v8/test/inspector/debugger/step-out-async-await-expected.txt

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StepOut from return position of async function.
Running test: testStepIntoAtReturnPosition
p.then(() => 1);
#debugger;
return p;
debugger;
#return p;
}
[async] Improve async function handling. This change introduces new intrinsics used to desugar async functions in the Parser and the BytecodeGenerator, namely we introduce a new %_AsyncFunctionEnter intrinsic that constructs the generator object for the async function (and in the future will also create the outer promise for the async function). This generator object is internal and never escapes to user code, plus since async functions don't have a "prototype" property, we can just a single map here instead of tracking the prototype/initial_map on every async function. This saves one word per async function plus one initial_map per async function that was invoked at least once. We also introduce two new intrinsics %_AsyncFunctionReject, which rejects the outer promise with the caught exception, and another %_AsyncFunctionResolve, which resolves the outer promise with the right hand side of the `return` statement. These functions also perform the DevTools part of the job (aka popping from the promise stack and sending the debug event). This allows us to get rid of the implicit try-finally from async functions completely; because the finally block only called to the %AsyncFunctionPromiseRelease builtin, which was used to inform DevTools. In essence we now turn an async function like ```js async function f(x) { return await bar(x); } ``` into something like this (in Parser and BytecodeGenerator respectively): ``` function f(x) { .generator_object = %_AsyncFunctionEnter(.closure, this); .promise = %AsyncFunctionCreatePromise(); try { .tmp = await bar(x); return %_AsyncFunctionResolve(.promise, .tmp); } catch (e) { return %_AsyncFunctionReject(.promise, e); } } ``` Overall the bytecode for async functions gets significantly shorter already (and will get even shorter once we put the outer promise into the async function generator object). For example the bytecode for a simple async function ```js async function f(x) { return await x; } ``` goes from 175 bytes to 110 bytes (a ~38% reduction in size), which is in particular due to the simplification around the try-finally removal. Overall this seems to improve the doxbee-async-es2017-native test by around 2-3%. On the test case mentioned in v8:8276 we go from 1124ms to 441ms, which corresponds to a 60% reduction in total execution time! Tbr: marja@chromium.org Bug: v8:7253, v8:7522, v8:8276 Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel Change-Id: Id29dc92de7490b387ff697860c900cee44c9a7a4 Reviewed-on: https://chromium-review.googlesource.com/c/1269041 Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org> Reviewed-by: Maya Lekova <mslekova@chromium.org> Reviewed-by: Yang Guo <yangguo@chromium.org> Cr-Commit-Position: refs/heads/master@{#56502}
2018-10-10 05:54:39 +00:00
debugger;
return p;#
}
await foo();
#}
Running test: testStepOverAtReturnPosition
p.then(() => 1);
#debugger;
return p;
debugger;
#return p;
}
[async] Improve async function handling. This change introduces new intrinsics used to desugar async functions in the Parser and the BytecodeGenerator, namely we introduce a new %_AsyncFunctionEnter intrinsic that constructs the generator object for the async function (and in the future will also create the outer promise for the async function). This generator object is internal and never escapes to user code, plus since async functions don't have a "prototype" property, we can just a single map here instead of tracking the prototype/initial_map on every async function. This saves one word per async function plus one initial_map per async function that was invoked at least once. We also introduce two new intrinsics %_AsyncFunctionReject, which rejects the outer promise with the caught exception, and another %_AsyncFunctionResolve, which resolves the outer promise with the right hand side of the `return` statement. These functions also perform the DevTools part of the job (aka popping from the promise stack and sending the debug event). This allows us to get rid of the implicit try-finally from async functions completely; because the finally block only called to the %AsyncFunctionPromiseRelease builtin, which was used to inform DevTools. In essence we now turn an async function like ```js async function f(x) { return await bar(x); } ``` into something like this (in Parser and BytecodeGenerator respectively): ``` function f(x) { .generator_object = %_AsyncFunctionEnter(.closure, this); .promise = %AsyncFunctionCreatePromise(); try { .tmp = await bar(x); return %_AsyncFunctionResolve(.promise, .tmp); } catch (e) { return %_AsyncFunctionReject(.promise, e); } } ``` Overall the bytecode for async functions gets significantly shorter already (and will get even shorter once we put the outer promise into the async function generator object). For example the bytecode for a simple async function ```js async function f(x) { return await x; } ``` goes from 175 bytes to 110 bytes (a ~38% reduction in size), which is in particular due to the simplification around the try-finally removal. Overall this seems to improve the doxbee-async-es2017-native test by around 2-3%. On the test case mentioned in v8:8276 we go from 1124ms to 441ms, which corresponds to a 60% reduction in total execution time! Tbr: marja@chromium.org Bug: v8:7253, v8:7522, v8:8276 Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel Change-Id: Id29dc92de7490b387ff697860c900cee44c9a7a4 Reviewed-on: https://chromium-review.googlesource.com/c/1269041 Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org> Reviewed-by: Maya Lekova <mslekova@chromium.org> Reviewed-by: Yang Guo <yangguo@chromium.org> Cr-Commit-Position: refs/heads/master@{#56502}
2018-10-10 05:54:39 +00:00
debugger;
return p;#
}
await foo();
#}
Running test: testStepOutAtReturnPosition
p.then(() => 1);
#debugger;
return p;
debugger;
#return p;
}
[async] Improve async function handling. This change introduces new intrinsics used to desugar async functions in the Parser and the BytecodeGenerator, namely we introduce a new %_AsyncFunctionEnter intrinsic that constructs the generator object for the async function (and in the future will also create the outer promise for the async function). This generator object is internal and never escapes to user code, plus since async functions don't have a "prototype" property, we can just a single map here instead of tracking the prototype/initial_map on every async function. This saves one word per async function plus one initial_map per async function that was invoked at least once. We also introduce two new intrinsics %_AsyncFunctionReject, which rejects the outer promise with the caught exception, and another %_AsyncFunctionResolve, which resolves the outer promise with the right hand side of the `return` statement. These functions also perform the DevTools part of the job (aka popping from the promise stack and sending the debug event). This allows us to get rid of the implicit try-finally from async functions completely; because the finally block only called to the %AsyncFunctionPromiseRelease builtin, which was used to inform DevTools. In essence we now turn an async function like ```js async function f(x) { return await bar(x); } ``` into something like this (in Parser and BytecodeGenerator respectively): ``` function f(x) { .generator_object = %_AsyncFunctionEnter(.closure, this); .promise = %AsyncFunctionCreatePromise(); try { .tmp = await bar(x); return %_AsyncFunctionResolve(.promise, .tmp); } catch (e) { return %_AsyncFunctionReject(.promise, e); } } ``` Overall the bytecode for async functions gets significantly shorter already (and will get even shorter once we put the outer promise into the async function generator object). For example the bytecode for a simple async function ```js async function f(x) { return await x; } ``` goes from 175 bytes to 110 bytes (a ~38% reduction in size), which is in particular due to the simplification around the try-finally removal. Overall this seems to improve the doxbee-async-es2017-native test by around 2-3%. On the test case mentioned in v8:8276 we go from 1124ms to 441ms, which corresponds to a 60% reduction in total execution time! Tbr: marja@chromium.org Bug: v8:7253, v8:7522, v8:8276 Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel Change-Id: Id29dc92de7490b387ff697860c900cee44c9a7a4 Reviewed-on: https://chromium-review.googlesource.com/c/1269041 Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org> Reviewed-by: Maya Lekova <mslekova@chromium.org> Reviewed-by: Yang Guo <yangguo@chromium.org> Cr-Commit-Position: refs/heads/master@{#56502}
2018-10-10 05:54:39 +00:00
debugger;
return p;#
}
await foo();
#}
Running test: testStepOut
p.then(() => 1);
#debugger;
return p;
await foo();
#}