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Expand error messages: print symbol names, parentheses and shift tokens,

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and negative shift counts.

Fix error messages: print "Division" instead of "Divide"; print
multiplier-like, addition-like and logical operator tokens instead of
garbage (usually the command name).

ddb has a primitive lexer with excessive information hiding that makes
it hard to find even the point in the line where a syntax error is
detected.  Old ddb just printed "Syntax error" and this was unimproved
in most places by printing a garbage token.
This commit is contained in:
Bruce Evans 2016-08-28 19:33:09 +00:00
parent 252664bd71
commit 27a465b033
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=304962
1 changed files with 21 additions and 15 deletions
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36
sys/ddb/db_expr.c
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@ -57,7 +57,8 @@ db_term(db_expr_t *valuep)
if (!db_value_of_name(db_tok_string, valuep) &&
!db_value_of_name_pcpu(db_tok_string, valuep) &&
!db_value_of_name_vnet(db_tok_string, valuep)) {
db_error("Symbol not found\n");
db_printf("Symbol '%s' not found\n", db_tok_string);
db_error(NULL);
/*NOTREACHED*/
}
return (true);
@ -89,12 +90,14 @@ db_term(db_expr_t *valuep)
}
if (t == tLPAREN) {
if (!db_expression(valuep)) {
db_error("Syntax error\n");
db_printf("Expression syntax error after '%c'\n", '(');
db_error(NULL);
/*NOTREACHED*/
}
t = db_read_token();
if (t != tRPAREN) {
db_error("Syntax error\n");
db_printf("Expression syntax error -- expected '%c'\n", ')');
db_error(NULL);
/*NOTREACHED*/
}
return (true);
@ -164,7 +167,9 @@ db_mult_expr(db_expr_t *valuep)
while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH ||
t == tBIT_AND ) {
if (!db_term(&rhs)) {
db_printf("Expression syntax error after '%c'\n", '!');
db_printf("Expression syntax error after '%c'\n",
t == tSTAR ? '*' : t == tSLASH ? '/' : t == tPCT ? '%' :
t == tHASH ? '#' : '&');
db_error(NULL);
/*NOTREACHED*/
}
@ -177,7 +182,7 @@ db_mult_expr(db_expr_t *valuep)
break;
default:
if (rhs == 0) {
db_error("Divide by 0\n");
db_error("Division by 0\n");
/*NOTREACHED*/
}
if (t == tSLASH)
@ -199,7 +204,6 @@ db_add_expr(db_expr_t *valuep)
{
db_expr_t lhs, rhs;
int t;
char c;
if (!db_mult_expr(&lhs))
return (false);
@ -207,8 +211,8 @@ db_add_expr(db_expr_t *valuep)
t = db_read_token();
while (t == tPLUS || t == tMINUS || t == tBIT_OR) {
if (!db_mult_expr(&rhs)) {
c = db_tok_string[0];
db_printf("Expression syntax error after '%c'\n", c);
db_printf("Expression syntax error after '%c'\n",
t == tPLUS ? '+' : t == tMINUS ? '-' : '|');
db_error(NULL);
/*NOTREACHED*/
}
@ -243,11 +247,14 @@ db_shift_expr(db_expr_t *valuep)
t = db_read_token();
while (t == tSHIFT_L || t == tSHIFT_R) {
if (!db_add_expr(&rhs)) {
db_error("Syntax error\n");
db_printf("Expression syntax error after '%s'\n",
t == tSHIFT_L ? "<<" : ">>");
db_error(NULL);
/*NOTREACHED*/
}
if (rhs < 0) {
db_error("Negative shift amount\n");
db_printf("Negative shift amount %jd\n", (intmax_t)rhs);
db_error(NULL);
/*NOTREACHED*/
}
if (t == tSHIFT_L)
@ -269,7 +276,6 @@ db_logical_relation_expr(
{
db_expr_t lhs, rhs;
int t;
char op[3];
if (!db_shift_expr(&lhs))
return (false);
@ -277,11 +283,11 @@ db_logical_relation_expr(
t = db_read_token();
while (t == tLOG_EQ || t == tLOG_NOT_EQ || t == tGREATER ||
t == tGREATER_EQ || t == tLESS || t == tLESS_EQ) {
op[0] = db_tok_string[0];
op[1] = db_tok_string[1];
op[2] = 0;
if (!db_shift_expr(&rhs)) {
db_printf("Expression syntax error after \"%s\"\n", op);
db_printf("Expression syntax error after '%s'\n",
t == tLOG_EQ ? "==" : t == tLOG_NOT_EQ ? "!=" :
t == tGREATER ? ">" : t == tGREATER_EQ ? ">=" :
t == tLESS ? "<" : "<=");
db_error(NULL);
/*NOTREACHED*/
}