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author | Tom de Vries <tdevries@suse.de> | 2020-10-23 18:49:48 +0200 |
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committer | Tom de Vries <tdevries@suse.de> | 2020-10-23 18:49:48 +0200 |
commit | 7d72802bfc3fc52fe0f35854694941c9534e0bcb (patch) | |
tree | 2acdb665d7d85b2b6a168d142548afb7528f0600 /gdb/testsuite/lib | |
parent | 9476b583cb3e72e57355f5a6bfcd5ba69e71ea31 (diff) | |
download | gdb-7d72802bfc3fc52fe0f35854694941c9534e0bcb.zip gdb-7d72802bfc3fc52fe0f35854694941c9534e0bcb.tar.gz gdb-7d72802bfc3fc52fe0f35854694941c9534e0bcb.tar.bz2 |
[gdb/testsuite] Don't use default form in Dwarf::_guess_form
The only possible form for a DW_AT_low_pc attribute is DW_FORM_addr.
When specifying in dwarf assembly a low_pc attribute without explicit form:
...
{low_pc {main_label - 4}}
...
the resulting attribute uses DW_FORM_string, which is misinterpreted by gdb
when reading it as:
...
cu->base_address = attr->as_address ();
...
Stop using DW_FORM_string as default form. Instead, use a default form based
on the attribute name, if possible and unambiguous. Otherwise, error out.
F.i.:
- for DW_AT_low_pc we use DW_FORM_addr.
- For DW_AT_high_pc, we don't specify a default form because it could be
either address or constant class.
- For DW_AT_name, we use DW_FORM_string. While we could encode with
DW_FORM_strp instead, DW_FORM_string is always ok.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-10-23 Tom de Vries <tdevries@suse.de>
* lib/dwarf.exp (Dwarf::_guess_form): Return "" by default instead of
DW_FORM_string.
(Dwarf::_default_form): New proc.
(Dwarf::_handle_DW_TAG): Use _default_form. Error out if no form was
guessed.
Diffstat (limited to 'gdb/testsuite/lib')
-rw-r--r-- | gdb/testsuite/lib/dwarf.exp | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp index 5c84063..1a0cbf6 100644 --- a/gdb/testsuite/lib/dwarf.exp +++ b/gdb/testsuite/lib/dwarf.exp @@ -247,11 +247,10 @@ proc get_func_info { name {options {debug}} } { # and DW_FORM_ref4 is used. See 'new_label' and 'define_label'. # * If VALUE starts with the "%" character, then it is a label # reference too, but DW_FORM_ref_addr is used. -# * Otherwise, VALUE is taken to be a string and DW_FORM_string is -# used. In order to prevent bugs where a numeric value is given but -# no form is specified, it is an error if the value looks like a number -# (using Tcl's "string is integer") and no form is provided. -# More form-guessing functionality may be added. +# * Otherwise, if the attribute name has a default form (f.i. DW_FORM_addr for +# DW_AT_low_pc), then that one is used. +# * Otherwise, an error is reported. Either specify a form explicitly, or +# add a default for the the attribute name in _default_form. # # CHILDREN is just Tcl code that can be used to define child DIEs. It # is evaluated in the caller's context. @@ -590,9 +589,25 @@ namespace eval Dwarf { } default { + return "" + } + } + } + + proc _default_form { attr } { + switch -exact -- $attr { + DW_AT_low_pc { + return DW_FORM_addr + } + DW_AT_producer - + DW_AT_comp_dir - + DW_AT_linkage_name - + DW_AT_MIPS_linkage_name - + DW_AT_name { return DW_FORM_string } } + return "" } # Map NAME to its canonical form. @@ -692,11 +707,13 @@ namespace eval Dwarf { _guess_form $attr_value attr_value } } else { - # If the value looks like an integer, a form is required. - if [string is integer $attr_value] { - error "Integer value requires a form" - } set attr_form [_guess_form $attr_value attr_value] + if { $attr_form eq "" } { + set attr_form [_default_form $attr_name] + } + if { $attr_form eq "" } { + error "No form for $attr_name $attr_value" + } } set attr_form [_map_name $attr_form _FORM] |