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Fix control flow analysis for nested try-catch-finally statements #39399

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Merged
merged 2 commits into from
Jul 3, 2020
Merged

Fix control flow analysis for nested try-catch-finally statements #39399

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b6cd7ba
Fix control flow analysis for nested try-catch-finally statements
ahejlsberg Jul 2, 2020
6a3d460
Add tests
ahejlsberg Jul 2, 2020
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5 changes: 5 additions & 0 deletions src/compiler/binder.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -1245,6 +1245,11 @@ namespace ts {
if (currentReturnTarget && returnLabel.antecedents) {
addAntecedent(currentReturnTarget, createReduceLabel(finallyLabel, returnLabel.antecedents, currentFlow));
}
// If we have an outer exception target (i.e. a containing try-finally or try-catch-finally), add a
// control flow that goes back through the finally blok and back through each possible exception source.
if (currentExceptionTarget && exceptionLabel.antecedents) {
addAntecedent(currentExceptionTarget, createReduceLabel(finallyLabel, exceptionLabel.antecedents, currentFlow));
}
// If the end of the finally block is reachable, but the end of the try and catch blocks are not,
// convert the current flow to unreachable. For example, 'try { return 1; } finally { ... }' should
// result in an unreachable current control flow.
Expand Down
70 changes: 70 additions & 0 deletions tests/baselines/reference/tryCatchFinallyControlFlow.errors.txt
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Expand Up @@ -275,4 +275,74 @@ tests/cases/compiler/tryCatchFinallyControlFlow.ts(255,9): error TS7027: Unreach
})();
x; // Reachable
}

// Repro from #39043

type State = { tag: "one" } | { tag: "two" } | { tag: "three" };

function notallowed(arg: number) {
let state: State = { tag: "one" };
try {
state = { tag: "two" };
try {
state = { tag: "three" };
}
finally { }
}
catch (err) {
state.tag;
if (state.tag !== "one" && state.tag !== "two") {
console.log(state.tag);
}
}
}

function f20() {
let x: 0 | 1 | 2 | 3 | 4 | 5 | 6 = 0;
try {
x = 1;
try {
x = 2;
try {
x = 3;
}
finally {
if (!!true) x = 4;
}
x; // 3 | 4
}
finally {
if (!!true) x = 5;
}
x; // 3 | 4 | 5
}
finally {
if (!!true) x = 6;
}
x; // 3 | 4 | 5 | 6
}

function f21() {
let x: 0 | 1 | 2 | 3 | 4 | 5 = 0;
try {
x = 1;
try {
x = 2;
try {
x = 3;
}
finally {
if (!!true) x = 4;
}
x; // 3 | 4
}
finally {
if (!!true) x = 5;
}
x; // 3 | 4 | 5
}
catch (e) {
x; // 0 | 1 | 2 | 3 | 4 | 5
}
}

138 changes: 138 additions & 0 deletions tests/baselines/reference/tryCatchFinallyControlFlow.js
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Expand Up @@ -257,6 +257,76 @@ function t1() {
})();
x; // Reachable
}

// Repro from #39043

type State = { tag: "one" } | { tag: "two" } | { tag: "three" };

function notallowed(arg: number) {
let state: State = { tag: "one" };
try {
state = { tag: "two" };
try {
state = { tag: "three" };
}
finally { }
}
catch (err) {
state.tag;
if (state.tag !== "one" && state.tag !== "two") {
console.log(state.tag);
}
}
}

function f20() {
let x: 0 | 1 | 2 | 3 | 4 | 5 | 6 = 0;
try {
x = 1;
try {
x = 2;
try {
x = 3;
}
finally {
if (!!true) x = 4;
}
x; // 3 | 4
}
finally {
if (!!true) x = 5;
}
x; // 3 | 4 | 5
}
finally {
if (!!true) x = 6;
}
x; // 3 | 4 | 5 | 6
}

function f21() {
let x: 0 | 1 | 2 | 3 | 4 | 5 = 0;
try {
x = 1;
try {
x = 2;
try {
x = 3;
}
finally {
if (!!true) x = 4;
}
x; // 3 | 4
}
finally {
if (!!true) x = 5;
}
x; // 3 | 4 | 5
}
catch (e) {
x; // 0 | 1 | 2 | 3 | 4 | 5
}
}


//// [tryCatchFinallyControlFlow.js]
Expand Down Expand Up @@ -503,3 +573,71 @@ function t1() {
})();
x; // Reachable
}
function notallowed(arg) {
var state = { tag: "one" };
try {
state = { tag: "two" };
try {
state = { tag: "three" };
}
finally { }
}
catch (err) {
state.tag;
if (state.tag !== "one" && state.tag !== "two") {
console.log(state.tag);
}
}
}
function f20() {
var x = 0;
try {
x = 1;
try {
x = 2;
try {
x = 3;
}
finally {
if (!!true)
x = 4;
}
x; // 3 | 4
}
finally {
if (!!true)
x = 5;
}
x; // 3 | 4 | 5
}
finally {
if (!!true)
x = 6;
}
x; // 3 | 4 | 5 | 6
}
function f21() {
var x = 0;
try {
x = 1;
try {
x = 2;
try {
x = 3;
}
finally {
if (!!true)
x = 4;
}
x; // 3 | 4
}
finally {
if (!!true)
x = 5;
}
x; // 3 | 4 | 5
}
catch (e) {
x; // 0 | 1 | 2 | 3 | 4 | 5
}
}
136 changes: 136 additions & 0 deletions tests/baselines/reference/tryCatchFinallyControlFlow.symbols
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Original file line number Diff line number Diff line change
Expand Up @@ -445,3 +445,139 @@ function t1() {
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 247, 9))
}

// Repro from #39043

type State = { tag: "one" } | { tag: "two" } | { tag: "three" };
>State : Symbol(State, Decl(tryCatchFinallyControlFlow.ts, 257, 1))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 14))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 31))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 48))

function notallowed(arg: number) {
>notallowed : Symbol(notallowed, Decl(tryCatchFinallyControlFlow.ts, 261, 64))
>arg : Symbol(arg, Decl(tryCatchFinallyControlFlow.ts, 263, 20))

let state: State = { tag: "one" };
>state : Symbol(state, Decl(tryCatchFinallyControlFlow.ts, 264, 7))
>State : Symbol(State, Decl(tryCatchFinallyControlFlow.ts, 257, 1))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 264, 24))

try {
state = { tag: "two" };
>state : Symbol(state, Decl(tryCatchFinallyControlFlow.ts, 264, 7))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 266, 17))

try {
state = { tag: "three" };
>state : Symbol(state, Decl(tryCatchFinallyControlFlow.ts, 264, 7))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 268, 21))
}
finally { }
}
catch (err) {
>err : Symbol(err, Decl(tryCatchFinallyControlFlow.ts, 272, 11))

state.tag;
>state.tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 14), Decl(tryCatchFinallyControlFlow.ts, 261, 31), Decl(tryCatchFinallyControlFlow.ts, 261, 48))
>state : Symbol(state, Decl(tryCatchFinallyControlFlow.ts, 264, 7))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 14), Decl(tryCatchFinallyControlFlow.ts, 261, 31), Decl(tryCatchFinallyControlFlow.ts, 261, 48))

if (state.tag !== "one" && state.tag !== "two") {
>state.tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 14), Decl(tryCatchFinallyControlFlow.ts, 261, 31), Decl(tryCatchFinallyControlFlow.ts, 261, 48))
>state : Symbol(state, Decl(tryCatchFinallyControlFlow.ts, 264, 7))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 14), Decl(tryCatchFinallyControlFlow.ts, 261, 31), Decl(tryCatchFinallyControlFlow.ts, 261, 48))
>state.tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 31), Decl(tryCatchFinallyControlFlow.ts, 261, 48))
>state : Symbol(state, Decl(tryCatchFinallyControlFlow.ts, 264, 7))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 31), Decl(tryCatchFinallyControlFlow.ts, 261, 48))

console.log(state.tag);
>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
>state.tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 48))
>state : Symbol(state, Decl(tryCatchFinallyControlFlow.ts, 264, 7))
>tag : Symbol(tag, Decl(tryCatchFinallyControlFlow.ts, 261, 48))
}
}
}

function f20() {
>f20 : Symbol(f20, Decl(tryCatchFinallyControlFlow.ts, 278, 1))

let x: 0 | 1 | 2 | 3 | 4 | 5 | 6 = 0;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))

try {
x = 1;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))

try {
x = 2;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))

try {
x = 3;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))
}
finally {
if (!!true) x = 4;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))
}
x; // 3 | 4
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))
}
finally {
if (!!true) x = 5;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))
}
x; // 3 | 4 | 5
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))
}
finally {
if (!!true) x = 6;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))
}
x; // 3 | 4 | 5 | 6
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 281, 7))
}

function f21() {
>f21 : Symbol(f21, Decl(tryCatchFinallyControlFlow.ts, 303, 1))

let x: 0 | 1 | 2 | 3 | 4 | 5 = 0;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))

try {
x = 1;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))

try {
x = 2;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))

try {
x = 3;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))
}
finally {
if (!!true) x = 4;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))
}
x; // 3 | 4
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))
}
finally {
if (!!true) x = 5;
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))
}
x; // 3 | 4 | 5
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))
}
catch (e) {
>e : Symbol(e, Decl(tryCatchFinallyControlFlow.ts, 324, 11))

x; // 0 | 1 | 2 | 3 | 4 | 5
>x : Symbol(x, Decl(tryCatchFinallyControlFlow.ts, 306, 7))
}
}

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