From aa659cfad638376ab535bc5a7b65c164327e9e21 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Wed, 24 Feb 2021 23:58:42 +0100 Subject: [gdb/symtab] Handle DW_AT_decl_file with form DW_FORM_implicit_const With test-case gdb.cp/temargs.exp on target board \ unix/gdb:debug_flags=-gdwarf-5 I run into: ... (gdb) info addr I^M ERROR: GDB process no longer exists GDB process exited with wait status 32286 exp19 0 0 CHILDKILLED SIGABRT SIGABRT UNRESOLVED: gdb.cp/temargs.exp: test address of I in templ_m ... This is a regression since commit 529908cbd0a "Remove DW_UNSND". The problem is that this DW_AT_decl_file: ... <1><221>: Abbrev Number: 4 (DW_TAG_structure_type) <222> DW_AT_name : Base <226> DW_AT_byte_size : 1 <226> DW_AT_decl_file : 1 <226> DW_AT_decl_line : 30 <227> DW_AT_sibling : <0x299> ... is not read by this code in new_symbol: .... attr = dwarf2_attr (die, inlined_func ? DW_AT_call_file : DW_AT_decl_file, cu); if (attr != nullptr && attr->form_is_unsigned ()) ... because DW_AT_decl_file has form DW_FORM_implicit_const: ... 4 DW_TAG_structure_type [has children] DW_AT_name DW_FORM_strp DW_AT_byte_size DW_FORM_implicit_const: 1 DW_AT_decl_file DW_FORM_implicit_const: 1 DW_AT_decl_line DW_FORM_data1 DW_AT_sibling DW_FORM_ref4 DW_AT value: 0 DW_FORM value: 0 ... which is a signed LEB128, so attr->form_is_unsigned () returns false. Fix this by introducing new functions is_nonnegative and as_nonnegative, and use these instead of form_is_unsigned and as_unsigned. Tested on x86_64-linux. gdb/ChangeLog: 2021-02-24 Tom de Vries PR symtab/27336 * dwarf2/attribute.c (attribute::form_is_signed): New function factored out of ... * dwarf2/attribute.h (attribute::as_signed): ... here. (attribute::is_nonnegative, attribute::as_nonnegative): New function. (attribute::form_is_signed): Declare. * dwarf2/read.c (new_symbol): Use is_nonnegative and as_nonnegative for DW_AT_decl_file. --- gdb/dwarf2/attribute.h | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) (limited to 'gdb/dwarf2/attribute.h') diff --git a/gdb/dwarf2/attribute.h b/gdb/dwarf2/attribute.h index 56776d6..0af7470 100644 --- a/gdb/dwarf2/attribute.h +++ b/gdb/dwarf2/attribute.h @@ -70,7 +70,7 @@ struct attribute form. */ LONGEST as_signed () const { - gdb_assert (form == DW_FORM_sdata || form == DW_FORM_implicit_const); + gdb_assert (form_is_signed ()); return u.snd; } @@ -92,6 +92,28 @@ struct attribute return u.unsnd; } + /* Return true if the value is nonnegative. Requires that that + reprocessing not be needed. */ + bool is_nonnegative () const + { + if (form_is_unsigned ()) + return true; + if (form_is_signed ()) + return as_signed () >= 0; + return false; + } + + /* Return the nonnegative value. Requires that that reprocessing not be + needed. */ + ULONGEST as_nonnegative () const + { + if (form_is_unsigned ()) + return as_unsigned (); + if (form_is_signed ()) + return (ULONGEST)as_signed (); + gdb_assert (false); + } + /* Return non-zero if ATTR's value is a section offset --- classes lineptr, loclistptr, macptr or rangelistptr --- or zero, otherwise. You may use the as_unsigned method to retrieve such offsets. @@ -147,6 +169,9 @@ struct attribute /* Check if the attribute's form is an unsigned integer form. */ bool form_is_unsigned () const; + /* Check if the attribute's form is a signed integer form. */ + bool form_is_signed () const; + /* Check if the attribute's form is a form that requires "reprocessing". */ bool form_requires_reprocessing () const; -- cgit v1.1