dwarf2read: Get rid of VEC (dwarf2_section_info_def)

This patch removes uses of VEC (dwarf2_section_info_def) in favor of
std::vector<dwarf2_section_info>.  The conversion is relatively
straightforward, no function changes are intended.

gdb/ChangeLog:

	* dwarf2read.h (dwarf2_section_info_def): Remove.
	(DEF_VEC_O (dwarf2_section_info_def)): Remove.
	* dwarf2read.c (struct dwo_sections) <types>: Change type to
	std::vector<dwarf2_section_info>.
	(struct dwo_file) <~dwo_file>: Remove.
	(dwarf2_per_objfile::~dwarf2_per_objfile): Don't manually free
	types field.
	(dwarf2_per_objfile::locate_sections): Adjust to std::vector.
	(dwarf2_read_debug_names): Likewise.
	(create_debug_types_hash_table): Change parameter type to
	array_view, adjust code accordingly.
	(dwarf2_locate_dwo_sections): Adjust to std::vector.
	(partial_die_info::fixup): Likewise.
	(determine_prefix): Likewise.
	* dwarf-index-write.c (write_psymtabs_to_index): Adjust.
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c17ca42..a31d078 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,21 @@
+2019-06-21  Simon Marchi  <simon.marchi@efficios.com>
+
+	* dwarf2read.h (dwarf2_section_info_def): Remove.
+	(DEF_VEC_O (dwarf2_section_info_def)): Remove.
+	* dwarf2read.c (struct dwo_sections) <types>: Change type to
+	std::vector<dwarf2_section_info>.
+	(struct dwo_file) <~dwo_file>: Remove.
+	(dwarf2_per_objfile::~dwarf2_per_objfile): Don't manually free
+	types field.
+	(dwarf2_per_objfile::locate_sections): Adjust to std::vector.
+	(dwarf2_read_debug_names): Likewise.
+	(create_debug_types_hash_table): Change parameter type to
+	array_view, adjust code accordingly.
+	(dwarf2_locate_dwo_sections): Adjust to std::vector.
+	(partial_die_info::fixup): Likewise.
+	(determine_prefix): Likewise.
+	* dwarf-index-write.c (write_psymtabs_to_index): Adjust.
+
 2019-06-21  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* dwarf2read.c (struct dwo_file) <dbfd>: Change type to
diff --git a/gdb/dwarf-index-write.c b/gdb/dwarf-index-write.c
index 9979ae4..3f5862a 100644
--- a/gdb/dwarf-index-write.c
+++ b/gdb/dwarf-index-write.c
@@ -1638,7 +1638,7 @@
   if (dwarf2_per_objfile->using_index)
     error (_("Cannot use an index to create the index"));
 
-  if (VEC_length (dwarf2_section_info_def, dwarf2_per_objfile->types) > 1)
+  if (dwarf2_per_objfile->types.size () > 1)
     error (_("Cannot make an index when the file has multiple .debug_types sections"));
 
   if (!objfile->partial_symtabs->psymtabs
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 05c8720..fccbd05 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -655,7 +655,7 @@
   struct dwarf2_section_info str_offsets;
   /* In the case of a virtual DWO file, these two are unused.  */
   struct dwarf2_section_info info;
-  VEC (dwarf2_section_info_def) *types;
+  std::vector<dwarf2_section_info> types;
 };
 
 /* CUs/TUs in DWP/DWO files.  */
@@ -706,11 +706,6 @@
   dwo_file () = default;
   DISABLE_COPY_AND_ASSIGN (dwo_file);
 
-  ~dwo_file ()
-  {
-    VEC_free (dwarf2_section_info_def, sections.types);
-  }
-
   /* The DW_AT_GNU_dwo_name attribute.
      For virtual DWO files the name is constructed from the section offsets
      of abbrev,line,loc,str_offsets so that we combine virtual DWO files
@@ -2160,8 +2155,6 @@
   for (signatured_type *sig_type : all_type_units)
     VEC_free (dwarf2_per_cu_ptr, sig_type->per_cu.imported_symtabs);
 
-  VEC_free (dwarf2_section_info_def, types);
-
   /* Everything else should be on the objfile obstack.  */
 }
 
@@ -2418,8 +2411,7 @@
       type_section.s.section = sectp;
       type_section.size = bfd_get_section_size (sectp);
 
-      VEC_safe_push (dwarf2_section_info_def, this->types,
-		     &type_section);
+      this->types.push_back (type_section);
     }
   else if (section_is_p (sectp->name, &names.gdb_index))
     {
@@ -3592,15 +3584,12 @@
 
   if (types_list_elements)
     {
-      struct dwarf2_section_info *section;
-
       /* We can only handle a single .debug_types when we have an
 	 index.  */
-      if (VEC_length (dwarf2_section_info_def, dwarf2_per_objfile->types) != 1)
+      if (dwarf2_per_objfile->types.size () != 1)
 	return 0;
 
-      section = VEC_index (dwarf2_section_info_def,
-			   dwarf2_per_objfile->types, 0);
+      dwarf2_section_info *section = &dwarf2_per_objfile->types[0];
 
       create_signatured_type_table_from_index (dwarf2_per_objfile, section,
 					       types_list, types_list_elements);
@@ -5636,11 +5625,10 @@
     {
       /* We can only handle a single .debug_types when we have an
 	 index.  */
-      if (VEC_length (dwarf2_section_info_def, dwarf2_per_objfile->types) != 1)
+      if (dwarf2_per_objfile->types.size () != 1)
 	return false;
 
-      dwarf2_section_info *section = VEC_index (dwarf2_section_info_def,
-						dwarf2_per_objfile->types, 0);
+      dwarf2_section_info *section = &dwarf2_per_objfile->types[0];
 
       create_signatured_type_table_from_debug_names
 	(dwarf2_per_objfile, *map, section, &dwarf2_per_objfile->abbrev);
@@ -6817,19 +6805,11 @@
 static void
 create_debug_types_hash_table (struct dwarf2_per_objfile *dwarf2_per_objfile,
 			       struct dwo_file *dwo_file,
-			       VEC (dwarf2_section_info_def) *types,
+			       gdb::array_view<dwarf2_section_info> type_sections,
 			       htab_t &types_htab)
 {
-  int ix;
-  struct dwarf2_section_info *section;
-
-  if (VEC_empty (dwarf2_section_info_def, types))
-    return;
-
-  for (ix = 0;
-       VEC_iterate (dwarf2_section_info_def, types, ix, section);
-       ++ix)
-    create_debug_type_hash_table (dwarf2_per_objfile, dwo_file, section,
+  for (dwarf2_section_info &section : type_sections)
+    create_debug_type_hash_table (dwarf2_per_objfile, dwo_file, &section,
 				  types_htab, rcuh_kind::TYPE);
 }
 
@@ -12943,8 +12923,7 @@
       memset (&type_section, 0, sizeof (type_section));
       type_section.s.section = sectp;
       type_section.size = bfd_get_section_size (sectp);
-      VEC_safe_push (dwarf2_section_info_def, dwo_sections->types,
-		     &type_section);
+      dwo_sections->types.push_back (type_section);
     }
 }
 
@@ -19030,8 +19009,7 @@
      children, see if we can determine the namespace from their linkage
      name.  */
   if (cu->language == language_cplus
-      && !VEC_empty (dwarf2_section_info_def,
-		     cu->per_cu->dwarf2_per_objfile->types)
+      && !cu->per_cu->dwarf2_per_objfile->types.empty ()
       && die_parent == NULL
       && has_children
       && (tag == DW_TAG_class_type
@@ -22533,7 +22511,7 @@
       case DW_TAG_partial_unit:
 	/* gcc-4.5 -gdwarf-4 can drop the enclosing namespace.  Cope.  */
 	if (cu->language == language_cplus
-	    && !VEC_empty (dwarf2_section_info_def, dwarf2_per_objfile->types)
+	    && !dwarf2_per_objfile->types.empty ()
 	    && die->child != NULL
 	    && (die->tag == DW_TAG_class_type
 		|| die->tag == DW_TAG_structure_type
diff --git a/gdb/dwarf2read.h b/gdb/dwarf2read.h
index 4a1cd9c..9251bde 100644
--- a/gdb/dwarf2read.h
+++ b/gdb/dwarf2read.h
@@ -73,9 +73,6 @@
   bool is_virtual;
 };
 
-typedef struct dwarf2_section_info dwarf2_section_info_def;
-DEF_VEC_O (dwarf2_section_info_def);
-
 /* Read the contents of the section INFO.
    OBJFILE is the main object file, but not necessarily the file where
    the section comes from.  E.g., for DWO files the bfd of INFO is the bfd
@@ -167,7 +164,7 @@
   dwarf2_section_info debug_names {};
   dwarf2_section_info debug_aranges {};
 
-  VEC (dwarf2_section_info_def) *types = NULL;
+  std::vector<dwarf2_section_info> types;
 
   /* Back link.  */
   struct objfile *objfile = NULL;