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| author | Richard Smith <richard-llvm@metafoo.co.uk> | 2019-05-09 03:31:27 +0000 |
|---|---|---|
| committer | Richard Smith <richard-llvm@metafoo.co.uk> | 2019-05-09 03:31:27 +0000 |
| commit | fb98e7c13da639f34f34830a4e675367e0816cb6 (patch) | |
| tree | 70e025e9b4a31559d1f061e72439b5414537ad3b /lib/Sema/SemaOverload.cpp | |
| parent | 70cd574857c6023b8c60e325c4029a23f716c2dd (diff) | |
| download | clang-fb98e7c13da639f34f34830a4e675367e0816cb6.tar.gz | |
[c++20] Implement P0846R0: allow (ADL-only) calls to template-ids whose
template name is not visible to unqualified lookup.
In order to support this without a severe degradation in our ability to
diagnose typos in template names, this change significantly restructures
the way we handle template-id-shaped syntax for which lookup of the
template name finds nothing.
Instead of eagerly diagnosing an undeclared template name, we now form a
placeholder template-name representing a name that is known to not find
any templates. When the parser sees such a name, it attempts to
disambiguate whether we have a less-than comparison or a template-id.
Any diagnostics or typo-correction for the name are delayed until its
point of use.
The upshot should be a small improvement of our diagostic quality
overall: we now take more syntactic context into account when trying to
resolve an undeclared identifier on the left hand side of a '<'. In
fact, this works well enough that the backwards-compatible portion (for
an undeclared identifier rather than a lookup that finds functions but
no function templates) is enabled in all language modes.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@360308 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Sema/SemaOverload.cpp')
| -rw-r--r-- | lib/Sema/SemaOverload.cpp | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp index 3fbd635607..19ac2bf33a 100644 --- a/lib/Sema/SemaOverload.cpp +++ b/lib/Sema/SemaOverload.cpp @@ -12017,7 +12017,8 @@ bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn, // We don't perform ADL for implicit declarations of builtins. // Verify that this was correctly set up. FunctionDecl *F; - if (ULE->decls_begin() + 1 == ULE->decls_end() && + if (ULE->decls_begin() != ULE->decls_end() && + ULE->decls_begin() + 1 == ULE->decls_end() && (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && F->getBuiltinID() && F->isImplicit()) llvm_unreachable("performing ADL for builtin"); @@ -12201,10 +12202,9 @@ ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, OverloadingResult OverloadResult = CandidateSet.BestViableFunction(*this, Fn->getBeginLoc(), Best); - return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, - RParenLoc, ExecConfig, &CandidateSet, - &Best, OverloadResult, - AllowTypoCorrection); + return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, RParenLoc, + ExecConfig, &CandidateSet, &Best, + OverloadResult, AllowTypoCorrection); } static bool IsOverloaded(const UnresolvedSetImpl &Functions) { |