xfnw/plan9fox
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

hoc: don't nest calls to follow() when lexing ++/+= and --/-= (#287)

Browse source 
The code had a nested use of the follow() function that could cause +=+
and -=- to register as ++ and --.  The first follow() to execute could
consume a character and match and then the second follow() could consume
another character and match.  For example i-=-10 would result in a syntax
error and i-=- would decrement i.

(imported from plan9port commit f1dd3f065a97f57bf59db2e3284868e181734159)
This commit is contained in:
Ori Bernstein 2019-12-06 11:53:44 -08:00
parent c3779afdd6
commit 450ec696ee
1 changed files with 2 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
sys/src/cmd/hoc/hoc.y
View file

@ -214,8 +214,8 @@ yylex(void) /* hoc6 */
return STRING;
}
switch (c) {
case '+': return follow('+', INC, follow('=', ADDEQ, '+'));
case '-': return follow('-', DEC, follow('=', SUBEQ, '-'));
case '+': return follow('+', INC, '+') == INC ? INC : follow('=', ADDEQ, '+');
case '-': return follow('-', DEC, '-') == DEC ? DEC : follow('=', SUBEQ, '-');
case '*': return follow('=', MULEQ, '*');
case '/': return follow('=', DIVEQ, '/');
case '%': return follow('=', MODEQ, '%');