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bc: add code to detect errors like "print 1 print 2"

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function                                             old     new   delta
zbc_vm_process                                       831     925     +94
zbc_program_exec                                    3964    3976     +12
zdc_program_execStr                                  506     512      +6
zbc_lex_next                                        2161    2167      +6
zbc_program_assign                                   419     424      +5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/0 up/down: 123/0)             Total: 123 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2018-12-25 18:37:52 +01:00
parent 5fa74b9efc
commit 2638454464
1 changed files with 39 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
miscutils/bc.c
View File

@@ -711,6 +711,7 @@ dc_LEX_to_INST[] = { // starts at XC_LEX_OP_POWER // corresponding XC/DC_L
typedef struct BcLex {
const char *buf;
const char *lex_next_at; // last lex_next() was called at this string
size_t i;
size_t line;
size_t len;
@@ -2990,9 +2991,11 @@ static BC_STATUS zbc_lex_next(BcLex *l)
}
// here it's guaranteed that l->i is below l->len
}
l->lex_next_at = l->buf + l->i;
dbg_lex("next string to parse:'%.*s'",
(int)(strchrnul(l->buf + l->i, '\n') - (l->buf + l->i)),
l->buf + l->i);
(int)(strchrnul(l->lex_next_at, '\n') - l->lex_next_at),
l->lex_next_at
);
if (IS_BC) {
IF_BC(s = zbc_lex_token(l));
} else {
@@ -6756,13 +6759,38 @@ 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);
if (IS_BC) {
// FIXME: "eating" of stmt delimiters is coded inconsistently
// (sometimes zbc_parse_stmt() eats the delimiter, sometimes don't),
// which causes bugs such as "print 1 print 2" erroneously accepted,
// or "print 1 else 2" detecting parse error only after executing
// "print 1" part.
IF_BC(s = zbc_parse_stmt_or_funcdef(&G.prs));
#if ENABLE_BC
s = zbc_parse_stmt_or_funcdef(&G.prs);
if (s) goto err;
// Check that next token is not bogus, and skip over
// stmt delimiter(s) - newlines and semicolons
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
&& G.prs.l.lex != XC_LEX_NLINE
) {
const char *err_at;
// Not newline and not semicolon
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";
bc_error_fmt("bad statement terminator at '%.*s'",
(int)(strchrnul(err_at, '\n') - err_at),
err_at
);
goto err;
}
// NL or semicolon: skip it, set s = 0, repeat
s = zbc_lex_next(&G.prs.l);
if (s) goto err;
}
#endif
} else {
#if ENABLE_DC
// Most of dc parsing assumes all whitespace,
// including '\n', is eaten.
while (G.prs.l.lex == XC_LEX_NLINE) {
@@ -6771,14 +6799,15 @@ static BC_STATUS zbc_vm_process(const char *text)
if (G.prs.l.lex == XC_LEX_EOF)
goto done;
}
IF_DC(s = zdc_parse_expr(&G.prs));
s = zdc_parse_expr(&G.prs);
#endif
}
if (s || G_interrupt) {
err:
bc_parse_reset(&G.prs); // includes bc_program_reset()
RETURN_STATUS(BC_STATUS_FAILURE);
}
IF_BC(execute:)
dbg_lex("%s:%d executing...", __func__, __LINE__);
s = zbc_program_exec();
if (s) {