
+	      gold_exit(false);
+	    }
+
+	  p += vd_next;
+	}
+    }
+
+  if (sd->verneed != NULL)
+    {
+      const unsigned char* pverneed = sd->verneed->data();
+      const unsigned int count = sd->verneed_info;
+
+      const unsigned char* p = pverneed;
+      for (unsigned int i = 0; i < count; ++i)
+	{
+	  elfcpp::Verneed<size, big_endian> verneed(p);
+
+	  const unsigned int vn_aux = verneed.get_vn_aux();
+	  const unsigned int vn_cnt = verneed.get_vn_cnt();
+	  const unsigned char* pvna = p + vn_aux;
+	  for (unsigned int j = 0; j < vn_cnt; ++j)
+	    {
+	      elfcpp::Vernaux<size, big_endian> vernaux(pvna);
+
+	      const unsigned int vna_name = vernaux.get_vna_name();
+	      if (vna_name >= names_size)
+		{
+		  fprintf(stderr,
+			  _("%s: %s: vernaux vna_name field "
+			    "out of range: %u\n"),
+			  program_name, this->name().c_str(), vna_name);
+		  gold_exit(false);
+		}
+
+	      this->set_version_map(version_map, vernaux.get_vna_other(),
+				    names + vna_name);
+
+	      pvna += vernaux.get_vna_next();
+	    }
+
+	  p += verneed.get_vn_next();
+	}
+    }
+}
+
+// Add the dynamic symbols to the symbol table.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
+					       Read_symbols_data* sd)
+{
+  if (sd->symbols == NULL)
+    {
+      assert(sd->symbol_names == NULL);
+      assert(sd->versym == NULL && sd->verdef == NULL && sd->verneed == NULL);
+      return;
+    }
+
+  const int sym_size = This::sym_size;
+  const size_t symcount = sd->symbols_size / sym_size;
+  if (symcount * sym_size != sd->symbols_size)
+    {
+      fprintf(stderr,
+	      _("%s: %s: size of dynamic symbols is not "
+		"multiple of symbol size\n"),
+	      program_name, this->name().c_str());
+      gold_exit(false);
+    }
+
+  Version_map version_map;
+  this->make_version_map(sd, &version_map);
+
+  const char* sym_names =
+    reinterpret_cast<const char*>(sd->symbol_names->data());
+  symtab->add_from_dynobj(this, sd->symbols->data(), symcount,
+			  sym_names, sd->symbol_names_size,
+			  (sd->versym == NULL
+			   ? NULL
+			   : sd->versym->data()),
+			  sd->versym_size,
+			  &version_map);
+
+  delete sd->symbols;
+  sd->symbols = NULL;
+  delete sd->symbol_names;
+  sd->symbol_names = NULL;
+  if (sd->versym != NULL)
+    {
+      delete sd->versym;
+      sd->versym = NULL;
+    }
+  if (sd->verdef != NULL)
+    {
+      delete sd->verdef;
+      sd->verdef = NULL;
+    }
+  if (sd->verneed != NULL)
+    {
+      delete sd->verneed;
+      sd->verneed = NULL;
+    }
+}
+
+// Instantiate the templates we need.  We could use the configure
+// script to restrict this to only the ones for implemented targets.
+
+template
+class Sized_dynobj<32, false>;
+
+template
+class Sized_dynobj<32, true>;
+
+template
+class Sized_dynobj<64, false>;
+
+template
+class Sized_dynobj<64, true>;
+
+} // End namespace gold.