mirror of
https://github.com/fluencelabs/assemblyscript
synced 2025-04-25 15:12:12 +00:00
Report if a function isn't guaranteed to return
This commit is contained in:
dcodeIO
parent
7be4f9fabb
commit
ef7a095494
@ -749,4 +749,4 @@ function check_pool(pool: usize): i32 {
|
||||
return integrity_status;
|
||||
}
|
||||
|
||||
// export { check, check_pool }; // Uncomment to enable in tests/index.js
|
||||
export { check, check_pool }; // Uncomment to enable in tests/index.js
|
||||
|
||||
@ -203,7 +203,7 @@ export class Compiler extends DiagnosticEmitter {
|
||||
var startFunctionTemplate = new FunctionPrototype(program, "start", "start", null);
|
||||
var startFunctionInstance = new Function(startFunctionTemplate, startFunctionTemplate.internalName, [], [], Type.void, null);
|
||||
this.currentFunction = this.startFunction = startFunctionInstance;
|
||||
}
|
||||
}
|
||||
|
||||
/** Performs compilation of the underlying {@link Program} to a {@link Module}. */
|
||||
compile(): Module {
|
||||
@ -568,7 +568,12 @@ export class Compiler extends DiagnosticEmitter {
|
||||
if (!instance.is(ElementFlags.DECLARED)) {
|
||||
var previousFunction = this.currentFunction;
|
||||
this.currentFunction = instance;
|
||||
stmts = this.compileStatements(<Statement[]>declaration.statements);
|
||||
var statements = assert(declaration.statements);
|
||||
stmts = this.compileStatements(statements);
|
||||
// make sure the top-level branch or all child branches return
|
||||
var allBranchesReturn = this.currentFunction.flow.finalize();
|
||||
if (instance.returnType != Type.void && !allBranchesReturn)
|
||||
this.error(DiagnosticCode.A_function_whose_declared_type_is_not_void_must_return_a_value, assert(declaration.returnType).range);
|
||||
this.currentFunction = previousFunction;
|
||||
}
|
||||
|
||||
@ -854,12 +859,15 @@ export class Compiler extends DiagnosticEmitter {
|
||||
// optimizer.
|
||||
|
||||
// Not actually a branch, but can contain its own scoped variables.
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranchOrScope();
|
||||
|
||||
var stmt = this.module.createBlock(null, this.compileStatements(statements), NativeType.None);
|
||||
var stmtReturns = this.currentFunction.flow.is(FlowFlags.RETURNS);
|
||||
|
||||
// Switch back to the parent flow
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranchOrScope();
|
||||
if (stmtReturns)
|
||||
this.currentFunction.flow.set(FlowFlags.RETURNS);
|
||||
|
||||
return stmt;
|
||||
}
|
||||
@ -938,7 +946,7 @@ export class Compiler extends DiagnosticEmitter {
|
||||
// A for statement initiates a new branch with its own scoped variables
|
||||
// possibly declared in its initializer, and break context.
|
||||
var context = this.currentFunction.enterBreakContext();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranchOrScope();
|
||||
var breakLabel = this.currentFunction.flow.breakLabel = "break|" + context;
|
||||
var continueLabel = this.currentFunction.flow.continueLabel = "continue|" + context;
|
||||
|
||||
@ -947,12 +955,14 @@ export class Compiler extends DiagnosticEmitter {
|
||||
var condition = statement.condition ? this.compileExpression(<Expression>statement.condition, Type.i32) : this.module.createI32(1);
|
||||
var incrementor = statement.incrementor ? this.compileExpression(<Expression>statement.incrementor, Type.void) : this.module.createNop();
|
||||
var body = this.compileStatement(statement.statement);
|
||||
var alwaysReturns = !statement.condition && this.currentFunction.flow.is(FlowFlags.RETURNS);
|
||||
// TODO: check other always-true conditions as well, not just omitted
|
||||
|
||||
// Switch back to the parent flow
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranchOrScope();
|
||||
this.currentFunction.leaveBreakContext();
|
||||
|
||||
return this.module.createBlock(breakLabel, [
|
||||
var expr = this.module.createBlock(breakLabel, [
|
||||
initializer,
|
||||
this.module.createLoop(continueLabel, this.module.createBlock(null, [
|
||||
this.module.createIf(condition, this.module.createBlock(null, [
|
||||
@ -962,6 +972,16 @@ export class Compiler extends DiagnosticEmitter {
|
||||
], NativeType.None))
|
||||
], NativeType.None))
|
||||
], NativeType.None);
|
||||
|
||||
// If the loop is guaranteed to run and return, propagate that and append a hint
|
||||
if (alwaysReturns) {
|
||||
this.currentFunction.flow.set(FlowFlags.RETURNS);
|
||||
expr = this.module.createBlock(null, [
|
||||
expr,
|
||||
this.module.createUnreachable()
|
||||
]);
|
||||
}
|
||||
return expr;
|
||||
}
|
||||
|
||||
compileIfStatement(statement: IfStatement): ExpressionRef {
|
||||
@ -970,16 +990,21 @@ export class Compiler extends DiagnosticEmitter {
|
||||
var condition = this.compileExpression(statement.condition, Type.i32);
|
||||
|
||||
// Each arm initiates a branch
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranchOrScope();
|
||||
var ifTrue = this.compileStatement(statement.ifTrue);
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranch();
|
||||
var ifTrueReturns = this.currentFunction.flow.is(FlowFlags.RETURNS);
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranchOrScope();
|
||||
|
||||
var ifFalse: ExpressionRef = 0;
|
||||
var ifFalseReturns = false;
|
||||
if (statement.ifFalse) {
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranchOrScope();
|
||||
ifFalse = this.compileStatement(statement.ifFalse);
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranch();
|
||||
ifFalseReturns = this.currentFunction.flow.is(FlowFlags.RETURNS);
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranchOrScope();
|
||||
}
|
||||
if (ifTrueReturns && ifFalseReturns) // not necessary to append a hint
|
||||
this.currentFunction.flow.set(FlowFlags.RETURNS);
|
||||
return this.module.createIf(condition, ifTrue, ifFalse);
|
||||
}
|
||||
|
||||
@ -1035,6 +1060,7 @@ export class Compiler extends DiagnosticEmitter {
|
||||
|
||||
// nest blocks in order
|
||||
var currentBlock = this.module.createBlock("case0|" + context, breaks, NativeType.None);
|
||||
var alwaysReturns = true;
|
||||
for (i = 0; i < k; ++i) {
|
||||
case_ = statement.cases[i];
|
||||
var l = case_.statements.length;
|
||||
@ -1042,26 +1068,38 @@ export class Compiler extends DiagnosticEmitter {
|
||||
body[0] = currentBlock;
|
||||
|
||||
// Each switch case initiates a new branch
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranchOrScope();
|
||||
var breakLabel = this.currentFunction.flow.breakLabel = "break|" + context;
|
||||
|
||||
var nextLabel = i == k - 1 ? breakLabel : "case" + (i + 1).toString(10) + "|" + context;
|
||||
var fallsThrough = i != k - 1;
|
||||
var nextLabel = !fallsThrough ? breakLabel : "case" + (i + 1).toString(10) + "|" + context;
|
||||
for (var j = 0; j < l; ++j)
|
||||
body[j + 1] = this.compileStatement(case_.statements[j]);
|
||||
if (!(fallsThrough || this.currentFunction.flow.is(FlowFlags.RETURNS)))
|
||||
alwaysReturns = false; // ignore fall-throughs
|
||||
|
||||
// Switch back to the parent flow
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranchOrScope();
|
||||
|
||||
currentBlock = this.module.createBlock(nextLabel, body, NativeType.None);
|
||||
}
|
||||
this.currentFunction.leaveBreakContext();
|
||||
|
||||
// If the switch has a default and always returns, propagate that
|
||||
if (defaultIndex >= 0 && alwaysReturns) {
|
||||
this.currentFunction.flow.set(FlowFlags.RETURNS);
|
||||
// Binaryen understands that so we don't need a hint
|
||||
}
|
||||
return currentBlock;
|
||||
}
|
||||
|
||||
compileThrowStatement(statement: ThrowStatement): ExpressionRef {
|
||||
|
||||
// Remember that this branch possibly throws
|
||||
this.currentFunction.flow.set(FlowFlags.THROWS);
|
||||
this.currentFunction.flow.set(FlowFlags.POSSIBLY_THROWS);
|
||||
|
||||
// FIXME: without try-catch it is safe to assume RETURNS as well for now
|
||||
this.currentFunction.flow.set(FlowFlags.RETURNS);
|
||||
|
||||
// TODO: requires exception-handling spec.
|
||||
return this.module.createUnreachable();
|
||||
@ -1176,17 +1214,19 @@ export class Compiler extends DiagnosticEmitter {
|
||||
|
||||
// Statements initiate a new branch with its own break context
|
||||
var label = this.currentFunction.enterBreakContext();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.enterBranchOrScope();
|
||||
var breakLabel = this.currentFunction.flow.breakLabel = "break|" + label;
|
||||
var continueLabel = this.currentFunction.flow.continueLabel = "continue|" + label;
|
||||
|
||||
var body = this.compileStatement(statement.statement);
|
||||
var alwaysReturns = false && this.currentFunction.flow.is(FlowFlags.RETURNS);
|
||||
// TODO: evaluate possible always-true conditions
|
||||
|
||||
// Switch back to the parent flow
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranch();
|
||||
this.currentFunction.flow = this.currentFunction.flow.leaveBranchOrScope();
|
||||
this.currentFunction.leaveBreakContext();
|
||||
|
||||
return this.module.createBlock(breakLabel, [
|
||||
var expr = this.module.createBlock(breakLabel, [
|
||||
this.module.createLoop(continueLabel,
|
||||
this.module.createIf(condition, this.module.createBlock(null, [
|
||||
body,
|
||||
@ -1194,6 +1234,15 @@ export class Compiler extends DiagnosticEmitter {
|
||||
], NativeType.None))
|
||||
)
|
||||
], NativeType.None);
|
||||
|
||||
// If the loop is guaranteed to run and return, propagate that and append a hint
|
||||
if (alwaysReturns) {
|
||||
expr = this.module.createBlock(null, [
|
||||
expr,
|
||||
this.module.createUnreachable()
|
||||
]);
|
||||
}
|
||||
return expr;
|
||||
}
|
||||
|
||||
// expressions
|
||||
|
||||
@ -70,6 +70,7 @@ export enum DiagnosticCode {
|
||||
_super_can_only_be_referenced_in_a_derived_class = 2335,
|
||||
Property_0_does_not_exist_on_type_1 = 2339,
|
||||
Cannot_invoke_an_expression_whose_type_lacks_a_call_signature_Type_0_has_no_compatible_call_signatures = 2349,
|
||||
A_function_whose_declared_type_is_not_void_must_return_a_value = 2355,
|
||||
The_operand_of_an_increment_or_decrement_operator_must_be_a_variable_or_a_property_access = 2357,
|
||||
The_left_hand_side_of_an_assignment_expression_must_be_a_variable_or_a_property_access = 2364,
|
||||
_get_and_set_accessor_must_have_the_same_type = 2380,
|
||||
@ -158,6 +159,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
|
||||
case 2335: return "'super' can only be referenced in a derived class.";
|
||||
case 2339: return "Property '{0}' does not exist on type '{1}'.";
|
||||
case 2349: return "Cannot invoke an expression whose type lacks a call signature. Type '{0}' has no compatible call signatures.";
|
||||
case 2355: return "A function whose declared type is not 'void' must return a value.";
|
||||
case 2357: return "The operand of an increment or decrement operator must be a variable or a property access.";
|
||||
case 2364: return "The left-hand side of an assignment expression must be a variable or a property access.";
|
||||
case 2380: return "'get' and 'set' accessor must have the same type.";
|
||||
|
||||
@ -70,6 +70,7 @@
|
||||
"'super' can only be referenced in a derived class.": 2335,
|
||||
"Property '{0}' does not exist on type '{1}'.": 2339,
|
||||
"Cannot invoke an expression whose type lacks a call signature. Type '{0}' has no compatible call signatures.": 2349,
|
||||
"A function whose declared type is not 'void' must return a value.": 2355,
|
||||
"The operand of an increment or decrement operator must be a variable or a property access.": 2357,
|
||||
"The left-hand side of an assignment expression must be a variable or a property access.": 2364,
|
||||
"'get' and 'set' accessor must have the same type.": 2380,
|
||||
|
||||
@ -2123,9 +2123,12 @@ export class Interface extends Class {
|
||||
|
||||
/** Control flow flags indicating specific conditions. */
|
||||
export const enum FlowFlags {
|
||||
/** No specific conditions. */
|
||||
NONE = 0,
|
||||
/** This branch always returns. */
|
||||
RETURNS = 1 << 0,
|
||||
THROWS = 1 << 1
|
||||
/** This branch possibly throws. */
|
||||
POSSIBLY_THROWS = 1 << 1,
|
||||
}
|
||||
|
||||
/** A control flow evaluator. */
|
||||
@ -2147,6 +2150,7 @@ export class Flow {
|
||||
/** Creates the parent flow of the specified function. */
|
||||
static create(currentFunction: Function): Flow {
|
||||
var parentFlow = new Flow();
|
||||
parentFlow.parent = null;
|
||||
parentFlow.flags = FlowFlags.NONE;
|
||||
parentFlow.currentFunction = currentFunction;
|
||||
parentFlow.continueLabel = null;
|
||||
@ -2162,8 +2166,8 @@ export class Flow {
|
||||
/** Sets the specified flag or flags. */
|
||||
set(flag: FlowFlags): void { this.flags |= flag; }
|
||||
|
||||
/** Enters a new branch and returns the new flow. */
|
||||
enterBranch(): Flow {
|
||||
/** Enters a new branch or scope and returns the new flow. */
|
||||
enterBranchOrScope(): Flow {
|
||||
var branchFlow = new Flow();
|
||||
branchFlow.parent = this;
|
||||
branchFlow.flags = this.flags;
|
||||
@ -2173,14 +2177,21 @@ export class Flow {
|
||||
return branchFlow;
|
||||
}
|
||||
|
||||
/** Leaves the current branch and returns the parent flow. */
|
||||
leaveBranch(): Flow {
|
||||
/** Leaves the current branch or scope and returns the parent flow. */
|
||||
leaveBranchOrScope(): Flow {
|
||||
var parent = assert(this.parent);
|
||||
if (this.scopedLocals) {
|
||||
for (var scopedLocal of this.scopedLocals.values())
|
||||
this.currentFunction.freeTempLocal(scopedLocal);
|
||||
this.scopedLocals = null;
|
||||
}
|
||||
return assert(this.parent);
|
||||
// Mark parent as THROWS if any child throws
|
||||
if (this.is(FlowFlags.POSSIBLY_THROWS))
|
||||
parent.set(FlowFlags.POSSIBLY_THROWS);
|
||||
|
||||
this.continueLabel = null;
|
||||
this.breakLabel = null;
|
||||
return parent;
|
||||
}
|
||||
|
||||
/** Adds a new scoped local of the specified name. */
|
||||
@ -2197,7 +2208,6 @@ export class Flow {
|
||||
|
||||
/** Gets the local of the specified name in the current scope. */
|
||||
getScopedLocal(name: string): Local | null {
|
||||
// console.log("checking: " + name);
|
||||
var local: Local | null;
|
||||
var current: Flow | null = this;
|
||||
do {
|
||||
@ -2206,4 +2216,12 @@ export class Flow {
|
||||
} while (current = current.parent);
|
||||
return this.currentFunction.locals.get(name);
|
||||
}
|
||||
|
||||
/** Finalizes this flow. Must be the topmost parent flow of the function. */
|
||||
finalize(): bool {
|
||||
assert(this.parent == null, "must be the topmost parent flow");
|
||||
this.continueLabel = null;
|
||||
this.breakLabel = null;
|
||||
return this.is(FlowFlags.RETURNS);
|
||||
}
|
||||
}
|
||||
|
||||
@ -64,7 +64,6 @@ glob.sync(filter, { cwd: __dirname + "/compiler" }).forEach(filename => {
|
||||
+ "\n[program.exports]\n " + elements(program.exports)
|
||||
+ "\n;)\n";
|
||||
var actualOptimized = null;
|
||||
// var actualInlined = null;
|
||||
|
||||
console.log("parse incl. I/O: " + ((parseTime[0] * 1e9 + parseTime[1]) / 1e6).toFixed(3) + "ms / compile: " + ((compileTime[0] * 1e9 + compileTime[1]) / 1e6).toFixed(3) + "ms");
|
||||
|
||||
@ -72,7 +71,10 @@ glob.sync(filter, { cwd: __dirname + "/compiler" }).forEach(filename => {
|
||||
if (module.validate()) {
|
||||
console.log(chalk.green("validate OK"));
|
||||
try {
|
||||
// module.interpret();
|
||||
// already covered by instantiate below, which is also able to use imports, but doesn't
|
||||
// provide as much debugging information. might be necessary to remove this one once imports
|
||||
// are tested more.
|
||||
module.interpret();
|
||||
console.log(chalk.green("interpret OK"));
|
||||
try {
|
||||
var binary = module.toBinary();
|
||||
|
||||
@ -5,6 +5,7 @@
|
||||
(export "ifThenElse" (func $if/ifThenElse))
|
||||
(export "ifThen" (func $if/ifThen))
|
||||
(export "ifThenElseBlock" (func $if/ifThenElse))
|
||||
(export "ifAlwaysReturns" (func $if/ifAlwaysReturns))
|
||||
(export "memory" (memory $0))
|
||||
(start $start)
|
||||
(func $if/ifThenElse (; 0 ;) (type $ii) (param $0 i32) (result i32)
|
||||
@ -23,7 +24,16 @@
|
||||
)
|
||||
(i32.const 0)
|
||||
)
|
||||
(func $start (; 2 ;) (type $v)
|
||||
(func $if/ifAlwaysReturns (; 2 ;) (type $ii) (param $0 i32) (result i32)
|
||||
(if
|
||||
(get_local $0)
|
||||
(return
|
||||
(i32.const 1)
|
||||
)
|
||||
(unreachable)
|
||||
)
|
||||
)
|
||||
(func $start (; 3 ;) (type $v)
|
||||
(if
|
||||
(call $if/ifThenElse
|
||||
(i32.const 0)
|
||||
|
||||
@ -29,3 +29,10 @@ export function ifThenElseBlock(n: i32): bool {
|
||||
|
||||
assert(ifThenElseBlock(0) == false);
|
||||
assert(ifThenElseBlock(1) == true);
|
||||
|
||||
export function ifAlwaysReturns(n: i32): bool {
|
||||
if (n)
|
||||
return true;
|
||||
else
|
||||
throw new Error("error");
|
||||
}
|
||||
|
||||
@ -6,6 +6,7 @@
|
||||
(export "ifThenElse" (func $if/ifThenElse))
|
||||
(export "ifThen" (func $if/ifThen))
|
||||
(export "ifThenElseBlock" (func $if/ifThenElseBlock))
|
||||
(export "ifAlwaysReturns" (func $if/ifAlwaysReturns))
|
||||
(export "memory" (memory $0))
|
||||
(start $start)
|
||||
(func $if/ifThenElse (; 0 ;) (type $ii) (param $0 i32) (result i32)
|
||||
@ -47,7 +48,16 @@
|
||||
)
|
||||
)
|
||||
)
|
||||
(func $start (; 3 ;) (type $v)
|
||||
(func $if/ifAlwaysReturns (; 3 ;) (type $ii) (param $0 i32) (result i32)
|
||||
(if
|
||||
(get_local $0)
|
||||
(return
|
||||
(i32.const 1)
|
||||
)
|
||||
(unreachable)
|
||||
)
|
||||
)
|
||||
(func $start (; 4 ;) (type $v)
|
||||
(if
|
||||
(i32.eqz
|
||||
(i32.eq
|
||||
@ -163,8 +173,10 @@
|
||||
FUNCTION_PROTOTYPE: if/ifThenElse
|
||||
FUNCTION_PROTOTYPE: if/ifThen
|
||||
FUNCTION_PROTOTYPE: if/ifThenElseBlock
|
||||
FUNCTION_PROTOTYPE: if/ifAlwaysReturns
|
||||
[program.exports]
|
||||
FUNCTION_PROTOTYPE: if/ifThenElse
|
||||
FUNCTION_PROTOTYPE: if/ifThen
|
||||
FUNCTION_PROTOTYPE: if/ifThenElseBlock
|
||||
FUNCTION_PROTOTYPE: if/ifAlwaysReturns
|
||||
;)
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user