Rename dwarf2/comp-unit.h

Simon pointed out that dwarf2/cu.h and dwarf2/comp-unit.h seemingly
mean the same thing.  He suggested renaming the latter to
comp-unit-head.h, which is what this patch does.

gdb/ChangeLog
2021-05-17  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.h: Update include.
	* dwarf2/read.c: Update include.
	* dwarf2/line-header.c: Update include.
	* dwarf2/cu.h: Update include.
	* dwarf2/comp-unit-head.h: Rename from comp-unit.h.
	* dwarf2/comp-unit-head.c: Rename from comp-unit.c.
	* Makefile.in (COMMON_SFILES): Update.

1 files changed, 246 insertions, 0 deletions

diff --git a/gdb/dwarf2/comp-unit-head.c b/gdb/dwarf2/comp-unit-head.c
new file mode 100644
index 0000000..8cc741d
--- /dev/null
+++ b/gdb/dwarf2/comp-unit-head.c
@@ -0,0 +1,246 @@
+/* DWARF 2 debugging format support for GDB.
+
+   Copyright (C) 1994-2021 Free Software Foundation, Inc.
+
+   Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
+   Inc.  with support from Florida State University (under contract
+   with the Ada Joint Program Office), and Silicon Graphics, Inc.
+   Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
+   based on Fred Fish's (Cygnus Support) implementation of DWARF 1
+   support.
+
+   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/comp-unit-head.h"
+#include "dwarf2/leb.h"
+#include "dwarf2/read.h"
+#include "dwarf2/section.h"
+#include "dwarf2/stringify.h"
+
+/* See comp-unit-head.h.  */
+
+const gdb_byte *
+read_comp_unit_head (struct comp_unit_head *cu_header,
+		     const gdb_byte *info_ptr,
+		     struct dwarf2_section_info *section,
+		     rcuh_kind section_kind)
+{
+  int signed_addr;
+  unsigned int bytes_read;
+  const char *filename = section->get_file_name ();
+  bfd *abfd = section->get_bfd_owner ();
+
+  cu_header->length = read_initial_length (abfd, info_ptr, &bytes_read);
+  cu_header->initial_length_size = bytes_read;
+  cu_header->offset_size = (bytes_read == 4) ? 4 : 8;
+  info_ptr += bytes_read;
+  unsigned version = read_2_bytes (abfd, info_ptr);
+  if (version < 2 || version > 5)
+    error (_("Dwarf Error: wrong version in compilation unit header "
+	   "(is %d, should be 2, 3, 4 or 5) [in module %s]"),
+	   version, filename);
+  cu_header->version = version;
+  info_ptr += 2;
+  if (cu_header->version < 5)
+    switch (section_kind)
+      {
+      case rcuh_kind::COMPILE:
+	cu_header->unit_type = DW_UT_compile;
+	break;
+      case rcuh_kind::TYPE:
+	cu_header->unit_type = DW_UT_type;
+	break;
+      default:
+	internal_error (__FILE__, __LINE__,
+			_("read_comp_unit_head: invalid section_kind"));
+      }
+  else
+    {
+      cu_header->unit_type = static_cast<enum dwarf_unit_type>
+						 (read_1_byte (abfd, info_ptr));
+      info_ptr += 1;
+      switch (cu_header->unit_type)
+	{
+	case DW_UT_compile:
+	case DW_UT_partial:
+	case DW_UT_skeleton:
+	case DW_UT_split_compile:
+	  if (section_kind != rcuh_kind::COMPILE)
+	    error (_("Dwarf Error: wrong unit_type in compilation unit header "
+		   "(is %s, should be %s) [in module %s]"),
+		   dwarf_unit_type_name (cu_header->unit_type),
+		   dwarf_unit_type_name (DW_UT_type), filename);
+	  break;
+	case DW_UT_type:
+	case DW_UT_split_type:
+	  section_kind = rcuh_kind::TYPE;
+	  break;
+	default:
+	  error (_("Dwarf Error: wrong unit_type in compilation unit header "
+		 "(is %#04x, should be one of: %s, %s, %s, %s or %s) "
+		 "[in module %s]"), cu_header->unit_type,
+		 dwarf_unit_type_name (DW_UT_compile),
+		 dwarf_unit_type_name (DW_UT_skeleton),
+		 dwarf_unit_type_name (DW_UT_split_compile),
+		 dwarf_unit_type_name (DW_UT_type),
+		 dwarf_unit_type_name (DW_UT_split_type), filename);
+	}
+
+      cu_header->addr_size = read_1_byte (abfd, info_ptr);
+      info_ptr += 1;
+    }
+  cu_header->abbrev_sect_off
+    = (sect_offset) cu_header->read_offset (abfd, info_ptr, &bytes_read);
+  info_ptr += bytes_read;
+  if (cu_header->version < 5)
+    {
+      cu_header->addr_size = read_1_byte (abfd, info_ptr);
+      info_ptr += 1;
+    }
+  signed_addr = bfd_get_sign_extend_vma (abfd);
+  if (signed_addr < 0)
+    internal_error (__FILE__, __LINE__,
+		    _("read_comp_unit_head: dwarf from non elf file"));
+  cu_header->signed_addr_p = signed_addr;
+
+  bool header_has_signature = section_kind == rcuh_kind::TYPE
+    || cu_header->unit_type == DW_UT_skeleton
+    || cu_header->unit_type == DW_UT_split_compile;
+
+  if (header_has_signature)
+    {
+      cu_header->signature = read_8_bytes (abfd, info_ptr);
+      info_ptr += 8;
+    }
+
+  if (section_kind == rcuh_kind::TYPE)
+    {
+      LONGEST type_offset;
+      type_offset = cu_header->read_offset (abfd, info_ptr, &bytes_read);
+      info_ptr += bytes_read;
+      cu_header->type_cu_offset_in_tu = (cu_offset) type_offset;
+      if (to_underlying (cu_header->type_cu_offset_in_tu) != type_offset)
+	error (_("Dwarf Error: Too big type_offset in compilation unit "
+	       "header (is %s) [in module %s]"), plongest (type_offset),
+	       filename);
+    }
+
+  return info_ptr;
+}
+
+/* Subroutine of read_and_check_comp_unit_head and
+   read_and_check_type_unit_head to simplify them.
+   Perform various error checking on the header.  */
+
+static void
+error_check_comp_unit_head (dwarf2_per_objfile *per_objfile,
+			    struct comp_unit_head *header,
+			    struct dwarf2_section_info *section,
+			    struct dwarf2_section_info *abbrev_section)
+{
+  const char *filename = section->get_file_name ();
+
+  if (to_underlying (header->abbrev_sect_off)
+      >= abbrev_section->get_size (per_objfile->objfile))
+    error (_("Dwarf Error: bad offset (%s) in compilation unit header "
+	   "(offset %s + 6) [in module %s]"),
+	   sect_offset_str (header->abbrev_sect_off),
+	   sect_offset_str (header->sect_off),
+	   filename);
+
+  /* Cast to ULONGEST to use 64-bit arithmetic when possible to
+     avoid potential 32-bit overflow.  */
+  if (((ULONGEST) header->sect_off + header->get_length ())
+      > section->size)
+    error (_("Dwarf Error: bad length (0x%x) in compilation unit header "
+	   "(offset %s + 0) [in module %s]"),
+	   header->length, sect_offset_str (header->sect_off),
+	   filename);
+}
+
+/* See comp-unit-head.h.  */
+
+const gdb_byte *
+read_and_check_comp_unit_head (dwarf2_per_objfile *per_objfile,
+			       struct comp_unit_head *header,
+			       struct dwarf2_section_info *section,
+			       struct dwarf2_section_info *abbrev_section,
+			       const gdb_byte *info_ptr,
+			       rcuh_kind section_kind)
+{
+  const gdb_byte *beg_of_comp_unit = info_ptr;
+
+  header->sect_off = (sect_offset) (beg_of_comp_unit - section->buffer);
+
+  info_ptr = read_comp_unit_head (header, info_ptr, section, section_kind);
+
+  header->first_die_cu_offset = (cu_offset) (info_ptr - beg_of_comp_unit);
+
+  error_check_comp_unit_head (per_objfile, header, section, abbrev_section);
+
+  return info_ptr;
+}
+
+CORE_ADDR
+comp_unit_head::read_address (bfd *abfd, const gdb_byte *buf,
+			      unsigned int *bytes_read) const
+{
+  CORE_ADDR retval = 0;
+
+  if (signed_addr_p)
+    {
+      switch (addr_size)
+	{
+	case 2:
+	  retval = bfd_get_signed_16 (abfd, buf);
+	  break;
+	case 4:
+	  retval = bfd_get_signed_32 (abfd, buf);
+	  break;
+	case 8:
+	  retval = bfd_get_signed_64 (abfd, buf);
+	  break;
+	default:
+	  internal_error (__FILE__, __LINE__,
+			  _("read_address: bad switch, signed [in module %s]"),
+			  bfd_get_filename (abfd));
+	}
+    }
+  else
+    {
+      switch (addr_size)
+	{
+	case 2:
+	  retval = bfd_get_16 (abfd, buf);
+	  break;
+	case 4:
+	  retval = bfd_get_32 (abfd, buf);
+	  break;
+	case 8:
+	  retval = bfd_get_64 (abfd, buf);
+	  break;
+	default:
+	  internal_error (__FILE__, __LINE__,
+			  _("read_address: bad switch, "
+			    "unsigned [in module %s]"),
+			  bfd_get_filename (abfd));
+	}
+    }
+
+  *bytes_read = addr_size;
+  return retval;
+}