[all-commits] [llvm/llvm-project] 32aa7d: [clang] Fix CTAD not work for C++ explicit type co...

[Haojian Wu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 32aa7d823c8ae7183e65da2f29ed08a84d6a1b6b
      https://github.com/llvm/llvm-project/commit/32aa7d823c8ae7183e65da2f29ed08a84d6a1b6b
  Author: Haojian Wu <hokein.wu at gmail.com>
  Date:   2023-12-19 (Tue, 19 Dec 2023)

  Changed paths:
    M clang/docs/ReleaseNotes.rst
    M clang/include/clang/Sema/Sema.h
    M clang/lib/Sema/SemaDecl.cpp
    M clang/lib/Sema/SemaInit.cpp
    A clang/test/SemaCXX/ctad.cpp

  Log Message:
  -----------
  [clang] Fix CTAD not work for C++ explicit type conversion (functional annotation). (#75779)

This fixes https://github.com/llvm/llvm-project/issues/64347.

The CTAD for an aggregate class is missing to handle the explicit type
conversion case, e.g. `TemplateFooClass(1, 2);`. Per C++ expr.type.conv
p1, the deduced type is the return type of the deduction guide selected
by the CTAD for the reminder.

In the deduction implementation
`DeduceTemplateSpecializationFromInitializer`, the parenthesized
express-list case relies on the `ParenListExpr` parameter (default is
nullptr), the AST `ParenListExpr` node is not built for all variant
initializer cases (`BuildCXXTypeConstructorExpr`, `BuildCXXNew` etc),
thus the deduction doesn't perform for these cases. This patch fixes it
by removing the `ParenListExpr` and using the `Inits` instead (which
also simplifies the interface and implementation).