src: support thin strings and stub frames

[joyeecheung]

Fixes: #117

In Node.js v8.3.0 Turbofan has been enabled by default, so thin strings have also been enabled and now Turbofan would put stub frames on the stack (to store register states for bytecode handlers, I think).

Before this change, when viewing the backtrace of test/fixtures/inspect-scenario.js with Node.js v8.3.0, frames containing functions with thin string arguments or in thin string paths would be broken:

See backtrace of inspect-scenario.js

 * thread #1: tid = 0x81d450, 0x0000000100bbe942 node`v8::base::OS::Abort() at platform-posix.cc:261, queue = 'com.apple.main-thread', stop reason = EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) * frame #0: 0x0000000100bbe942 node`v8::base::OS::Abort() at platform-posix.cc:261 [opt] frame #1: 0x00000001008a27cb node`v8::internal::Runtime_Throw(int, v8::internal::Object**, v8::internal::Isolate*) [inlined] v8::internal::__RT_impl_Runtime_Throw(v8::internal::Arguments, v8::internal::Isolate*) at runtime-internal.cc:74 [opt] frame #2: 0x00000001008a27aa node`v8::internal::Runtime_Throw(args_length=<unavailable>, args_object=<unavailable>, isolate=0x00000001030492e0) at runtime-internal.cc:71 [opt] frame #3: 0x00001a1235b840dd <exit> frame #4: 0x00001a1235c8523a frame #5: 0x00001a1235b92f12 method(this=0x00002976af95c089:<Object: Class>) at (no script):20:43 fn=0x000026033eb8f931 frame #6: 0x00001a1235c735e9 frame #7: 0x00001a1235b92f12 closure(this=0x000022d8c1402241:<undefined>) at (no script):11:17 fn=0x00002976af905ad9 frame #8: 0x00001a1235c73fa1 frame #9: 0x00001a1235b92f12 frame #10: 0x00001a1235c72cc8 frame #11: 0x00001a1235b92f12 frame #12: 0x00001a1235c738aa frame #13: 0x00001a1235b92f12 frame #14: 0x00001a1235c738aa frame #15: 0x00001a1235b92f12 frame #16: 0x00001a1235c7373c frame #17: 0x00001a1235b92f12 frame #18: 0x00001a1235c74242 frame #19: 0x00001a1235b92f12 Module._load(this=0x0000135cdc0bb3b1:<function: Module at module.js:55:16>, 0x0000135cdc0c7119:<String: "/Users/joyee/pro...">, 0x000022d8c1402211:<null>, 0x000022d8c14022c1:<true>) at module.js:434:24 fn=0x000012d14eec2e29 frame #20: 0x00001a1235c72cc8 frame #21: 0x00001a1235b92f12 Module.runMain(this=0x0000135cdc0bb3b1:<function: Module at module.js:55:16>) at module.js:607:26 fn=0x000012d14eec3099 frame #22: 0x00001a1235c93c29 frame #23: 0x00001a1235b92f12 startup(this=0x000022d8c1402241:<undefined>) at bootstrap_node.js:1:10 fn=0x0000304c372feb79 frame #24: 0x00001a1235c73fa1 frame #25: 0x00001a1235b92f12 (anonymous)(this=0x000022d8c1402211:<null>, 0x0000304c372febf9:<Object: process>) at bootstrap_node.js:1:10 fn=0x0000304c372fec49 frame #26: 0x00001a1235b90650 <internal> frame #27: 0x00001a1235c64ead <entry> frame #28: 0x00000001005daed1 node`v8::internal::(anonymous namespace)::Invoke(isolate=0x0000000000000049, is_construct=<unavailable>, target=<unavailable>, receiver=<unavailable>, argc=1, args=<unavailable>, new_target=<unavailable>, message_handling=<unavailable>) at execution.cc:145 [opt] frame #29: 0x00000001005dabb9 node`v8::internal::Execution::Call(v8::internal::Isolate*, v8::internal::Handle<v8::internal::Object>, v8::internal::Handle<v8::internal::Object>, int, v8::internal::Handle<v8::internal::Object>*) [inlined] v8::internal::(anonymous namespace)::CallInternal(message_handling=kReport) at execution.cc:181 [opt] frame #30: 0x00000001005dab30 node`v8::internal::Execution::Call(isolate=0x0000000103000c00, callable=Handle<v8::internal::Object> @ r12, receiver=<unavailable>, argc=1, argv=<unavailable>) at execution.cc:191 [opt] frame #31: 0x0000000100204b98 node`v8::Function::Call(this=0x0000000103049238, context=<unavailable>, recv=<unavailable>, argc=1, argv=0x00007fff5fbfe1f0) at api.cc:5279 [opt] frame #32: 0x0000000100a4d083 node`node::LoadEnvironment(env=0x00007fff5fbfe290) at node.cc:3613 [opt] frame #33: 0x0000000100a53de8 node`node::Start(isolate=0x0000000103000c00, isolate_data=<unavailable>, argc=2, argv=<unavailable>, exec_argc=1, exec_argv=0x0000000102503c70) at node.cc:4528 [opt] frame #34: 0x0000000100a4e9a0 node`node::Start(event_loop=0x000000010154ef90, argc=2, argv=0x00000001025043a0, exec_argc=<unavailable>, exec_argv=<unavailable>) at node.cc:4607 [opt] frame #35: 0x0000000100a4e62d node`node::Start(argc=<unavailable>, argv=0x00000001025043a0) at node.cc:4662 [opt] frame #36: 0x0000000100001434 node`start + 52 

After (with patch in #117 (comment)):

See backtrace of inspect-scenario.js

 * thread #1: tid = 0x81cad8, 0x0000000100bbe942 node`v8::base::OS::Abort() at platform-posix.cc:261, queue = 'com.apple.main-thread', stop reason = EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) * frame #0: 0x0000000100bbe942 node`v8::base::OS::Abort() at platform-posix.cc:261 [opt] frame #1: 0x00000001008a27cb node`v8::internal::Runtime_Throw(int, v8::internal::Object**, v8::internal::Isolate*) [inlined] v8::internal::__RT_impl_Runtime_Throw(v8::internal::Arguments, v8::internal::Isolate*) at runtime-internal.cc:74 [opt] frame #2: 0x00000001008a27aa node`v8::internal::Runtime_Throw(args_length=<unavailable>, args_object=<unavailable>, isolate=0x00000001030492e0) at runtime-internal.cc:71 [opt] frame #3: 0x000016c7041040dd <exit> frame #4: 0x000016c70420523a <stub> frame #5: 0x000016c704112f12 method(this=0x00000a7bd42dc201:<Object: Class>) at /Users/joyee/projects/llnode/test/fixtures/inspect-scenario.js:27:43 fn=0x00003aeebdc8faa9 frame #6: 0x000016c7041f35e9 <stub> frame #7: 0x000016c704112f12 closure(this=0x0000156976502241:<undefined>) at /Users/joyee/projects/llnode/test/fixtures/inspect-scenario.js:18:17 fn=0x00000a7bd4285c81 frame #8: 0x000016c7041f3fa1 <stub> frame #9: 0x000016c704112f12 (anonymous)(this=0x00000a7bd4283a61:<Object: Object>, 0x00000a7bd4283a61:<Object: Object>, 0x00000a7bd42857e9:<function: require at (external).js:8:19>, 0x00000a7bd42839a1:<Object: Module>, 0x00000a7bd4282dd9:<String: "/Users/joyee/pro...">, 0x00000a7bd4285781:<String: "/Users/joyee/pro...">) at /Users/joyee/projects/llnode/test/fixtures/inspect-scenario.js:1:10 fn=0x00000a7bd4285739 frame #10: 0x000016c7041f2cc8 <stub> frame #11: 0x000016c704112f12 Module._compile(this=0x00000a7bd42839a1:<Object: Module>, 0x00000a7bd42847b1:<String: "'use strict'; c...">, 0x00000a7bd4282dd9:<String: "/Users/joyee/pro...">) at module.js:530:37 fn=0x0000170c90843011 frame #12: 0x000016c7041f38aa <stub> frame #13: 0x000016c704112f12 Module._extensions..js(this=0x000037f6cb67e271:<Object: Object>, 0x00000a7bd42839a1:<Object: Module>, 0x00000a7bd4282dd9:<String: "/Users/joyee/pro...">) at module.js:582:37 fn=0x0000170c90843059 frame #14: 0x000016c7041f38aa <stub> frame #15: 0x000016c704112f12 Module.load(this=0x00000a7bd42839a1:<Object: Module>, 0x00000a7bd4282dd9:<String: "/Users/joyee/pro...">) at module.js:498:33 fn=0x0000170c90842f81 frame #16: 0x000016c7041f373c <stub> frame #17: 0x000016c704112f12 tryModuleLoad(this=0x0000156976502241:<undefined>, 0x00000a7bd42839a1:<Object: Module>, 0x00000a7bd4282dd9:<String: "/Users/joyee/pro...">) at module.js:467:23 fn=0x000037f6cb63b561 frame #18: 0x000016c7041f4242 <stub> frame #19: 0x000016c704112f12 Module._load(this=0x000037f6cb63b3b1:<function: Module at module.js:55:16>, 0x000037f6cb647081:<String: "/Users/joyee/pro...">, 0x0000156976502211:<null>, 0x00001569765022c1:<true>) at module.js:434:24 fn=0x0000170c90842ec1 frame #20: 0x000016c7041f2cc8 <stub> frame #21: 0x000016c704112f12 Module.runMain(this=0x000037f6cb63b3b1:<function: Module at module.js:55:16>) at module.js:607:26 fn=0x0000170c90843131 frame #22: 0x000016c704213c29 <stub> frame #23: 0x000016c704112f12 startup(this=0x0000156976502241:<undefined>) at bootstrap_node.js:1:10 fn=0x000027f86ea7eb79 frame #24: 0x000016c7041f3fa1 <stub> frame #25: 0x000016c704112f12 (anonymous)(this=0x0000156976502211:<null>, 0x000027f86ea7ebf9:<Object: process>) at bootstrap_node.js:1:10 fn=0x000027f86ea7ec49 frame #26: 0x000016c704110650 <internal> frame #27: 0x000016c7041e4ead <entry> frame #28: 0x00000001005daed1 node`v8::internal::(anonymous namespace)::Invoke(isolate=0x0000000000000049, is_construct=<unavailable>, target=<unavailable>, receiver=<unavailable>, argc=1, args=<unavailable>, new_target=<unavailable>, message_handling=<unavailable>) at execution.cc:145 [opt] frame #29: 0x00000001005dabb9 node`v8::internal::Execution::Call(v8::internal::Isolate*, v8::internal::Handle<v8::internal::Object>, v8::internal::Handle<v8::internal::Object>, int, v8::internal::Handle<v8::internal::Object>*) [inlined] v8::internal::(anonymous namespace)::CallInternal(message_handling=kReport) at execution.cc:181 [opt] frame #30: 0x00000001005dab30 node`v8::internal::Execution::Call(isolate=0x0000000103000c00, callable=Handle<v8::internal::Object> @ r12, receiver=<unavailable>, argc=1, argv=<unavailable>) at execution.cc:191 [opt] frame #31: 0x0000000100204b98 node`v8::Function::Call(this=0x0000000103049238, context=<unavailable>, recv=<unavailable>, argc=1, argv=0x00007fff5fbfe1f0) at api.cc:5279 [opt] frame #32: 0x0000000100a4d083 node`node::LoadEnvironment(env=0x00007fff5fbfe290) at node.cc:3613 [opt] frame #33: 0x0000000100a53de8 node`node::Start(isolate=0x0000000103000c00, isolate_data=<unavailable>, argc=2, argv=<unavailable>, exec_argc=1, exec_argv=0x0000000102503c70) at node.cc:4528 [opt] frame #34: 0x0000000100a4e9a0 node`node::Start(event_loop=0x000000010154ef90, argc=2, argv=0x00000001025043a0, exec_argc=<unavailable>, exec_argv=<unavailable>) at node.cc:4607 [opt] frame #35: 0x0000000100a4e62d node`node::Start(argc=<unavailable>, argv=0x00000001025043a0) at node.cc:4662 [opt] frame #36: 0x0000000100001434 node`start + 52 

Also display stub frames as <stub> to fix frame-test.js.

This would need a patch in v8 to get the kThinStringTag constant: #117 (comment)

Tested with v4.8.4, v6.11.1, v8.2.1 and v8.3.0(with patch from #117 (comment))

[joyeecheung]

@indutny Doing make format on my mac results in:

clang-format -i src/* Problem while looking for clang-format in Chromium source tree: Could not find checkout in any parent of the current path. Set CHROMIUM_BUILDTOOLS_PATH to use outside of a chromium checkout. make: *** [format] Error 1 

I have a (very old) chromium checkout on my machine but setting CHROMIUM_BUILDTOOLS_PATH to chromium/src/buildtools then run clang-format -i src/* all I got was silence :/...I will try to update my chromium checkout (not sure if that's the right way to fix this though).

[joyeecheung]

OK, turns out silence was what it was supposed to be, the file would be formatted directly by the script. o.0 I've fixed the style, PTAL @indutny@bnoordhuis

[bnoordhuis]

Still LGTM. I'm trying to sort out https://ci.nodejs.org/view/post-mortem/job/llnode-pipeline/ but you can land this if you want, @joyeecheung.

[bnoordhuis]

For good measure: https://ci.nodejs.org/view/post-mortem/job/llnode-pipeline/13/