hanchenye-llvm-project/clang
Faisal Vali 81b756e6a3 [C++17] Fix PR34970 - tweak overload resolution for class template deduction-guides in line with WG21's p0620r0.
In order to identify the copy deduction candidate, I considered two approaches:
  - attempt to determine whether an implicit guide is a copy deduction candidate by checking certain properties of its subsituted parameter during overload-resolution.
  - using one of the many bits (WillHaveBody) from FunctionDecl (that CXXDeductionGuideDecl inherits from) that are otherwise irrelevant for deduction guides

After some brittle gymnastics w the first strategy, I settled on the second, although to avoid confusion and to give that bit a better name, i turned it into a member of an anonymous union.

Given this identification 'bit', the tweak to overload resolution was a simple reordering of the deduction guide checks (in SemaOverload.cpp::isBetterOverloadCandidate), in-line with Jason Merrill's p0620r0 drafting which made it into the working paper.  Concordant with that, I made sure the copy deduction candidate is always added.


References:
See https://bugs.llvm.org/show_bug.cgi?id=34970 
See http://wg21.link/p0620r0

llvm-svn: 316292
2017-10-22 14:45:08 +00:00
..
INPUTS
bindings Reverting r316278 due to failing build bots. 2017-10-21 21:52:48 +00:00
cmake [clang-proto-fuzzer] Use ToT protobuf-mutator. 2017-10-18 18:38:04 +00:00
docs Add release notes for the recent -fdouble-square-bracket-attributes and -fno-double-square-bracket-attributes compiler flags. 2017-10-21 16:45:08 +00:00
examples
include [C++17] Fix PR34970 - tweak overload resolution for class template deduction-guides in line with WG21's p0620r0. 2017-10-22 14:45:08 +00:00
lib [C++17] Fix PR34970 - tweak overload resolution for class template deduction-guides in line with WG21's p0620r0. 2017-10-22 14:45:08 +00:00
runtime Allow building libFuzzer tests in two-stage compiler-rt build. 2017-10-13 23:50:53 +00:00
test [C++17] Fix PR34970 - tweak overload resolution for class template deduction-guides in line with WG21's p0620r0. 2017-10-22 14:45:08 +00:00
tools Reverting r316278 due to failing build bots. 2017-10-21 21:52:48 +00:00
unittests [clang-format] Sort whole block of using declarations while partially formatting 2017-10-18 22:13:25 +00:00
utils Silence -Wimplicit-fallthrough warnings with the generated code; NFC. 2017-10-18 12:11:58 +00:00
www Typos in tutorial 2017-10-13 00:31:07 +00:00
.arcconfig
.clang-format
.clang-tidy
.gitignore
CMakeLists.txt [CMake][OpenMP] Customize default offloading arch 2017-10-17 13:37:36 +00:00
CODE_OWNERS.TXT
INSTALL.txt
LICENSE.TXT
ModuleInfo.txt
NOTES.txt
README.txt Test commit 2017-10-21 16:03:17 +00:00

README.txt

//===----------------------------------------------------------------------===//
// C Language Family Front-end
//===----------------------------------------------------------------------===//

Welcome to Clang.  This is a compiler front-end for the C family of languages
(C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM
compiler infrastructure project.

Unlike many other compiler frontends, Clang is useful for a number of things
beyond just compiling code: we intend for Clang to be host to a number of
different source-level tools.  One example of this is the Clang Static Analyzer.

If you're interested in more (including how to build Clang) it is best to read
the relevant web sites.  Here are some pointers:

Information on Clang:             http://clang.llvm.org/
Building and using Clang:         http://clang.llvm.org/get_started.html
Clang Static Analyzer:            http://clang-analyzer.llvm.org/
Information on the LLVM project:  http://llvm.org/

If you have questions or comments about Clang, a great place to discuss them is
on the Clang development mailing list:
  http://lists.llvm.org/mailman/listinfo/cfe-dev

If you find a bug in Clang, please file it in the LLVM bug tracker:
  http://llvm.org/bugs/