[SYCLomatic] Support migration of thrust::null_type (#837)

Signed-off-by: chenwei.sun <[email protected]>

Author: tomflinda

clang/lib/DPCT/APINamesTemplateType.inc

@@ -171,3 +171,5 @@ TYPE_REWRITE_ENTRY(
 
 TYPE_REWRITE_ENTRY("thrust::identity",
                    TYPE_FACTORY(STR("oneapi::dpl::identity")))
+
+TYPE_REWRITE_ENTRY("thrust::null_type", TYPE_FACTORY(STR("dpct::null_type")))

clang/lib/DPCT/ThrustAPIMigration.cpp

@@ -297,7 +297,8 @@ void ThrustTypeRule::registerMatcher(ast_matchers::MatchFinder &MF) {
     return hasAnyName("thrust::greater_equal", "thrust::less_equal",
                       "thrust::logical_and", "thrust::bit_and",
                       "thrust::bit_or", "thrust::minimum", "thrust::bit_xor",
-                      "thrust::modulus", "thrust::greater", "thrust::identity");
+                      "thrust::modulus", "thrust::greater", "thrust::identity",
+                      "thrust::null_type");
   };
   MF.addMatcher(typeLoc(loc(hasCanonicalType(qualType(
                             hasDeclaration(namedDecl(ThrustTypeHasNames()))))))

clang/test/dpct/thrust-placeholders.cu

@@ -11,6 +11,7 @@
 #include <thrust/memory.h>
 #include <thrust/transform.h>
 #include <thrust/functional.h>
+#include <thrust/tuple.h>
 #include <cuda_runtime.h>
 
 // CHECK: // COMMENT_A
@@ -34,6 +35,11 @@ __global__ void kernel(float *src, float *dst) {
   auto tmp2 = _1 + logf(2.0) + thrust::placeholders::_2;
 }
 
+// CHECK: template <typename T1, typename T2 = dpct::null_type>
+// CHECK-NEXT:void print_tuple(const std::tuple<T1, T2> &t) {}
+template <typename T1, typename T2 = thrust::null_type>
+void print_tuple(const thrust::tuple<T1, T2> &t) {}
+
 int main() {
   float x[] = {1.0f, 2.0f, 3.0f, 4.0f};
   float y[] = {2.0f, 1.0f, 1.0f, 1.0f};