Allow caffe2 to detect if cuda lib has been linked, and also fix oss build error.

Summary: Closes https://github.com/caffe2/caffe2/pull/1114

Reviewed By: pietern

Differential Revision: D5686557

Pulled By: Yangqing

fbshipit-source-id: 6b7245ebbe4eeb025ce9d0fe8fda427a0c3d9770

caffe2/core/common.cc

@@ -0,0 +1,5 @@
+#include "caffe2/core/common.h"
+
+namespace caffe2 {
+bool g_caffe2_has_cuda_linked = false;
+} // namespace caffe2

caffe2/core/common.h

@@ -208,6 +208,19 @@ class SkipIndices<> {
   }
 };
 
+// A global variable to mark if Caffe2 has cuda linked to the current runtime.
+// Do not directly use this variable, but instead use the HasCudaRuntime()
+// function below.
+extern bool g_caffe2_has_cuda_linked;
+
+// HasCudaRuntime() tells the program whether the binary has Cuda runtime
+// linked. This function should not be used in static initialization functions
+// as the underlying boolean variable is going to be switched on when one
+// loads libcaffe2_gpu.so.
+inline bool HasCudaRuntime() {
+  return g_caffe2_has_cuda_linked;
+}
+
 }  // namespace caffe2
 
 #endif  // CAFFE2_CORE_COMMON_H_

caffe2/core/common_gpu.cc

@@ -268,4 +268,18 @@ const char* curandGetErrorString(curandStatus_t error) {
   // To suppress compiler warning.
   return "Unrecognized curand error string";
 }
+
+// Turn on the flag g_caffe2_has_cuda_linked to true for HasCudaRuntime()
+// function.
+extern bool g_caffe2_has_cuda_linked;
+namespace {
+class CudaRuntimeFlagFlipper {
+ public:
+  CudaRuntimeFlagFlipper() {
+    g_caffe2_has_cuda_linked = true;
+  }
+};
+static CudaRuntimeFlagFlipper g_flipper;
+} // namespace
+
 }  // namespace caffe2

caffe2/core/common_gpu.h

@@ -90,6 +90,11 @@ int NumCudaDevices();
  * cuda gpus present in the machine, or there are hardware configuration
  * problems like an insufficient driver, this function will still return false,
  * meaning that there is no usable GPU present.
+ *
+ * In the open source build, it is possible that Caffe2's GPU code is
+ * dynamically loaded, and as a result a library could be only linked to the
+ * CPU code, but want to test if cuda is later available or not. In this case,
+ * one should use HasCudaRuntime() from common.h.
  */
 inline bool HasCudaGPU() { return NumCudaDevices() > 0; }
 

caffe2/core/context_gpu_test.cc

@@ -16,6 +16,10 @@ std::shared_ptr<void> shared_from_new(std::pair<void*, MemoryDeleter>&& p) {
 }
 }
 
+TEST(CUDATest, HasCudaRuntime) {
+  EXPECT_TRUE(HasCudaRuntime());
+}
+
 TEST(CUDAContextTest, TestAllocDealloc) {
   if (!HasCudaGPU()) return;
   CUDAContext context(0);

caffe2/core/net_test.cc

@@ -233,7 +233,9 @@ TEST(NetTest, ChainingForDifferentDevices) {
           }
         }
 )DOC";
-  checkChainingAndRun(spec, {{0, {0}}, {1, {1, 2}}, {3, {3}}});
+  if (HasCudaRuntime()) {
+    checkChainingAndRun(spec, {{0, {0}}, {1, {1, 2}}, {3, {3}}});
+  }
 }
 
 TEST(NetTest, ChainingForFork) {

caffe2/core/operator_test.cc

@@ -90,9 +90,14 @@ TEST(OperatorTest, RegistryWorks) {
   op_def.set_type("JustTest");
   unique_ptr<OperatorBase> op = CreateOperator(op_def, &ws);
   EXPECT_NE(nullptr, op.get());
-  op_def.mutable_device_option()->set_device_type(CUDA);
-  op = CreateOperator(op_def, &ws);
-  EXPECT_NE(nullptr, op.get());
+  // After introducing events, CUDA operator creation has to have CUDA compiled
+  // as it needs to instantiate an Event object with CUDAContext. Thus we will
+  // guard this test below.
+  if (HasCudaRuntime()) {
+    op_def.mutable_device_option()->set_device_type(CUDA);
+    op = CreateOperator(op_def, &ws);
+    EXPECT_NE(nullptr, op.get());
+  }
 }
 
 TEST(OperatorTest, RegistryWrongDevice) {

caffe2/operators/sinusoid_position_encoding_op.h

@@ -1,6 +1,11 @@
 #ifndef CAFFE2_OPERATORS_SINUSOID_POSITION_ENCODING_OP_H_
 #define CAFFE2_OPERATORS_SINUSOID_POSITION_ENCODING_OP_H_
 
+#ifdef _MSC_VER
+#define _USE_MATH_DEFINES
+#endif // _MSC_VER
+#include <cmath>
+
 #include "caffe2/core/operator.h"
 
 #include "Eigen/Core"

cmake/MiscCheck.cmake

@@ -94,3 +94,9 @@ endif()
 if (IOS)
   add_definitions("-mfpu=neon-fp16")
 endif()
+
+# ---[ If we are buidling on ios, we should turn off deprecated-declarations
+# due to protobuf.
+if (IOS)
+  add_definitions("-Wno-deprecated-declarations")
+endif()

scripts/build_ios.sh

@@ -35,6 +35,7 @@ cmake .. \
     -DCMAKE_BUILD_TYPE=Release \
     -DIOS_PLATFORM=${IOS_PLATFORM} \
     -DUSE_CUDA=OFF \
+    -DUSE_OPENCV=OFF \
     -DBUILD_TEST=OFF \
     -DBUILD_BINARY=OFF \
     -DCMAKE_C_FLAGS=-fembed-bitcode \