mirror of https://github.com/svaarala/duktape.git
Sami Vaarala
9 years ago
4 changed files with 178 additions and 42 deletions
@ -1,43 +1,176 @@ |
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/* |
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* Exercise various code paths related to fast return handling. |
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* |
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* Duktape executor supports two kinds of return: |
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* |
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* - A slow return is implemented using longjmp() and handles all cases |
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* like label catchers, try-catch-finally blocks, etc. |
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* |
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* - A fast return avoids the longjmp() but is limited to common cases |
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* only. |
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* |
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* Longjmp has a moderate performance impact on normal platforms. However |
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* it has a much larger relative impact when Duktape is compiled with |
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* Emscripten. |
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*/ |
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/* XXX: incomplete, finish when fast return implemented. */ |
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/*=== |
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testReturn1 |
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returned 123 |
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testReturn2 |
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returned undefined |
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testReturn3 |
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returned undefined |
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testForLoop1 |
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returned 123 |
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testTryCatch1 |
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returned 123 |
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testTryCatch2 |
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returned 123 |
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testTryFinally1 |
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finally intercepted, return continues |
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returned 123 |
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testTryFinally2 |
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finally intercepted, replace return value |
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returned 321 |
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testTryFinally3 |
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returned 123 |
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testTryFinally4 |
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Error: canceled return |
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still here |
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returned 432 |
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===*/ |
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/* Basic case, call to test1() is from Ecmascript, so a fast return is |
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* allowed. |
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*/ |
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/* Basic case: fast return allowed. */ |
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function testReturn1() { |
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return 123; |
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} |
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|
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/* Basic case, implicit return value (undefined). */ |
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/* Basic case, implicit return value (undefined). Fast return allowed. */ |
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function testReturn2() { |
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return; |
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} |
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|
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/* Basic case, implicit return value with no explicit return statement. */ |
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/* Basic case, implicit return value with no explicit return statement. |
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* Fast return allowed. |
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*/ |
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function testReturn3() { |
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} |
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|
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/* Return from inside a label site (created by for-loop) */ |
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/* Return from inside a label site (created by for-loop). Fast return |
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* is allowed for label catchers. |
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*/ |
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function testForLoop1() { |
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for (;;) { |
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return 123; |
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} |
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} |
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|
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/* Return from inside the try block of a try-catch is currently not a |
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* fast return. |
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* XXX: could allow if there's no finally clause? |
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*/ |
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function testTryCatch1() { |
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try { |
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return 123; |
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} catch (e) { |
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} |
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} |
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|
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/* Return from inside the catch block of a try-catch is currently not a |
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* fast return. |
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* XXX: could allow if there's no finally clause? |
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*/ |
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function testTryCatch2() { |
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try { |
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throw new Error('test'); |
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} catch (e) { |
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return 123; |
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} |
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} |
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|
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/* Return from inside the try block of a try-finally is not a fast |
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* return because the finally block intercepts the return (and can |
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* even cancel it). |
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*/ |
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function testTryFinally1() { |
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try { |
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return 123; |
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} finally { |
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print('finally intercepted, return continues'); |
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} |
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} |
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|
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function testTryFinally2() { |
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try { |
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return 123; |
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} finally { |
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print('finally intercepted, replace return value'); |
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return 321; |
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} |
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} |
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|
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/* Return from inside the finally block of a try-finally is not a fast |
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* return. |
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* XXX: it could be, because there's no longer a chance of anyone |
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* catching the return. |
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*/ |
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function testTryFinally3() { |
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try { |
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; |
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} finally { |
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return 123; |
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} |
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} |
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function testTryFinally4() { |
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// Here 'finally' cancels the return and replaces it with a thrown error.
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// The outer try-catch catches and neutralizes that, so that execution
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// resumes within the function normally.
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try { |
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try { |
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return 123; |
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} finally { |
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throw new Error('canceled return'); |
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} |
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} catch (e) { |
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print(e); |
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} |
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print('still here'); |
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return 432; |
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} |
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try { |
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print('testReturn1'); |
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print('returned', testReturn1()); |
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print('testReturn2'); |
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print('returned', testReturn2()); |
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print('testReturn3'); |
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print('returned', testReturn3()); |
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print('testForLoop1'); |
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print('returned', testForLoop1()); |
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print('testTryCatch1'); |
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print('returned', testTryCatch1()); |
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print('testTryCatch2'); |
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print('returned', testTryCatch2()); |
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print('testTryFinally1'); |
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print('returned', testTryFinally1()); |
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print('testTryFinally2'); |
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print('returned', testTryFinally2()); |
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print('testTryFinally3'); |
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print('returned', testTryFinally3()); |
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print('testTryFinally4'); |
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print('returned', testTryFinally4()); |
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} catch (e) { |
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print(e); |
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} |
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