Move DWARF code to dwarf2/ subdirectory

This moves all the remaining DWARF code to the new dwarf2
subdirectory.  This is just a simple renaming, with updates to
includes as needed.

gdb/ChangeLog
2020-02-08  Tom Tromey  <tom@tromey.com>

	* dwarf2/expr.c: Rename from dwarf2expr.c.
	* dwarf2/expr.h: Rename from dwarf2expr.h.
	* dwarf2/frame-tailcall.c: Rename from dwarf2-frame-tailcall.c.
	* dwarf2/frame-tailcall.h: Rename from dwarf2-frame-tailcall.h.
	* dwarf2/frame.c: Rename from dwarf2-frame.c.
	* dwarf2/frame.h: Rename from dwarf2-frame.h.
	* dwarf2/index-cache.c: Rename from dwarf-index-cache.c.
	* dwarf2/index-cache.h: Rename from dwarf-index-cache.h.
	* dwarf2/index-common.c: Rename from dwarf-index-common.c.
	* dwarf2/index-common.h: Rename from dwarf-index-common.h.
	* dwarf2/index-write.c: Rename from dwarf-index-write.c.
	* dwarf2/index-write.h: Rename from dwarf-index-write.h.
	* dwarf2/loc.c: Rename from dwarf2loc.c.
	* dwarf2/loc.h: Rename from dwarf2loc.h.
	* dwarf2/read.c: Rename from dwarf2read.c.
	* dwarf2/read.h: Rename from dwarf2read.h.
	* dwarf2/abbrev.c, aarch64-tdep.c, alpha-tdep.c,
	amd64-darwin-tdep.c, arc-tdep.c, arm-tdep.c, bfin-tdep.c,
	compile/compile-c-symbols.c, compile/compile-cplus-symbols.c,
	compile/compile-loc2c.c, cris-tdep.c, csky-tdep.c, findvar.c,
	gdbtypes.c, guile/scm-type.c, h8300-tdep.c, hppa-bsd-tdep.c,
	hppa-linux-tdep.c, i386-darwin-tdep.c, i386-linux-tdep.c,
	i386-tdep.c, iq2000-tdep.c, m32c-tdep.c, m68hc11-tdep.c,
	m68k-tdep.c, microblaze-tdep.c, mips-tdep.c, mn10300-tdep.c,
	msp430-tdep.c, nds32-tdep.c, nios2-tdep.c, or1k-tdep.c,
	riscv-tdep.c, rl78-tdep.c, rs6000-tdep.c, rx-tdep.c, s12z-tdep.c,
	s390-tdep.c, score-tdep.c, sh-tdep.c, sparc-linux-tdep.c,
	sparc-tdep.c, sparc64-linux-tdep.c, sparc64-tdep.c, tic6x-tdep.c,
	tilegx-tdep.c, v850-tdep.c, xstormy16-tdep.c, xtensa-tdep.c:
	Update.
	* Makefile.in (COMMON_SFILES): Update.
	(HFILES_NO_SRCDIR): Update.

Change-Id: Ied9ce1436cd27ac4a4cffef10ec92e396f181928

1 files changed, 383 insertions, 0 deletions

diff --git a/gdb/dwarf2/index-cache.c b/gdb/dwarf2/index-cache.c
new file mode 100644
index 0000000..7b4d9975
--- /dev/null
+++ b/gdb/dwarf2/index-cache.c
@@ -0,0 +1,383 @@
+/* Caching of GDB/DWARF index files.
+
+   Copyright (C) 1994-2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "dwarf2/index-cache.h"
+
+#include "build-id.h"
+#include "cli/cli-cmds.h"
+#include "command.h"
+#include "gdbsupport/scoped_mmap.h"
+#include "gdbsupport/pathstuff.h"
+#include "dwarf2/index-write.h"
+#include "dwarf2/read.h"
+#include "objfiles.h"
+#include "gdbsupport/selftest.h"
+#include <string>
+#include <stdlib.h>
+
+/* When set to true, show debug messages about the index cache.  */
+static bool debug_index_cache = false;
+
+/* The index cache directory, used for "set/show index-cache directory".  */
+static char *index_cache_directory = NULL;
+
+/* See dwarf-index.cache.h.  */
+index_cache global_index_cache;
+
+/* set/show index-cache commands.  */
+static cmd_list_element *set_index_cache_prefix_list;
+static cmd_list_element *show_index_cache_prefix_list;
+
+/* Default destructor of index_cache_resource.  */
+index_cache_resource::~index_cache_resource () = default;
+
+/* See dwarf-index-cache.h.  */
+
+void
+index_cache::set_directory (std::string dir)
+{
+  gdb_assert (!dir.empty ());
+
+  m_dir = std::move (dir);
+
+  if (debug_index_cache)
+    printf_unfiltered ("index cache: now using directory %s\n", m_dir.c_str ());
+}
+
+/* See dwarf-index-cache.h.  */
+
+void
+index_cache::enable ()
+{
+  if (debug_index_cache)
+    printf_unfiltered ("index cache: enabling (%s)\n", m_dir.c_str ());
+
+  m_enabled = true;
+}
+
+/* See dwarf-index-cache.h.  */
+
+void
+index_cache::disable ()
+{
+  if (debug_index_cache)
+    printf_unfiltered ("index cache: disabling\n");
+
+  m_enabled = false;
+}
+
+/* See dwarf-index-cache.h.  */
+
+void
+index_cache::store (struct dwarf2_per_objfile *dwarf2_per_objfile)
+{
+  objfile *obj = dwarf2_per_objfile->objfile;
+
+  if (!enabled ())
+    return;
+
+  /* Get build id of objfile.  */
+  const bfd_build_id *build_id = build_id_bfd_get (obj->obfd);
+  if (build_id == nullptr)
+    {
+      if (debug_index_cache)
+	printf_unfiltered ("index cache: objfile %s has no build id\n",
+			   objfile_name (obj));
+      return;
+    }
+
+  std::string build_id_str = build_id_to_string (build_id);
+
+  /* Get build id of dwz file, if present.  */
+  gdb::optional<std::string> dwz_build_id_str;
+  const dwz_file *dwz = dwarf2_get_dwz_file (dwarf2_per_objfile);
+  const char *dwz_build_id_ptr = NULL;
+
+  if (dwz != nullptr)
+    {
+      const bfd_build_id *dwz_build_id = build_id_bfd_get (dwz->dwz_bfd.get ());
+
+      if (dwz_build_id == nullptr)
+	{
+	  if (debug_index_cache)
+	    printf_unfiltered ("index cache: dwz objfile %s has no build id\n",
+			       dwz->filename ());
+	  return;
+	}
+
+      dwz_build_id_str = build_id_to_string (dwz_build_id);
+      dwz_build_id_ptr = dwz_build_id_str->c_str ();
+    }
+
+  if (m_dir.empty ())
+    {
+      warning (_("The index cache directory name is empty, skipping store."));
+      return;
+    }
+
+  try
+    {
+      /* Try to create the containing directory.  */
+      if (!mkdir_recursive (m_dir.c_str ()))
+	{
+	  warning (_("index cache: could not make cache directory: %s"),
+		   safe_strerror (errno));
+	  return;
+	}
+
+      if (debug_index_cache)
+        printf_unfiltered ("index cache: writing index cache for objfile %s\n",
+			   objfile_name (obj));
+
+      /* Write the index itself to the directory, using the build id as the
+         filename.  */
+      write_psymtabs_to_index (dwarf2_per_objfile, m_dir.c_str (),
+			       build_id_str.c_str (), dwz_build_id_ptr,
+			       dw_index_kind::GDB_INDEX);
+    }
+  catch (const gdb_exception_error &except)
+    {
+      if (debug_index_cache)
+	printf_unfiltered ("index cache: couldn't store index cache for objfile "
+			   "%s: %s", objfile_name (obj), except.what ());
+    }
+}
+
+#if HAVE_SYS_MMAN_H
+
+/* Hold the resources for an mmapped index file.  */
+
+struct index_cache_resource_mmap final : public index_cache_resource
+{
+  /* Try to mmap FILENAME.  Throw an exception on failure, including if the
+     file doesn't exist. */
+  index_cache_resource_mmap (const char *filename)
+    : mapping (mmap_file (filename))
+  {}
+
+  scoped_mmap mapping;
+};
+
+/* See dwarf-index-cache.h.  */
+
+gdb::array_view<const gdb_byte>
+index_cache::lookup_gdb_index (const bfd_build_id *build_id,
+			       std::unique_ptr<index_cache_resource> *resource)
+{
+  if (!enabled ())
+    return {};
+
+  if (m_dir.empty ())
+    {
+      warning (_("The index cache directory name is empty, skipping cache "
+		 "lookup."));
+      return {};
+    }
+
+  /* Compute where we would expect a gdb index file for this build id to be.  */
+  std::string filename = make_index_filename (build_id, INDEX4_SUFFIX);
+
+  try
+    {
+      if (debug_index_cache)
+        printf_unfiltered ("index cache: trying to read %s\n",
+			   filename.c_str ());
+
+      /* Try to map that file.  */
+      index_cache_resource_mmap *mmap_resource
+	= new index_cache_resource_mmap (filename.c_str ());
+
+      /* Yay, it worked!  Hand the resource to the caller.  */
+      resource->reset (mmap_resource);
+
+      return gdb::array_view<const gdb_byte>
+	  ((const gdb_byte *) mmap_resource->mapping.get (),
+	   mmap_resource->mapping.size ());
+    }
+  catch (const gdb_exception_error &except)
+    {
+      if (debug_index_cache)
+	printf_unfiltered ("index cache: couldn't read %s: %s\n",
+			   filename.c_str (), except.what ());
+    }
+
+  return {};
+}
+
+#else /* !HAVE_SYS_MMAN_H */
+
+/* See dwarf-index-cache.h.  This is a no-op on unsupported systems.  */
+
+gdb::array_view<const gdb_byte>
+index_cache::lookup_gdb_index (const bfd_build_id *build_id,
+			       std::unique_ptr<index_cache_resource> *resource)
+{
+  return {};
+}
+
+#endif
+
+/* See dwarf-index-cache.h.  */
+
+std::string
+index_cache::make_index_filename (const bfd_build_id *build_id,
+				  const char *suffix) const
+{
+  std::string build_id_str = build_id_to_string (build_id);
+
+  return m_dir + SLASH_STRING + build_id_str + suffix;
+}
+
+/* "set index-cache" handler.  */
+
+static void
+set_index_cache_command (const char *arg, int from_tty)
+{
+  printf_unfiltered (_("\
+Missing arguments.  See \"help set index-cache\" for help.\n"));
+}
+
+/* True when we are executing "show index-cache".  This is used to improve the
+   printout a little bit.  */
+static bool in_show_index_cache_command = false;
+
+/* "show index-cache" handler.  */
+
+static void
+show_index_cache_command (const char *arg, int from_tty)
+{
+  /* Note that we are executing "show index-cache".  */
+  auto restore_flag = make_scoped_restore (&in_show_index_cache_command, true);
+
+  /* Call all "show index-cache" subcommands.  */
+  cmd_show_list (show_index_cache_prefix_list, from_tty, "");
+
+  printf_unfiltered ("\n");
+  printf_unfiltered
+    (_("The index cache is currently %s.\n"),
+     global_index_cache.enabled () ? _("enabled") : _("disabled"));
+}
+
+/* "set index-cache on" handler.  */
+
+static void
+set_index_cache_on_command (const char *arg, int from_tty)
+{
+  global_index_cache.enable ();
+}
+
+/* "set index-cache off" handler.  */
+
+static void
+set_index_cache_off_command (const char *arg, int from_tty)
+{
+  global_index_cache.disable ();
+}
+
+/* "set index-cache directory" handler.  */
+
+static void
+set_index_cache_directory_command (const char *arg, int from_tty,
+				   cmd_list_element *element)
+{
+  /* Make sure the index cache directory is absolute and tilde-expanded.  */
+  gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (index_cache_directory));
+  xfree (index_cache_directory);
+  index_cache_directory = abs.release ();
+  global_index_cache.set_directory (index_cache_directory);
+}
+
+/* "show index-cache stats" handler.  */
+
+static void
+show_index_cache_stats_command (const char *arg, int from_tty)
+{
+  const char *indent = "";
+
+  /* If this command is invoked through "show index-cache", make the display a
+     bit nicer.  */
+  if (in_show_index_cache_command)
+    {
+      indent = "  ";
+      printf_unfiltered ("\n");
+    }
+
+  printf_unfiltered (_("%s  Cache hits (this session): %u\n"),
+		     indent, global_index_cache.n_hits ());
+  printf_unfiltered (_("%sCache misses (this session): %u\n"),
+		     indent, global_index_cache.n_misses ());
+}
+
+void _initialize_index_cache ();
+void
+_initialize_index_cache ()
+{
+  /* Set the default index cache directory.  */
+  std::string cache_dir = get_standard_cache_dir ();
+  if (!cache_dir.empty ())
+    {
+      index_cache_directory = xstrdup (cache_dir.c_str ());
+      global_index_cache.set_directory (std::move (cache_dir));
+    }
+  else
+    warning (_("Couldn't determine a path for the index cache directory."));
+
+  /* set index-cache */
+  add_prefix_cmd ("index-cache", class_files, set_index_cache_command,
+		  _("Set index-cache options."), &set_index_cache_prefix_list,
+		  "set index-cache ", false, &setlist);
+
+  /* show index-cache */
+  add_prefix_cmd ("index-cache", class_files, show_index_cache_command,
+		  _("Show index-cache options."), &show_index_cache_prefix_list,
+		  "show index-cache ", false, &showlist);
+
+  /* set index-cache on */
+  add_cmd ("on", class_files, set_index_cache_on_command,
+	   _("Enable the index cache."), &set_index_cache_prefix_list);
+
+  /* set index-cache off */
+  add_cmd ("off", class_files, set_index_cache_off_command,
+	   _("Disable the index cache."), &set_index_cache_prefix_list);
+
+  /* set index-cache directory */
+  add_setshow_filename_cmd ("directory", class_files, &index_cache_directory,
+			    _("Set the directory of the index cache."),
+			    _("Show the directory of the index cache."),
+			    NULL,
+			    set_index_cache_directory_command, NULL,
+			    &set_index_cache_prefix_list,
+			    &show_index_cache_prefix_list);
+
+  /* show index-cache stats */
+  add_cmd ("stats", class_files, show_index_cache_stats_command,
+	   _("Show some stats about the index cache."),
+	   &show_index_cache_prefix_list);
+
+  /* set debug index-cache */
+  add_setshow_boolean_cmd ("index-cache", class_maintenance,
+			   &debug_index_cache,
+			   _("Set display of index-cache debug messages."),
+			   _("Show display of index-cache debug messages."),
+			   _("\
+When non-zero, debugging output for the index cache is displayed."),
+			    NULL, NULL,
+			    &setdebuglist, &showdebuglist);
+}