Teach findAccessedStorage about global addressors. #16877
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@swift-ci test. |
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@swift-ci test source compatibility. |
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@swift-ci test. |
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@atrick d72c91a LGTM! |
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re PR - I do see this problem on the OS X bots: |
This information was getting lost in SIL printing/parsing. Some passes rely on it. Regardless of whether passes should rely on it, it is totally unacceptable for the SIL passes to have subtle differences in behavior depending on the frontend mode. So, if we don't want passes to rely on global variable decls, that needs to be enforced by the API independent of how the frontend is invoked or how SIL is serialized.
Move the utilities that are required for recognizing SILGlobalVariable access into SILGlobalVariable.[h|cpp]. Structural SIL properties that are assumed by the optimizer, and thus required for SIL verification, should never be embedded in SILOptimizer passes, or even in SILOptimizer/Utils. Structural SIL properties need to be defined in /SIL. They are as much part of the SIL language as the opcode list. These particular utilities are required for working with SILGlobalVariables, and will be used by a whole-module access enforcement optimization. The primary API for recognizing SIL globals is `getVariableOfGlobalInit`. It is required to find the association between the addressor SILFunction marked [global_init], and the SILGlobalVariable being addressed. Other helper APIs expose more details about the addressor's SIL patterns and are useful for transforming the initializer itself into an optimized form.
Add stronger SILVerifier support for formal access. Ensure that all formal access follows recognizable patterns at all points in the SIL pipeline. This is important to run acccess enforcement optimization late in the pipeline. To make verification reliable, teach findAccessedStorage about global addressors. AccessedStorage now properly represents access to global variables, even if they haven't been fully optimized down to global_addr instructions. This is essential for optimizing dynamic exclusivity checks. As a verified SIL property, all access to globals and class properties needs to be identifiable.
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All but the last commit are covered by: #16870.
The only new change here is to enable strict verification of formal access on global variables and add unit tests.
AccessedStorage now properly represents access to global variables, even if they
haven't been fully optimized down to global_addr instructions.
This is essential for optimizing dynamic exclusivity checks. As a verified SIL property, all access to globals and class properties needs to be identifiable.