qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-22 09:14:40 -07:00
Code Releases Activity

cmd/gc: Friendlier errors on oversized arrays.

Browse Source 
Someone new to the language may not know the connection between ints and arrays, which was the only thing that the previous error told you anything about.

Fixes #4256.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6739048
This commit is contained in:
Daniel Morsing 2012-10-21 19:22:51 +02:00
parent c1b7ddc6aa
commit a7a3fe7238
4 changed files with 38 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
src/cmd/gc/const.c
View File

@ -348,13 +348,9 @@ toint(Val v)
return v;
}
void
overflow(Val v, Type *t)
int
doesoverflow(Val v, Type *t)
{
// v has already been converted
// to appropriate form for t.
if(t == T || t->etype == TIDEAL)
return;
switch(v.ctype) {
case CTINT:
case CTRUNE:
@ -362,14 +358,14 @@ overflow(Val v, Type *t)
fatal("overflow: %T integer constant", t);
if(mpcmpfixfix(v.u.xval, minintval[t->etype]) < 0 ||
mpcmpfixfix(v.u.xval, maxintval[t->etype]) > 0)
yyerror("constant %B overflows %T", v.u.xval, t);
return 1;
break;
case CTFLT:
if(!isfloat[t->etype])
fatal("overflow: %T floating-point constant", t);
if(mpcmpfltflt(v.u.fval, minfltval[t->etype]) <= 0 ||
mpcmpfltflt(v.u.fval, maxfltval[t->etype]) >= 0)
yyerror("constant %#F overflows %T", v.u.fval, t);
return 1;
break;
case CTCPLX:
if(!iscomplex[t->etype])
@ -378,7 +374,33 @@ overflow(Val v, Type *t)
mpcmpfltflt(&v.u.cval->real, maxfltval[t->etype]) >= 0 ||
mpcmpfltflt(&v.u.cval->imag, minfltval[t->etype]) <= 0 ||
mpcmpfltflt(&v.u.cval->imag, maxfltval[t->etype]) >= 0)
yyerror("constant %#F overflows %T", v.u.fval, t);
return 1;
break;
}
return 0;
}
void
overflow(Val v, Type *t)
{
// v has already been converted
// to appropriate form for t.
if(t == T || t->etype == TIDEAL)
return;
if(!doesoverflow(v, t))
return;
switch(v.ctype) {
case CTINT:
case CTRUNE:
yyerror("constant %B overflows %T", v.u.xval, t);
break;
case CTFLT:
yyerror("constant %#F overflows %T", v.u.fval, t);
break;
case CTCPLX:
yyerror("constant %#F overflows %T", v.u.fval, t);
break;
}
}

3
src/cmd/gc/go.h
View File

@ -178,7 +178,7 @@ struct Type
Strlit* note; // literal string annotation
// TARRAY
int32 bound; // negative is dynamic array
vlong bound; // negative is dynamic array
int32 maplineno; // first use of TFORW as map key
int32 embedlineno; // first use of TFORW as embedded type
@ -977,6 +977,7 @@ int isconst(Node *n, int ct);
Node* nodcplxlit(Val r, Val i);
Node* nodlit(Val v);
long nonnegconst(Node *n);
int doesoverflow(Val v, Type *t);
void overflow(Val v, Type *t);
int smallintconst(Node *n);
Val toint(Val v);

6
src/cmd/gc/typecheck.c
View File

@ -390,8 +390,10 @@ reswitch:
if(t->bound < 0) {
yyerror("array bound must be non-negative");
goto error;
} else
overflow(v, types[TINT]);
} else if(doesoverflow(v, types[TINT])) {
yyerror("array bound is too large");
goto error;
}
}
typecheck(&r, Etype);
if(r->type == T)

2
test/fixedbugs/bug255.go
View File

@ -12,4 +12,4 @@ var c [1.5]int // ERROR "truncated"
var d ["abc"]int // ERROR "invalid array bound|not numeric"
var e [nil]int // ERROR "invalid array bound|not numeric"
var f [e]int // ERROR "invalid array bound|not constant"
var g [1<<65]int // ERROR "overflows"
var g [1<<65]int // ERROR "array bound is too large|overflows"