From: Simon Marchi Date: Tue, 2 Feb 2021 15:40:51 +0000 (-0500) Subject: gdb/dwarf: few fixes for handling DW_FORM_{rng,loc}listx X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=b1829e1bf2ee1c973694c802afaa3b7da2ffb4de;p=deliverable%2Fbinutils-gdb.git gdb/dwarf: few fixes for handling DW_FORM_{rng,loc}listx We hit an assertion when loading the binary from PR 26813. When fixing it, execution goes a up bit further but then hits another assert, and another, and another. With these fours fixes, I am able to load the binary and get to the prompt. An error is shown (index pointing outside of the section), because the DW_FORM_rnglistx attribute is not read correctly, but that one is taken care of by the next patch. The four fixes are: - attribute::form_requires_reprocessing needs to handle forms DW_FORM_rnglistx and DW_FORM_loclistx, because set_unsigned_reprocess is called for them in read_attribute_value. - read_attribute_reprocess must call set_unsigned for them, not set_address. The parameter of set_address is a CORE_ADDR, meaning it's for program addresses. Post-reprocess, DW_FORM_rnglistx and DW_FORM_loclistx are offsets into their respective sections (.debug_rnglists and .debug_loclists). set_unsigned is the current attribute value setter that fits the best. But perhaps we should have a setter that takes a sect_offset? - read_attribute_process must call as_unsigned_reprocess instead of as_unsigned to get the pre-reprocess value, otherwise we hit the assert inside as_unsigned that makes sure the attribute doesn't need reprocessing. - attribute::set_unsigned needs to clear the requires_reprocessing flag, otherwise it stays set when reprocessing DW_FORM_rnglistx and DW_FORM_loclistx attributes. There's another assert that we hit once the next patch is applied, but since it's in the same vein as the changes in this patch, I included it in this patch: - attribute::form_is_unsigned must handle form DW_FORM_loclistx, otherwise we hit the assert when trying to call set_unsigned for an attribute of this form. DW_FORM_rnglistx is already handled. gdb/ChangeLog: PR gdb/26813 * dwarf2/attribute.h (struct attribute) : Clear requires_reprocessing flag. * dwarf2/attribute.c (attribute::form_is_unsigned): Handle DW_FORM_loclistx. (attribute::form_requires_reprocessing): Handle DW_FORM_rnglistx and DW_FORM_loclistx. * dwarf2/read.c (read_attribute_reprocess): Use set_unsigned instead of set_address for DW_FORM_loclistx and DW_FORM_rnglistx. Change-Id: I06c156fa3913ca98e4e39085f4ef171645b4bc1e --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index b420a94118..4f9944aa0b 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2021-02-02 Simon Marchi + + PR gdb/26813 + * dwarf2/attribute.h (struct attribute) : Clear + requires_reprocessing flag. + * dwarf2/attribute.c (attribute::form_is_unsigned): Handle + DW_FORM_loclistx. + (attribute::form_requires_reprocessing): Handle DW_FORM_rnglistx + and DW_FORM_loclistx. + * dwarf2/read.c (read_attribute_reprocess): Use set_unsigned + instead of set_address for DW_FORM_loclistx and + DW_FORM_rnglistx. + 2021-02-02 Simon Marchi * dwarf2/read.c (read_loclist_index): Remove bound check for diff --git a/gdb/dwarf2/attribute.c b/gdb/dwarf2/attribute.c index 479261030c..b4f188a096 100644 --- a/gdb/dwarf2/attribute.c +++ b/gdb/dwarf2/attribute.c @@ -179,6 +179,7 @@ attribute::form_is_unsigned () const || form == DW_FORM_flag_present || form == DW_FORM_udata || form == DW_FORM_rnglistx + || form == DW_FORM_loclistx || form == DW_FORM_ref1 || form == DW_FORM_ref2 || form == DW_FORM_ref4 @@ -197,7 +198,9 @@ attribute::form_requires_reprocessing () const || form == DW_FORM_strx4 || form == DW_FORM_GNU_str_index || form == DW_FORM_addrx - || form == DW_FORM_GNU_addr_index); + || form == DW_FORM_GNU_addr_index + || form == DW_FORM_rnglistx + || form == DW_FORM_loclistx); } /* See attribute.h. */ diff --git a/gdb/dwarf2/attribute.h b/gdb/dwarf2/attribute.h index a3ff9b0eb9..56776d64ed 100644 --- a/gdb/dwarf2/attribute.h +++ b/gdb/dwarf2/attribute.h @@ -223,6 +223,7 @@ struct attribute { gdb_assert (form_is_unsigned ()); u.unsnd = unsnd; + requires_reprocessing = 0; } /* Temporarily set this attribute to an unsigned integer. This is diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index ee0f8bec44..4fe4f94a6e 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -20315,10 +20315,20 @@ read_attribute_reprocess (const struct die_reader_specs *reader, attr->as_unsigned_reprocess ())); break; case DW_FORM_loclistx: - attr->set_address (read_loclist_index (cu, attr->as_unsigned ())); - break; + { + CORE_ADDR loclists_sect_off + = read_loclist_index (cu, attr->as_unsigned_reprocess ()); + + attr->set_unsigned (loclists_sect_off); + } + break; case DW_FORM_rnglistx: - attr->set_address (read_rnglist_index (cu, attr->as_unsigned (), tag)); + { + CORE_ADDR rnglists_sect_off + = read_rnglist_index (cu, attr->as_unsigned_reprocess (), tag); + + attr->set_unsigned (rnglists_sect_off); + } break; case DW_FORM_strx: case DW_FORM_strx1: