Author: bde
Date: Sun Aug 28 19:33:09 2016
New Revision: 304962
URL: https://svnweb.freebsd.org/changeset/base/304962
Log:
Expand error messages: print symbol names, parentheses and shift tokens,
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.
Modified:
head/sys/ddb/db_expr.c
Modified: head/sys/ddb/db_expr.c
==============================================================================
--- head/sys/ddb/db_expr.c Sun Aug 28 19:32:14 2016 (r304961)
+++ head/sys/ddb/db_expr.c Sun Aug 28 19:33:09 2016 (r304962)
@@ -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*/
}
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