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bc: fix interactive read()

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Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-25 19:37:23 +01:00
parent 2638454464
commit 53e569c06b
1 changed files with 26 additions and 25 deletions
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31
miscutils/bc.c
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@ -6753,6 +6753,7 @@ static BC_STATUS zbc_vm_process(const char *text)
s = zbc_parse_text_init(&G.prs, text); // does the first zbc_lex_next() s = zbc_parse_text_init(&G.prs, text); // does the first zbc_lex_next()
if (s) RETURN_STATUS(s); if (s) RETURN_STATUS(s);
IF_BC(check_eof:)
while (G.prs.l.lex != XC_LEX_EOF) { while (G.prs.l.lex != XC_LEX_EOF) {
BcInstPtr *ip; BcInstPtr *ip;
BcFunc *f; BcFunc *f;
@ -6760,23 +6761,25 @@ static BC_STATUS zbc_vm_process(const char *text)
dbg_lex("%s:%d G.prs.l.lex:%d, parsing...", __func__, __LINE__, G.prs.l.lex); dbg_lex("%s:%d G.prs.l.lex:%d, parsing...", __func__, __LINE__, G.prs.l.lex);
if (IS_BC) { if (IS_BC) {
#if ENABLE_BC #if ENABLE_BC
if (G.prs.l.lex == BC_LEX_SCOLON
|| G.prs.l.lex == XC_LEX_NLINE
) {
s = zbc_lex_next(&G.prs.l);
if (s) goto err;
goto check_eof;
}
s = zbc_parse_stmt_or_funcdef(&G.prs); s = zbc_parse_stmt_or_funcdef(&G.prs);
if (s) goto err; if (s) goto err;
// Check that next token is not bogus, and skip over // Check that next token is a correct stmt delimiter -
// stmt delimiter(s) - newlines and semicolons // disallows "print 1 print 2" and such.
s = 1; // s == 1 on first iteration only
for (;;) {
if (G.prs.l.lex == XC_LEX_EOF)
goto execute; // this goto avoids resetting 's' to zero
if (G.prs.l.lex != BC_LEX_SCOLON if (G.prs.l.lex != BC_LEX_SCOLON
&& G.prs.l.lex != XC_LEX_NLINE && G.prs.l.lex != XC_LEX_NLINE
&& G.prs.l.lex != XC_LEX_EOF
) { ) {
const char *err_at; const char *err_at;
// Not newline and not semicolon //TODO: commonalize for other parse errors:
if (s == 0) // saw at least one NL/semicolon before it?
break; // yes, good
//TODO: commolalize for other parse errors:
err_at = G.prs.l.lex_next_at ? G.prs.l.lex_next_at : "UNKNOWN"; err_at = G.prs.l.lex_next_at ? G.prs.l.lex_next_at : "UNKNOWN";
bc_error_fmt("bad statement terminator at '%.*s'", bc_error_fmt("bad statement terminator at '%.*s'",
(int)(strchrnul(err_at, '\n') - err_at), (int)(strchrnul(err_at, '\n') - err_at),
@ -6784,10 +6787,8 @@ static BC_STATUS zbc_vm_process(const char *text)
); );
goto err; goto err;
} }
// NL or semicolon: skip it, set s = 0, repeat // The above logic is fragile. Check these examples:
s = zbc_lex_next(&G.prs.l); // - interative read() still works
if (s) goto err;
}
#endif #endif
} else { } else {
#if ENABLE_DC #if ENABLE_DC
@ -6807,7 +6808,7 @@ static BC_STATUS zbc_vm_process(const char *text)
bc_parse_reset(&G.prs); // includes bc_program_reset() bc_parse_reset(&G.prs); // includes bc_program_reset()
RETURN_STATUS(BC_STATUS_FAILURE); RETURN_STATUS(BC_STATUS_FAILURE);
} }
IF_BC(execute:)
dbg_lex("%s:%d executing...", __func__, __LINE__); dbg_lex("%s:%d executing...", __func__, __LINE__);
s = zbc_program_exec(); s = zbc_program_exec();
if (s) { if (s) {