bd5cc6575b
Previously we were calling glrRecover() ad-hoc at the end of input. Two main problems with this: - glrRecover() on two separate code paths is inelegant - We may have to recover several times in succession (e.g. to exit from nested scopes), so we need a loop at end-of-file Having an actual shift action for an EOF terminal allows us to handle both concerns in the main shift/recover/reduce loop. This revealed a recovery design bug where recovery could enter a loop by repeatedly choosing the same parent to identically recover from. Addressed this by allowing each node to be used as a recovery base once. Differential Revision: https://reviews.llvm.org/D130550
50 lines
1.6 KiB
Plaintext
50 lines
1.6 KiB
Plaintext
_ := expr EOF
|
|
expr := expr - expr # S/R conflict at state 4 on '-' token
|
|
expr := IDENTIFIER
|
|
|
|
# RUN: clang-pseudo -grammar %s -print-graph | FileCheck %s --check-prefix=GRAPH
|
|
# GRAPH: States
|
|
# GRAPH-NEXT: State 0
|
|
# GRAPH-NEXT: _ := • expr EOF
|
|
# GRAPH-NEXT: expr := • expr - expr
|
|
# GRAPH-NEXT: expr := • IDENTIFIER
|
|
# GRAPH-NEXT: State 1
|
|
# GRAPH-NEXT: _ := expr • EOF
|
|
# GRAPH-NEXT: expr := expr • - expr
|
|
# GRAPH-NEXT: State 2
|
|
# GRAPH-NEXT: expr := IDENTIFIER •
|
|
# GRAPH-NEXT: State 3
|
|
# GRAPH-NEXT: _ := expr EOF •
|
|
# GRAPH-NEXT: State 4
|
|
# GRAPH-NEXT: expr := • expr - expr
|
|
# GRAPH-NEXT: expr := expr - • expr
|
|
# GRAPH-NEXT: expr := • IDENTIFIER
|
|
# GRAPH-NEXT: State 5
|
|
# GRAPH-NEXT: expr := expr - expr •
|
|
# GRAPH-NEXT: expr := expr • - expr
|
|
# GRAPH-NEXT: 0 ->[expr] 1
|
|
# GRAPH-NEXT: 0 ->[IDENTIFIER] 2
|
|
# GRAPH-NEXT: 1 ->[EOF] 3
|
|
# GRAPH-NEXT: 1 ->[-] 4
|
|
# GRAPH-NEXT: 4 ->[expr] 5
|
|
# GRAPH-NEXT: 4 ->[IDENTIFIER] 2
|
|
# GRAPH-NEXT: 5 ->[-] 4
|
|
|
|
# RUN: clang-pseudo -grammar %s -print-table | FileCheck %s --check-prefix=TABLE
|
|
# TABLE: LRTable:
|
|
# TABLE-NEXT: State 0
|
|
# TABLE-NEXT: IDENTIFIER: shift state 2
|
|
# TABLE-NEXT: expr: go to state 1
|
|
# TABLE-NEXT: State 1
|
|
# TABLE-NEXT: EOF: shift state 3
|
|
# TABLE-NEXT: -: shift state 4
|
|
# TABLE-NEXT: State 2
|
|
# TABLE-NEXT: EOF -: reduce by rule 2 'expr := IDENTIFIER'
|
|
# TABLE-NEXT: State 3
|
|
# TABLE-NEXT: State 4
|
|
# TABLE-NEXT: IDENTIFIER: shift state 2
|
|
# TABLE-NEXT: expr: go to state 5
|
|
# TABLE-NEXT: State 5
|
|
# TABLE-NEXT: -: shift state 4
|
|
# TABLE-NEXT: EOF -: reduce by rule 1 'expr := expr - expr'
|