Allow LLDB repl to properly handle redefinition of expressions.

[bgogul]

Currently, lldb's REPL mode does not work well with extensions. Specifically, we cannot redefine an extension. Consider the following LLDB repl session:

Welcome to Swift version 5.0-dev (LLVM dcb9eb74a7, Clang 95cdf7c9af, Swift 56a798a3ea).
Type :help for assistance.
  1> struct Foo {}
  2> extension Foo { func f() -> Int { return 1 } }
  3> Foo().f()
$R0: Int = 1
  4> extension Foo { func f() -> Int { return 2 } }
  5> Foo().f()
error: repl.swift:5:1: error: ambiguous use of 'f()'
Foo().f()
^

repl.swift:2:22: note: found this candidate
extension Foo { func f() -> Int { return 1 } }
                     ^

repl.swift:4:22: note: found this candidate
extension Foo { func f() -> Int { return 2 } }
                     ^

As you can see redefining a function in an extension causes an ambiguous use diagnostic. This PR uses the additional hooks declared in apple/swift#23031 to deal with redefinition of extensions.

See the discussion on the swift forum for more context.

[jimingham]

Please use SwiftREPL::GetSourceFileBasename rather than hardcoding "repl.swift". Other than that, this should do the trick. Jim

…

On Mar 1, 2019, at 3:36 PM, Gogul Balakrishnan ***@***.***> wrote: Currently, lldb's REPL mode does not work well with extensions. Specifically, we cannot redefine an extension. Consider the following LLDB repl session: Welcome to Swift version 5.0-dev (LLVM dcb9eb74a7, Clang 95cdf7c9af, Swift 56a798a3ea). Type :help for assistance. 1> struct Foo {} 2> extension Foo { func f() -> Int { return 1 } } 3> Foo().f() $R0: Int = 1 4> extension Foo { func f() -> Int { return 2 } } 5> Foo().f() error: repl.swift:5:1: error: ambiguous use of 'f()' Foo().f() ^ repl.swift:2:22: note: found this candidate extension Foo { func f() -> Int { return 1 } } ^ repl.swift:4:22: note: found this candidate extension Foo { func f() -> Int { return 2 } } ^ As you can see redefining a function in an extension causes an ambiguous use diagnostic. This PR uses the additional hooks declared in apple/swift#23031 to deal with redefinition of extensions. See the discussion on the swift forum for more context. You can view, comment on, or merge this pull request online at: #1340 Commit Summary • Eliminate spurious ambiguous name errors in REPL. • Made three versions of finishLookup. File Changes • M source/Plugins/ExpressionParser/Swift/SwiftExpressionParser.cpp (75) Patch Links: • https://github.com/apple/swift-lldb/pull/1340.patch • https://github.com/apple/swift-lldb/pull/1340.diff — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or mute the thread.

[bgogul]

Please use SwiftREPL::GetSourceFileBasename rather than hardcoding "repl.swift". Other than that, this should do the trick.

Thanks for the quick response. Done!

[dcci]

This needs a test.

[dcci]

Also, somebody working on the frontend should sign this off.

[bgogul]

This needs a test.

Thanks @dcci. I will certainly add a test. I am waiting for the apple/swift#23031 PR to be merged in.