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authorFelix Willgerodt <felix.willgerodt@intel.com>2021-04-20 08:44:17 +0200
committerFelix Willgerodt <felix.willgerodt@intel.com>2021-04-20 08:44:17 +0200
commit184dcd81c7972c3fd3557ec4a04064529ee3ca8d (patch)
treefd8ff7933eddff55fed0a32f39347a1971fddb07 /gdb/c-exp.y
parent525174e886044ce3538b13545939421032f77a1b (diff)
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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.y2
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: