commit 24337db616668125b55781a82d7651800934ae4a
author Michael Liao <michael.hliao@gmail.com> Wed Sep 25 16:51:45 2019 +0000
committer Michael Liao <michael.hliao@gmail.com> Wed Sep 25 16:51:45 2019 +0000
tree 0c00504ba1b16f1cd4084e1c4965463532936424
parent 8535a8672e16a553f83eb2c21b1f9823d9293117

[CUDA][HIP] Enable kernel function return type deduction.

Summary:
- Even though only `void` is still accepted as the deduced return type,
  enabling deduction/instantiation on the return type allows more
  consistent coding.

Reviewers: tra, jlebar

Subscribers: cfe-commits, yaxunl

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68031

llvm-svn: 372898

clang/lib/Sema/SemaDeclAttr.cpp

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 242b81a..b69cb5d 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -4223,7 +4223,9 @@
     return;
   }
   const auto *FD = cast<FunctionDecl>(D);
-  if (!FD->getReturnType()->isVoidType()) {
+  if (!FD->getReturnType()->isVoidType() &&
+      !FD->getReturnType()->getAs<AutoType>() &&
+      !FD->getReturnType()->isInstantiationDependentType()) {
     SourceRange RTRange = FD->getReturnTypeSourceRange();
     S.Diag(FD->getTypeSpecStartLoc(), diag::err_kern_type_not_void_return)
         << FD->getType()

clang/lib/Sema/SemaExpr.cpp

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index a3808a9..4293ba1 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -5891,7 +5891,9 @@
             << FDecl << Fn->getSourceRange());
 
       // CUDA: Kernel function must have 'void' return type
-      if (!FuncT->getReturnType()->isVoidType())
+      if (!FuncT->getReturnType()->isVoidType() &&
+          !FuncT->getReturnType()->getAs<AutoType>() &&
+          !FuncT->getReturnType()->isInstantiationDependentType())
         return ExprError(Diag(LParenLoc, diag::err_kern_type_not_void_return)
             << Fn->getType() << Fn->getSourceRange());
     } else {

clang/lib/Sema/SemaStmt.cpp

diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index fdc85f2..bfdc550 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -3500,6 +3500,14 @@
       return true;
   }
 
+  // CUDA: Kernel function must have 'void' return type.
+  if (getLangOpts().CUDA)
+    if (FD->hasAttr<CUDAGlobalAttr>() && !Deduced->isVoidType()) {
+      Diag(FD->getLocation(), diag::err_kern_type_not_void_return)
+          << FD->getType() << FD->getSourceRange();
+      return true;
+    }
+
   //  If a function with a declared return type that contains a placeholder type
   //  has multiple return statements, the return type is deduced for each return
   //  statement. [...] if the type deduced is not the same in each deduction,

clang/lib/Sema/SemaTemplateDeduction.cpp

diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index db50830..8253858 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -3093,6 +3093,13 @@
                   Function->getTypeSpecStartLoc(), Function->getDeclName());
     if (ResultType.isNull() || Trap.hasErrorOccurred())
       return TDK_SubstitutionFailure;
+    // CUDA: Kernel function must have 'void' return type.
+    if (getLangOpts().CUDA)
+      if (Function->hasAttr<CUDAGlobalAttr>() && !ResultType->isVoidType()) {
+        Diag(Function->getLocation(), diag::err_kern_type_not_void_return)
+            << Function->getType() << Function->getSourceRange();
+        return TDK_SubstitutionFailure;
+      }
   }
 
   // Instantiate the types of each of the function parameters given the