Move DWARF line_header to new file

This moves the line_header class to a pair of new files, making
dwarf2/read.c somewhat smaller.

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

	* dwarf2/read.h (dwarf_line_debug): Declare.
	* Makefile.in (COMMON_SFILES): Add dwarf2/line-header.c.
	* dwarf2/read.c: Move line_header code to new files.
	(dwarf_line_debug): No longer static.
	* dwarf2/line-header.c: New file.
	* dwarf2/line-header.h: New file.

Change-Id: I8d9d8a2398b4e888e20cc5dd68d041c28b5a06e3

6 files changed, 317 insertions, 253 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 6df7f03..81e9746 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,14 @@
 2020-02-08  Tom Tromey  <tom@tromey.com>
 
+	* dwarf2/read.h (dwarf_line_debug): Declare.
+	* Makefile.in (COMMON_SFILES): Add dwarf2/line-header.c.
+	* dwarf2/read.c: Move line_header code to new files.
+	(dwarf_line_debug): No longer static.
+	* dwarf2/line-header.c: New file.
+	* dwarf2/line-header.h: New file.
+
+2020-02-08  Tom Tromey  <tom@tromey.com>
+
 	* dwarf2/read.c (struct line_header) <file_full_name,
 	file_file_name>: Return unique_xmalloc_ptr.
 	(line_header::file_file_name): Update.
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 7d44a6b..b4bd9d4 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1003,6 +1003,7 @@ COMMON_SFILES = \
 	dwarf2/index-common.c \
 	dwarf2/index-write.c \
 	dwarf2/leb.c \
+	dwarf2/line-header.c \
 	dwarf2/loc.c \
 	dwarf2/read.c \
 	dwarf2/section.c \
diff --git a/gdb/dwarf2/line-header.c b/gdb/dwarf2/line-header.c
new file mode 100644
index 0000000..56dfb5c
--- /dev/null
+++ b/gdb/dwarf2/line-header.c
@@ -0,0 +1,114 @@
+/* DWARF 2 debugging format support for GDB.
+
+   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/line-header.h"
+#include "dwarf2/read.h"
+#include "complaints.h"
+#include "filenames.h"
+
+void
+line_header::add_include_dir (const char *include_dir)
+{
+  if (dwarf_line_debug >= 2)
+    {
+      size_t new_size;
+      if (version >= 5)
+        new_size = m_include_dirs.size ();
+      else
+        new_size = m_include_dirs.size () + 1;
+      fprintf_unfiltered (gdb_stdlog, "Adding dir %zu: %s\n",
+			  new_size, include_dir);
+    }
+  m_include_dirs.push_back (include_dir);
+}
+
+void
+line_header::add_file_name (const char *name,
+			    dir_index d_index,
+			    unsigned int mod_time,
+			    unsigned int length)
+{
+  if (dwarf_line_debug >= 2)
+    {
+      size_t new_size;
+      if (version >= 5)
+        new_size = file_names_size ();
+      else
+        new_size = file_names_size () + 1;
+      fprintf_unfiltered (gdb_stdlog, "Adding file %zu: %s\n",
+			  new_size, name);
+    }
+  m_file_names.emplace_back (name, d_index, mod_time, length);
+}
+
+gdb::unique_xmalloc_ptr<char>
+line_header::file_file_name (int file)
+{
+  /* Is the file number a valid index into the line header's file name
+     table?  Remember that file numbers start with one, not zero.  */
+  if (is_valid_file_index (file))
+    {
+      const file_entry *fe = file_name_at (file);
+
+      if (!IS_ABSOLUTE_PATH (fe->name))
+	{
+	  const char *dir = fe->include_dir (this);
+	  if (dir != NULL)
+	    return gdb::unique_xmalloc_ptr<char> (concat (dir, SLASH_STRING,
+							  fe->name,
+							  (char *) NULL));
+	}
+      return make_unique_xstrdup (fe->name);
+    }
+  else
+    {
+      /* The compiler produced a bogus file number.  We can at least
+         record the macro definitions made in the file, even if we
+         won't be able to find the file by name.  */
+      char fake_name[80];
+
+      xsnprintf (fake_name, sizeof (fake_name),
+		 "<bad macro file number %d>", file);
+
+      complaint (_("bad file number in macro information (%d)"),
+                 file);
+
+      return make_unique_xstrdup (fake_name);
+    }
+}
+
+gdb::unique_xmalloc_ptr<char>
+line_header::file_full_name (int file, const char *comp_dir)
+{
+  /* Is the file number a valid index into the line header's file name
+     table?  Remember that file numbers start with one, not zero.  */
+  if (is_valid_file_index (file))
+    {
+      gdb::unique_xmalloc_ptr<char> relative = file_file_name (file);
+
+      if (IS_ABSOLUTE_PATH (relative.get ()) || comp_dir == NULL)
+	return relative;
+      return gdb::unique_xmalloc_ptr<char> (concat (comp_dir, SLASH_STRING,
+						    relative.get (),
+						    (char *) NULL));
+    }
+  else
+    return file_file_name (file);
+}
diff --git a/gdb/dwarf2/line-header.h b/gdb/dwarf2/line-header.h
new file mode 100644
index 0000000..08cf7b0
--- /dev/null
+++ b/gdb/dwarf2/line-header.h
@@ -0,0 +1,188 @@
+/* DWARF 2 debugging format support for GDB.
+
+   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/>.  */
+
+#ifndef DWARF2_LINE_HEADER_H
+#define DWARF2_LINE_HEADER_H
+
+#include "gdbtypes.h"
+
+/* dir_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5 and
+   later.  */
+typedef int dir_index;
+
+/* file_name_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5
+   and later.  */
+typedef int file_name_index;
+
+struct line_header;
+
+struct file_entry
+{
+  file_entry () = default;
+
+  file_entry (const char *name_, dir_index d_index_,
+	      unsigned int mod_time_, unsigned int length_)
+    : name (name_),
+      d_index (d_index_),
+      mod_time (mod_time_),
+      length (length_)
+  {}
+
+  /* Return the include directory at D_INDEX stored in LH.  Returns
+     NULL if D_INDEX is out of bounds.  */
+  const char *include_dir (const line_header *lh) const;
+
+  /* The file name.  Note this is an observing pointer.  The memory is
+     owned by debug_line_buffer.  */
+  const char *name {};
+
+  /* The directory index (1-based).  */
+  dir_index d_index {};
+
+  unsigned int mod_time {};
+
+  unsigned int length {};
+
+  /* True if referenced by the Line Number Program.  */
+  bool included_p {};
+
+  /* The associated symbol table, if any.  */
+  struct symtab *symtab {};
+};
+
+/* The line number information for a compilation unit (found in the
+   .debug_line section) begins with a "statement program header",
+   which contains the following information.  */
+struct line_header
+{
+  line_header ()
+    : offset_in_dwz {}
+  {}
+
+  /* Add an entry to the include directory table.  */
+  void add_include_dir (const char *include_dir);
+
+  /* Add an entry to the file name table.  */
+  void add_file_name (const char *name, dir_index d_index,
+		      unsigned int mod_time, unsigned int length);
+
+  /* Return the include dir at INDEX (0-based in DWARF 5 and 1-based before).
+     Returns NULL if INDEX is out of bounds.  */
+  const char *include_dir_at (dir_index index) const
+  {
+    int vec_index;
+    if (version >= 5)
+      vec_index = index;
+    else
+      vec_index = index - 1;
+    if (vec_index < 0 || vec_index >= m_include_dirs.size ())
+      return NULL;
+    return m_include_dirs[vec_index];
+  }
+
+  bool is_valid_file_index (int file_index)
+  {
+    if (version >= 5)
+      return 0 <= file_index && file_index < file_names_size ();
+    return 1 <= file_index && file_index <= file_names_size ();
+  }
+
+  /* Return the file name at INDEX (0-based in DWARF 5 and 1-based before).
+     Returns NULL if INDEX is out of bounds.  */
+  file_entry *file_name_at (file_name_index index)
+  {
+    int vec_index;
+    if (version >= 5)
+      vec_index = index;
+    else
+      vec_index = index - 1;
+    if (vec_index < 0 || vec_index >= m_file_names.size ())
+      return NULL;
+    return &m_file_names[vec_index];
+  }
+
+  /* The indexes are 0-based in DWARF 5 and 1-based in DWARF 4. Therefore,
+     this method should only be used to iterate through all file entries in an
+     index-agnostic manner.  */
+  std::vector<file_entry> &file_names ()
+  { return m_file_names; }
+
+  /* Offset of line number information in .debug_line section.  */
+  sect_offset sect_off {};
+
+  /* OFFSET is for struct dwz_file associated with dwarf2_per_objfile.  */
+  unsigned offset_in_dwz : 1; /* Can't initialize bitfields in-class.  */
+
+  unsigned int total_length {};
+  unsigned short version {};
+  unsigned int header_length {};
+  unsigned char minimum_instruction_length {};
+  unsigned char maximum_ops_per_instruction {};
+  unsigned char default_is_stmt {};
+  int line_base {};
+  unsigned char line_range {};
+  unsigned char opcode_base {};
+
+  /* standard_opcode_lengths[i] is the number of operands for the
+     standard opcode whose value is i.  This means that
+     standard_opcode_lengths[0] is unused, and the last meaningful
+     element is standard_opcode_lengths[opcode_base - 1].  */
+  std::unique_ptr<unsigned char[]> standard_opcode_lengths;
+
+  int file_names_size ()
+  { return m_file_names.size(); }
+
+  /* The start and end of the statement program following this
+     header.  These point into dwarf2_per_objfile->line_buffer.  */
+  const gdb_byte *statement_program_start {}, *statement_program_end {};
+
+  /* Return the full name of file number I in this object's file name
+     table.  Use COMP_DIR as the name of the current directory of the
+     compilation.  The result is allocated using xmalloc; the caller
+     is responsible for freeing it.  */
+  gdb::unique_xmalloc_ptr<char> file_full_name (int file,
+						const char *comp_dir);
+
+  /* Return file name relative to the compilation directory of file
+     number I in this object's file name table.  The result is
+     allocated using xmalloc; the caller is responsible for freeing
+     it.  */
+  gdb::unique_xmalloc_ptr<char> file_file_name (int file);
+
+ private:
+  /* The include_directories table.  Note these are observing
+     pointers.  The memory is owned by debug_line_buffer.  */
+  std::vector<const char *> m_include_dirs;
+
+  /* The file_names table. This is private because the meaning of indexes
+     differs among DWARF versions (The first valid index is 1 in DWARF 4 and
+     before, and is 0 in DWARF 5 and later).  So the client should use
+     file_name_at method for access.  */
+  std::vector<file_entry> m_file_names;
+};
+
+typedef std::unique_ptr<line_header> line_header_up;
+
+inline const char *
+file_entry::include_dir (const line_header *lh) const
+{
+  return lh->include_dir_at (d_index);
+}
+
+#endif /* DWARF2_LINE_HEADER_H */
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 6844ce1..9501a9e 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -35,6 +35,7 @@
 #include "dwarf2/index-cache.h"
 #include "dwarf2/index-common.h"
 #include "dwarf2/leb.h"
+#include "dwarf2/line-header.h"
 #include "bfd.h"
 #include "elf-bfd.h"
 #include "symtab.h"
@@ -90,7 +91,7 @@ static unsigned int dwarf_read_debug = 0;
 static unsigned int dwarf_die_debug = 0;
 
 /* When non-zero, dump line number entries as they are read in.  */
-static unsigned int dwarf_line_debug = 0;
+unsigned int dwarf_line_debug = 0;
 
 /* When true, cross-check physname against demangler.  */
 static bool check_physname = false;
@@ -946,167 +947,6 @@ private:
   abbrev_table_up m_dwo_abbrev_table;
 };
 
-/* dir_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5 and
-   later.  */
-typedef int dir_index;
-
-/* file_name_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5
-   and later.  */
-typedef int file_name_index;
-
-struct file_entry
-{
-  file_entry () = default;
-
-  file_entry (const char *name_, dir_index d_index_,
-	      unsigned int mod_time_, unsigned int length_)
-    : name (name_),
-      d_index (d_index_),
-      mod_time (mod_time_),
-      length (length_)
-  {}
-
-  /* Return the include directory at D_INDEX stored in LH.  Returns
-     NULL if D_INDEX is out of bounds.  */
-  const char *include_dir (const line_header *lh) const;
-
-  /* The file name.  Note this is an observing pointer.  The memory is
-     owned by debug_line_buffer.  */
-  const char *name {};
-
-  /* The directory index (1-based).  */
-  dir_index d_index {};
-
-  unsigned int mod_time {};
-
-  unsigned int length {};
-
-  /* True if referenced by the Line Number Program.  */
-  bool included_p {};
-
-  /* The associated symbol table, if any.  */
-  struct symtab *symtab {};
-};
-
-/* The line number information for a compilation unit (found in the
-   .debug_line section) begins with a "statement program header",
-   which contains the following information.  */
-struct line_header
-{
-  line_header ()
-    : offset_in_dwz {}
-  {}
-
-  /* Add an entry to the include directory table.  */
-  void add_include_dir (const char *include_dir);
-
-  /* Add an entry to the file name table.  */
-  void add_file_name (const char *name, dir_index d_index,
-		      unsigned int mod_time, unsigned int length);
-
-  /* Return the include dir at INDEX (0-based in DWARF 5 and 1-based before).
-     Returns NULL if INDEX is out of bounds.  */
-  const char *include_dir_at (dir_index index) const
-  {
-    int vec_index;
-    if (version >= 5)
-      vec_index = index;
-    else
-      vec_index = index - 1;
-    if (vec_index < 0 || vec_index >= m_include_dirs.size ())
-      return NULL;
-    return m_include_dirs[vec_index];
-  }
-
-  bool is_valid_file_index (int file_index)
-  {
-    if (version >= 5)
-      return 0 <= file_index && file_index < file_names_size ();
-    return 1 <= file_index && file_index <= file_names_size ();
-  }
-
-  /* Return the file name at INDEX (0-based in DWARF 5 and 1-based before).
-     Returns NULL if INDEX is out of bounds.  */
-  file_entry *file_name_at (file_name_index index)
-  {
-    int vec_index;
-    if (version >= 5)
-      vec_index = index;
-    else
-      vec_index = index - 1;
-    if (vec_index < 0 || vec_index >= m_file_names.size ())
-      return NULL;
-    return &m_file_names[vec_index];
-  }
-
-  /* The indexes are 0-based in DWARF 5 and 1-based in DWARF 4. Therefore,
-     this method should only be used to iterate through all file entries in an
-     index-agnostic manner.  */
-  std::vector<file_entry> &file_names ()
-  { return m_file_names; }
-
-  /* Offset of line number information in .debug_line section.  */
-  sect_offset sect_off {};
-
-  /* OFFSET is for struct dwz_file associated with dwarf2_per_objfile.  */
-  unsigned offset_in_dwz : 1; /* Can't initialize bitfields in-class.  */
-
-  unsigned int total_length {};
-  unsigned short version {};
-  unsigned int header_length {};
-  unsigned char minimum_instruction_length {};
-  unsigned char maximum_ops_per_instruction {};
-  unsigned char default_is_stmt {};
-  int line_base {};
-  unsigned char line_range {};
-  unsigned char opcode_base {};
-
-  /* standard_opcode_lengths[i] is the number of operands for the
-     standard opcode whose value is i.  This means that
-     standard_opcode_lengths[0] is unused, and the last meaningful
-     element is standard_opcode_lengths[opcode_base - 1].  */
-  std::unique_ptr<unsigned char[]> standard_opcode_lengths;
-
-  int file_names_size ()
-  { return m_file_names.size(); }
-
-  /* The start and end of the statement program following this
-     header.  These point into dwarf2_per_objfile->line_buffer.  */
-  const gdb_byte *statement_program_start {}, *statement_program_end {};
-
-  /* Return the full name of file number I in this object's file name
-     table.  Use COMP_DIR as the name of the current directory of the
-     compilation.  The result is allocated using xmalloc; the caller
-     is responsible for freeing it.  */
-  gdb::unique_xmalloc_ptr<char> file_full_name (int file,
-						const char *comp_dir);
-
-  /* Return file name relative to the compilation directory of file
-     number I in this object's file name table.  The result is
-     allocated using xmalloc; the caller is responsible for freeing
-     it.  */
-  gdb::unique_xmalloc_ptr<char> file_file_name (int file);
-
- private:
-  /* The include_directories table.  Note these are observing
-     pointers.  The memory is owned by debug_line_buffer.  */
-  std::vector<const char *> m_include_dirs;
-
-  /* The file_names table. This is private because the meaning of indexes
-     differs among DWARF versions (The first valid index is 1 in DWARF 4 and
-     before, and is 0 in DWARF 5 and later).  So the client should use
-     file_name_at method for access.  */
-  std::vector<file_entry> m_file_names;
-};
-
-typedef std::unique_ptr<line_header> line_header_up;
-
-const char *
-file_entry::include_dir (const line_header *lh) const
-{
-  return lh->include_dir_at (d_index);
-}
-
 /* When we construct a partial symbol table entry we only
    need this much information.  */
 struct partial_die_info : public allocate_on_obstack
@@ -19850,41 +19690,6 @@ free_line_header_voidp (void *arg)
   delete lh;
 }
 
-void
-line_header::add_include_dir (const char *include_dir)
-{
-  if (dwarf_line_debug >= 2)
-    {
-      size_t new_size;
-      if (version >= 5)
-        new_size = m_include_dirs.size ();
-      else
-        new_size = m_include_dirs.size () + 1;
-      fprintf_unfiltered (gdb_stdlog, "Adding dir %zu: %s\n",
-			  new_size, include_dir);
-    }
-  m_include_dirs.push_back (include_dir);
-}
-
-void
-line_header::add_file_name (const char *name,
-			    dir_index d_index,
-			    unsigned int mod_time,
-			    unsigned int length)
-{
-  if (dwarf_line_debug >= 2)
-    {
-      size_t new_size;
-      if (version >= 5)
-        new_size = file_names_size ();
-      else
-        new_size = file_names_size () + 1;
-      fprintf_unfiltered (gdb_stdlog, "Adding file %zu: %s\n",
-			  new_size, name);
-    }
-  m_file_names.emplace_back (name, d_index, mod_time, length);
-}
-
 /* A convenience function to find the proper .debug_line section for a CU.  */
 
 static struct dwarf2_section_info *
@@ -23756,62 +23561,6 @@ dwarf_alloc_die (struct dwarf2_cu *cu, int num_attrs)
 
 /* Macro support.  */
 
-gdb::unique_xmalloc_ptr<char>
-line_header::file_file_name (int file)
-{
-  /* Is the file number a valid index into the line header's file name
-     table?  Remember that file numbers start with one, not zero.  */
-  if (is_valid_file_index (file))
-    {
-      const file_entry *fe = file_name_at (file);
-
-      if (!IS_ABSOLUTE_PATH (fe->name))
-	{
-	  const char *dir = fe->include_dir (this);
-	  if (dir != NULL)
-	    return gdb::unique_xmalloc_ptr<char> (concat (dir, SLASH_STRING,
-							  fe->name,
-							  (char *) NULL));
-	}
-      return make_unique_xstrdup (fe->name);
-    }
-  else
-    {
-      /* The compiler produced a bogus file number.  We can at least
-         record the macro definitions made in the file, even if we
-         won't be able to find the file by name.  */
-      char fake_name[80];
-
-      xsnprintf (fake_name, sizeof (fake_name),
-		 "<bad macro file number %d>", file);
-
-      complaint (_("bad file number in macro information (%d)"),
-                 file);
-
-      return make_unique_xstrdup (fake_name);
-    }
-}
-
-gdb::unique_xmalloc_ptr<char>
-line_header::file_full_name (int file, const char *comp_dir)
-{
-  /* Is the file number a valid index into the line header's file name
-     table?  Remember that file numbers start with one, not zero.  */
-  if (is_valid_file_index (file))
-    {
-      gdb::unique_xmalloc_ptr<char> relative = file_file_name (file);
-
-      if (IS_ABSOLUTE_PATH (relative.get ()) || comp_dir == NULL)
-	return relative;
-      return gdb::unique_xmalloc_ptr<char> (concat (comp_dir, SLASH_STRING,
-						    relative.get (),
-						    (char *) NULL));
-    }
-  else
-    return file_file_name (file);
-}
-
-
 static struct macro_source_file *
 macro_start_file (struct dwarf2_cu *cu,
 		  int file, int line,
diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index fdaafbb..2dc657f 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -473,4 +473,7 @@ struct dwz_file
 extern struct dwz_file *dwarf2_get_dwz_file
     (struct dwarf2_per_objfile *dwarf2_per_objfile);
 
+/* When non-zero, dump line number entries as they are read in.  */
+extern unsigned int dwarf_line_debug;
+
 #endif /* DWARF2READ_H */