Some operators that have only recently been added, and so have not
generated all that much experience yet are "and then" and "or else" as
-short-circuit Boolean operators, and the "if ... else" trinary
-operator which can select between two expressions based on a third
-(which appears syntactically in the middle).
+short-circuit Boolean operators (which have since been remove), and the
+"if ... else" trinary operator which can select between two expressions
+based on a third (which appears syntactically in the middle).
The "func" clause currently only allows a "main" function to be
declared. That will be extended when proper function support is added.
## macros
struct parse_context;
## ast
+ ## ast late
struct parse_context {
struct token_config config;
char *file_name;
static void fput_loc(struct exec *loc, FILE *f);
static void type_err(struct parse_context *c,
char *fmt, struct exec *loc,
- struct type *t1, int rules, struct type *t2);
+ struct type *t1, enum val_rules rules, struct type *t2);
static void tok_err(struct parse_context *c, char *fmt, struct token *t);
###### core functions
static void type_err(struct parse_context *c,
char *fmt, struct exec *loc,
- struct type *t1, int rules, struct type *t2)
+ struct type *t1, enum val_rules rules, struct type *t2)
{
fprintf(stderr, "%s:", c->file_name);
fput_loc(loc, stderr);
which can be `NULL` signifying "unknown". A `prop_err` flag set is
passed by reference. It has `Efail` set when an error is found, and
`Eretry` when the type for some element is set via propagation. If
-any expression cannot be evaluated immediately, `Enoconst` is set.
+any expression cannot be evaluated a compile time, `Eruntime` is set.
If the expression can be copied, `Emaycopy` is set.
-If it remains unchanged at `0`, then no more propagation is needed.
+If `Erval` is set, then the value cannot be assigned to because it is
+a temporary result. If `Erval` is clear but `Econst` is set, then
+the value can only be assigned once, when the variable is declared.
###### ast
- enum val_rules {Rnolabel = 1<<0, Rboolok = 1<<1, Rnoconstant = 1<<2};
- enum prop_err {Efail = 1<<0, Eretry = 1<<1, Enoconst = 1<<2,
- Emaycopy = 1<<3};
-
-###### format cases
- case 'r':
- if (rules & Rnolabel)
- fputs(" (labels not permitted)", stderr);
- break;
+ enum val_rules {Rboolok = 1<<0, Rrefok = 1<<1,};
+ enum prop_err {Efail = 1<<0, Eretry = 1<<1, Eruntime = 1<<2,
+ Emaycopy = 1<<3, Erval = 1<<4, Econst = 1<<5};
###### forward decls
static struct type *propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,
- struct type *type, int rules);
+ struct type *type, enum val_rules rules);
###### core functions
static struct type *__propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,
- struct type *type, int rules)
+ enum prop_err *perr_local,
+ struct type *type, enum val_rules rules)
{
struct type *t;
}
static struct type *propagate_types(struct exec *prog, struct parse_context *c, enum prop_err *perr,
- struct type *type, int rules)
+ struct type *type, enum val_rules rules)
{
int pre_err = c->parse_error;
- struct type *ret = __propagate_types(prog, c, perr, type, rules);
+ enum prop_err perr_local = 0;
+ struct type *ret = __propagate_types(prog, c, perr, &perr_local, type, rules);
+ *perr |= perr_local & (Efail | Eretry);
if (c->parse_error > pre_err)
*perr |= Efail;
return ret;
};
};
+###### ast late
struct type {
struct text name;
struct type *next;
###### forward decls
static void free_value(struct type *type, struct value *v);
- static int type_compat(struct type *require, struct type *have, int rules);
+ static int type_compat(struct type *require, struct type *have, enum val_rules rules);
static void type_print(struct type *type, FILE *f);
static void val_init(struct type *type, struct value *v);
static void dup_value(struct type *type,
###### type functions
- int (*compat)(struct type *this, struct type *other);
+ int (*compat)(struct type *this, struct type *other, enum val_rules rules);
###### ast functions
- static int type_compat(struct type *require, struct type *have, int rules)
+ static int type_compat(struct type *require, struct type *have,
+ enum val_rules rules)
{
if ((rules & Rboolok) && have == Tbool)
return 1; // NOTEST
- if ((rules & Rnolabel) && have == Tlabel)
- return 0; // NOTEST
if (!require || !have)
return 1;
if (require->compat)
- return require->compat(require, have);
+ return require->compat(require, have, rules);
return require == have;
}
struct text str;
mpq_t num;
unsigned char bool;
- void *label;
+ int label;
###### ast functions
static void _free_value(struct type *type, struct value *v)
val->bool = 0;
break;
case Vlabel:
- val->label = NULL;
- break;
+ val->label = 0; // NOTEST
+ break; // NOTEST
}
}
case Vnone: // NOTEST
break; // NOTEST
case Vlabel:
- vnew->label = vold->label;
- break;
+ vnew->label = vold->label; // NOTEST
+ break; // NOTEST
case Vbool:
vnew->bool = vold->bool;
break;
{
int cmp;
if (tl != tr)
- return tl - tr; // NOTEST
+ return tl - tr;
switch (tl->vtype) {
case Vlabel: cmp = left->label == right->label ? 0 : 1; break;
case Vnum: cmp = mpq_cmp(left->num, right->num); break;
case Vnone: // NOTEST
fprintf(f, "*no-value*"); break; // NOTEST
case Vlabel: // NOTEST
- fprintf(f, "*label-%p*", v->label); break; // NOTEST
+ fprintf(f, "*label-%d*", v->label); break; // NOTEST
case Vstr:
fprintf(f, "%.*s", v->str.len, v->str.txt); break;
case Vbool:
return v;
}
-###### Grammar
-
+###### declare terminals
$TERM True False
+###### Grammar
+
$*val
Value -> True ${
$0 = new_val(Tbool, $1);
$0->val.bool = 0;
}$
| NUMBER ${ {
- char tail[3];
+ char tail[3] = "";
$0 = new_val(Tnum, $1);
- if (number_parse($0->val.num, tail, $1.txt) == 0)
- mpq_init($0->val.num); // UNTESTED
- if (tail[0])
- tok_err(c, "error: unsupported number suffix",
- &$1);
+ if (number_parse($0->val.num, tail, $1.txt) == 0) {
+ mpq_init($0->val.num);
+ tok_err(c, "error: unsupported number format", &$NUM);
+ } else if (tail[0])
+ tok_err(c, "error: unsupported number suffix", &$1);
} }$
| STRING ${ {
char tail[3];
{
struct val *val = cast(val, prog);
if (!type_compat(type, val->vtype, rules))
- type_err(c, "error: expected %1%r found %2",
+ type_err(c, "error: expected %1 found %2",
prog, type, rules, val->vtype);
+ *perr |= Erval;
return val->vtype;
}
return rv;
}
+#### Labels
+
+Labels are a temporary concept until I implement enums. There are an
+anonymous enum which is declared by usage. Thet are only allowed in
+`use` statements and corresponding `case` entries. They appear as a
+period followed by an identifier. All identifiers that are "used" must
+have a "case".
+
+For now, we have a global list of labels, and don't check that all "use"
+match "case".
+
+###### exec type
+ Xlabel,
+
+###### ast
+ struct label {
+ struct exec;
+ struct text name;
+ int value;
+ };
+###### free exec cases
+ case Xlabel:
+ free(e);
+ break;
+###### print exec cases
+ case Xlabel: {
+ struct label *l = cast(label, e);
+ printf(".%.*s", l->name.len, l->name.txt);
+ break;
+ }
+
+###### ast
+ struct labels {
+ struct labels *next;
+ struct text name;
+ int value;
+ };
+###### parse context
+ struct labels *labels;
+ int next_label;
+###### ast functions
+ static int label_lookup(struct parse_context *c, struct text name)
+ {
+ struct labels *l, **lp = &c->labels;
+ while (*lp && text_cmp((*lp)->name, name) < 0)
+ lp = &(*lp)->next;
+ if (*lp && text_cmp((*lp)->name, name) == 0)
+ return (*lp)->value;
+ l = calloc(1, sizeof(*l));
+ l->next = *lp;
+ l->name = name;
+ if (c->next_label == 0)
+ c->next_label = 2;
+ l->value = c->next_label;
+ c->next_label += 1;
+ *lp = l;
+ return l->value;
+ }
+
+###### free context storage
+ while (context.labels) {
+ struct labels *l = context.labels;
+ context.labels = l->next;
+ free(l);
+ }
+
+###### declare terminals
+ $TERM .
+###### term grammar
+ | . IDENTIFIER ${ {
+ struct label *l = new_pos(label, $ID);
+ l->name = $ID.txt;
+ $0 = l;
+ } }$
+###### propagate exec cases
+ case Xlabel: {
+ struct label *l = cast(label, prog);
+ l->value = label_lookup(c, l->name);
+ if (!type_compat(type, Tlabel, rules))
+ type_err(c, "error: expected %1 found %2",
+ prog, type, rules, Tlabel);
+ *perr |= Erval;
+ return Tlabel;
+ }
+###### interp exec cases
+ case Xlabel : {
+ struct label *l = cast(label, e);
+ rv.label = l->value;
+ rvtype = Tlabel;
+ break;
+ }
+
+
### Variables
Variables are scoped named values. We store the names in a linked list
v->previous->scope == PendingScope)
/* all previous branches used name */
v->scope = PendingScope;
- else if (v->type == Tlabel)
- /* Labels remain pending even when not used */
- v->scope = PendingScope; // UNTESTED
else
v->scope = OutScope;
if (ct == CloseElse) {
v->scope = InScope;
/* fallthrough */
case CloseSequential:
- if (v->type == Tlabel)
- v->scope = PendingScope;
switch (v->scope) {
case InScope:
v->scope = OutScope;
for (v2 = v;
v2 && v2->scope == PendingScope;
v2 = v2->previous)
- if (v2->type == Tlabel)
- v2->scope = CondScope;
- else
- v2->scope = OutScope;
+ v2->scope = OutScope;
break;
case CondScope:
case OutScope: break;
{
if (!v->global) {
if (!c->local || !v->type)
- return NULL; // UNTESTED
+ return NULL; // NOTEST
if (v->frame_pos + v->type->size > c->local_size) {
printf("INVALID frame_pos\n"); // NOTEST
exit(2); // NOTEST
t->prepare_type(c, t, 1); // NOTEST
if (c->global_size & (t->align - 1))
- c->global_size = (c->global_size + t->align) & ~(t->align-1); // NOTEST
+ c->global_size = (c->global_size + t->align) & ~(t->align-1);
if (!v) {
v = &scratch;
v->type = t;
if (init)
memcpy(ret, init, t->size);
else
- val_init(t, ret);
+ val_init(t, ret); // NOTEST
return ret;
}
if (v->merged != v)
continue;
if (!t)
- continue;
+ continue; // NOTEST
if (v->frame_pos >= 0)
continue;
while (done && done->scope_end < v->scope_start)
return Tnone; // NOTEST
}
v = v->merged;
- if (v->constant && (rules & Rnoconstant)) {
- type_err(c, "error: Cannot assign to a constant: %v",
- prog, NULL, 0, NULL);
- type_err(c, "info: name was defined as a constant here",
- v->where_decl, NULL, 0, NULL);
- return v->type;
- }
if (v->type == Tnone && v->where_decl == prog)
type_err(c, "error: variable used but not declared: %v",
prog, NULL, 0, NULL);
*perr |= Eretry;
}
} else if (!type_compat(type, v->type, rules)) {
- type_err(c, "error: expected %1%r but variable '%v' is %2", prog,
+ type_err(c, "error: expected %1 but variable '%v' is %2", prog,
type, rules, v->type);
type_err(c, "info: this is where '%v' was set to %1", v->where_set,
v->type, rules, NULL);
}
if (!v->global || v->frame_pos < 0)
- *perr |= Enoconst;
- if (!type)
- return v->type;
- return type;
+ *perr |= Eruntime;
+ if (v->constant)
+ *perr |= Econst;
+ return v->type;
}
###### interp exec cases
struct value *vsize;
mpz_t q;
if (type->array.static_size)
- return 1; // UNTESTED
+ return 1; // NOTEST - guard against reentry
if (type->array.unspec && parse_time)
- return 1; // UNTESTED
+ return 1; // NOTEST - unspec is still incomplete
if (parse_time && type->array.vsize && !type->array.vsize->global)
- return 1; // UNTESTED
+ return 1; // NOTEST - should be impossible
if (type->array.vsize) {
vsize = var_value(c, type->array.vsize);
if (!vsize)
- return 1; // UNTESTED
+ return 1; // NOTEST - should be impossible
mpz_init(q);
mpz_tdiv_q(q, mpq_numref(vsize->num), mpq_denref(vsize->num));
type->array.size = mpz_get_si(q);
if (!parse_time)
return 1;
if (type->array.member->size <= 0)
- return 0; // UNTESTED
+ return 0; // NOTEST - error caught before here
type->array.static_size = 1;
type->size = type->array.size * type->array.member->size;
free(ptr);
}
- static int array_compat(struct type *require, struct type *have)
+ static int array_compat(struct type *require, struct type *have,
+ enum val_rules rules)
{
if (have->compat != require->compat)
return 0;
/* Both are arrays, so we can look at details */
if (!type_compat(require->array.member, have->array.member, 0))
return 0;
- if (have->array.unspec && require->array.unspec) {
- if (have->array.vsize && require->array.vsize &&
- have->array.vsize != require->array.vsize) // UNTESTED
- /* sizes might not be the same */
- return 0; // UNTESTED
- return 1;
- }
+ if (have->array.unspec && require->array.unspec &&
+ have->array.size != require->array.size)
+ return 0; // NOTEST
if (have->array.unspec || require->array.unspec)
- return 1; // UNTESTED
+ return 1;
if (require->array.vsize == NULL && have->array.vsize == NULL)
return require->array.size == have->array.size;
- return require->array.vsize == have->array.vsize; // UNTESTED
+ return require->array.vsize == have->array.vsize;
}
static void array_print_type(struct type *type, FILE *f)
$0->array.vsize = v;
} }$
-###### Grammar
- $*type
- OptType -> Type ${ $0 = $<1; }$
- | ${ $0 = NULL; }$
-
###### formal type grammar
- | [ IDENTIFIER :: OptType ] Type ${ {
- struct variable *v = var_decl(c, $ID.txt);
-
- v->type = $<OT;
- v->constant = 1;
- if (!v->type)
- v->type = Tnum;
- $0 = add_anon_type(c, &array_prototype, "array[var]");
- $0->array.member = $<6;
+ | [ ] Type ${ {
+ $0 = add_anon_type(c, &array_prototype, "array[]");
+ $0->array.member = $<Type;
$0->array.size = 0;
$0->array.unspec = 1;
- $0->array.vsize = v;
+ $0->array.vsize = NULL;
} }$
###### Binode types
- Index,
+ Index, Length,
###### term grammar
$0 = b;
} }$
+ | Term [ ] ${ {
+ struct binode *b = new(binode);
+ b->op = Length;
+ b->left = $<Term;
+ $0 = b;
+ } }$
+
###### print binode cases
case Index:
print_exec(b->left, -1, bracket);
printf("]");
break;
+ case Length:
+ print_exec(b->left, -1, bracket);
+ printf("[]");
+ break;
+
###### propagate binode cases
case Index:
/* left must be an array, right must be a number,
* result is the member type of the array
*/
- propagate_types(b->right, c, perr, Tnum, 0);
- t = propagate_types(b->left, c, perr, NULL, rules & Rnoconstant);
+ propagate_types(b->right, c, perr_local, Tnum, 0);
+ t = propagate_types(b->left, c, perr, NULL, 0);
if (!t || t->compat != array_compat) {
type_err(c, "error: %1 cannot be indexed", prog, t, 0, NULL);
return NULL;
}
break;
+ case Length:
+ /* left must be an array, result is a number
+ */
+ t = propagate_types(b->left, c, perr, NULL, 0);
+ if (!t || t->compat != array_compat) {
+ type_err(c, "error: %1 cannot provide length", prog, t, 0, NULL);
+ return NULL;
+ }
+ if (!type_compat(type, Tnum, rules))
+ type_err(c, "error: have %1 but need %2", prog,
+ Tnum, rules, type);
+ return Tnum;
+ break;
+
###### interp binode cases
case Index: {
mpz_t q;
ltype = NULL;
break;
}
+ case Length: {
+ lleft = linterp_exec(c, b->left, <ype);
+ mpq_set_ui(rv.num, ltype->array.size, 1);
+ ltype = NULL;
+ rvtype = Tnum;
+ break;
+ }
#### Structs
###### type functions
void (*print_type_decl)(struct type *type, FILE *f);
+ struct type *(*fieldref)(struct type *t, struct parse_context *c,
+ struct fieldref *f, struct value **vp);
###### value functions
return 1;
}
+ static int find_struct_index(struct type *type, struct text field)
+ {
+ int i;
+ for (i = 0; i < type->structure.nfields; i++)
+ if (text_cmp(type->structure.fields[i].name, field) == 0)
+ return i;
+ return IndexInvalid;
+ }
+
+ static struct type *structure_fieldref(struct type *t, struct parse_context *c,
+ struct fieldref *f, struct value **vp)
+ {
+ if (f->index == IndexUnknown) {
+ f->index = find_struct_index(t, f->name);
+ if (f->index < 0)
+ type_err(c, "error: cannot find requested field in %1",
+ f->left, t, 0, NULL);
+ }
+ if (f->index < 0)
+ return NULL;
+ if (vp) {
+ struct value *v = *vp;
+ v = (void*)v->ptr + t->structure.fields[f->index].offset;
+ *vp = v;
+ }
+ return t->structure.fields[f->index].type;
+ }
+
static struct type structure_prototype = {
.init = structure_init,
.free = structure_free,
.free_type = structure_free_type,
.print_type_decl = structure_print_type,
.prepare_type = structure_prepare_type,
+ .fieldref = structure_fieldref,
};
###### exec type
int index;
struct text name;
};
+ enum { IndexUnknown = -1, IndexInvalid = -2 };
###### free exec cases
case Xfieldref:
break;
###### declare terminals
- $TERM struct .
+ $TERM struct
###### term grammar
struct fieldref *fr = new_pos(fieldref, $2);
fr->left = $<1;
fr->name = $3.txt;
- fr->index = -2;
+ fr->index = IndexUnknown;
$0 = fr;
} }$
break;
}
-###### ast functions
- static int find_struct_index(struct type *type, struct text field)
- {
- int i;
- for (i = 0; i < type->structure.nfields; i++)
- if (text_cmp(type->structure.fields[i].name, field) == 0)
- return i;
- return -1;
- }
-
###### propagate exec cases
case Xfieldref:
struct fieldref *f = cast(fieldref, prog);
struct type *st = propagate_types(f->left, c, perr, NULL, 0);
- if (!st)
- type_err(c, "error: unknown type for field access", f->left, // UNTESTED
- NULL, 0, NULL);
- else if (st->init != structure_init)
- type_err(c, "error: field reference attempted on %1, not a struct",
+ if (!st || !st->fieldref)
+ type_err(c, "error: field reference on %1 is not supported",
f->left, st, 0, NULL);
- else if (f->index == -2) {
- f->index = find_struct_index(st, f->name);
- if (f->index < 0)
- type_err(c, "error: cannot find requested field in %1",
- f->left, st, 0, NULL);
- }
- if (f->index >= 0) {
- struct type *ft = st->structure.fields[f->index].type;
- if (!type_compat(type, ft, rules))
+ else {
+ t = st->fieldref(st, c, f, NULL);
+ if (t && !type_compat(type, t, rules))
type_err(c, "error: have %1 but need %2", prog,
- ft, rules, type);
- return ft;
+ t, rules, type);
+ return t;
}
break;
}
struct fieldref *f = cast(fieldref, e);
struct type *ltype;
struct value *lleft = linterp_exec(c, f->left, <ype);
- lrv = (void*)lleft->ptr + ltype->structure.fields[f->index].offset;
- rvtype = ltype->structure.fields[f->index].type;
+ lrv = lleft;
+ rvtype = ltype->fieldref(ltype, c, f, &lrv);
break;
}
###### top level grammar
- DeclareStruct -> struct IDENTIFIER FieldBlock Newlines ${ {
- struct type *t;
- t = find_type(c, $ID.txt);
- if (!t)
- t = add_type(c, $ID.txt, &structure_prototype);
- else if (t->size >= 0) {
+ $*type
+ StructName -> IDENTIFIER ${ {
+ struct type *t = find_type(c, $ID.txt);
+
+ if (t && t->size >= 0) {
tok_err(c, "error: type already declared", &$ID);
tok_err(c, "info: this is location of declartion", &t->first_use);
- /* Create a new one - duplicate */
- t = add_type(c, $ID.txt, &structure_prototype);
- } else {
- struct type tmp = *t;
- *t = structure_prototype;
- t->name = tmp.name;
- t->next = tmp.next;
+ t = NULL;
}
- t->structure.field_list = $<FB;
+ if (!t)
+ t = add_type(c, $ID.txt, NULL);
t->first_use = $ID;
+ $0 = t;
+ } }$
+ $void
+ DeclareStruct -> struct StructName FieldBlock Newlines ${ {
+ struct type *t = $<SN;
+ struct type tmp = *t;
+
+ *t = structure_prototype;
+ t->name = tmp.name;
+ t->next = tmp.next;
+ t->first_use = tmp.first_use;
+
+ t->structure.field_list = $<FB;
} }$
$*fieldlist
| SimpleFieldList EOL ${ $0 = $<SFL; }$
FieldLines -> SimpleFieldList Newlines ${ $0 = $<SFL; }$
- | FieldLines SimpleFieldList Newlines ${
- $SFL->prev = $<FL;
- $0 = $<SFL;
- }$
+ | FieldLines SimpleFieldList Newlines ${ {
+ struct fieldlist *f = $<SFL;
+
+ if (f) {
+ $0 = f;
+ while (f->prev)
+ f = f->prev;
+ f->prev = $<FL;
+ } else
+ $0 = $<FL;
+ } }$
SimpleFieldList -> Field ${ $0 = $<F; }$
| SimpleFieldList ; Field ${
if (fl->type->print && fl->init) {
fprintf(f, " = ");
if (fl->type == Tstr)
- fprintf(f, "\""); // UNTESTED
+ fprintf(f, "\"");
print_value(fl->type, fl->init, f);
if (fl->type == Tstr)
- fprintf(f, "\""); // UNTESTED
+ fprintf(f, "\"");
}
fprintf(f, "\n");
}
/* Nothing to do here */
}
- static int reference_compat(struct type *require, struct type *have)
+ static int reference_compat(struct type *require, struct type *have,
+ enum val_rules rules)
{
+ if (rules & Rrefok)
+ if (require->reference.referent == have)
+ return 1;
if (have->compat != require->compat)
return 0;
if (have->reference.referent != require->reference.referent)
return val->ref != NULL;
}
+ static struct type *reference_fieldref(struct type *t, struct parse_context *c,
+ struct fieldref *f, struct value **vp)
+ {
+ struct type *rt = t->reference.referent;
+
+ if (rt->fieldref) {
+ if (vp)
+ *vp = (*vp)->ref;
+ return rt->fieldref(rt, c, f, vp);
+ }
+ type_err(c, "error: field reference on %1 is not supported",
+ f->left, rt, 0, NULL);
+ return Tnone;
+ }
+
static struct type reference_prototype = {
.print_type = reference_print_type,
.cmp_eq = reference_cmp,
.test = reference_test,
.free = reference_free,
.compat = reference_compat,
+ .fieldref = reference_fieldref,
.size = sizeof(void*),
.align = sizeof(void*),
};
r->reftype = type;
*perr |= Eretry;
}
+ *perr |= Erval;
return type;
case RefNil:
if (type && type->free != reference_free)
r->reftype = type;
*perr |= Eretry;
}
+ *perr |= Erval;
return type;
case RefFree:
- t = propagate_types(r->right, c, perr, NULL, 0);
+ t = propagate_types(r->right, c, perr_local, NULL, 0);
if (t && t->free != reference_free)
type_err(c, "error: @free can only be assigned a reference, not %1",
prog, t, 0, NULL);
###### Expressions: dereference
###### Binode types
- Deref,
+ Deref, AddressOf,
###### term grammar
print_exec(b->left, -1, bracket);
printf("@");
break;
+ case AddressOf:
+ print_exec(b->left, -1, bracket);
+ break;
###### propagate binode cases
case Deref:
/* left must be a reference, and we return what it refers to */
/* FIXME how can I pass the expected type down? */
t = propagate_types(b->left, c, perr, NULL, 0);
+ *perr &= ~Erval;
if (!t || t->free != reference_free)
type_err(c, "error: Cannot dereference %1", b, t, 0, NULL);
else
return t->reference.referent;
break;
+ case AddressOf:
+ /* left must be lval, we create reference to it */
+ if (!type || type->free != reference_free)
+ t = propagate_types(b->left, c, perr, type, 0); // NOTEST impossible
+ else
+ t = propagate_types(b->left, c, perr,
+ type->reference.referent, 0);
+ if (t)
+ t = find_anon_type(c, &reference_prototype, "@%.*s",
+ t->name.len, t->name.txt);
+ return t;
+
###### interp binode cases
- case Deref: {
+ case Deref:
left = interp_exec(c, b->left, <ype);
lrv = left.ref;
rvtype = ltype->reference.referent;
break;
- }
+
+ case AddressOf:
+ rv.ref = linterp_exec(c, b->left, &rvtype);
+ rvtype = find_anon_type(c, &reference_prototype, "@%.*s",
+ rvtype->name.len, rvtype->name.txt);
+ break;
#### Functions
val->function = NULL;
}
- static int function_compat(struct type *require, struct type *have)
+ static int function_compat(struct type *require, struct type *have,
+ enum val_rules rules)
{
// FIXME can I do anything here yet?
return 0;
}
+ static struct exec *take_addr(struct exec *e)
+ {
+ struct binode *rv = new(binode);
+ rv->op = AddressOf;
+ rv->left = e;
+ return rv;
+ }
+
static void function_check_args(struct parse_context *c, enum prop_err *perr,
struct type *require, struct exec *args)
{
while (param) {
struct var *pv = cast(var, param->left);
+ struct type *t = pv->var->type, *t2;
if (!arg) {
type_err(c, "error: insufficient arguments to function.",
args, NULL, 0, NULL);
break;
}
*perr = 0;
- propagate_types(arg->left, c, perr, pv->var->type, 0);
+ t2 = propagate_types(arg->left, c, perr, t, Rrefok);
+ if (t->free == reference_free &&
+ t->reference.referent == t2 &&
+ !(*perr & Erval)) {
+ arg->left = take_addr(arg->left);
+ } else if (!(*perr & Efail) && !type_compat(t2, t, 0)) {
+ type_err(c, "error: cannot pass rval when reference expected",
+ arg->left, NULL, 0, NULL);
+ }
param = cast(binode, param->right);
arg = cast(binode, arg->right);
}
static void function_print(struct type *type, struct value *val, FILE *f)
{
+ fprintf(f, "\n");
print_exec(val->function, 1, 0);
}
} else
type_print(type->function.return_type, f);
}
- fprintf(f, "\n");
}
static void function_free_type(struct type *t)
prog, NULL, 0, NULL);
return NULL;
}
- *perr |= Enoconst;
- v->var->type->check_args(c, perr, v->var->type, args);
+ *perr |= Eruntime;
+ v->var->type->check_args(c, perr_local, v->var->type, args);
if (v->var->type->function.inline_result)
*perr |= Emaycopy;
+ *perr |= Erval;
return v->var->type->function.return_type;
}
struct binode *b2 = cast(binode, b->right);
struct type *t2;
- propagate_types(b->left, c, perr, Tbool, 0);
- t = propagate_types(b2->left, c, perr, type, Rnolabel);
- t2 = propagate_types(b2->right, c, perr, type ?: t, Rnolabel);
+ propagate_types(b->left, c, perr_local, Tbool, 0);
+ t = propagate_types(b2->left, c, perr, type, 0);
+ t2 = propagate_types(b2->right, c, perr, type ?: t, 0);
return t ?: t2;
}
struct binode *b2 = cast(binode, b->right);
left = interp_exec(c, b->left, <ype);
if (left.bool)
- rv = interp_exec(c, b2->left, &rvtype); // UNTESTED
+ rv = interp_exec(c, b2->left, &rvtype);
else
rv = interp_exec(c, b2->right, &rvtype);
}
### Expressions: Boolean
The next class of expressions to use the `binode` will be Boolean
-expressions. "`and then`" and "`or else`" are similar to `and` and `or`
-have same corresponding precendence. The difference is that they don't
+expressions. `and` and `or` are short-circuit operators that don't
evaluate the second expression if not necessary.
###### Binode types
And,
- AndThen,
Or,
- OrElse,
Not,
###### declare terminals
b->right = $<3;
$0 = b;
} }$
- | Expression or else Expression ${ {
- struct binode *b = new(binode);
- b->op = OrElse;
- b->left = $<1;
- b->right = $<4;
- $0 = b;
- } }$
-
| Expression and Expression ${ {
struct binode *b = new(binode);
b->op = And;
b->right = $<3;
$0 = b;
} }$
- | Expression and then Expression ${ {
- struct binode *b = new(binode);
- b->op = AndThen;
- b->left = $<1;
- b->right = $<4;
- $0 = b;
- } }$
-
| not Expression ${ {
struct binode *b = new(binode);
b->op = Not;
print_exec(b->right, -1, bracket);
if (bracket) printf(")");
break;
- case AndThen:
- if (bracket) printf("(");
- print_exec(b->left, -1, bracket);
- printf(" and then ");
- print_exec(b->right, -1, bracket);
- if (bracket) printf(")");
- break;
case Or:
if (bracket) printf("(");
print_exec(b->left, -1, bracket);
print_exec(b->right, -1, bracket);
if (bracket) printf(")");
break;
- case OrElse:
- if (bracket) printf("(");
- print_exec(b->left, -1, bracket);
- printf(" or else ");
- print_exec(b->right, -1, bracket);
- if (bracket) printf(")");
- break;
case Not:
if (bracket) printf("(");
printf("not ");
###### propagate binode cases
case And:
- case AndThen:
case Or:
- case OrElse:
case Not:
/* both must be Tbool, result is Tbool */
propagate_types(b->left, c, perr, Tbool, 0);
if (type && type != Tbool)
type_err(c, "error: %1 operation found where %2 expected", prog,
Tbool, 0, type);
+ *perr |= Erval;
return Tbool;
###### interp binode cases
case And:
- rv = interp_exec(c, b->left, &rvtype);
- right = interp_exec(c, b->right, &rtype);
- rv.bool = rv.bool && right.bool;
- break;
- case AndThen:
rv = interp_exec(c, b->left, &rvtype);
if (rv.bool)
rv = interp_exec(c, b->right, NULL);
break;
case Or:
- rv = interp_exec(c, b->left, &rvtype);
- right = interp_exec(c, b->right, &rtype);
- rv.bool = rv.bool || right.bool;
- break;
- case OrElse:
rv = interp_exec(c, b->left, &rvtype);
if (!rv.bool)
rv = interp_exec(c, b->right, NULL);
case Eql:
case NEql:
/* Both must match but not be labels, result is Tbool */
- t = propagate_types(b->left, c, perr, NULL, Rnolabel);
+ t = propagate_types(b->left, c, perr, NULL, 0);
if (t)
propagate_types(b->right, c, perr, t, 0);
else {
- t = propagate_types(b->right, c, perr, NULL, Rnolabel); // UNTESTED
- if (t) // UNTESTED
- t = propagate_types(b->left, c, perr, t, 0); // UNTESTED
+ t = propagate_types(b->right, c, perr, NULL, 0); // NOTEST
+ if (t) // NOTEST
+ t = propagate_types(b->left, c, perr, t, 0); // NOTEST
}
if (!type_compat(type, Tbool, 0))
type_err(c, "error: Comparison returns %1 but %2 expected", prog,
Tbool, rules, type);
+ *perr |= Erval;
return Tbool;
###### interp binode cases
if (bracket) printf(")");
break;
case Bracket:
- printf("(");
+ /* Avoid double brackets... */
+ if (!bracket) printf("(");
print_exec(b->right, indent, bracket);
- printf(")");
+ if (!bracket) printf(")");
break;
###### propagate binode cases
if (!type_compat(type, Tnum, 0))
type_err(c, "error: Arithmetic returns %1 but %2 expected", prog,
Tnum, rules, type);
+ *perr |= Erval;
return Tnum;
case Concat:
if (!type_compat(type, Tstr, 0))
type_err(c, "error: Concat returns %1 but %2 expected", prog,
Tstr, rules, type);
+ *perr |= Erval;
return Tstr;
case StringConv:
/* op must be string, result is number */
propagate_types(b->left, c, perr, Tstr, 0);
if (!type_compat(type, Tnum, 0))
- type_err(c, // UNTESTED
+ type_err(c,
"error: Can only convert string to number, not %1",
prog, type, 0, NULL);
+ *perr |= Erval;
return Tnum;
case Test:
if (!t || !t->test)
type_err(c, "error: '?' requires a testable value, not %1",
prog, t, 0, NULL);
+ *perr |= Erval;
return Tbool;
case Choose:
if (t && t->test == NULL)
type_err(c, "error: \"??\" requires a testable value, not %1",
prog, t, 0, NULL);
+ *perr |= Erval;
return t;
case Bracket:
- return propagate_types(b->right, c, perr, type, 0);
+ return propagate_types(b->right, c, perr, type, rules);
###### interp binode cases
rvtype = Tnum;
struct text tx = right.str;
- char tail[3];
+ char tail[3] = "";
int neg = 0;
if (tx.txt[0] == '-') {
- neg = 1; // UNTESTED
- tx.txt++; // UNTESTED
- tx.len--; // UNTESTED
+ neg = 1;
+ tx.txt++;
+ tx.len--;
}
if (number_parse(rv.num, tail, tx) == 0)
- mpq_init(rv.num); // UNTESTED
+ mpq_init(rv.num);
else if (neg)
- mpq_neg(rv.num, rv.num); // UNTESTED
+ mpq_neg(rv.num, rv.num);
if (tail[0])
- printf("Unsupported suffix: %.*s\n", tx.len, tx.txt); // UNTESTED
+ printf("Unsupported suffix: %.*s\n", tx.len, tx.txt);
break;
case Test:
Block -> { IN OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
| { SimpleStatements } ${ $0 = reorder_bilist($<SS); }$
| SimpleStatements ; ${ $0 = reorder_bilist($<SS); }$
- | SimpleStatements EOL ${ $0 = reorder_bilist($<SS); }$
+ | SimpleStatements EOL ${ $0 = reorder_bilist($<SS);
+ }$
| IN OptNL Statementlist OUT ${ $0 = $<Sl; }$
OpenBlock -> OpenScope { IN OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
| OpenScope SimpleStatements EOL ${ $0 = reorder_bilist($<SS); }$
| IN OpenScope OptNL Statementlist OUT ${ $0 = $<Sl; }$
- UseBlock -> { OpenScope IN OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
+ UseBlock -> { IN OpenScope OptNL Statementlist OUT OptNL } ${ $0 = $<Sl; }$
| { OpenScope SimpleStatements } ${ $0 = reorder_bilist($<SS); }$
| IN OpenScope OptNL Statementlist OUT ${ $0 = $<Sl; }$
ComplexStatements -> ComplexStatements ComplexStatement ${
if ($2 == NULL) {
- $0 = $<1;
+ $0 = $<1; // NOTEST - impossible
} else {
$0 = new(binode);
$0->op = Block;
}$
| ComplexStatement ${
if ($1 == NULL) {
- $0 = NULL;
+ $0 = NULL; // NOTEST - impossible
} else {
$0 = new(binode);
$0->op = Block;
###### print binode cases
case Block:
- if (indent < 0) {
- // simple statement
- if (b->left == NULL) // UNTESTED
- printf("pass"); // UNTESTED
- else
- print_exec(b->left, indent, bracket); // UNTESTED
- if (b->right) { // UNTESTED
- printf("; "); // UNTESTED
- print_exec(b->right, indent, bracket); // UNTESTED
- }
- } else {
- // block, one per line
- if (b->left == NULL)
- do_indent(indent, "pass\n");
- else
- print_exec(b->left, indent, bracket);
- if (b->right)
- print_exec(b->right, indent, bracket);
- }
+ // block, one per line
+ if (b->left == NULL)
+ do_indent(indent, "pass\n");
+ else
+ print_exec(b->left, indent, bracket);
+ if (b->right)
+ print_exec(b->right, indent, bracket);
break;
###### propagate binode cases
struct binode *e;
for (e = b; e; e = cast(binode, e->right)) {
- t = propagate_types(e->left, c, perr, NULL, rules);
+ *perr |= *perr_local;
+ *perr_local = 0;
+ t = propagate_types(e->left, c, perr_local, NULL, rules);
if ((rules & Rboolok) && (t == Tbool || t == Tnone))
t = NULL;
if (t == Tnone && e->right)
if (!type)
type = t;
else if (t != type)
- type_err(c, "error: expected %1%r, found %2",
+ type_err(c, "error: expected %1, found %2",
e->left, type, rules, t);
}
}
else
b = cast(binode, b->right);
while (b) {
- propagate_types(b->left, c, perr, NULL, Rnolabel);
+ propagate_types(b->left, c, perr_local, NULL, 0);
b = cast(binode, b->right);
}
break;
been declared as a constant. The analysis phase ensures that the type
will be correct so the interpreter just needs to perform the
calculation. There is a form of assignment which declares a new
-variable as well as assigning a value. If a name is assigned before
-it is declared, and error will be raised as the name is created as
-`Tlabel` and it is illegal to assign to such names.
+variable as well as assigning a value. If a name is used before
+it is declared, it is assumed to be a global constant which are allowed to
+be declared at any time.
###### Binode types
Assign,
case Assign:
case Declare:
- /* Both must match and not be labels,
+ /* Both must match, or left may be ref and right an lval
* Type must support 'dup',
* For Assign, left must not be constant.
* result is Tnone
*/
- t = propagate_types(b->left, c, perr, NULL,
- Rnolabel | (b->op == Assign ? Rnoconstant : 0));
+ *perr &= ~(Erval | Econst);
+ t = propagate_types(b->left, c, perr, NULL, 0);
if (!b->right)
return Tnone;
if (t) {
- if (propagate_types(b->right, c, perr, t, 0) != t)
- if (b->left->type == Xvar)
- type_err(c, "info: variable '%v' was set as %1 here.",
- cast(var, b->left)->var->where_set, t, rules, NULL);
+ struct type *t2 = propagate_types(b->right, c, perr_local,
+ t, Rrefok);
+ if (!t2 || t2 == t || (*perr_local & Efail))
+ ; // No more effort needed
+ else if (t->free == reference_free &&
+ t->reference.referent == t2 &&
+ !(*perr_local & Erval))
+ b->right = take_addr(b->right);
+ else if (t->free == reference_free &&
+ t->reference.referent == t2 &&
+ (*perr_local & Erval))
+ type_err(c, "error: Cannot assign an rval to a reference.",
+ b, NULL, 0, NULL);
} else {
- t = propagate_types(b->right, c, perr, NULL, Rnolabel);
+ t = propagate_types(b->right, c, perr_local, NULL, 0);
if (t)
- propagate_types(b->left, c, perr, t,
- (b->op == Assign ? Rnoconstant : 0));
+ propagate_types(b->left, c, perr, t, 0);
}
- if (t && t->dup == NULL && !(*perr & Emaycopy))
+ if (*perr & Erval)
+ type_err(c, "error: cannot assign to an rval", b,
+ NULL, 0, NULL);
+ else if (b->op == Assign && (*perr & Econst)) {
+ type_err(c, "error: Cannot assign to a constant: %v",
+ b->left, NULL, 0, NULL);
+ if (b->left->type == Xvar) {
+ struct var *var = cast(var, b->left);
+ struct variable *v = var->var;
+ type_err(c, "info: name was defined as a constant here",
+ v->where_decl, NULL, 0, NULL);
+ }
+ }
+ if (t && t->dup == NULL && !(*perr_local & Emaycopy))
type_err(c, "error: cannot assign value of type %1", b, t, 0, NULL);
+ if (b->left->type == Xvar && (*perr_local & Efail))
+ type_err(c, "info: variable '%v' was set as %1 here.",
+ cast(var, b->left)->var->where_set, t, rules, NULL);
return Tnone;
break;
val = var_value(c, v);
if (v->type->prepare_type)
v->type->prepare_type(c, v->type, 0);
- if (b->right)
- dinterp_exec(c, b->right, val, v->type, 0);
- else
+ if (!b->right)
val_init(v->type, val);
+ else
+ dinterp_exec(c, b->right, val, v->type, 0);
break;
}
$0 = b = new_pos(binode, $1);
b->op = Use;
b->right = $<2;
- if (b->right->type == Xvar) {
- struct var *v = cast(var, b->right);
- if (v->var->type == Tnone) {
- /* Convert this to a label */
- struct value *val;
-
- v->var->type = Tlabel;
- val = global_alloc(c, Tlabel, v->var, NULL);
- val->label = val;
- }
- }
}$
###### print binode cases
###### propagate binode cases
case Loop:
- t = propagate_types(b->right, c, perr, Tnone, 0);
- if (!type_compat(Tnone, t, 0))
- *perr |= Efail; // UNTESTED
+ propagate_types(b->right, c, perr_local, Tnone, 0);
return propagate_types(b->left, c, perr, type, rules);
###### propagate exec cases
struct casepart *cp;
t = propagate_types(cs->forpart, c, perr, Tnone, 0);
- if (!type_compat(Tnone, t, 0))
- *perr |= Efail; // UNTESTED
if (cs->looppart) {
t = propagate_types(cs->thenpart, c, perr, Tnone, 0);
- if (!type_compat(Tnone, t, 0))
- *perr |= Efail; // UNTESTED
}
if (cs->casepart == NULL) {
propagate_types(cs->condpart, c, perr, Tbool, 0);
cp && !t; cp = cp->next)
t = propagate_types(cp->value, c, perr, NULL, 0);
if (!t && cs->condpart)
- t = propagate_types(cs->condpart, c, perr, NULL, Rboolok); // UNTESTED
+ t = propagate_types(cs->condpart, c, perr, NULL, Rboolok); // NOTEST
if (!t && cs->looppart)
- t = propagate_types(cs->looppart, c, perr, NULL, Rboolok); // UNTESTED
+ t = propagate_types(cs->looppart, c, perr, NULL, Rboolok); // NOTEST
// Now we have a type (I hope) push it down
if (t) {
for (cp = cs->casepart; cp; cp = cp->next)
type = propagate_types(cs->elsepart, c, perr, NULL, rules);
for (cp = cs->casepart;
cp && !type;
- cp = cp->next) // UNTESTED
- type = propagate_types(cp->action, c, perr, NULL, rules); // UNTESTED
+ cp = cp->next) // NOTEST
+ type = propagate_types(cp->action, c, perr, NULL, rules); // NOTEST
if (type) {
if (!cs->looppart)
propagate_types(cs->thenpart, c, perr, type, rules);
| DeclarationList Declaration
Declaration -> ERROR Newlines ${
- tok_err(c, // UNTESTED
+ tok_err(c, // NOTEST
"error: unhandled parse error", &$1);
}$
| DeclareConstant
} while (perr & Eretry);
if (perr & Efail)
c->parse_error += 1;
- else if (!(perr & Enoconst)) {
+ else if (!(perr & Eruntime)) {
progress = some;
struct value res = interp_exec(
c, vb->right, &v->var->type);
struct value fn = {.function = code};
struct type *t;
var_block_close(c, CloseFunction, code);
- t = add_anon_type(c, &function_prototype,
- "func %.*s", name->name->name.len,
+ t = add_anon_type(c, &function_prototype,
+ "func %.*s", name->name->name.len,
name->name->name.txt);
name->type = t;
t->function.params = reorder_bilist(args);
struct value *val = var_value(&context, v);
printf("func %.*s", v->name->name.len, v->name->name.txt);
v->type->print_type_decl(v->type, stdout);
- if (brackets)
- print_exec(val->function, 0, brackets);
- else
+ if (brackets) {
+ printf(" {\n");
+ print_exec(val->function, 1, brackets);
+ printf("}\n");
+ } else {
print_value(v->type, val, stdout);
+ }
printf("/* frame size %d */\n", v->type->function.local_size);
target -= 1;
}
all_ok = 0;
if (!v->type->function.inline_result &&
!v->type->function.return_type->dup) {
- type_err(c, "error: function cannot return value of type %1",
+ type_err(c, "error: function cannot return value of type %1",
v->where_decl, v->type->function.return_type, 0, NULL);
}
struct value *vl = var_value(c, v->var);
struct value arg;
struct type *t;
- mpq_t argcq;
int i;
switch (anum++) {
case 0: /* argv */
t = v->var->type;
- mpq_init(argcq);
- mpq_set_ui(argcq, argc, 1);
- memcpy(var_value(c, t->array.vsize), &argcq, sizeof(argcq));
+ t->array.size = argc;
t->prepare_type(c, t, 0);
array_init(v->var->type, vl);
for (i = 0; i < argc; i++) {
name:string
alive:Boolean
- func main(argv:[argc::]string)
+ func main(argv:[]string)
print "Hello World, what lovely oceans you have!"
print "Are there", five, "?"
print pi, pie, "but", cake
a : number
a = A;
b:number = B
- if a > 0 and then b > 0:
+ if a > 0 and b > 0:
while a != b:
if a < b:
b = b - a
while
mid := (lo + hi) / 2
if mid == target:
- use Found
+ use .Found
if mid < target:
lo = mid
else
hi = mid
if hi - lo < 1:
lo = mid
- use GiveUp
+ use .GiveUp
use True
do pass
- case Found:
+ case .Found:
print "Yay, I found", target
- case GiveUp:
+ case .GiveUp:
print "Closest I found was", lo
size::= 10
code / ocean / blobdiff