1 files changed, 379 insertions, 0 deletions
diff --git a/gold/fileread.cc b/gold/fileread.cc
new file mode 100644
index 000000000000..1a142022569a
--- /dev/null
+++ b/gold/fileread.cc
@@ -0,0 +1,379 @@
+// fileread.cc -- read files for gold
+
+#include "gold.h"
+
+#include <cstring>
+#include <cerrno>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "options.h"
+#include "dirsearch.h"
+#include "fileread.h"
+
+namespace gold
+{
+
+// Class File_read::View.
+
+File_read::View::~View()
+{
+  gold_assert(!this->is_locked());
+  delete[] this->data_;
+}
+
+void
+File_read::View::lock()
+{
+  ++this->lock_count_;
+}
+
+void
+File_read::View::unlock()
+{
+  gold_assert(this->lock_count_ > 0);
+  --this->lock_count_;
+}
+
+bool
+File_read::View::is_locked()
+{
+  return this->lock_count_ > 0;
+}
+
+// Class File_read.
+
+// The File_read class is designed to support file descriptor caching,
+// but this is not currently implemented.
+
+File_read::~File_read()
+{
+  gold_assert(this->lock_count_ == 0);
+  if (this->descriptor_ >= 0)
+    {
+      if (close(this->descriptor_) < 0)
+	fprintf(stderr, _("%s: warning: close(%s) failed: %s"),
+		program_name, this->name_.c_str(), strerror(errno));
+      this->descriptor_ = -1;
+    }
+  this->name_.clear();
+  this->clear_views(true);
+}
+
+// Open the file.
+
+bool
+File_read::open(const std::string& name)
+{
+  gold_assert(this->lock_count_ == 0
+	      && this->descriptor_ < 0
+	      && this->name_.empty());
+  this->name_ = name;
+  this->descriptor_ = ::open(this->name_.c_str(), O_RDONLY);
+  ++this->lock_count_;
+  return this->descriptor_ >= 0;
+}
+
+// Open the file for testing purposes.
+
+bool
+File_read::open(const std::string& name, const unsigned char* contents,
+		off_t contents_size)
+{
+  gold_assert(this->lock_count_ == 0
+	      && this->descriptor_ < 0
+	      && this->name_.empty());
+  this->name_ = name;
+  this->contents_ = contents;
+  this->contents_size_ = contents_size;
+  ++this->lock_count_;
+  return true;
+}
+
+void
+File_read::lock()
+{
+  ++this->lock_count_;
+}
+
+void
+File_read::unlock()
+{
+  gold_assert(this->lock_count_ > 0);
+  --this->lock_count_;
+}
+
+bool
+File_read::is_locked()
+{
+  return this->lock_count_ > 0;
+}
+
+// See if we have a view which covers the file starting at START for
+// SIZE bytes.  Return a pointer to the View if found, NULL if not.
+
+inline File_read::View*
+File_read::find_view(off_t start, off_t size)
+{
+  off_t page = File_read::page_offset(start);
+  Views::iterator p = this->views_.find(page);
+  if (p == this->views_.end())
+    return NULL;
+  if (p->second->size() - (start - page) < size)
+    return NULL;
+  return p->second;
+}
+
+// Read data from the file.  Return the number of bytes read.  If
+// PBYTES is not NULL, store the number of bytes in *PBYTES, otherwise
+// require that we read exactly the number of bytes requested.
+
+off_t
+File_read::do_read(off_t start, off_t size, void* p, off_t* pbytes)
+{
+  gold_assert(this->lock_count_ > 0);
+
+  off_t bytes;
+  if (this->contents_ == NULL)
+    {
+      int o = this->descriptor_;
+
+      if (lseek(o, start, SEEK_SET) < 0)
+	{
+	  fprintf(stderr, _("%s: %s: lseek to %lld failed: %s"),
+		  program_name, this->filename().c_str(),
+		  static_cast<long long>(start),
+		  strerror(errno));
+	  gold_exit(false);
+	}
+
+      bytes = ::read(o, p, size);
+      if (bytes < 0)
+	{
+	  fprintf(stderr, _("%s: %s: read failed: %s\n"),
+		  program_name, this->filename().c_str(), strerror(errno));
+	  gold_exit(false);
+	}
+    }
+  else
+    {
+      bytes = this->contents_size_ - start;
+      if (bytes < 0)
+	bytes = 0;
+      else if (bytes > size)
+	bytes = size;
+      memcpy(p, this->contents_ + start, bytes);
+    }
+
+  if (pbytes != NULL)
+    *pbytes = bytes;
+  else if (bytes != size)
+    {
+      fprintf(stderr,
+	      _("%s: %s: file too short: read only %lld of %lld "
+		"bytes at %lld\n"),
+	      program_name, this->filename().c_str(),
+	      static_cast<long long>(bytes),
+	      static_cast<long long>(size),
+	      static_cast<long long>(start));
+      gold_exit(false);
+    }
+
+  return bytes;
+}
+
+void
+File_read::read(off_t start, off_t size, void* p, off_t* pbytes)
+{
+  gold_assert(this->lock_count_ > 0);
+
+  File_read::View* pv = this->find_view(start, size);
+  if (pv != NULL)
+    {
+      memcpy(p, pv->data() + (start - pv->start()), size);
+      if (pbytes != NULL)
+	*pbytes = size;
+      return;
+    }
+
+  this->do_read(start, size, p, pbytes);
+}
+
+// Find an existing view or make a new one.
+
+File_read::View*
+File_read::find_or_make_view(off_t start, off_t size, off_t* pbytes)
+{
+  gold_assert(this->lock_count_ > 0);
+
+  off_t poff = File_read::page_offset(start);
+
+  File_read::View* const vnull = NULL;
+  std::pair<Views::iterator, bool> ins =
+    this->views_.insert(std::make_pair(poff, vnull));
+
+  if (!ins.second)
+    {
+      // There was an existing view at this offset.
+      File_read::View* v = ins.first->second;
+      if (v->size() - (start - v->start()) >= size)
+	{
+	  if (pbytes != NULL)
+	    *pbytes = size;
+	  return v;
+	}
+
+      // This view is not large enough.
+      this->saved_views_.push_back(v);
+    }
+
+  // We need to read data from the file.
+
+  off_t psize = File_read::pages(size + (start - poff));
+  unsigned char* p = new unsigned char[psize];
+
+  off_t got_bytes;
+  off_t bytes = this->do_read(poff, psize, p, &got_bytes);
+
+  File_read::View* v = new File_read::View(poff, bytes, p);
+
+  ins.first->second = v;
+
+  if (bytes - (start - poff) >= size)
+    {
+      if (pbytes != NULL)
+	*pbytes = size;
+      return v;
+    }
+
+  if (pbytes != NULL)
+    {
+      *pbytes = bytes - (start - poff);
+      return v;
+    }
+
+  fprintf(stderr,
+	  _("%s: %s: file too short: read only %lld of %lld bytes at %lld\n"),
+	  program_name, this->filename().c_str(),
+	  static_cast<long long>(bytes - (start - poff)),
+	  static_cast<long long>(size),
+	  static_cast<long long>(start));
+  gold_exit(false);
+}
+
+// This implementation of get_view just reads into a memory buffer,
+// which we store on view_list_.  At some point we should support
+// mmap.
+
+const unsigned char*
+File_read::get_view(off_t start, off_t size, off_t* pbytes)
+{
+  gold_assert(this->lock_count_ > 0);
+  File_read::View* pv = this->find_or_make_view(start, size, pbytes);
+  return pv->data() + (start - pv->start());
+}
+
+File_view*
+File_read::get_lasting_view(off_t start, off_t size, off_t* pbytes)
+{
+  gold_assert(this->lock_count_ > 0);
+  File_read::View* pv = this->find_or_make_view(start, size, pbytes);
+  pv->lock();
+  return new File_view(*this, pv, pv->data() + (start - pv->start()));
+}
+
+// Remove all the file views.
+
+void
+File_read::clear_views(bool destroying)
+{
+  for (Views::iterator p = this->views_.begin();
+       p != this->views_.end();
+       ++p)
+    {
+      if (!p->second->is_locked())
+	delete p->second;
+      else
+	{
+	  gold_assert(!destroying);
+	  this->saved_views_.push_back(p->second);
+	}
+    }
+  this->views_.clear();
+
+  Saved_views::iterator p = this->saved_views_.begin();
+  while (p != this->saved_views_.end())
+    {
+      if (!(*p)->is_locked())
+	{
+	  delete *p;
+	  p = this->saved_views_.erase(p);
+	}
+      else
+	{
+	  gold_assert(!destroying);
+	  ++p;
+	}
+    }
+}
+
+// Class File_view.
+
+File_view::~File_view()
+{
+  gold_assert(this->file_.is_locked());
+  this->view_->unlock();
+}
+
+// Class Input_file.
+
+// Create a file for testing.
+
+Input_file::Input_file(const char* name, const unsigned char* contents,
+		       off_t size)
+  : file_()
+{
+  this->input_argument_ =
+    new Input_file_argument(name, false, Position_dependent_options());
+  bool ok = file_.open(name, contents, size);
+  gold_assert(ok);
+}
+
+// Open the file.
+
+void
+Input_file::open(const General_options& options, const Dirsearch& dirpath)
+{
+  std::string name;
+  if (!this->input_argument_->is_lib())
+    name = this->input_argument_->name();
+  else
+    {
+      std::string n1("lib");
+      n1 += this->input_argument_->name();
+      std::string n2;
+      if (options.is_static())
+	n1 += ".a";
+      else
+	{
+	  n2 = n1 + ".a";
+	  n1 += ".so";
+	}
+      name = dirpath.find(n1, n2);
+      if (name.empty())
+	{
+	  fprintf(stderr, _("%s: cannot find %s\n"), program_name,
+		  this->input_argument_->name());
+	  gold_exit(false);
+	}
+    }
+
+  if (!this->file_.open(name))
+    {
+      fprintf(stderr, _("%s: cannot open %s: %s\n"), program_name,
+	      name.c_str(), strerror(errno));
+      gold_exit(false);
+    }
+}
+
+} // End namespace gold.