From e77813c8e1981a8ca08d5d060830464762a6c8c4 Mon Sep 17 00:00:00 2001 From: Pierre Muller Date: Wed, 2 Jun 2010 06:24:00 +0000 Subject: [PATCH] * dwarf2read.c (read_subrange_type): Handle missing base type according to Dwarf-2 specifications. --- gdb/ChangeLog | 5 ++++ gdb/dwarf2read.c | 62 +++++++++++++++++++++++++++++++++++++++--------- 2 files changed, 56 insertions(+), 11 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 4fe625b250..16b5801509 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2010-06-02 Pierre Muller + + * dwarf2read.c (read_subrange_type): Handle missing base type + according to Dwarf-2 specifications. + 2010-06-01 Sergio Durigan Junior * expprint.c (print_subexp_standard): Remove exp_opcodes BINOP_INCL, diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index 254d8999b7..da895737dc 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -6131,16 +6131,8 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu) LONGEST high = -1; char *name; LONGEST negative_mask; - + base_type = die_type (die, cu); - if (TYPE_CODE (base_type) == TYPE_CODE_VOID) - { - complaint (&symfile_complaints, - _("DW_AT_type missing from DW_TAG_subrange_type")); - base_type - = init_type (TYPE_CODE_INT, gdbarch_addr_bit (gdbarch) / 8, - 0, NULL, cu->objfile); - } if (cu->language == language_fortran) { @@ -6158,10 +6150,10 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu) attr = dwarf2_attr (die, DW_AT_upper_bound, cu); if (attr) { - if (attr->form == DW_FORM_block1) + if (attr->form == DW_FORM_block1 || is_ref_attr (attr)) { /* GCC encodes arrays with unspecified or dynamic length - with a DW_FORM_block1 attribute. + with a DW_FORM_block1 attribute or a reference attribute. FIXME: GDB does not yet know how to handle dynamic arrays properly, treat them as arrays with unspecified length for now. @@ -6176,6 +6168,54 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu) else high = dwarf2_get_attr_constant_value (attr, 1); } + else + { + attr = dwarf2_attr (die, DW_AT_count, cu); + if (attr) + { + int count = dwarf2_get_attr_constant_value (attr, 1); + high = low + count - 1; + } + } + + /* Dwarf-2 specifications explicitly allows to create subrange types + without specifying a base type. + In that case, the base type must be set to the type of + the lower bound, upper bound or count, in that order, if any of these + three attributes references an object that has a type. + If no base type is found, the Dwarf-2 specifications say that + a signed integer type of size equal to the size of an address should + be used. + For the following C code: `extern char gdb_int [];' + GCC produces an empty range DIE. + FIXME: muller/2010-05-28: Possible references to object for low bound, + high bound or count are not yet handled by this code. + */ + if (TYPE_CODE (base_type) == TYPE_CODE_VOID) + { + struct objfile *objfile = cu->objfile; + struct gdbarch *gdbarch = get_objfile_arch (objfile); + int addr_size = gdbarch_addr_bit (gdbarch) /8; + struct type *int_type = objfile_type (objfile)->builtin_int; + + /* Test "int", "long int", and "long long int" objfile types, + and select the first one having a size above or equal to the + architecture address size. */ + if (int_type && TYPE_LENGTH (int_type) >= addr_size) + base_type = int_type; + else + { + int_type = objfile_type (objfile)->builtin_long; + if (int_type && TYPE_LENGTH (int_type) >= addr_size) + base_type = int_type; + else + { + int_type = objfile_type (objfile)->builtin_long_long; + if (int_type && TYPE_LENGTH (int_type) >= addr_size) + base_type = int_type; + } + } + } negative_mask = (LONGEST) -1 << (TYPE_LENGTH (base_type) * TARGET_CHAR_BIT - 1);