summaryrefslogtreecommitdiff
path: root/infer.c
blob: f5779883a8f9c07bfadc43d2b97213d92688170d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
static bool call_arg_param_order(Allocator *allocr, FnExpr *fn, Type *fn_type, Argument *args, Location where, U16 **param_indices);
static bool types_expr(Typer *tr, Expression *e);

/* resolved_to should have the same value as to, but not consist of any identifiers which aren't in scope right now */
static bool infer_from_expr(Typer *tr, Expression *match, Expression *to, Expression *resolved_to, Identifier *idents, Value *vals, Type *types) {
	assert(!(match->flags & EXPR_FOUND_TYPE));
	assert(to->flags & EXPR_FOUND_TYPE);
	switch (match->kind) {
	case EXPR_IDENT:
		/* an identifier! maybe it's one of idents... */
		arr_foreach(idents, Identifier, ident) {
			if (*ident == match->ident) {
				long idx = ident - idents;
				types[idx] = to->type;
				if (!eval_expr(tr->evalr, resolved_to, &vals[idx]))
					return false;
				Copier c = copier_create(tr->allocr, tr->block);
				Value new_val;
				copy_val_full(&c, &new_val, &vals[idx], &to->type);
				vals[idx] = new_val;
				break;
			}
		}
		break;
	case EXPR_CALL: {
		while (to->kind == EXPR_IDENT) {
			IdentDecl *idecl = ident_decl(to->ident);
			if (idecl->kind == IDECL_DECL) {
				Declaration *decl = idecl->decl;
				int index = ident_index_in_decl(to->ident, decl);
				Expression *expr = NULL;
				if (decl->type.kind == TYPE_TUPLE) {
					if (decl->expr.kind == EXPR_TUPLE) {
						expr = &decl->expr.tuple[index];
					}
				} else {
					expr = &decl->expr;
				}
				if (expr) to = expr;
			} else break;
		}
		if (to->kind != EXPR_CALL) return true; /* give up */
		Argument *m_args = match->call.args;
		Expression *t_args = to->call.arg_exprs;
		size_t nargs = arr_len(m_args);
		
		U16 *order = NULL;
		Expression *f = match->call.fn;
		IdentDecl *idecl = ident_decl(f->ident);
		bool is_direct_fn = idecl && idecl->kind == IDECL_DECL && (idecl->decl->flags & DECL_HAS_EXPR) && idecl->decl->expr.kind == EXPR_FN;
		if (is_direct_fn) {
			if (!types_expr(tr, f))
				return false;
			FnExpr *fn_decl = idecl->decl->expr.fn;
			if (!call_arg_param_order(tr->allocr, fn_decl, &f->type, m_args, match->where, &order))
				return false;
		}
		for (size_t i = 0; i < nargs; ++i) {
			Argument *m_arg = &m_args[i];
			Expression *t_arg;
			if (is_direct_fn) {
				t_arg = &t_args[order[i]];
			} else {
				t_arg = &t_args[i];
			}
			if (t_arg->kind == EXPR_VAL) {
				/* was evaluated, because it's const */
				if (!infer_from_expr(tr, &m_arg->val, t_arg, t_arg, idents, vals, types))
					return false;
			}
		}
	} break;
	default: break;
	}
	return true;
}

/* if match is not the same kind of type as to, returns true */
static bool infer_from_type(Typer *tr, Type *match, Type *to, Identifier *idents, Value *vals, Type *types) {
	assert(to->flags & TYPE_IS_RESOLVED);
	
	switch (match->kind) {
	case TYPE_VOID:
	case TYPE_UNKNOWN:
	case TYPE_BUILTIN:
		break; /* nothing we can do here */
	case TYPE_TUPLE: {
		if (to->kind != TYPE_TUPLE) return true;
		if (arr_len(match->tuple) != arr_len(to->tuple)) return true;
		Type *b = to->tuple;
		arr_foreach(match->tuple, Type, a) {
			if (!infer_from_type(tr, a, b, idents, vals, types))
				return false;
			++b;
		}
	} break;
	case TYPE_FN: {
		if (match->fn.constness || to->fn.constness) {
			return true;
		}
		if (to->kind != TYPE_FN) return true;
		if (arr_len(match->fn.types) != arr_len(to->fn.types)) return true;
		size_t i, len = arr_len(match->fn.types);
		for (i = 0; i < len; ++i) {
			if (!infer_from_type(tr, &match->fn.types[i], &to->fn.types[i], idents, vals, types))
				return false;
		}
	} break;
	case TYPE_PTR:
		if (to->kind != TYPE_PTR) return true;
		if (!infer_from_type(tr, match->ptr, to->ptr, idents, vals, types))
			return false;
		break;
	case TYPE_SLICE:
		if (to->kind != TYPE_SLICE) return true;
		if (!infer_from_type(tr, match->slice, to->slice, idents, vals, types))
			return false;
		break;
	case TYPE_STRUCT: {
		if (to->kind != TYPE_STRUCT) return true;
		Field *fields_m = match->struc->fields;
		Field *fields_t = to->struc->fields;
		size_t i, len = arr_len(fields_m);
		if (len != arr_len(fields_t)) return true;
		for (i = 0; i < len; ++i) {
			if (!infer_from_type(tr, &fields_m[i].type, &fields_t[i].type, idents, vals, types))
				return false;
		}
	} break;
	case TYPE_EXPR: {
		Expression *to_expr = to->was_expr;
		Expression e = {0};
		e.kind = EXPR_TYPE;
		e.typeval = *to;
		e.flags = EXPR_FOUND_TYPE;
		Type *type = &e.type;
		type->flags = TYPE_IS_RESOLVED;
		type->kind = TYPE_BUILTIN;
		type->builtin = BUILTIN_TYPE;
		if (!to_expr) {
			to_expr = &e;
		}
		if (!infer_from_expr(tr, match->expr, to_expr, &e, idents, vals, types))
			return false;
	} break;
	case TYPE_ARR: {
		if (to->kind != TYPE_ARR) return true;
		Expression to_n_expr = {0};
		to_n_expr.kind = EXPR_LITERAL_INT;
		to_n_expr.intl = to->arr.n;
		to_n_expr.flags = EXPR_FOUND_TYPE;
		Type *n_type = &to_n_expr.type;
		n_type->kind = TYPE_BUILTIN;
		n_type->builtin = BUILTIN_I64;
		n_type->flags = TYPE_IS_RESOLVED;
		if (!infer_from_expr(tr, match->arr.n_expr, &to_n_expr, &to_n_expr, idents, vals, types))
			return false;
		if (!infer_from_type(tr, match->arr.of, to->arr.of, idents, vals, types))
			return false;
	} break;
	}
	return true;
}

/* 
match and to are dynamic arrays of equal size
idents is a dyn array of distinct identifiers
find the value of each ident by matching match[i] to to[i], i = 0..arr_len(match)-1
all the types in match must be unresolved, and all the types in to must be resolved
*/
static bool infer_ident_vals(Typer *tr, Type **match, Type **to, Identifier *idents, Value *vals, Type *types) {
	size_t ntypes = arr_len(match);
	size_t i;
	size_t nidents = arr_len(idents);
	
	Type *t = types;
			
	for (i = 0; i < nidents; ++i) {
		t->kind = TYPE_UNKNOWN;
		++t;
	}
	
	for (i = 0; i < ntypes; ++i) {
		if (!infer_from_type(tr, *match, *to, idents, vals, types))
			return false;
		++match, ++to;
	}
	return true;
}