[NFC] Explicitly control alignment of Identifiers #27414
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@swift-ci please smoke test |
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There's no real way to unit test this, but I've checked that bumping the spare bits to 3 breaks the things it ought to break. |
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The custom addresses for special DeclBaseNames should probably be pointers to Identifier::Aligner now too. |
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jrose-apple
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Identifier contains a pointer to character data, and we need to ensure that this pointer has enough spare bits in it for DeclBaseName and DeclName. This currently happens to be true because the StringMap used to intern Identifier pointers happens to place a 32-bit size field in the MapTableEntry object, but it would be better to explicitly force the alignment we want and assert that it’s correct.
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@swift-ci please smoke test |
jrose-apple
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Oct 1, 2019
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@swift-ci please smoke test macos platform |
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Might need a rebase, but let’s try one more time. @swift-ci please smoke test macos platform |
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Identifiercontains a pointer to character data, and we need to ensure that this pointer has enough spare bits in it forDeclBaseNameandDeclName. This currently happens to be true because theStringMapused to internIdentifierpointers happens to place a 32-bit size field in theMapTableEntryobject, but it would be better to explicitly force the alignment we want and assert that it’s correct.(I need this commit because I will soon need to add spare bits to
Identifierso that there are spare bits inDeclName.)