Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Heapster: Avoid shift/reduce conflicts involving bitvector negation #1795

Merged
merged 1 commit into from
Jan 4, 2023
Merged

Heapster: Avoid shift/reduce conflicts involving bitvector negation #1795

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 6 additions & 1 deletion heapster-saw/src/Verifier/SAW/Heapster/Parser.y
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,8 @@ import Verifier.SAW.Heapster.UntypedAST

}

%expect 0 -- shift/reduce conflicts

%tokentype { Located Token }
%token
'(' { Located $$ TOpenParen }
Expand Down Expand Up @@ -108,6 +110,7 @@ NAT { (traverse tokenNat -> Just $$) }
%left '+'
%left '*'
%nonassoc '@'
%left NEGPREC

%%

Expand Down Expand Up @@ -136,7 +139,9 @@ expr :: { AstExpr }
| NAT { ExNat (pos $1) (locThing $1) }
| 'unit' { ExUnit (pos $1) }
| expr '+' expr { ExAdd (pos $2) $1 $3 }
| '-' expr { ExNeg (pos $1) $2 }
-- NB: Give negation the highest possible precedence to avoid shift/reduce
-- conflicts with other operators, such as + and *.
| '-' expr %prec NEGPREC { ExNeg (pos $1) $2 }
| expr '*' expr { ExMul (pos $2) $1 $3 }
| 'struct' '(' list(expr) ')' { ExStruct (pos $1) $3 }
| lifetime 'array' '(' expr ',' expr ',' '<' expr ',' '*' expr ',' expr ')'
Expand Down