Hi, I found a segmentation fault while running GNU Bison 3.8.2 on Ubuntu 22.04.
The crash occurs when I run Bison with the --trace=all option on the attached grammar file. Environment: OS: Ubuntu 22.04 Bison version: GNU Bison 3.8.2 Build method: downloaded bison-3.8.2.tar.xz and ran ./configure and make Command used: ./bison --trace=all example.yy Expected behavior: Bison should process the grammar file and print trace output without crashing. Actual behavior: Bison crashes with a segmentation fault. Here is the relevant part of the output: $ ./bison --trace=all example.yy bison (GNU Bison) 3.8.2 Starting parse Entering state 0 Stack now 0 Reducing stack by rule 2 (line 319): -> $$ = nterm prologue_declarations (example.yy:[email protected]:1.1@1: ) Entering state 2 Stack now 0 2 Reading a token --(end of buffer or a NUL) --accepting rule at line 219 ("/*") --accepting rule at line 527 (" ") ... Reducing stack by rule 24 (line 363): $1 = token %skeleton (example.yy:[email protected]:20.10@10: ) $2 = token string (example.yy:[email protected]:20.21@21: "lalr1.cc") -> $$ = nterm prologue_declaration (example.yy:[email protected]:20.21@21: ) Entering state 43 Stack now 0 2 43 ... --accepting rule at line 247 ("%define") Next token is token %define (example.yy:[email protected]:24.8@8: ) LAC: initial context established for %define LAC: checking lookahead %define: R55 G60 R8 G43 R3 G2 S16 Reducing stack by rule 55 (line 488): -> $$ = nterm string.opt (example.yy:[email protected]:22.8@8: Segmentation fault (core dumped) I am attaching the example.yy file used to reproduce the crash. Best regards, Minjong Kim
example.yy
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