[OPENMP] Enable c++ exceptions outside of the target constructs iff they are

enabled for the host.

If the compilation for the host enables C++ exceptions, but they are not
supported by the device, we still need to allow the code with the
exception handling constructs outside of the target regions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@331372 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/LangOptions.def

@@ -202,6 +202,7 @@ LANGOPT(OpenMPSimd        , 1, 0, "Use SIMD only OpenMP support.")
 LANGOPT(OpenMPUseTLS      , 1, 0, "Use TLS for threadprivates or runtime calls")
 LANGOPT(OpenMPIsDevice    , 1, 0, "Generate code only for OpenMP target device")
 LANGOPT(OpenMPCUDAMode    , 1, 0, "Generate code for OpenMP pragmas in SIMT/SPMD mode")
+LANGOPT(OpenMPHostCXXExceptions    , 1, 0, "C++ exceptions handling in the host code.")
 LANGOPT(RenderScript      , 1, 0, "RenderScript")
 
 LANGOPT(CUDAIsDevice      , 1, 0, "compiling for CUDA device")

lib/Frontend/CompilerInvocation.cpp

@@ -2586,6 +2586,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
 
   // Set the flag to prevent the implementation from emitting device exception
   // handling code for those requiring so.
+  Opts.OpenMPHostCXXExceptions = Opts.Exceptions && Opts.CXXExceptions;
   if (Opts.OpenMPIsDevice && T.isNVPTX()) {
     Opts.Exceptions = 0;
     Opts.CXXExceptions = 0;

lib/Sema/SemaExprCXX.cpp

@@ -695,7 +695,11 @@ ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
                                bool IsThrownVarInScope) {
   // Don't report an error if 'throw' is used in system headers.
   if (!getLangOpts().CXXExceptions &&
-      !getSourceManager().isInSystemHeader(OpLoc))
+      !getSourceManager().isInSystemHeader(OpLoc) &&
+      (!getLangOpts().OpenMPIsDevice ||
+       !getLangOpts().OpenMPHostCXXExceptions ||
+       isInOpenMPTargetExecutionDirective() ||
+       isInOpenMPDeclareTargetContext()))
     Diag(OpLoc, diag::err_exceptions_disabled) << "throw";
 
   // Exceptions aren't allowed in CUDA device code.

lib/Sema/SemaStmt.cpp

@@ -3942,7 +3942,11 @@ StmtResult Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
                                   ArrayRef<Stmt *> Handlers) {
   // Don't report an error if 'try' is used in system headers.
   if (!getLangOpts().CXXExceptions &&
-      !getSourceManager().isInSystemHeader(TryLoc))
+      !getSourceManager().isInSystemHeader(TryLoc) &&
+      (!getLangOpts().OpenMPIsDevice ||
+       !getLangOpts().OpenMPHostCXXExceptions ||
+       isInOpenMPTargetExecutionDirective() ||
+       isInOpenMPDeclareTargetContext()))
     Diag(TryLoc, diag::err_exceptions_disabled) << "try";
 
   // Exceptions aren't allowed in CUDA device code.

test/OpenMP/nvptx_target_exceptions_messages.cpp

@@ -0,0 +1,71 @@
+// RUN: %clang_cc1 -fopenmp -x c++ -triple powerpc64le-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm-bc %s -o %t-ppc-host.bc -fexceptions -fcxx-exceptions
+// RUN: %clang_cc1 -verify -fopenmp -x c++ -triple nvptx64-unknown-unknown -fopenmp-targets=nvptx64-nvidia-cuda -emit-llvm %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-ppc-host.bc -o - -fexceptions -fcxx-exceptions -ferror-limit 100
+
+#ifndef HEADER
+#define HEADER
+
+template <typename T>
+class TemplateClass {
+  T a;
+public:
+  TemplateClass() { throw 1;}
+  T f_method() const { return a; }
+};
+
+int foo();
+
+int baz1();
+
+int baz2();
+
+int baz4() { return 5; }
+
+template <typename T>
+T FA() {
+  TemplateClass<T> s;
+  return s.f_method();
+}
+
+#pragma omp declare target
+struct S {
+  int a;
+  S(int a) : a(a) { throw 1; } // expected-error {{cannot use 'throw' with exceptions disabled}}
+};
+
+int foo() { return 0; }
+int b = 15;
+int d;
+#pragma omp end declare target
+int c;
+
+int bar() { return 1 + foo() + bar() + baz1() + baz2(); }
+
+int maini1() {
+  int a;
+  static long aa = 32;
+  try {
+#pragma omp target map(tofrom \
+                       : a, b)
+  {
+    S s(a);
+    static long aaa = 23;
+    a = foo() + bar() + b + c + d + aa + aaa + FA<int>();
+    if (!a)
+      throw "Error"; // expected-error {{cannot use 'throw' with exceptions disabled}}
+  }
+  } catch(...) {
+  }
+  return baz4();
+}
+
+int baz3() { return 2 + baz2(); }
+int baz2() {
+#pragma omp target
+  try { // expected-error {{cannot use 'try' with exceptions disabled}}
+  ++c;
+  } catch (...) {
+  }
+  return 2 + baz3();
+}
+
+#endif // HEADER