diff options
Diffstat (limited to 'src/eval.cpp')
| -rw-r--r-- | src/eval.cpp | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/src/eval.cpp b/src/eval.cpp new file mode 100644 index 0000000000..08a858ab2c --- /dev/null +++ b/src/eval.cpp @@ -0,0 +1,607 @@ +#include "eval.hpp" +#include "analyze.hpp" + +static bool eval_fn_args(EvalFnRoot *efr, FnTableEntry *fn, ConstExprValue *args, ConstExprValue *out_val); + +bool const_values_equal(ConstExprValue *a, ConstExprValue *b, TypeTableEntry *type_entry) { + switch (type_entry->id) { + case TypeTableEntryIdEnum: + { + ConstEnumValue *enum1 = &a->data.x_enum; + ConstEnumValue *enum2 = &b->data.x_enum; + if (enum1->tag == enum2->tag) { + TypeEnumField *enum_field = &type_entry->data.enumeration.fields[enum1->tag]; + if (type_has_bits(enum_field->type_entry)) { + zig_panic("TODO const expr analyze enum special value for equality"); + } else { + return true; + } + } + return false; + } + case TypeTableEntryIdMetaType: + return a->data.x_type == b->data.x_type; + case TypeTableEntryIdVoid: + return true; + case TypeTableEntryIdPureError: + return a->data.x_err.err == b->data.x_err.err; + case TypeTableEntryIdFn: + return a->data.x_fn == b->data.x_fn; + case TypeTableEntryIdBool: + return a->data.x_bool == b->data.x_bool; + case TypeTableEntryIdInt: + case TypeTableEntryIdFloat: + case TypeTableEntryIdNumLitFloat: + case TypeTableEntryIdNumLitInt: + return bignum_cmp_eq(&a->data.x_bignum, &b->data.x_bignum); + case TypeTableEntryIdPointer: + zig_panic("TODO"); + case TypeTableEntryIdArray: + zig_panic("TODO"); + case TypeTableEntryIdStruct: + zig_panic("TODO"); + case TypeTableEntryIdUndefLit: + zig_panic("TODO"); + case TypeTableEntryIdMaybe: + zig_panic("TODO"); + case TypeTableEntryIdErrorUnion: + zig_panic("TODO"); + case TypeTableEntryIdTypeDecl: + zig_panic("TODO"); + case TypeTableEntryIdNamespace: + zig_panic("TODO"); + case TypeTableEntryIdGenericFn: + case TypeTableEntryIdInvalid: + case TypeTableEntryIdUnreachable: + zig_unreachable(); + } + zig_unreachable(); +} + + +static bool eval_expr(EvalFn *ef, AstNode *node, ConstExprValue *out); + +static bool eval_block(EvalFn *ef, AstNode *node, ConstExprValue *out) { + assert(node->type == NodeTypeBlock); + + EvalScope *my_scope = allocate<EvalScope>(1); + my_scope->block_context = node->block_context; + ef->scope_stack.append(my_scope); + + for (int i = 0; i < node->data.block.statements.length; i += 1) { + AstNode *child = node->data.block.statements.at(i); + if (eval_expr(ef, child, out)) return true; + } + + ef->scope_stack.pop(); + + return false; +} + +static bool eval_return(EvalFn *ef, AstNode *node, ConstExprValue *out) { + assert(node->type == NodeTypeReturnExpr); + + eval_expr(ef, node->data.return_expr.expr, ef->return_expr); + return true; +} + +static bool eval_bool_bin_op_bool(bool a, BinOpType bin_op, bool b) { + if (bin_op == BinOpTypeBoolOr) { + return a || b; + } else if (bin_op == BinOpTypeBoolAnd) { + return a && b; + } else { + zig_unreachable(); + } +} + +static void eval_const_expr_bin_op_bignum(ConstExprValue *op1_val, ConstExprValue *op2_val, + ConstExprValue *out_val, bool (*bignum_fn)(BigNum *, BigNum *, BigNum *)) +{ + bool overflow = bignum_fn(&out_val->data.x_bignum, &op1_val->data.x_bignum, &op2_val->data.x_bignum); + assert(!overflow); + out_val->ok = true; + out_val->depends_on_compile_var = op1_val->depends_on_compile_var || op2_val->depends_on_compile_var; +} + +void eval_const_expr_bin_op(ConstExprValue *op1_val, TypeTableEntry *op1_type, + BinOpType bin_op, ConstExprValue *op2_val, TypeTableEntry *op2_type, ConstExprValue *out_val) +{ + assert(op1_val->ok); + assert(op2_val->ok); + assert(op1_type == op2_type); + + switch (bin_op) { + case BinOpTypeAssign: + case BinOpTypeAssignTimes: + case BinOpTypeAssignDiv: + case BinOpTypeAssignMod: + case BinOpTypeAssignPlus: + case BinOpTypeAssignMinus: + case BinOpTypeAssignBitShiftLeft: + case BinOpTypeAssignBitShiftRight: + case BinOpTypeAssignBitAnd: + case BinOpTypeAssignBitXor: + case BinOpTypeAssignBitOr: + case BinOpTypeAssignBoolAnd: + case BinOpTypeAssignBoolOr: + out_val->ok = true; + return; + case BinOpTypeBoolOr: + case BinOpTypeBoolAnd: + assert(op1_type->id == TypeTableEntryIdBool); + assert(op2_type->id == TypeTableEntryIdBool); + out_val->data.x_bool = eval_bool_bin_op_bool(op1_val->data.x_bool, bin_op, op2_val->data.x_bool); + out_val->ok = true; + out_val->depends_on_compile_var = op1_val->depends_on_compile_var || op2_val->depends_on_compile_var; + return; + case BinOpTypeCmpEq: + case BinOpTypeCmpNotEq: + case BinOpTypeCmpLessThan: + case BinOpTypeCmpGreaterThan: + case BinOpTypeCmpLessOrEq: + case BinOpTypeCmpGreaterOrEq: + { + bool type_can_gt_lt_cmp = (op1_type->id == TypeTableEntryIdNumLitFloat || + op1_type->id == TypeTableEntryIdNumLitInt || + op1_type->id == TypeTableEntryIdFloat || + op1_type->id == TypeTableEntryIdInt); + bool answer; + if (type_can_gt_lt_cmp) { + bool (*bignum_cmp)(BigNum *, BigNum *); + if (bin_op == BinOpTypeCmpEq) { + bignum_cmp = bignum_cmp_eq; + } else if (bin_op == BinOpTypeCmpNotEq) { + bignum_cmp = bignum_cmp_neq; + } else if (bin_op == BinOpTypeCmpLessThan) { + bignum_cmp = bignum_cmp_lt; + } else if (bin_op == BinOpTypeCmpGreaterThan) { + bignum_cmp = bignum_cmp_gt; + } else if (bin_op == BinOpTypeCmpLessOrEq) { + bignum_cmp = bignum_cmp_lte; + } else if (bin_op == BinOpTypeCmpGreaterOrEq) { + bignum_cmp = bignum_cmp_gte; + } else { + zig_unreachable(); + } + + answer = bignum_cmp(&op1_val->data.x_bignum, &op2_val->data.x_bignum); + } else { + bool are_equal = const_values_equal(op1_val, op2_val, op1_type); + if (bin_op == BinOpTypeCmpEq) { + answer = are_equal; + } else if (bin_op == BinOpTypeCmpNotEq) { + answer = !are_equal; + } else { + zig_unreachable(); + } + } + + out_val->depends_on_compile_var = + op1_val->depends_on_compile_var || op2_val->depends_on_compile_var; + out_val->data.x_bool = answer; + out_val->ok = true; + return; + } + case BinOpTypeAdd: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_add); + case BinOpTypeBinOr: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_or); + case BinOpTypeBinXor: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_xor); + case BinOpTypeBinAnd: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_and); + case BinOpTypeBitShiftLeft: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_shl); + case BinOpTypeBitShiftRight: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_shr); + case BinOpTypeSub: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_sub); + case BinOpTypeMult: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_mul); + case BinOpTypeDiv: + { + bool is_int = false; + bool is_float = false; + if (op1_type->id == TypeTableEntryIdInt || + op1_type->id == TypeTableEntryIdNumLitInt) + { + is_int = true; + } else if (op1_type->id == TypeTableEntryIdFloat || + op1_type->id == TypeTableEntryIdNumLitFloat) + { + is_float = true; + } + if ((is_int && op2_val->data.x_bignum.data.x_uint == 0) || + (is_float && op2_val->data.x_bignum.data.x_float == 0.0)) + { + zig_panic("TODO handle errors in eval"); + } else { + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_div); + } + } + case BinOpTypeMod: + return eval_const_expr_bin_op_bignum(op1_val, op2_val, out_val, bignum_mod); + case BinOpTypeUnwrapMaybe: + zig_panic("TODO"); + case BinOpTypeStrCat: + zig_panic("TODO"); + case BinOpTypeInvalid: + zig_unreachable(); + } + zig_unreachable(); +} + +static bool eval_bin_op_expr(EvalFn *ef, AstNode *node, ConstExprValue *out_val) { + assert(node->type == NodeTypeBinOpExpr); + + AstNode *op1 = node->data.bin_op_expr.op1; + AstNode *op2 = node->data.bin_op_expr.op2; + + TypeTableEntry *op1_type = get_resolved_expr(op1)->type_entry; + TypeTableEntry *op2_type = get_resolved_expr(op2)->type_entry; + + ConstExprValue op1_val = {0}; + if (eval_expr(ef, op1, &op1_val)) return true; + + ConstExprValue op2_val = {0}; + if (eval_expr(ef, op2, &op2_val)) return true; + + BinOpType bin_op = node->data.bin_op_expr.bin_op; + + eval_const_expr_bin_op(&op1_val, op1_type, bin_op, &op2_val, op2_type, out_val); + + return false; +} + +static EvalVar *find_var(EvalFn *ef, Buf *name) { + int scope_index = ef->scope_stack.length - 1; + while (scope_index >= 0) { + EvalScope *scope = ef->scope_stack.at(scope_index); + for (int var_i = 0; var_i < scope->vars.length; var_i += 1) { + EvalVar *var = &scope->vars.at(var_i); + if (buf_eql_buf(var->name, name)) { + return var; + } + } + scope_index -= 1; + } + + return nullptr; +} + +static bool eval_symbol_expr(EvalFn *ef, AstNode *node, ConstExprValue *out_val) { + assert(node->type == NodeTypeSymbol); + + Buf *name = &node->data.symbol_expr.symbol; + EvalVar *var = find_var(ef, name); + + *out_val = var->value; + + return false; +} + +static TypeTableEntry *resolve_expr_type(AstNode *node) { + Expr *expr = get_resolved_expr(node); + TypeTableEntry *type_entry = expr->type_entry; + assert(type_entry->id == TypeTableEntryIdMetaType); + ConstExprValue *const_val = &expr->const_val; + assert(const_val->ok); + return const_val->data.x_type; +} + +static bool eval_container_init_expr(EvalFn *ef, AstNode *node, ConstExprValue *out_val) { + assert(node->type == NodeTypeContainerInitExpr); + + AstNodeContainerInitExpr *container_init_expr = &node->data.container_init_expr; + ContainerInitKind kind = container_init_expr->kind; + TypeTableEntry *container_type = resolve_expr_type(container_init_expr->type); + out_val->ok = true; + + if (container_type->id == TypeTableEntryIdStruct && + !container_type->data.structure.is_unknown_size_array && + kind == ContainerInitKindStruct) + { + int expr_field_count = container_init_expr->entries.length; + int actual_field_count = container_type->data.structure.src_field_count; + assert(expr_field_count == actual_field_count); + + out_val->data.x_struct.fields = allocate<ConstExprValue*>(actual_field_count); + + for (int i = 0; i < expr_field_count; i += 1) { + AstNode *val_field_node = container_init_expr->entries.at(i); + assert(val_field_node->type == NodeTypeStructValueField); + + TypeStructField *type_field = val_field_node->data.struct_val_field.type_struct_field; + int field_index = type_field->src_index; + + ConstExprValue src_field_val = {0}; + if (eval_expr(ef, val_field_node->data.struct_val_field.expr, &src_field_val)) return true; + + ConstExprValue *dest_field_val = allocate<ConstExprValue>(1); + *dest_field_val = src_field_val; + + out_val->data.x_struct.fields[field_index] = dest_field_val; + out_val->depends_on_compile_var = out_val->depends_on_compile_var || + src_field_val.depends_on_compile_var; + } + } else if (container_type->id == TypeTableEntryIdVoid) { + return false; + } else { + zig_panic("TODO"); + } + + + return false; +} + +static bool eval_if_bool_expr(EvalFn *ef, AstNode *node, ConstExprValue *out_val) { + assert(node->type == NodeTypeIfBoolExpr); + + ConstExprValue cond_val = {0}; + if (eval_expr(ef, node->data.if_bool_expr.condition, &cond_val)) return true; + + AstNode *exec_node = cond_val.data.x_bool ? + node->data.if_bool_expr.then_block : node->data.if_bool_expr.else_node; + + if (exec_node) { + if (eval_expr(ef, exec_node, out_val)) return true; + } + out_val->ok = true; + return false; +} + +void eval_const_expr_implicit_cast(CastOp cast_op, + ConstExprValue *other_val, TypeTableEntry *other_type, + ConstExprValue *const_val) +{ + const_val->depends_on_compile_var = other_val->depends_on_compile_var; + const_val->undef = other_val->undef; + + assert(other_val != const_val); + switch (cast_op) { + case CastOpNoCast: + zig_unreachable(); + case CastOpNoop: + case CastOpWidenOrShorten: + case CastOpPointerReinterpret: + *const_val = *other_val; + break; + case CastOpPtrToInt: + case CastOpIntToPtr: + // can't do it + break; + case CastOpToUnknownSizeArray: + { + assert(other_type->id == TypeTableEntryIdArray); + + ConstExprValue *all_fields = allocate<ConstExprValue>(2); + ConstExprValue *ptr_field = &all_fields[0]; + ConstExprValue *len_field = &all_fields[1]; + + const_val->data.x_struct.fields = allocate<ConstExprValue*>(2); + const_val->data.x_struct.fields[0] = ptr_field; + const_val->data.x_struct.fields[1] = len_field; + + ptr_field->ok = true; + ptr_field->data.x_ptr.ptr = other_val->data.x_array.fields; + ptr_field->data.x_ptr.len = other_type->data.array.len; + + len_field->ok = true; + bignum_init_unsigned(&len_field->data.x_bignum, other_type->data.array.len); + + const_val->ok = true; + break; + } + case CastOpMaybeWrap: + const_val->data.x_maybe = other_val; + const_val->ok = true; + break; + case CastOpErrorWrap: + const_val->data.x_err.err = nullptr; + const_val->data.x_err.payload = other_val; + const_val->ok = true; + break; + case CastOpPureErrorWrap: + const_val->data.x_err.err = other_val->data.x_err.err; + const_val->ok = true; + break; + case CastOpErrToInt: + { + uint64_t value = other_val->data.x_err.err ? other_val->data.x_err.err->value : 0; + bignum_init_unsigned(&const_val->data.x_bignum, value); + const_val->ok = true; + break; + } + case CastOpIntToFloat: + bignum_cast_to_float(&const_val->data.x_bignum, &other_val->data.x_bignum); + const_val->ok = true; + break; + case CastOpFloatToInt: + bignum_cast_to_int(&const_val->data.x_bignum, &other_val->data.x_bignum); + const_val->ok = true; + break; + case CastOpBoolToInt: + bignum_init_unsigned(&const_val->data.x_bignum, other_val->data.x_bool ? 1 : 0); + const_val->ok = true; + break; + } +} + +static bool eval_fn_call_expr(EvalFn *ef, AstNode *node, ConstExprValue *out_val) { + assert(node->type == NodeTypeFnCallExpr); + + CastOp cast_op = node->data.fn_call_expr.cast_op; + if (node->data.fn_call_expr.is_builtin) { + zig_panic("TODO"); + } else if (cast_op != CastOpNoCast) { + AstNode *expr_node = node->data.fn_call_expr.params.at(0); + Expr *expr = get_resolved_expr(expr_node); + eval_const_expr_implicit_cast(cast_op, &expr->const_val, expr->type_entry, out_val); + return false; + } + + AstNode *fn_ref_expr = node->data.fn_call_expr.fn_ref_expr; + if (node->data.fn_call_expr.enum_type) { + zig_panic("TODO"); + } + + FnTableEntry *fn_table_entry = node->data.fn_call_expr.fn_entry; + + if (fn_ref_expr->type == NodeTypeFieldAccessExpr && + fn_ref_expr->data.field_access_expr.is_member_fn) + { + zig_panic("TODO"); + } + + if (!fn_table_entry) { + zig_panic("TODO"); + } + + int param_count = node->data.fn_call_expr.params.length; + ConstExprValue *args = allocate<ConstExprValue>(param_count); + for (int i = 0; i < param_count; i += 1) { + AstNode *param_expr_node = node->data.fn_call_expr.params.at(i); + ConstExprValue *param_val = &args[i]; + if (eval_expr(ef, param_expr_node, param_val)) return true; + } + + ef->root->branches_used += 1; + + eval_fn_args(ef->root, fn_table_entry, args, out_val); + return false; +} + +static bool eval_expr(EvalFn *ef, AstNode *node, ConstExprValue *out) { + if (ef->root->branches_used > ef->root->branch_quota) { + ef->root->exceeded_quota_node = node; + return true; + } + switch (node->type) { + case NodeTypeBlock: + return eval_block(ef, node, out); + case NodeTypeReturnExpr: + return eval_return(ef, node, out); + case NodeTypeBinOpExpr: + return eval_bin_op_expr(ef, node, out); + case NodeTypeSymbol: + return eval_symbol_expr(ef, node, out); + case NodeTypeContainerInitExpr: + return eval_container_init_expr(ef, node, out); + case NodeTypeIfBoolExpr: + return eval_if_bool_expr(ef, node, out); + case NodeTypeFnCallExpr: + return eval_fn_call_expr(ef, node, out); + case NodeTypeRoot: + case NodeTypeFnProto: + case NodeTypeFnDef: + case NodeTypeFnDecl: + case NodeTypeParamDecl: + case NodeTypeDirective: + case NodeTypeDefer: + case NodeTypeVariableDeclaration: + case NodeTypeTypeDecl: + case NodeTypeErrorValueDecl: + case NodeTypeUnwrapErrorExpr: + case NodeTypeNumberLiteral: + case NodeTypeStringLiteral: + case NodeTypeCharLiteral: + case NodeTypePrefixOpExpr: + case NodeTypeArrayAccessExpr: + case NodeTypeSliceExpr: + case NodeTypeFieldAccessExpr: + case NodeTypeUse: + case NodeTypeBoolLiteral: + case NodeTypeNullLiteral: + case NodeTypeUndefinedLiteral: + case NodeTypeIfVarExpr: + case NodeTypeWhileExpr: + case NodeTypeForExpr: + case NodeTypeSwitchExpr: + case NodeTypeSwitchProng: + case NodeTypeSwitchRange: + case NodeTypeLabel: + case NodeTypeGoto: + case NodeTypeBreak: + case NodeTypeContinue: + case NodeTypeAsmExpr: + case NodeTypeStructDecl: + case NodeTypeStructField: + case NodeTypeStructValueField: + case NodeTypeArrayType: + case NodeTypeErrorType: + case NodeTypeTypeLiteral: + zig_unreachable(); + } +} + +static bool eval_fn_args(EvalFnRoot *efr, FnTableEntry *fn, ConstExprValue *args, ConstExprValue *out_val) { + EvalFn ef = {0}; + ef.root = efr; + ef.fn = fn; + ef.return_expr = out_val; + + EvalScope *root_scope = allocate<EvalScope>(1); + root_scope->block_context = fn->fn_def_node->data.fn_def.body->block_context; + ef.scope_stack.append(root_scope); + + int param_count = fn->type_entry->data.fn.fn_type_id.param_count; + for (int i = 0; i < param_count; i += 1) { + AstNode *decl_param_node = fn->proto_node->data.fn_proto.params.at(i); + assert(decl_param_node->type == NodeTypeParamDecl); + + ConstExprValue *src_const_val = &args[i]; + assert(src_const_val->ok); + + root_scope->vars.add_one(); + EvalVar *eval_var = &root_scope->vars.last(); + eval_var->name = &decl_param_node->data.param_decl.name; + eval_var->value = *src_const_val; + } + + return eval_expr(&ef, fn->fn_def_node->data.fn_def.body, out_val); + +} + +bool eval_fn(CodeGen *g, AstNode *node, FnTableEntry *fn, ConstExprValue *out_val, + int branch_quota, AstNode *struct_node) +{ + assert(node->type == NodeTypeFnCallExpr); + + EvalFnRoot efr = {0}; + efr.codegen = g; + efr.fn = fn; + efr.call_node = node; + efr.branch_quota = branch_quota; + + int call_param_count = node->data.fn_call_expr.params.length; + int type_param_count = fn->type_entry->data.fn.fn_type_id.param_count; + ConstExprValue *args = allocate<ConstExprValue>(type_param_count); + int next_arg_index = 0; + if (struct_node) { + ConstExprValue *struct_val = &get_resolved_expr(struct_node)->const_val; + assert(struct_val->ok); + args[next_arg_index] = *struct_val; + next_arg_index += 1; + } + for (int call_index = 0; call_index < call_param_count; call_index += 1) { + AstNode *call_param_node = node->data.fn_call_expr.params.at(call_index); + ConstExprValue *src_const_val = &get_resolved_expr(call_param_node)->const_val; + assert(src_const_val->ok); + args[next_arg_index] = *src_const_val; + next_arg_index += 1; + } + eval_fn_args(&efr, fn, args, out_val); + + if (efr.exceeded_quota_node) { + ErrorMsg *msg = add_node_error(g, fn->fn_def_node, + buf_sprintf("function evaluation exceeded %d branches", efr.branch_quota)); + + add_error_note(g, msg, efr.call_node, buf_sprintf("called from here")); + add_error_note(g, msg, efr.exceeded_quota_node, buf_sprintf("quota exceeded here")); + return true; + } + + return false; +} + |