Adding onto the commit message, here is the relevant state of the compiler when parsing the following code, where the ^ represents the variable pos in collect_variables() and code is printed before synt each time:
buf = buffer_create(32000, buffer_grow, 4);
local double i = 0.0;
local double j = 0.5;FOUND LOCAL/GLOBAL KEYWORD:
{buf=buffer_create(32000,buffer_grow,4);localdoublei=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);LLLLLttttttn=000;LLLLLttttttn=000;};
^
Declared double i as local
WHILE DECLARING:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;LLLLLttttttn=000;};
^
ERASE FROM CODE: i
dec_name: i
AFTER ERASING INIT:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;LLLLLttttttn=000;};
^
FOUND LOCAL/GLOBAL KEYWORD:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;LLLLLttttttn=000;};
^
Declared ouble j as local
WHILE DECLARING:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;lj=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;Ln=000;};
^
ERASE FROM CODE: j
dec_name: j
AFTER ERASING INIT:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;lj=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;Ln=000;};
^After erasing the initializer of the variable i, the pos is set at the first l of local instead of the semicolon, because of which it skips to the o of local when it starts parsing j because of the pos++ at the end of the loop. Therefore, by setting pos to be one character behind, it leads to the following state:
FOUND LOCAL/GLOBAL KEYWORD:
{buf=buffer_create(32000,buffer_grow,4);localdoublei=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);LLLLLttttttn=000;LLLLLttttttn=000;};
^
Declared double i as local
WHILE DECLARING:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;LLLLLttttttn=000;};
^
ERASE FROM CODE: i
dec_name: i
AFTER ERASING INIT:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;LLLLLttttttn=000;};
^
FOUND LOCAL/GLOBAL KEYWORD:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;localdoublej=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;LLLLLttttttn=000;};
^
Declared double j as local
WHILE DECLARING:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;j=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;n=000;};
^
ERASE FROM CODE: j
dec_name: j
AFTER ERASING INIT:
{buf=buffer_create(32000,buffer_grow,4);i=0.0;j=0.5;};
{nnn=nnnnnnnnnnnnn(00000,nnnnnnnnnnn,0);n=000;n=000;};
^Thus pos points to the right character at the end of parsing the initializer and the bug is fixed.
Leave a commentView this issue on GitHub
Please sign in to post comments, or you can view this issue on GitHub.