From 43816ebc335481c99808c4fdfffb9ea3f510b19a Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Thu, 31 Oct 2019 10:31:28 -0600 Subject: [PATCH] Remove some explicit memory management from dwarf2read.c I noticed a few spots in dwarf2read.c that could be improved by moving to unique_xmalloc_ptr or, in one case, std::vector. gdb/ChangeLog 2020-01-08 Tom Tromey * dwarf2read.c (add_partial_symbol): Use unique_xmalloc_ptr. (dwarf2_compute_name, open_dwo_file): Likewise. (process_enumeration_scope): Use std::vector. (guess_partial_die_structure_name): Use unique_xmalloc_ptr. (partial_die_info::fixup, dwarf2_start_subfile) (guess_full_die_structure_name, dwarf2_name): Likewise. (determine_prefix): Update. (guess_full_die_structure_name): Make return type const. (partial_die_full_name): Return unique_xmalloc_ptr. (DW_FIELD_ALLOC_CHUNK): Remove. Change-Id: I1cb278c608041ef36ef1f77c7e7565c921038d08 --- gdb/ChangeLog | 13 +++++ gdb/dwarf2read.c | 143 ++++++++++++++++++----------------------------- 2 files changed, 68 insertions(+), 88 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 13099276a4..ab9aa9fbd6 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2020-01-08 Tom Tromey + + * dwarf2read.c (add_partial_symbol): Use unique_xmalloc_ptr. + (dwarf2_compute_name, open_dwo_file): Likewise. + (process_enumeration_scope): Use std::vector. + (guess_partial_die_structure_name): Use unique_xmalloc_ptr. + (partial_die_info::fixup, dwarf2_start_subfile) + (guess_full_die_structure_name, dwarf2_name): Likewise. + (determine_prefix): Update. + (guess_full_die_structure_name): Make return type const. + (partial_die_full_name): Return unique_xmalloc_ptr. + (DW_FIELD_ALLOC_CHUNK): Remove. + 2020-01-07 Tom Tromey PR build/24937: diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index 63d533a445..03c27982b1 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -1343,11 +1343,6 @@ struct dwarf_block #define ATTR_ALLOC_CHUNK 4 #endif -/* Allocate fields for structs, unions and enums in this size. */ -#ifndef DW_FIELD_ALLOC_CHUNK -#define DW_FIELD_ALLOC_CHUNK 4 -#endif - /* FIXME: We might want to set this from BFD via bfd_arch_bits_per_byte, but this would require a corresponding change in unpack_field_as_long and friends. */ @@ -8907,7 +8902,7 @@ partial_die_parent_scope (struct partial_die_info *pdi, /* Return the fully scoped name associated with PDI, from compilation unit CU. The result will be allocated with malloc. */ -static char * +static gdb::unique_xmalloc_ptr partial_die_full_name (struct partial_die_info *pdi, struct dwarf2_cu *cu) { @@ -8933,7 +8928,7 @@ partial_die_full_name (struct partial_die_info *pdi, attr.u.unsnd = to_underlying (pdi->sect_off); die = follow_die_ref (NULL, &attr, &ref_cu); - return xstrdup (dwarf2_full_name (NULL, die, ref_cu)); + return make_unique_xstrdup (dwarf2_full_name (NULL, die, ref_cu)); } } @@ -8941,7 +8936,8 @@ partial_die_full_name (struct partial_die_info *pdi, if (parent_scope == NULL) return NULL; else - return typename_concat (NULL, parent_scope, pdi->name, 0, cu); + return gdb::unique_xmalloc_ptr (typename_concat (NULL, parent_scope, + pdi->name, 0, cu)); } static void @@ -8954,13 +8950,13 @@ add_partial_symbol (struct partial_die_info *pdi, struct dwarf2_cu *cu) CORE_ADDR addr = 0; const char *actual_name = NULL; CORE_ADDR baseaddr; - char *built_actual_name; baseaddr = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile)); - built_actual_name = partial_die_full_name (pdi, cu); + gdb::unique_xmalloc_ptr built_actual_name + = partial_die_full_name (pdi, cu); if (built_actual_name != NULL) - actual_name = built_actual_name; + actual_name = built_actual_name.get (); if (actual_name == NULL) actual_name = pdi->name; @@ -9053,10 +9049,7 @@ add_partial_symbol (struct partial_die_info *pdi, struct dwarf2_cu *cu) /* Static Variable. Skip symbols whose value we cannot know (those without location descriptors or constant values). */ if (!has_loc && !pdi->has_const_value) - { - xfree (built_actual_name); - return; - } + return; add_psymbol_to_list (actual_name, built_actual_name != NULL, @@ -9106,10 +9099,7 @@ add_partial_symbol (struct partial_die_info *pdi, struct dwarf2_cu *cu) union or class entry that does not have a byte size attribute and that has a DW_AT_declaration attribute." */ if (!pdi->has_byte_size && pdi->is_declaration) - { - xfree (built_actual_name); - return; - } + return; /* NOTE: carlton/2003-10-07: See comment in new_symbol about static vs. global. */ @@ -9134,8 +9124,6 @@ add_partial_symbol (struct partial_die_info *pdi, struct dwarf2_cu *cu) default: break; } - - xfree (built_actual_name); } /* Read a partial die corresponding to a namespace; also, add a symbol @@ -10912,11 +10900,10 @@ dwarf2_compute_name (const char *name, prefix = determine_prefix (die, cu); if (*prefix != '\0') { - char *prefixed_name = typename_concat (NULL, prefix, name, - physname, cu); + gdb::unique_xmalloc_ptr prefixed_name + (typename_concat (NULL, prefix, name, physname, cu)); - buf.puts (prefixed_name); - xfree (prefixed_name); + buf.puts (prefixed_name.get ()); } else buf.puts (name); @@ -12958,16 +12945,15 @@ open_dwo_file (struct dwarf2_per_objfile *dwarf2_per_objfile, if (comp_dir != NULL) { - char *path_to_try = concat (comp_dir, SLASH_STRING, - file_name, (char *) NULL); + gdb::unique_xmalloc_ptr path_to_try + (concat (comp_dir, SLASH_STRING, file_name, (char *) NULL)); /* NOTE: If comp_dir is a relative path, this will also try the search path, which seems useful. */ gdb_bfd_ref_ptr abfd (try_open_dwop_file (dwarf2_per_objfile, - path_to_try, + path_to_try.get (), 0 /*is_dwp*/, 1 /*search_cwd*/)); - xfree (path_to_try); if (abfd != NULL) return abfd; } @@ -16548,8 +16534,7 @@ process_enumeration_scope (struct die_info *die, struct dwarf2_cu *cu) { struct die_info *child_die; struct symbol *sym; - struct field *fields = NULL; - int num_fields = 0; + std::vector fields; const char *name; child_die = die->child; @@ -16566,34 +16551,26 @@ process_enumeration_scope (struct die_info *die, struct dwarf2_cu *cu) { sym = new_symbol (child_die, this_type, cu); - if ((num_fields % DW_FIELD_ALLOC_CHUNK) == 0) - { - fields = (struct field *) - xrealloc (fields, - (num_fields + DW_FIELD_ALLOC_CHUNK) - * sizeof (struct field)); - } - - FIELD_NAME (fields[num_fields]) = sym->linkage_name (); - FIELD_TYPE (fields[num_fields]) = NULL; - SET_FIELD_ENUMVAL (fields[num_fields], SYMBOL_VALUE (sym)); - FIELD_BITSIZE (fields[num_fields]) = 0; + fields.emplace_back (); + struct field &field = fields.back (); - num_fields++; + FIELD_NAME (field) = sym->linkage_name (); + FIELD_TYPE (field) = NULL; + SET_FIELD_ENUMVAL (field, SYMBOL_VALUE (sym)); + FIELD_BITSIZE (field) = 0; } } child_die = sibling_die (child_die); } - if (num_fields) + if (!fields.empty ()) { - TYPE_NFIELDS (this_type) = num_fields; + TYPE_NFIELDS (this_type) = fields.size (); TYPE_FIELDS (this_type) = (struct field *) - TYPE_ALLOC (this_type, sizeof (struct field) * num_fields); - memcpy (TYPE_FIELDS (this_type), fields, - sizeof (struct field) * num_fields); - xfree (fields); + TYPE_ALLOC (this_type, sizeof (struct field) * fields.size ()); + memcpy (TYPE_FIELDS (this_type), fields.data (), + sizeof (struct field) * fields.size ()); } } @@ -19345,16 +19322,15 @@ guess_partial_die_structure_name (struct partial_die_info *struct_pdi, if (child_pdi->tag == DW_TAG_subprogram && child_pdi->linkage_name != NULL) { - char *actual_class_name - = language_class_name_from_physname (cu->language_defn, - child_pdi->linkage_name); + gdb::unique_xmalloc_ptr actual_class_name + (language_class_name_from_physname (cu->language_defn, + child_pdi->linkage_name)); if (actual_class_name != NULL) { struct objfile *objfile = cu->per_cu->dwarf2_per_objfile->objfile; struct_pdi->name = obstack_strdup (&objfile->per_bfd->storage_obstack, - actual_class_name); - xfree (actual_class_name); + actual_class_name.get ()); } break; } @@ -19419,24 +19395,22 @@ partial_die_info::fixup (struct dwarf2_cu *cu) || tag == DW_TAG_union_type) && linkage_name != NULL) { - char *demangled; - - demangled = gdb_demangle (linkage_name, DMGL_TYPES); - if (demangled) + gdb::unique_xmalloc_ptr demangled + (gdb_demangle (linkage_name, DMGL_TYPES)); + if (demangled != nullptr) { const char *base; /* Strip any leading namespaces/classes, keep only the base name. DW_AT_name for named DIEs does not contain the prefixes. */ - base = strrchr (demangled, ':'); - if (base && base > demangled && base[-1] == ':') + base = strrchr (demangled.get (), ':'); + if (base && base > demangled.get () && base[-1] == ':') base++; else - base = demangled; + base = demangled.get (); struct objfile *objfile = cu->per_cu->dwarf2_per_objfile->objfile; name = obstack_strdup (&objfile->per_bfd->storage_obstack, base); - xfree (demangled); } } @@ -21716,7 +21690,7 @@ static void dwarf2_start_subfile (struct dwarf2_cu *cu, const char *filename, const char *dirname) { - char *copy = NULL; + gdb::unique_xmalloc_ptr copy; /* In order not to lose the line information directory, we concatenate it to the filename when it makes sense. @@ -21727,14 +21701,11 @@ dwarf2_start_subfile (struct dwarf2_cu *cu, const char *filename, if (!IS_ABSOLUTE_PATH (filename) && dirname != NULL) { - copy = concat (dirname, SLASH_STRING, filename, (char *)NULL); - filename = copy; + copy.reset (concat (dirname, SLASH_STRING, filename, (char *) NULL)); + filename = copy.get (); } cu->get_builder ()->start_subfile (filename); - - if (copy != NULL) - xfree (copy); } /* Start a symtab for DWARF. NAME, COMP_DIR, LOW_PC are passed to the @@ -22702,7 +22673,7 @@ read_type_die_1 (struct die_info *die, struct dwarf2_cu *cu) This is the full-die version of guess_partial_die_structure_name. In this case we know DIE has no useful parent. */ -static char * +static const char * guess_full_die_structure_name (struct die_info *die, struct dwarf2_cu *cu) { struct die_info *spec_die; @@ -22728,33 +22699,32 @@ guess_full_die_structure_name (struct die_info *die, struct dwarf2_cu *cu) if (linkage_name != NULL) { - char *actual_name - = language_class_name_from_physname (cu->language_defn, - linkage_name); - char *name = NULL; + gdb::unique_xmalloc_ptr actual_name + (language_class_name_from_physname (cu->language_defn, + linkage_name)); + const char *name = NULL; if (actual_name != NULL) { const char *die_name = dwarf2_name (die, cu); if (die_name != NULL - && strcmp (die_name, actual_name) != 0) + && strcmp (die_name, actual_name.get ()) != 0) { /* Strip off the class name from the full name. We want the prefix. */ int die_name_len = strlen (die_name); - int actual_name_len = strlen (actual_name); + int actual_name_len = strlen (actual_name.get ()); + const char *ptr = actual_name.get (); /* Test for '::' as a sanity check. */ if (actual_name_len > die_name_len + 2 - && actual_name[actual_name_len - - die_name_len - 1] == ':') + && ptr[actual_name_len - die_name_len - 1] == ':') name = obstack_strndup ( &objfile->per_bfd->storage_obstack, - actual_name, actual_name_len - die_name_len - 2); + ptr, actual_name_len - die_name_len - 2); } } - xfree (actual_name); return name; } } @@ -22941,7 +22911,7 @@ determine_prefix (struct die_info *die, struct dwarf2_cu *cu) || die->tag == DW_TAG_structure_type || die->tag == DW_TAG_union_type)) { - char *name = guess_full_die_structure_name (die, cu); + const char *name = guess_full_die_structure_name (die, cu); if (name != NULL) return name; } @@ -23115,8 +23085,6 @@ dwarf2_name (struct die_info *die, struct dwarf2_cu *cu) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47510. */ if (!attr || DW_STRING (attr) == NULL) { - char *demangled = NULL; - attr = dw2_linkage_name_attr (die, cu); if (attr == NULL || DW_STRING (attr) == NULL) return NULL; @@ -23124,18 +23092,17 @@ dwarf2_name (struct die_info *die, struct dwarf2_cu *cu) /* Avoid demangling DW_STRING (attr) the second time on a second call for the same DIE. */ if (!DW_STRING_IS_CANONICAL (attr)) - demangled = gdb_demangle (DW_STRING (attr), DMGL_TYPES); - - if (demangled) { + gdb::unique_xmalloc_ptr demangled + (gdb_demangle (DW_STRING (attr), DMGL_TYPES)); + const char *base; /* FIXME: we already did this for the partial symbol... */ DW_STRING (attr) = obstack_strdup (&objfile->per_bfd->storage_obstack, - demangled); + demangled.get ()); DW_STRING_IS_CANONICAL (attr) = 1; - xfree (demangled); /* Strip any leading namespaces/classes, keep only the base name. DW_AT_name for named DIEs does not contain the prefixes. */ -- 2.34.1