Implement re-declaration checking for declarations in local context #34125
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…calDecls()
This will be used to implement re-declaration checking for local
declarations. Currently this is handled by parse-time lookup.
To make it work with ASTScope, we need to perform lookups that
look into the innermost local scope only; for example, this is
an invalid redeclaration:
do {
let x = 321
let x = 123
}
But the following is fine, even though both VarDecls are in the same
*DeclContext*:
do {
let x = 321
do {
let x = 123
}
}
…parser lookup is off The existing redeclaration checking can be extended for declarations in local scope, but it won't catch these.
slavapestov
commented
Sep 30, 2020
| NamedDeclConsumer::foundDecl(VD, Reason, dynamicLookupInfo); | ||
| unsigned after = results.size(); | ||
| if (after > before) | ||
| factory->addedResult(results.back()); |
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@davidungar This is another debugging code path that you added, which has since become dead code. Notice how the Consumer instance variable was never used, and in fact we call addedResult() elsewhere, so we don't lose anything by deleting this code here.
|
@swift-ci Please smoke test |
|
@swift-ci Please test source compatibility |
|
@swift-ci Please test Linux |
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Currently parse-time lookup diagnoses these, so we need to implement it in Sema to prepare for disabling parse-time lookup.
There are two cases:
finishLookupInBraceStmtflag toASTScope::lookupLocalDecls(); when set, this stops the lookup at the innermost BraceStmt, because for purposes of re-declaration checking we only want to consider other declarations with the same name contained in the same BraceStmt. This is because shadowing of local declarations from outer scopes is, in fact, permitted.While we're here, delete a couple of bits of dead code as well.