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Native calling on x86_64 *nix gcc

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Started by gargltk February 03, 2009 06:54 PM

77 comments, last by WitchLord 15 years, 2 months ago

gargltk

125

Author

February 13, 2009 07:45 AM

This is the valgrind log for a run of all the tests in the latest SVN revision (362) after changing new[] to malloc(): http://pastebin.com/m537cb3b0

I think I know how to fix one of them, I'll post an updated 'as_callfunc_x64_gcc.cpp' soon

// moments later:
Ok, here is a new version of 'as_callfunc_x64_gcc.cpp': http://pastebin.com/m379d3ec8

It fixes this valgrind-detected problem:

==10404== Invalid write of size 8==10404==    at 0x4C5181: CallSystemFunction(int, asCContext*, void*) (as_callfunc_x64_gcc.cpp:616)==10404==    by 0x47FA0D: asCContext::ExecuteNext() (as_context.cpp:2044)==10404==    by 0x483E2B: asCContext::Execute() (as_context.cpp:1096)==10404==    by 0x4A223F: asCScriptEngine::ExecuteString(char const*, char const*, asIScriptContext**, unsigned int) (as_scriptengine.cpp:2501)==10404==    by 0x452A10: TestVector3_2::Test() (test_vector3_2.cpp:130)==10404==    by 0x404DE8: main (main.cpp:250)==10404==  Address 0x641da70 is 8 bytes inside a block of size 12 alloc'd==10404==    at 0x4C23CFE: malloc (in /usr/lib64/valgrind/amd64-linux/vgpreload_memcheck.so)==10404==    by 0x464DD9: MyAllocWithStats(unsigned long, char const*, int) (utils.cpp:93)==10404==    by 0x496FD3: asCScriptEngine::CallAlloc(asCObjectType*) (as_scriptengine.cpp:2994)==10404==    by 0x4C44B7: CallSystemFunction(int, asCContext*, void*) (as_callfunc_x64_gcc.cpp:290)==10404==    by 0x47FA0D: asCContext::ExecuteNext() (as_context.cpp:2044)==10404==    by 0x483E2B: asCContext::Execute() (as_context.cpp:1096)==10404==    by 0x4A223F: asCScriptEngine::ExecuteString(char const*, char const*, asIScriptContext**, unsigned int) (as_scriptengine.cpp:2501)==10404==    by 0x452A10: TestVector3_2::Test() (test_vector3_2.cpp:130)==10404==    by 0x404DE8: main (main.cpp:250)

WitchLord

4,834

February 13, 2009 09:21 AM

All the warnings about the conditional jumps depending on uninitialized values seems to be 'false positives'. I think that valgrind may be wrong with these.

It may be that the optimization made by the C++ compiler is fooling valgrind a bit. According to valgrind's manual it is recommended to compile the application with -O0 (no optimazation) to avoid valgrind reporting false errors.

I'll investigate the 'invalid read of size 4' problem. I think valgrind have really found a bug here. A bug that probably only happens with the removal of dynamic configuration groups (which few are likely to do) thus going unnoticed until now.

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WitchLord

4,834

February 14, 2009 07:30 PM

I've fixed the memory leak in as_callfunc_x64_gcc.cpp. It was caused by the CallSystemFunction not deleting the object that AngelScript sent by value as it should. This in turn was because the as_callfunc_x64_gcc.cpp doesn't support passing non-complex types by value, because of the very high complexity of having to split the object into separate registers based on the type of each member in the object.

To fix this AngelScript needs to know the exact memory layout of the type. I may add this support in a future version, but for now AngelScript will just report an error when the application tries to register a function that takes these types by value.

I've also fixed the other memory errors that Valgrind reported, i.e. the conditional jumps based on uninitialized memory. These really were uninitialized memory though it was a bit difficult to find.

Valgrind discovered another memory leak that I've yet to look into though. Hopefully I'll be able to take care of it tomorrow.

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WitchLord

4,834

February 15, 2009 08:22 AM

The last memory leak has now been fixed. The as_callfunc_x64_gcc wasn't releasing the autohandles properly.

Valgrind is now reporting 0 errors while running the test_features app. I think we can now safely say that AngelScript supports native calling conventions on 64bit Linux.

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_Vicious_

330

February 15, 2009 09:04 AM

Hooray! :)

Edit: btw, don't forget to remove the debugging flags in the makefile ;)

WitchLord

4,834

February 15, 2009 09:42 AM

Done! Thanks! :)

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gargltk

125

Author

February 15, 2009 07:39 PM

Quote:Original post by WitchLord
The last memory leak has now been fixed. The as_callfunc_x64_gcc wasn't releasing the autohandles properly.

Valgrind is now reporting 0 errors while running the test_features app. I think we can now safely say that AngelScript supports native calling conventions on 64bit Linux.

This is great news indeed :D
Looking forward to actually using the library now ;) Expect n00b questions soon.

_Vicious_

330

February 16, 2009 01:40 PM

In fact, both jal_ and me represent the warsow development team here, we've already released a version at our forums containing the WIP version of AS with native x64 support included. If we encounter any bugs, we'll report back to you :) Thanks!

WitchLord

4,834

February 16, 2009 01:53 PM

Ah, that's great. I knew someone on your team was looking into 64bit support, but I didn't remember who it was.

I've added Warsow to the users list. When I buy a new computer I'll give the game a go as well. ;)

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