diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/compile.c | 127 |
1 files changed, 86 insertions, 41 deletions
diff --git a/compiler/compile.c b/compiler/compile.c index 25a761b..69bfdb5 100644 --- a/compiler/compile.c +++ b/compiler/compile.c @@ -80,7 +80,7 @@ typedef struct Expr { } Expr; typedef enum { S_ASSIGN, S_IF, S_REPLACE, S_REPLY, S_REQUIRE, S_INSERT, S_REMOVE, S_APPEND, S_ADD, S_SET, S_SEND, S_FOR, - S_LET, S_COUNT, S_BREAK } StmtKind; + S_LET, S_COUNT, S_BREAK, S_RETURN } StmtKind; typedef struct Stmt { StmtKind kind; int line, column; @@ -180,6 +180,7 @@ typedef struct { /* Views in order; a table (no value) is followed by its columns. */ char view_names[VIEWS][NAME], view_row[VIEWS][NAME], view_list[VIEWS][NAME]; Expr *view_value[VIEWS]; + Stmt *view_body[VIEWS]; /* a view that computes: its statements, return last (view_value) */ Expr *view_filter[VIEWS]; /* a table's where condition, or NULL */ unsigned char view_byte[VIEWS]; /* a filtered table's list + 1 */ int view_table[VIEWS]; /* a column's table + 1, or 0 */ @@ -207,6 +208,9 @@ typedef struct { struct { char name[NAME]; int list, item; Scope *scope; } loops[NESTING]; unsigned loop_count; unsigned nested; /* blocks within the handler's own (an if's, a for's) */ + bool handling; /* statements of a handler (else of a view's body: they change no state) */ + Kind returned; /* the value a view's body returned, once it has */ + bool has_returned; /* Libraries: module 0 is the main source; each module lists the libraries it uses. */ struct { char name[NAME], path[AUP_PATH]; bool uses[MODULES], parsing; } modules[MODULES]; unsigned module_count; @@ -232,7 +236,7 @@ static const char *const reserved[] = {"state", "input", "view", "on", "if", "el "dt", "min", "max", "clamp", "message", "by", "bytes", "u32", "reply", "require", "record", "each", "fn", "use", "now", "every", "floor", "output", "send", "for", "let", "true", "false", - "transient", "break"}; + "transient", "break", "return"}; /* An error in the module being parsed or inlined; inside a fn it names the call. */ static _Noreturn void fail_at(Compiler *c, int line, int column, const char *format, ...) { @@ -1026,6 +1030,11 @@ static Stmt *statement(Compiler *c, unsigned depth) { s->kind = S_BREAK; return s; } + if (!strcmp(token.text, "return")) { /* a view's body's last line: its value */ + s->kind = S_RETURN; + s->value = expression(c, 0, false); + return s; + } if (!strcmp(token.text, "for")) { /* for item in list [where condition] { ... }: the block runs once for every item the list has */ s->kind = S_FOR; @@ -1807,10 +1816,19 @@ static void declaration(Compiler *c) { if (c->views == VIEWS) fail_at(c, name.line, name.column, "at most 64 views are allowed"); unsigned index = c->views++; if (is(c, "(")) view_arguments(c, index, &name); - expect(c, "=", "'='"); memcpy(c->view_names[index], name.text, NAME); - if (!word(c, "each")) c->view_value[index] = expression(c, 0, false); - else table_declaration(c, index); + if (is(c, "{")) { /* view name(arguments) { statements ... return value }: a view that computes */ + Stmt *body = block(c, 0), *last = body; + while (last && last->next) last = last->next; + if (!last || last->kind != S_RETURN) + fail_at(c, name.line, name.column, "a view's body ends with return and its value, as in return total"); + c->view_body[index] = body; + c->view_value[index] = last->value; + } else { + expect(c, "=", "'='"); + if (!word(c, "each")) c->view_value[index] = expression(c, 0, false); + else table_declaration(c, index); + } } else if (!strcmp(kind.text, "on")) { if (c->handler_count == HANDLERS) fail_at(c, kind.line, kind.column, "at most 64 handlers are allowed"); Token event = expect_name(c, "frame or an input"); @@ -2635,7 +2653,7 @@ static Kind value(Compiler *c, const Expr *e, bool handler, int height) { /* Bytes, or text sent as its UTF-8 bytes. */ static void bytes_value(Compiler *c, const Expr *e, int height, const char *what) { - Kind kind = value(c, e, true, height); + Kind kind = value(c, e, c->handling, height); if (kind.type == TEXT) emit(c, e->line, e->column, BYTES_FROM, 0, 0); else if (kind.type != BYTES) fail_at(c, e->line, e->column, "%s takes bytes or text, not %s", what, type_name(kind.type)); } @@ -2737,7 +2755,7 @@ static void record_fields(Compiler *c, const Expr *e, int list, int height) { record_values(c, e, list, values); for (unsigned k = 0; k < r->fields; ++k) { int at = height + (int)k; - if (values[k]) expect_kind(c, values[k], wanted(c, values[k], true, at, field_kind(r, k)), field_kind(r, k)); + if (values[k]) expect_kind(c, values[k], wanted(c, values[k], c->handling, at, field_kind(r, k)), field_kind(r, k)); else if (at + 1 > STACK) fail_at(c, e->line, e->column, "expression needs more than 64 stack values"); else if (r->field_kinds[k] == TEXT) emit(c, e->line, e->column, TEXT_CONST, r->field_constant[k], 0); else if (r->field_kinds[k] == I64) emit_integer(c, e->line, e->column, r->field_integer[k]); @@ -2774,6 +2792,12 @@ static void send_values(Compiler *c, const Input *out, const Expr *group, const } } +/* A view's body changes only its lets and its own lists (a let's list): its states are a snapshot's. */ +static void view_changes(Compiler *c, const Stmt *s, int list, const char *name) { + if (!c->handling && (list < 0 || !c->state_event[list])) + fail_at(c, s->line, s->column, "a view's body changes only its lets and its own lists, not '%s'", name); +} + static void statements(Compiler *c, const Stmt *s) { unsigned scope = c->local_count; /* a block's lets end with it */ for (; s; s = s->next) { @@ -2800,7 +2824,7 @@ static void statements(Compiler *c, const Stmt *s) { break; } if (c->local_slots == LOCALS) fail_at(c, s->line, s->column, "at most %d lets are allowed in a handler", LOCALS); - Kind held = value(c, s->value, true, 0); + Kind held = value(c, s->value, c->handling, 0); if (held.type != NUM && held.type != BOOL && held.type != I64 && held.type != INDEX) fail_at(c, s->value->line, s->value->column, "a let holds a number, a bool, an i64 or an index, not %s", type_name(held.type)); @@ -2818,7 +2842,7 @@ static void statements(Compiler *c, const Stmt *s) { if (local >= 0 && c->locals[local].counter) fail_at(c, s->line, s->column, "'%s' is what this for counts; it is not assigned", s->name); if (local >= 0) { /* a let takes a new value of its kind */ - Kind kind = wanted(c, s->value, true, 0, c->locals[local].kind.type); + Kind kind = wanted(c, s->value, c->handling, 0, c->locals[local].kind.type); if (kind.type != c->locals[local].kind.type || (kind.type == INDEX && kind.owner != c->locals[local].kind.owner)) fail_at(c, s->value->line, s->value->column, "'%s' holds %s", s->name, c->locals[local].kind.type == INDEX ? "an index of its list" : type_name(c->locals[local].kind.type)); @@ -2831,29 +2855,31 @@ static void statements(Compiler *c, const Stmt *s) { if (kind) fail_at(c, s->line, s->column, "cannot assign to %s '%s'", kind, s->name); fail_at(c, s->line, s->column, "unknown state '%s'", s->name); } + view_changes(c, s, -1, s->name); if (c->state_types[index] == STATE_I64) { - integer(c, s->value, true, 0); + integer(c, s->value, c->handling, 0); emit(c, s->line, s->column, STORE, (uint32_t)index, 0); } else if (c->state_types[index] == STATE_NUM || c->state_types[index] == STATE_BOOL) { - expect_kind(c, s->value, value(c, s->value, true, 0), c->state_types[index] == STATE_BOOL ? BOOL : NUM); + expect_kind(c, s->value, value(c, s->value, c->handling, 0), c->state_types[index] == STATE_BOOL ? BOOL : NUM); emit(c, s->line, s->column, STORE, (uint32_t)index, 0); } else if (c->state_types[index] == STATE_LIST) { fail_at(c, s->line, s->column, "a list changes by append, insert, remove and %s[index].field = value", s->name); } else if (c->state_types[index] == STATE_INDEX) { - index_of(c, s->value, true, 0, cursor_owner(c, index)); + index_of(c, s->value, c->handling, 0, cursor_owner(c, index)); emit(c, s->line, s->column, INDEX_STORE, (uint32_t)index, 0); } else if (c->state_types[index] == STATE_TEXT) { - expect_kind(c, s->value, value(c, s->value, true, 0), TEXT); + expect_kind(c, s->value, value(c, s->value, c->handling, 0), TEXT); emit(c, s->line, s->column, TEXT_SET, (uint32_t)index, 0); } else { int owner = cursor_owner(c, index); - cursor_of(c, s->value, true, 0, owner, c->state_names[owner]); + cursor_of(c, s->value, c->handling, 0, owner, c->state_names[owner]); emit(c, s->line, s->column, CUR_STORE, (uint32_t)index, 0); } break; } case S_INSERT: case S_REMOVE: { int list = state_index(c, s->name); + view_changes(c, s, list >= 0 && c->state_types[list] == STATE_LIST ? list : -1, s->name); if (list >= 0 && c->state_types[list] == STATE_LIST) { if (s->last) fail_at(c, s->last->line, s->last->column, "a list removes one item, as in %s.remove(index)", s->name); if (s->kind == S_INSERT && walked(c, list)) @@ -2863,27 +2889,28 @@ static void statements(Compiler *c, const Stmt *s) { if (s->kind == S_INSERT && keyed_by(c, list)) fail_at(c, s->line, s->column, "'%s' is keyed by %s: %s.add(%s { ... }) places an item by its key", s->name, keyed_by(c, list), s->name, record_shown(c, c->module, record_of(c, list))); - if (s->kind == S_REMOVE) item_of(c, s->first, true, 0, list); - else index_of(c, s->first, true, 0, list); + if (s->kind == S_REMOVE) item_of(c, s->first, c->handling, 0, list); + else index_of(c, s->first, c->handling, 0, list); if (s->kind == S_INSERT) record_fields(c, s->value, list, 1); emit(c, s->line, s->column, s->kind == S_INSERT ? LIST_INSERT : LIST_REMOVE, (uint32_t)list, 0); break; } int text = text_state(c, s->name, s->line, s->column); - cursor_of(c, s->first, true, 0, text, s->name); + cursor_of(c, s->first, c->handling, 0, text, s->name); if (s->kind == S_INSERT) { - expect_kind(c, s->value, value(c, s->value, true, 1), TEXT); + expect_kind(c, s->value, value(c, s->value, c->handling, 1), TEXT); emit(c, s->line, s->column, TEXT_INSERT, (uint32_t)text, 0); break; } if (!s->last) fail_at(c, s->line, s->column, "a text removes a range, as in %s.remove(first .. last)", s->name); - cursor_of(c, s->last, true, 1, text, s->name); + cursor_of(c, s->last, c->handling, 1, text, s->name); emit(c, s->line, s->column, TEXT_REMOVE, (uint32_t)text, 0); break; } case S_APPEND: case S_ADD: { /* A keyed list places an added item by its key (it fails if the key is there); others append. */ int list = list_state(c, s->name, s->line, s->column, NULL); + view_changes(c, s, list, s->name); if (walked(c, list)) fail_at(c, s->line, s->column, "a for does not add to the list it walks; add to another list, or after the for"); const char *key = keyed_by(c, list), *record = record_shown(c, c->module, record_of(c, list)); @@ -2900,6 +2927,7 @@ static void statements(Compiler *c, const Stmt *s) { case S_SET: { int list = *s->name ? list_state(c, s->name, s->line, s->column, s->first) : -1; if (!s->member[0]) { /* tasks[at] = Task { ... }: each field set, the key the same */ + view_changes(c, s, list, s->name); const Record *r = record_of(c, list); const Expr *values[FIELDS_PER_RECORD]; record_values(c, s->value, list, values); @@ -2917,40 +2945,43 @@ static void statements(Compiler *c, const Stmt *s) { same->args[0] = item; same->args[1] = (Expr *)values[key]; same->count = 2; - truth(c, same, true, 0, "require"); + truth(c, same, c->handling, 0, "require"); emit(c, s->line, s->column, REQUIRE, 0, 0); } for (unsigned k = 0; k < r->fields; ++k) { if ((int)k == key) continue; - item_of(c, s->first, true, 0, list); - expect_kind(c, values[k], wanted(c, values[k], true, 1, field_kind(r, k)), field_kind(r, k)); + item_of(c, s->first, c->handling, 0, list); + expect_kind(c, values[k], wanted(c, values[k], c->handling, 1, field_kind(r, k)), field_kind(r, k)); emit(c, s->line, s->column, ITEM_SET, (uint32_t)list | k << 16, 0); } break; } if (list < 0) { - Kind index = value(c, s->first, true, 0); + Kind index = value(c, s->first, c->handling, 0); expect_kind(c, s->first, index, INDEX); list = index.owner; } + view_changes(c, s, list, c->state_names[list]); const Record *r = record_of(c, list); unsigned field = record_field(c, r, s->member, s->line, s->column); if (c->list_key[list] == (int)field + 1) fail_at(c, s->line, s->column, "the key of '%s' does not change; remove the item and add it again", c->state_names[list]); - if (*s->name) item_of(c, s->first, true, 0, list); - expect_kind(c, s->value, wanted(c, s->value, true, 1, field_kind(r, field)), field_kind(r, field)); + if (*s->name) item_of(c, s->first, c->handling, 0, list); + expect_kind(c, s->value, wanted(c, s->value, c->handling, 1, field_kind(r, field)), field_kind(r, field)); emit(c, s->line, s->column, ITEM_SET, (uint32_t)list | field << 16, 0); break; } case S_REPLACE: { + view_changes(c, s, -1, s->name); uint32_t target = collection(c, s->name, s->line, s->column); - number(c, s->first, true, 0); - number(c, s->last, true, 1); + number(c, s->first, c->handling, 0); + number(c, s->last, c->handling, 1); bytes_value(c, s->value, 2, "replace"); emit(c, s->line, s->column, REPLACE, target, 0); break; } case S_SEND: { + if (!c->handling) fail_at(c, s->line, s->column, "a view sends nothing; a handler sends"); int output = input_index(c, s->name); if (output < 0 || c->inputs[output].kind != KIND_OUTPUT) { const char *kind = declared_kind(c, s->name); @@ -2968,7 +2999,7 @@ static void statements(Compiler *c, const Stmt *s) { if (!given[f]) fail_at(c, s->line, s->column, "send %s needs '%s'", s->name, out->field_names[f]); int type = out->field_types[f]; if (type == FIELD_BYTES) bytes_value(c, given[f], (int)f, "a bytes field"); - else expect_kind(c, given[f], wanted(c, given[f], true, (int)f, message_kind(type)), message_kind(type)); + else expect_kind(c, given[f], wanted(c, given[f], c->handling, (int)f, message_kind(type)), message_kind(type)); } emit(c, s->line, s->column, SEND, (uint32_t)output, 0); break; @@ -2981,7 +3012,8 @@ static void statements(Compiler *c, const Stmt *s) { emit(c, s->line, s->column, REPLY, 0, 0); break; case S_REQUIRE: - truth(c, s->value, true, 0, "require"); + if (!c->handling) fail_at(c, s->line, s->column, "a view requires nothing; its value says what it found"); + truth(c, s->value, c->handling, 0, "require"); emit(c, s->line, s->column, REQUIRE, 0, 0); break; case S_FOR: { @@ -2997,8 +3029,8 @@ static void statements(Compiler *c, const Stmt *s) { if (key != NUM && key != I64) fail_at(c, s->first->line, s->first->column, "'%s' is not keyed by a number or an i64: a slice takes one", s->member); - expect_kind(c, s->low, wanted(c, s->low, true, 0, key), key); - expect_kind(c, s->high, wanted(c, s->high, true, 1, key), key); + expect_kind(c, s->low, wanted(c, s->low, c->handling, 0, key), key); + expect_kind(c, s->high, wanted(c, s->high, c->handling, 1, key), key); } unsigned at = c->code_count, jump = 0, loop = c->loop_count++; emit(c, s->line, s->column, EACH, 0, 0); @@ -3007,7 +3039,7 @@ static void statements(Compiler *c, const Stmt *s) { c->loops[loop].item = -1; c->loops[loop].scope = c->scope; if (s->value) { - truth(c, s->value, true, 0, "where"); + truth(c, s->value, c->handling, 0, "where"); jump = c->code_count; emit(c, s->line, s->column, JZ, 0, 0); } @@ -3034,7 +3066,7 @@ static void statements(Compiler *c, const Stmt *s) { break; } case S_IF: { - truth(c, s->value, true, 0, "if"); + truth(c, s->value, c->handling, 0, "if"); unsigned jump = c->code_count; emit(c, s->line, s->column, JZ, 0, 0); ++c->nested; @@ -3059,10 +3091,10 @@ static void statements(Compiler *c, const Stmt *s) { fail_at(c, s->line, s->column, "'%s' is already a let or a for's name here", s->name); if (c->local_slots == LOCALS || c->local_count == LOCALS) fail_at(c, s->line, s->column, "at most %d lets are allowed in a handler", LOCALS); - bool integer = probe(c, s->low, true, 0) == I64 || probe(c, s->high, true, 0) == I64; + bool integer = probe(c, s->low, c->handling, 0) == I64 || probe(c, s->high, c->handling, 0) == I64; Type type = integer ? I64 : NUM; - expect_kind(c, s->low, wanted(c, s->low, true, 0, type), type); - expect_kind(c, s->high, wanted(c, s->high, true, 1, type), type); + expect_kind(c, s->low, wanted(c, s->low, c->handling, 0, type), type); + expect_kind(c, s->high, wanted(c, s->high, c->handling, 1, type), type); unsigned scope = c->local_count, local = c->local_count++, loop = c->loop_count++, at = c->code_count; memcpy(c->locals[local].name, s->name, NAME); c->locals[local].slot = c->local_slots++; @@ -3086,6 +3118,12 @@ static void statements(Compiler *c, const Stmt *s) { if (!c->loop_count) fail_at(c, s->line, s->column, "break ends a for; this one is outside any"); emit(c, s->line, s->column, BREAK, 0, 0); break; + case S_RETURN: /* a view's body's value, its last line */ + if (c->handling) fail_at(c, s->line, s->column, "return gives a view's body its value; a handler returns nothing"); + if (s->next || c->nested) fail_at(c, s->line, s->column, "return is the last line of a view's body"); + c->returned = value(c, s->value, false, 0); + c->has_returned = true; + break; } } c->local_count = scope; @@ -3133,8 +3171,8 @@ static uint32_t intern(unsigned char *strings, size_t *used, const char *text) { * blocks, which hold one record keyed one way; no two handlers of one event * have one, so each begins empty. */ static void event_lists(Compiler *c) { - for (unsigned h = 0; h < c->handler_count; ++h) - for (const Stmt *s = c->handlers[h].body; s; s = s->next) { + for (unsigned h = 0; h < c->handler_count + c->views; ++h) /* the handlers', then the views' bodies' */ + for (const Stmt *s = h < c->handler_count ? c->handlers[h].body : c->view_body[h - c->handler_count]; s; s = s->next) { if (s->kind != S_LET || !s->listed) continue; char path[2 * NAME]; snprintf(path, sizeof(path), "let.%s", s->name); @@ -3148,7 +3186,7 @@ static void event_lists(Compiler *c) { strcmp(c->state_key[found], s->key)) fail_at(c, s->line, s->column, "'%s' is a let's list of another record or key in another handler; one name " "holds one kind of list", s->name); - for (unsigned k = 0; k < h; ++k) { + for (unsigned k = 0; h < c->handler_count && k < h; ++k) { if (strcmp(c->handlers[k].input, c->handlers[h].input) || c->handlers[k].edge != c->handlers[h].edge) continue; for (const Stmt *t = c->handlers[k].body; t; t = t->next) if (t->kind == S_LET && t->listed && !strcmp(t->name, s->name)) @@ -3337,7 +3375,13 @@ static void generate(Compiler *c, unsigned char **module, size_t *size) { c->row = c->view_table[i] - 1; c->arguments = c->view_arguments[c->row >= 0 ? (unsigned)c->row : i] - 1; c->view_code[i][0] = c->code_count; - Kind kind = value(c, c->view_value[i], false, 0); + Kind kind; + if (c->view_body[i]) { /* statements as a handler's, changing only its lets and lists, and the value returned */ + c->local_count = c->local_slots = c->loop_count = c->nested = 0; + c->handling = c->has_returned = false; + statements(c, c->view_body[i]); + kind = c->returned; + } else kind = value(c, c->view_value[i], false, 0); if (kind.type != NUM && kind.type != BOOL && kind.type != I64 && kind.type != TEXT) fail_at(c, c->view_value[i]->line, c->view_value[i]->column, "a %s is a number, a bool, an i64 or text, not %s", c->row >= 0 ? "column" : "view", type_name(kind.type)); @@ -3347,10 +3391,11 @@ static void generate(Compiler *c, unsigned char **module, size_t *size) { c->row = -1; c->arguments = -1; c->fold_list = -1; + c->handling = true; for (unsigned i = 0; i < c->handler_count; ++i) { int input = handler_input[i]; c->message = input >= 0 && c->inputs[input].kind != KIND_KEY ? input : -1; - c->local_count = c->local_slots = 0; + c->local_count = c->local_slots = c->loop_count = c->nested = 0; c->handler_code[i][0] = c->code_count; statements(c, c->handlers[i].body); c->handler_code[i][1] = c->code_count - c->handler_code[i][0]; |