Use the same alignment for writing and reading .swift_ast section contents #28574
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…ents. This fixes a bug that made it impossible to read any subsequent Swift modules out of a .swift_ast section a previous section had a size divisible by 4. rdar://problem/57110020
adrian-prantl
changed the title
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@swift-ci test |
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@adrian-prantl awesome! Do you think this would also be suitable for swift-5.1-branch ? That way we could release this with the next monthly linux release |
The review for the backport is here: #28576 |
| // RUN: %target-build-swift %t/a2.swift -emit-module -emit-module-path %t/a2.swiftmodule | ||
| // RUN: %target-build-swift %t/a3.swift -emit-module -emit-module-path %t/a3.swiftmodule | ||
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| // RUN: %target-swift-modulewrap %t/a0.swiftmodule -o %t/a0-mod.o |
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Does swift-modulewrap build a MachO container for a swiftmodule?
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Technically that would work, but it's not wired up correctly at the moment and returns an IRGen error "Unable to find a runtime library path".
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Ah, sorry, my unfamiliarity with this code is showing. What does swift-modulewrap do?
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it invokes swift -modulewrap which is used on Linux (where we don't control the linker) to wrap a .swfitmodule inside a .swift_ast section in an object file, so it can be linked together with the program. The linker concatenates all the .swift_ast sections for LLDB to be found.
| if (data.size() % 4 != 0 || | ||
| reinterpret_cast<uintptr_t>(data.data()) % 4 != 0) | ||
| if (data.size() % SWIFTMODULE_ALIGNMENT != 0 || | ||
| reinterpret_cast<uintptr_t>(data.data()) % SWIFTMODULE_ALIGNMENT != 0) |
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It's probably not worth changing right now, but in the future, perhaps we could use the new Alignment.h helpers, like:
Align moduleAlignment = SWIFTMODULE_ALIGNMENT;
if (!isAligned(moduleAlignment, data.size()) || !isAddrAligned(moduleAlignment, data.data())) ...
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Oh, the // Check 32-bit alignment comment may need an update.
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lgtm |
This fixes a bug that made it impossible to read any subsequent Swift modules
out of a .swift_ast section a previous section had a size divisible by 4.
https://bugs.swift.org/browse/SR-7932
rdar://problem/57110020