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bc: fix handling of comment/string interactions while buffering input

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function                                             old     new   delta
zbc_lex_next                                        1965    1982     +17
zbc_num_divmod                                       150     156      +6
bc_read_line                                         411     394     -17
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 23/-17)              Total: 6 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2018-12-26 12:23:05 +01:00
parent 94576d2b97
commit 63ad799384
1 changed files with 74 additions and 38 deletions
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112
miscutils/bc.c
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@@ -1147,23 +1147,6 @@ static void bc_vec_string(BcVec *v, size_t len, const char *str)
bc_vec_pushZeroByte(v);
}
#if ENABLE_FEATURE_BC_SIGNALS && ENABLE_FEATURE_EDITING
static void bc_vec_concat(BcVec *v, const char *str)
{
size_t len, slen;
if (v->len == 0) bc_vec_pushZeroByte(v);
slen = strlen(str);
len = v->len + slen;
if (v->cap < len) bc_vec_grow(v, slen);
strcpy(v->v + v->len - 1, str);
v->len = len;
}
#endif
static void *bc_vec_item(const BcVec *v, size_t idx)
{
return v->v + v->size * idx;
@@ -2491,6 +2474,21 @@ static FAST_FUNC void bc_result_free(void *result)
}
}
#if ENABLE_FEATURE_BC_SIGNALS && ENABLE_FEATURE_EDITING
static void bc_vec_concat(BcVec *v, const char *str)
{
size_t len, slen;
slen = strlen(str);
len = v->len + slen + 1;
if (v->cap < len) bc_vec_grow(v, slen);
strcpy(v->v + v->len, str);
v->len = len;
}
#endif
static int bad_input_byte(char c)
{
if ((c < ' ' && c != '\t' && c != '\r' && c != '\n') // also allow '\v' '\f'?
@@ -2887,7 +2885,7 @@ static void bc_lex_file(void)
static bool bc_lex_more_input(void)
{
BcParse *p = &G.prs;
size_t str;
unsigned str; // bool for bc, string nest count for dc
bool comment;
bc_vec_pop_all(&G.input_buffer);
@@ -2896,8 +2894,23 @@ static bool bc_lex_more_input(void)
// with a backslash to the parser. The reason for that is because the parser
// treats a backslash+newline combo as whitespace, per the bc spec. In that
// case, and for strings and comments, the parser will expect more stuff.
comment = false;
//
// bc cases to test interactively:
// 1 #comment\ - prints "1<newline>" at once (comment is not continued)
// 1 #comment/* - prints "1<newline>" at once
// 1 #comment" - prints "1<newline>" at once
// 1\#comment - error at once (\ is not a line continuation)
// 1 + /*"*/2 - prints "3<newline>" at once
// 1 + /*#*/2 - prints "3<newline>" at once
// "str\" - prints "str\" at once
// "str#" - prints "str#" at once
// "str/*" - prints "str/*" at once
// "str#\ - waits for second line
// end" - ...prints "str#\<newline>end"
//This is way too complex, we duplicate comment/string logic of lexer
//TODO: switch to char-by-char input like hush does it
str = 0;
comment = false; // stays always false for dc
for (;;) {
size_t prevlen = G.input_buffer.len;
char *string;
@@ -2909,39 +2922,61 @@ static bool bc_lex_more_input(void)
string = G.input_buffer.v + prevlen;
while (*string) {
char c = *string;
if (!comment) {
if (string == G.input_buffer.v || string[-1] != '\\') {
if (IS_BC)
str ^= (c == '"');
else {
if (c == ']')
str -= 1;
else if (c == '[')
str += 1;
}
char c = *string++;
#if ENABLE_BC
if (comment) {
// We are in /**/ comment, exit only on "*/"
if (c == '*' && *string == '/') {
comment = false;
string++;
}
continue;
}
string++;
if (!str) {
#endif
// We are not in /**/ comment
if (str) {
// We are in "string" (bc) or [string] (dc)
if (IS_BC) {
// bc strings have no escapes: \\ is not special,
// \n is not, \" is not, \<newline> is not.
str = (c != '"'); // clear flag when " is seen
} else {
// dc strings have no escapes as well, can nest
if (c == ']')
str--;
if (c == '[')
str++;
}
continue;
}
// We are not in a string or /**/ comment
// Is it a #comment? Return the string (can't have continuation)
if (c == '#')
goto return_string;
#if ENABLE_BC
if (IS_BC) {
// bc: is it a start of /**/ comment or string?
if (c == '/' && *string == '*') {
comment = true;
string++;
continue;
}
if (c == '*' && *string == '/') {
comment = false;
string++;
}
str = (c == '"'); // set flag if " is seen
continue;
}
}
#endif
// dc: is it a start of string?
str = (c == '[');
} // end of "check all chars in string" loop
if (str != 0 || comment) {
G.input_buffer.len--; // backstep over the trailing NUL byte
continue;
}
// Check for backslash+newline.
// we do not check that last char is '\n' -
// We do not check that last char is '\n' -
// if it is not, then it's EOF, and looping back
// to bc_read_line() will detect it:
string -= 2;
@@ -2952,6 +2987,7 @@ static bool bc_lex_more_input(void)
break;
}
return_string:
p->lex_inbuf = G.input_buffer.v;
// bb_error_msg("G.input_buffer.len:%d '%s'", G.input_buffer.len, G.input_buffer.v);