Add EscapeAnalysis verification to catch unmapped SILValues. #29410
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Noticed via code inspection. This could potentially miscompile, but we haven't seen that happen to my knowledge. Both value_to_bridge_object and strong_copy_XXX need to escape their resulting value. The implementation seemed to assume that it is conservatively correct simply to avoid building a connection graph node for an value. This is *not* true. Any value that has a pointer type requires a connection graph node. The only way to be conservative is to create the value node *and* point it to an escaping content node. We can always declare that certain special types are not considered pointer types, but then we need to handle all conversions from those types to pointer types by escaping the resulting pointer. BridgeObjects are often on the performance-critical path.
This verification would have prevented the following recent miscompilation: commit fbe38ce Fix EscapeAnalysis losing precision during merge.
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@swift-ci test |
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@swift-ci test source compatibility |
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This verification would have prevented the following recent miscompilation:
commit fbe38ce
Fix EscapeAnalysis losing precision during merge.
Only the second commit has new changes.