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| author | Felix Willgerodt <felix.willgerodt@intel.com> | 2021-04-20 08:44:17 +0200 |
|---|---|---|
| committer | Felix Willgerodt <felix.willgerodt@intel.com> | 2021-04-20 08:44:17 +0200 |
| commit | 184dcd81c7972c3fd3557ec4a04064529ee3ca8d (patch) | |
| tree | fd8ff7933eddff55fed0a32f39347a1971fddb07 /gdb/c-exp.y | |
| parent | 525174e886044ce3538b13545939421032f77a1b (diff) | |
| download | gdb-184dcd81c7972c3fd3557ec4a04064529ee3ca8d.zip gdb-184dcd81c7972c3fd3557ec4a04064529ee3ca8d.tar.gz gdb-184dcd81c7972c3fd3557ec4a04064529ee3ca8d.tar.bz2 | |
gdb: Fix reduce/reduce conflicts for qualifier_seq_noopt in the C parser.
This fixes a problem with GDB's address space qualifier parsing. GDB uses
'@' as a way to express an address space in expression evaluation. This can
currently lead to a crash for "Add support for the __flash qualifier on AVR"
(487d975399dfcb2bb2f0998a7d12bd62acdd9fa1), the only user I am aware of.
Program:
~~~
const __flash char data_in_flash = 0xab;
int
main (void)
{
const __flash char *pointer_to_flash = &data_in_flash;
}
~~~
Before:
~~~
(gdb) p data_in_flash
$1 = -85 '\253'
(gdb) p *(const char * @flash) pointer_to_flash
$2 = -85 '\253'
(gdb) p *(@flash const char *) pointer_to_flash
type-stack.c:201: internal-error: type* type_stack::follow_types(type*): unrecognized tp_ value in follow_types
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
~~~
After:
~~~
(gdb) p data_in_flash
$1 = -85 '\253'
(gdb) p *(const char *) pointer_to_flash
$2 = 0 '\000'
(gdb) p *(const char * @flash) pointer_to_flash
$3 = -85 '\253'
(gdb) p *(@flash const char *) pointer_to_flash
$4 = 0 '\000'
(gdb)
~~~
Note that how the binding of this qualifier is interpreted and resolved for an
address/pointer is target specific. Hence only the prepended qualifier works
for AVR, even if it seems syntactically incorrect. I won't change this for
AVR, as I am not familiar with that target.
Bison now also complains about less conflicts:
Before:
YACC c-exp.c
gdb/gdb/c-exp.y: warning: 153 shift/reduce conflicts [-Wconflicts-sr]
gdb/gdb/c-exp.y: warning: 70 reduce/reduce conflicts [-Wconflicts-rr]
After:
YACC c-exp.c
gdb/gdb/c-exp.y: warning: 60 shift/reduce conflicts [-Wconflicts-sr]
gdb/gdb/c-exp.y: warning: 69 reduce/reduce conflicts [-Wconflicts-rr]
gdb/ChangeLog:
2021-04-20 Felix Willgerodt <felix.willgerodt@intel.com>
* c-exp.y (qualifier_seq_noopt): Replace qualifier_seq with
qualifier_seq_noopt.
Diffstat (limited to 'gdb/c-exp.y')
| -rw-r--r-- | gdb/c-exp.y | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/gdb/c-exp.y b/gdb/c-exp.y index 3e416f4..93b10f0 100644 --- a/gdb/c-exp.y +++ b/gdb/c-exp.y @@ -1276,7 +1276,7 @@ single_qualifier: qualifier_seq_noopt: single_qualifier - | qualifier_seq single_qualifier + | qualifier_seq_noopt single_qualifier ; qualifier_seq: |