Strip -fPIC compiler flag during compilation #10209
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This is a partial revert of #9750. The binaryen change that was designed to allow this to work was reverted: WebAssembly/binaryen#2513
| @@ -1937,6 +1937,9 @@ def is_link_flag(flag): | |||
| return any(flag.startswith(x) for x in ('-l', '-L', '-Wl,')) | |||
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| compile_args = [a for a in newargs if a and not is_link_flag(a)] | |||
| if '-fPIC' in compile_args and not shared.Settings.RELOCATABLE: | |||
| shared.warning('ignoring -fPIC flag when not building with SIDE_MODULE or MAIN_MODULE') | |||
| compile_args.remove('-fPIC') | |||
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This change means that people need to compile with SIDE/MAIN_MODULE and not just link? Is that new or am I forgetting how upstream worked here?
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Yes, I think that is true. But they will see this warning so it should be clear.
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I think this is pretty good intermediate fix until the binaryen fix is ready.
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Sounds good.
How do our current tests pass, then? It seems like all dylink/dlfcn tests should warn if they include more than 1 file, since I don't see this flag added to their compile commands?
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Agreed it's good to have a temp fix. I'm just trying to fully understand it.
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But none of our dylink currently pass -fPIC. So this means they must all be passing SIDE/MAIN_MODULE during both compile and link.
As far as I know we never advertised the fact that -fPIC could be used at compile time instead of SIDE/MAIN_MODULE.
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Interesting, good point.
We should probably add more realistic tests then, if users are using -fPIC for dynamic linking but our tests aren't.
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IIUC users are not using fPIC for dyamic linking, they are using it simply because their build system always adds it in, but they are doing static linking.
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Can confirm that the warning works :) |
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As binaryen fix WebAssembly/binaryen#2622 is ready, are you gonna revert this change again. Because with latest emscripten , I am trying to build with SIDE_MODULE/MAIN_MODULE I am getting lots of warning "ignoring -fPIC flag when not building with SIDE_MODULE or MAIN_MODULE" and also error something like "recompile with -fPIC" even when I passed -fPIC flag. Or am I missing something ? |
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Yes the plan is to remove this code/warning. For now, you should be able to add SIDE_MODULE/MAIN_MODULE to all your compilation steps to avoid the linker error. |
Now that we have landed (for the third time) the binaryen fix for WebAssembly/binaryen#2180 we can once again allow `-fPIC` at compile time as an alternative to MAIN_MODULE or SIDE_MODULE. This reverts commit 19a9e35.
Now that we have landed (for the third time) the binaryen fix for WebAssembly/binaryen#2180 we can once again allow `-fPIC` at compile time as an alternative to MAIN_MODULE or SIDE_MODULE. This reverts commit 19a9e35.
This is a partial revert of #9750.
The binaryen change that was designed to allow this to work was
reverted: WebAssembly/binaryen#2513