From 0fad0ba6a9b0e4900a6e247831c83f665bde2a6b Mon Sep 17 00:00:00 2001
From: Justin Lebar <jlebar@google.com>
Date: Fri, 30 Sep 2016 17:14:48 +0000
Subject: [PATCH] [CUDA] Handle attributes on CUDA lambdas appearing between
 [...] and (...).

Summary: This is ugh, but it makes us compatible with NVCC.  Fixes bug 26341.

Reviewers: rnk

Subscribers: cfe-commits, tra

Differential Revision: https://reviews.llvm.org/D25103

llvm-svn: 282879
---
 clang/lib/Parse/ParseExprCXX.cpp | 19 ++++++++++++-------
 clang/test/Parser/lambda-attr.cu | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 7 deletions(-)
 create mode 100644 clang/test/Parser/lambda-attr.cu

diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 35661d5..2287e07 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -1124,7 +1124,17 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
   DeclSpec DS(AttrFactory);
   Declarator D(DS, Declarator::LambdaExprContext);
   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
-  Actions.PushLambdaScope();    
+  Actions.PushLambdaScope();
+
+  ParsedAttributes Attr(AttrFactory);
+  SourceLocation DeclLoc = Tok.getLocation();
+  SourceLocation DeclEndLoc = DeclLoc;
+  if (getLangOpts().CUDA) {
+    // In CUDA code, GNU attributes are allowed to appear immediately after the
+    // "[...]", even if there is no "(...)" before the lambda body.
+    MaybeParseGNUAttributes(Attr, &DeclEndLoc);
+    D.takeAttributes(Attr, DeclEndLoc);
+  }
 
   TypeResult TrailingReturnType;
   if (Tok.is(tok::l_paren)) {
@@ -1133,13 +1143,11 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
                               Scope::FunctionDeclarationScope |
                               Scope::DeclScope);
 
-    SourceLocation DeclEndLoc;
     BalancedDelimiterTracker T(*this, tok::l_paren);
     T.consumeOpen();
     SourceLocation LParenLoc = T.getOpenLocation();
 
     // Parse parameter-declaration-clause.
-    ParsedAttributes Attr(AttrFactory);
     SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
     SourceLocation EllipsisLoc;
     
@@ -1245,12 +1253,10 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
     Diag(Tok, diag::err_lambda_missing_parens)
       << TokKind
       << FixItHint::CreateInsertion(Tok.getLocation(), "() ");
-    SourceLocation DeclLoc = Tok.getLocation();
-    SourceLocation DeclEndLoc = DeclLoc;
+    DeclEndLoc = DeclLoc;
 
     // GNU-style attributes must be parsed before the mutable specifier to be
     // compatible with GCC.
-    ParsedAttributes Attr(AttrFactory);
     MaybeParseGNUAttributes(Attr, &DeclEndLoc);
 
     // Parse 'mutable', if it's there.
@@ -1297,7 +1303,6 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
                                                TrailingReturnType),
                   Attr, DeclEndLoc);
   }
-  
 
   // FIXME: Rename BlockScope -> ClosureScope if we decide to continue using
   // it.
diff --git a/clang/test/Parser/lambda-attr.cu b/clang/test/Parser/lambda-attr.cu
new file mode 100644
index 0000000..c51e0a2
--- /dev/null
+++ b/clang/test/Parser/lambda-attr.cu
@@ -0,0 +1,33 @@
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -fcuda-is-device -verify %s
+
+// expected-no-diagnostics
+
+__attribute__((device)) void device_fn() {}
+__attribute__((device)) void hd_fn() {}
+
+__attribute__((device)) void device_attr() {
+  ([]() __attribute__((device)) { device_fn(); })();
+  ([] __attribute__((device)) () { device_fn(); })();
+  ([] __attribute__((device)) { device_fn(); })();
+
+  ([&]() __attribute__((device)){ device_fn(); })();
+  ([&] __attribute__((device)) () { device_fn(); })();
+  ([&] __attribute__((device)) { device_fn(); })();
+
+  ([&](int) __attribute__((device)){ device_fn(); })(0);
+  ([&] __attribute__((device)) (int) { device_fn(); })(0);
+}
+
+__attribute__((host)) __attribute__((device)) void host_device_attrs() {
+  ([]() __attribute__((host)) __attribute__((device)){ hd_fn(); })();
+  ([] __attribute__((host)) __attribute__((device)) () { hd_fn(); })();
+  ([] __attribute__((host)) __attribute__((device)) { hd_fn(); })();
+
+  ([&]() __attribute__((host)) __attribute__((device)){ hd_fn(); })();
+  ([&] __attribute__((host)) __attribute__((device)) () { hd_fn(); })();
+  ([&] __attribute__((host)) __attribute__((device)) { hd_fn(); })();
+
+  ([&](int) __attribute__((host)) __attribute__((device)){ hd_fn(); })(0);
+  ([&] __attribute__((host)) __attribute__((device)) (int) { hd_fn(); })(0);
+}
-- 
2.7.4