Snapshot. Now able to produce a minimal executable which actually

runs.

1 files changed, 360 insertions, 0 deletions

diff --git a/gold/archive.cc b/gold/archive.cc
new file mode 100644
index 0000000..6019325
--- /dev/null
+++ b/gold/archive.cc
@@ -0,0 +1,360 @@
+// archive.cc -- archive support for gold
+
+#include "gold.h"
+
+#include <cerrno>
+#include <cstring>
+#include <climits>
+#include <vector>
+
+#include "elfcpp.h"
+#include "fileread.h"
+#include "symtab.h"
+#include "object.h"
+#include "archive.h"
+
+namespace gold
+{
+
+// The header of an entry in the archive.  This is all readable text,
+// padded with spaces where necesary.  If the contents of an archive
+// are all text file, the entire archive is readable.
+
+struct Archive::Archive_header
+{
+  // The entry name.
+  char ar_name[16];
+  // The file modification time.
+  char ar_date[12];
+  // The user's UID in decimal.
+  char ar_uid[6];
+  // The user's GID in decimal.
+  char ar_gid[6];
+  // The file mode in octal.
+  char ar_mode[8];
+  // The file size in decimal.
+  char ar_size[10];
+  // The final magic code.
+  char ar_fmag[2];
+};
+
+// Archive methods.
+
+const char Archive::armag[sarmag] =
+{
+  '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
+};
+
+const char Archive::arfmag[2] = { '`', '\n' };
+
+// Get a view into the underlying file.
+
+const unsigned char*
+Archive::get_view(off_t start, off_t size)
+{
+  return this->input_file_->file().get_view(start, size);
+}
+
+// Set up the archive: read the symbol map and the extended name
+// table.
+
+void
+Archive::setup()
+{
+  // The first member of the archive should be the symbol table.
+  std::string armap_name;
+  off_t armap_size = this->read_header(sarmag, &armap_name);
+  if (!armap_name.empty())
+    {
+      fprintf(stderr, _("%s: %s: no archive symbol table (run ranlib)\n"),
+	      program_name, this->name().c_str());
+      gold_exit(false);
+    }
+
+  // Read in the entire armap.
+  const unsigned char* p = this->get_view(sarmag + sizeof(Archive_header),
+					  armap_size);
+
+  // Numbers in the armap are always big-endian.
+  const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
+  unsigned int nsyms = elfcpp::read_elf_word<true>(pword);
+  ++pword;
+
+  // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
+  const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
+
+  this->armap_.resize(nsyms);
+
+  for (unsigned int i = 0; i < nsyms; ++i)
+    {
+      this->armap_[i].name = pnames;
+      this->armap_[i].offset = elfcpp::read_elf_word<true>(pword);
+      pnames += strlen(pnames) + 1;
+      ++pword;
+    }
+
+  if (reinterpret_cast<const unsigned char*>(pnames) - p > armap_size)
+    {
+      fprintf(stderr, _("%s: %s: bad archive symbol table names\n"),
+	      program_name, this->name().c_str());
+      gold_exit(false);
+    }
+
+  // See if there is an extended name table.
+  off_t off = sarmag + sizeof(Archive_header) + armap_size;
+  if ((off & 1) != 0)
+    ++off;
+  std::string xname;
+  off_t extended_size = this->read_header(off, &xname);
+  if (xname == "/")
+    {
+      p = this->get_view(off + sizeof(Archive_header), extended_size);
+      const char* px = reinterpret_cast<const char*>(p);
+      this->extended_names_.assign(px, extended_size);
+    }
+
+  // Opening the file locked it.  Unlock it now.
+  this->input_file_->file().unlock();
+}
+
+// Read the header of an archive member at OFF.  Fail if something
+// goes wrong.  Return the size of the member.  Set *PNAME to the name
+// of the member.
+
+off_t
+Archive::read_header(off_t off, std::string* pname)
+{
+  const unsigned char* p = this->get_view(off, sizeof(Archive_header));
+  const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
+
+  if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
+    {
+      fprintf(stderr, _("%s; %s: malformed archive header at %ld\n"),
+	      program_name, this->name().c_str(),
+	      static_cast<long>(off));
+      gold_exit(false);
+    }
+
+  const int size_string_size = sizeof hdr->ar_size;
+  char size_string[size_string_size + 1];
+  memcpy(size_string, hdr->ar_size, size_string_size);
+  char* ps = size_string + size_string_size;
+  while (ps[-1] == ' ')
+    --ps;
+  *ps = '\0';
+
+  errno = 0;
+  char* end;
+  off_t member_size = strtol(size_string, &end, 10);
+  if (*end != '\0'
+      || member_size < 0
+      || (member_size == LONG_MAX && errno == ERANGE))
+    {
+      fprintf(stderr, _("%s: %s: malformed archive header size at %ld\n"),
+	      program_name, this->name().c_str(),
+	      static_cast<long>(off));
+      gold_exit(false);
+    }
+
+  if (hdr->ar_name[0] != '/')
+    {
+      const char* name_end = strchr(hdr->ar_name, '/');
+      if (name_end == NULL
+	  || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
+	{
+	  fprintf(stderr, _("%s: %s: malformed archive header name at %ld\n"),
+		  program_name, this->name().c_str(),
+		  static_cast<long>(off));
+	  gold_exit(false);
+	}
+      pname->assign(hdr->ar_name, name_end - hdr->ar_name);
+    }
+  else if (hdr->ar_name[1] == ' ')
+    {
+      // This is the symbol table.
+      pname->clear();
+    }
+  else if (hdr->ar_name[1] == '/')
+    {
+      // This is the extended name table.
+      pname->assign(1, '/');
+    }
+  else
+    {
+      errno = 0;
+      long x = strtol(hdr->ar_name + 1, &end, 10);
+      if (*end != ' '
+	  || x < 0
+	  || (x == LONG_MAX && errno == ERANGE)
+	  || static_cast<size_t>(x) >= this->extended_names_.size())
+	{
+	  fprintf(stderr, _("%s: %s: bad extended name index at %ld\n"),
+		  program_name, this->name().c_str(),
+		  static_cast<long>(off));
+	  gold_exit(false);
+	}
+
+      const char* name = this->extended_names_.data() + x;
+      const char* name_end = strchr(name, '/');
+      if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
+	  || name_end[1] != '\n')
+	{
+	  fprintf(stderr, _("%s: %s: bad extended name entry at header %ld\n"),
+		  program_name, this->name().c_str(),
+		  static_cast<long>(off));
+	  gold_exit(false);
+	}
+      pname->assign(name, name_end - name);
+    }
+
+  return member_size;
+}
+
+// Select members from the archive and add them to the link.  We walk
+// through the elements in the archive map, and look each one up in
+// the symbol table.  If it exists as a strong undefined symbol, we
+// pull in the corresponding element.  We have to do this in a loop,
+// since pulling in one element may create new undefined symbols which
+// may be satisfied by other objects in the archive.
+
+void
+Archive::add_symbols(Symbol_table* symtab, Input_objects* input_objects)
+{
+  size_t armap_size = this->armap_.size();
+  std::vector<bool> seen;
+  seen.resize(this->armap_.size());
+  seen.clear();
+
+  bool added_new_object;
+  do
+    {
+      added_new_object = false;
+      off_t last = -1;
+      for (size_t i = 0; i < armap_size; ++i)
+	{
+	  if (seen[i])
+	    continue;
+	  if (this->armap_[i].offset == last)
+	    {
+	      seen[i] = true;
+	      continue;
+	    }
+
+	  Symbol* sym = symtab->lookup(this->armap_[i].name);
+	  if (sym == NULL)
+	    continue;
+	  else if (sym->shnum() != elfcpp::SHN_UNDEF)
+	    {
+	      seen[i] = true;
+	      continue;
+	    }
+	  else if (sym->binding() == elfcpp::STB_WEAK)
+	    continue;
+
+	  // We want to include this object in the link.
+	  last = this->armap_[i].offset;
+	  this->include_member(symtab, input_objects, last);
+	  added_new_object = true;
+	}
+    }
+  while (added_new_object);
+}
+
+// Include an archive member in the link.  OFF is the file offset of
+// the member header.
+
+void
+Archive::include_member(Symbol_table* symtab, Input_objects* input_objects,
+			off_t off)
+{
+  std::string n;
+  this->read_header(off, &n);
+
+  size_t memoff = off + sizeof(Archive_header);
+
+  // Read enough of the file to pick up the entire ELF header.
+  int ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
+  off_t bytes;
+  const unsigned char* p = this->input_file_->file().get_view(memoff,
+							      ehdr_size,
+							      &bytes);
+  if (bytes < 4)
+    {
+      fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
+	      program_name, this->name().c_str(),
+	      static_cast<long>(off));
+      gold_exit(false);
+    }
+
+  static unsigned char elfmagic[4] =
+    {
+      elfcpp::ELFMAG0, elfcpp::ELFMAG1,
+      elfcpp::ELFMAG2, elfcpp::ELFMAG3
+    };
+  if (memcmp(p, elfmagic, 4) != 0)
+    {
+      fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
+	      program_name, this->name().c_str(),
+	      static_cast<long>(off));
+      gold_exit(false);
+    }
+
+  Object* obj = make_elf_object((std::string(this->input_file_->name())
+				 + "(" + n + ")"),
+				this->input_file_, memoff, p, bytes);
+
+  input_objects->add_object(obj);
+
+  Read_symbols_data sd = obj->read_symbols();
+  obj->add_symbols(symtab, sd);
+}
+
+// Add_archive_symbols methods.
+
+Add_archive_symbols::~Add_archive_symbols()
+{
+  if (this->this_blocker_ != NULL)
+    delete this->this_blocker_;
+  // next_blocker_ is deleted by the task associated with the next
+  // input file.
+}
+
+// Return whether we can add the archive symbols.  We are blocked by
+// this_blocker_.  We block next_blocker_.  We also lock the file.
+
+Task::Is_runnable_type
+Add_archive_symbols::is_runnable(Workqueue*)
+{
+  if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
+    return IS_BLOCKED;
+  return IS_RUNNABLE;
+}
+
+class Add_archive_symbols::Add_archive_symbols_locker : public Task_locker
+{
+ public:
+  Add_archive_symbols_locker(Task_token& token, Workqueue* workqueue,
+			     Archive* archive)
+    : blocker_(token, workqueue), archlock_(*archive)
+  { }
+
+ private:
+  Task_locker_block blocker_;
+  Task_locker_obj<Archive> archlock_;			     
+};
+
+Task_locker*
+Add_archive_symbols::locks(Workqueue* workqueue)
+{
+  return new Add_archive_symbols_locker(*this->next_blocker_,
+					workqueue,
+					this->archive_);
+}
+
+void
+Add_archive_symbols::run(Workqueue*)
+{
+  this->archive_->add_symbols(this->symtab_, this->input_objects_);
+}
+
+} // End namespace gold.