P0035R4: Semantic analysis and code generation for C++17 overaligned

allocation.

llvm-svn: 283722

1 files changed, 28 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaCUDA.cpp b/clang/lib/Sema/SemaCUDA.cpp
index d6c0606674e..827eb02bcd6 100644
--- a/clang/lib/Sema/SemaCUDA.cpp
+++ b/clang/lib/Sema/SemaCUDA.cpp
@@ -158,6 +158,34 @@ Sema::IdentifyCUDAPreference(const FunctionDecl *Caller,
   llvm_unreachable("All cases should've been handled by now.");
 }
 
+void Sema::EraseUnwantedCUDAMatches(const FunctionDecl *Caller,
+                                    LookupResult &R) {
+  if (R.isSingleResult())
+    return;
+
+  // Gets the CUDA function preference for a call from Caller to Match.
+  auto GetCFP = [&](const NamedDecl *D) {
+    if (auto *Callee = dyn_cast<FunctionDecl>(D->getUnderlyingDecl()))
+      return IdentifyCUDAPreference(Caller, Callee);
+    return CFP_Never;
+  };
+
+  // Find the best call preference among the functions in R.
+  CUDAFunctionPreference BestCFP = GetCFP(*std::max_element(
+      R.begin(), R.end(), [&](const NamedDecl *D1, const NamedDecl *D2) {
+        return GetCFP(D1) < GetCFP(D2);
+      }));
+
+  // Erase all functions with lower priority.
+  auto Filter = R.makeFilter();
+  while (Filter.hasNext()) {
+    auto *Callee = dyn_cast<FunctionDecl>(Filter.next()->getUnderlyingDecl());
+    if (Callee && GetCFP(Callee) < BestCFP)
+      Filter.erase();
+  }
+  Filter.done();
+}
+
 template <typename T>
 static void EraseUnwantedCUDAMatchesImpl(
     Sema &S, const FunctionDecl *Caller, llvm::SmallVectorImpl<T> &Matches,