[ObjC] Remove OSReadLittle* due to alignment requirements #6678
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The OSReadLittleInt64 function as defined by Apple reduces down to: `return *(volatile uint64_t *)((uintptr_t)base + byteOffset);` which means we are type-punning using a cast. On ARMv7 and other aligned architectures this can cause crashes. Minimal example: https://gist.github.com/dmaclach/b10b0a71ae614d304c067cb9bd264336
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) The OSReadLittleInt64 function as defined by Apple reduces down to: `return *(volatile uint64_t *)((uintptr_t)base + byteOffset);` which means we are type-punning using a cast. On ARMv7 and other aligned architectures this can cause crashes. Minimal example: https://gist.github.com/dmaclach/b10b0a71ae614d304c067cb9bd264336 Fixes protocolbuffers#6679
thomasvl
pushed a commit
to thomasvl/protobuf
that referenced
this pull request
Sep 20, 2019
) The OSReadLittleInt64 function as defined by Apple reduces down to: `return *(volatile uint64_t *)((uintptr_t)base + byteOffset);` which means we are type-punning using a cast. On ARMv7 and other aligned architectures this can cause crashes. Minimal example: https://gist.github.com/dmaclach/b10b0a71ae614d304c067cb9bd264336 Fixes protocolbuffers#6679
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Objective C Protocol buffers can crash on ARM32.
The OSReadLittleInt64 function as defined by Apple reduces down to:
return *(volatile uint64_t *)((uintptr_t)base + byteOffset);which means we are type-punning using a cast. On ARMv7 and other aligned architectures this can cause crashes.
Minimal example: https://gist.github.com/dmaclach/b10b0a71ae614d304c067cb9bd264336
Language: objective-c
release notes: yes