[PATCH] D25166: [CUDA] Mark device functions as nounwind.

[Justin Lebar via cfe-commits]

jlebar created this revision.
jlebar added a reviewer: tra.
jlebar added a subscriber: cfe-commits.

This prevents clang from emitting 'invoke's and catch statements.

Things previously mostly worked thanks to TryToMarkNoThrow() in
CodeGenFunction.  But this is not a proper IPO, and it doesn't properly
handle cases like mutual recursion.

Fixes bug 30593.


https://reviews.llvm.org/D25166

Files:
  clang/lib/Sema/SemaDecl.cpp
  clang/test/CodeGenCUDA/convergent.cu
  clang/test/CodeGenCUDA/device-var-init.cu
  clang/test/CodeGenCUDA/nothrow.cu


Index: clang/test/CodeGenCUDA/nothrow.cu
===================================================================
--- /dev/null
+++ clang/test/CodeGenCUDA/nothrow.cu
@@ -0,0 +1,29 @@
+// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -fcuda-is-device -triple nvptx-nvidia-cuda -emit-llvm \
+// RUN:   -disable-llvm-passes -o - %s | FileCheck -check-prefix DEVICE %s
+
+// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -triple x86_64-unknown-linux-gnu -emit-llvm \
+// RUN:   -disable-llvm-passes -o - %s | \
+// RUN:  FileCheck -check-prefix HOST %s
+
+#include "Inputs/cuda.h"
+
+__host__ __device__ void f();
+
+// HOST: define void @_Z7host_fnv() [[HOST_ATTR:#[0-9]+]]
+void host_fn() { f(); }
+
+// DEVICE: define void @_Z3foov() [[DEVICE_ATTR:#[0-9]+]]
+__device__ void foo() { f(); }
+
+// This is nounwind only on the device side.
+// CHECK: define void @_Z3foov() [[DEVICE_ATTR:#[0-9]+]]
+__host__ __device__ void bar() { f(); }
+
+// DEVICE: define void @_Z3bazv() [[DEVICE_ATTR:#[0-9]+]]
+__global__ void baz() { f(); }
+
+// DEVICE: attributes [[DEVICE_ATTR]] = {
+// DEVICE-SAME: nounwind
+// HOST: attributes [[HOST_ATTR]] = {
+// HOST-NOT: nounwind
+// HOST-SAME: }
Index: clang/test/CodeGenCUDA/device-var-init.cu
===================================================================
--- clang/test/CodeGenCUDA/device-var-init.cu
+++ clang/test/CodeGenCUDA/device-var-init.cu
@@ -182,9 +182,9 @@
   df(); // CHECK: call void @_Z2dfv()
 
   // Verify that we only call non-empty destructors
-  // CHECK-NEXT: call void @_ZN8T_FA_NEDD1Ev(%struct.T_FA_NED* %t_fa_ned) #6
-  // CHECK-NEXT: call void @_ZN7T_F_NEDD1Ev(%struct.T_F_NED* %t_f_ned) #6
-  // CHECK-NEXT: call void @_ZN7T_B_NEDD1Ev(%struct.T_B_NED* %t_b_ned) #6
+  // CHECK-NEXT: call void @_ZN8T_FA_NEDD1Ev(%struct.T_FA_NED* %t_fa_ned)
+  // CHECK-NEXT: call void @_ZN7T_F_NEDD1Ev(%struct.T_F_NED* %t_f_ned)
+  // CHECK-NEXT: call void @_ZN7T_B_NEDD1Ev(%struct.T_B_NED* %t_b_ned)
   // CHECK-NEXT: call void @_ZN2VDD1Ev(%struct.VD* %vd)
   // CHECK-NEXT: call void @_ZN3NEDD1Ev(%struct.NED* %ned)
   // CHECK-NEXT: call void @_ZN2UDD1Ev(%struct.UD* %ud)
Index: clang/test/CodeGenCUDA/convergent.cu
===================================================================
--- clang/test/CodeGenCUDA/convergent.cu
+++ clang/test/CodeGenCUDA/convergent.cu
@@ -36,8 +36,8 @@
 // DEVICE: attributes [[BAZ_ATTR]] = {
 // DEVICE-SAME: convergent
 // DEVICE-SAME: }
-// DEVICE: attributes [[CALL_ATTR]] = { convergent }
-// DEVICE: attributes [[ASM_ATTR]] = { convergent
+// DEVICE-DAG: attributes [[CALL_ATTR]] = { convergent
+// DEVICE-DAG: attributes [[ASM_ATTR]] = { convergent
 
 // HOST: declare void @_Z3bazv() [[BAZ_ATTR:#[0-9]+]]
 // HOST: attributes [[BAZ_ATTR]] = {
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -12074,6 +12074,14 @@
       FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
   }
 
+  // CUDA device functions cannot throw.
+  if (getLangOpts().CUDA && !FD->hasAttr<NoThrowAttr>()) {
+    CUDAFunctionTarget T = IdentifyCUDATarget(FD);
+    if (T == CFT_Device || T == CFT_Global ||
+        (getLangOpts().CUDAIsDevice && T == CFT_HostDevice))
+      FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
+  }
+
   IdentifierInfo *Name = FD->getIdentifier();
   if (!Name)
     return;


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