[SYCL] Start fully-qualifying our inline kernel names in forward declarations.

Erich Keane · Erich Keane · commit b986c304bd91 · 2021-07-29T16:35:06.000-07:00
This has the ability to make a number easy-to-make mistakes no longer
issues when using named kernels.  This causes us to differentiate the
inline-named kernels when they are in different namespaces, which will
hopefully make running into duplicate-kernel-name issues more difficult.
diff --git a/clang/lib/Sema/SemaSYCL.cpp b/clang/lib/Sema/SemaSYCL.cpp
@@ -4383,17 +4383,32 @@ class SYCLFwdDeclEmitter
     const DeclContext *DC = D->getDeclContext();
 
     while (DC) {
-      const auto *NS = dyn_cast_or_null<NamespaceDecl>(DC);
-
-      if (!NS)
-        break;
-
-      ++NamespaceCnt;
-      const StringRef NSInlinePrefix = NS->isInline() ? "inline " : "";
-      NSStr.insert(
-          0,
-          Twine(NSInlinePrefix + "namespace " + NS->getName() + " { ").str());
-      DC = NS->getDeclContext();
+      if (const auto *NS = dyn_cast<NamespaceDecl>(DC)) {
+        ++NamespaceCnt;
+        const StringRef NSInlinePrefix = NS->isInline() ? "inline " : "";
+        NSStr.insert(
+            0,
+            Twine(NSInlinePrefix + "namespace " + NS->getName() + " { ").str());
+        DC = NS->getDeclContext();
+      } else {
+        // We should be able to handle a subset of the decl-context types to
+        // make our namespaces for forward declarations as specific as possible,
+        // so just skip them here.  We can't use their names, since they would
+        // not be forward declarable, but we can try to make them as specific as
+        // possible.
+        // This permits things such as:
+        // namespace N1 { void foo() { kernel<class K>(...); }}
+        // and
+        // namespace N2 { void foo() { kernel<class K>(...); }}
+        // to co-exist, despite technically being against the SYCL rules.
+        // See SYCLKernelNameTypePrinter for the corresponding part that prints
+        // the kernel information for this type. These two must match.
+        if (isa<FunctionDecl, RecordDecl, LinkageSpecDecl>(DC)) {
+          DC = cast<Decl>(DC)->getDeclContext();
+        } else {
+          break;
+        }
+      }
     }
     OS << NSStr;
     if (NamespaceCnt > 0)
@@ -4568,6 +4583,19 @@ class SYCLKernelNameTypePrinter
     Quals.print(OS, Policy, /*appendSpaceIfNotEmpty*/ true);
   }
 
+  // Use recursion to print the namespace-qualified name for the purposes of the
+  // canonical sycl example of a type being created in the kernel call.
+  void PrintNamespaceScopes(const DeclContext *DC) {
+    if (isa<NamespaceDecl, FunctionDecl, RecordDecl, LinkageSpecDecl>(DC)) {
+      const auto *D = cast<Decl>(DC);
+      PrintNamespaceScopes(D->getDeclContext());
+
+      const auto *NS = dyn_cast<NamespaceDecl>(DC);
+      if (NS && !NS->isAnonymousNamespace())
+        OS << NS->getName() << "::";
+    }
+  }
+
 public:
   SYCLKernelNameTypePrinter(raw_ostream &OS, PrintingPolicy &Policy)
       : OS(OS), Policy(Policy) {}
@@ -4606,12 +4634,16 @@ class SYCLKernelNameTypePrinter
 
       return;
     }
-    // TODO: Next part of code results in printing of "class" keyword before
-    // class name in case if kernel name doesn't belong to some namespace. It
-    // seems if we don't print it, the integration header still represents valid
-    // c++ code. Probably we don't need to print it at all.
-    if (RD->getDeclContext()->isFunctionOrMethod()) {
-      OS << QualType::getAsString(T, Qualifiers(), Policy);
+
+    // Handle the canonical sycl example where the type is created for the first
+    // time in the kernel naming. We want to qualify this as fully as we can,
+    // but not in a way that won't be forward declarable.  See
+    // SYCLFwdDeclEmitter::printForwardDecl for the corresponding list for
+    // printing the forward declaration, these two must match.
+    DeclContext *DC = RD->getDeclContext();
+    if (isa<FunctionDecl, RecordDecl, LinkageSpecDecl>(DC)) {
+      PrintNamespaceScopes(DC);
+      RD->printName(OS);
       return;
     }
 
diff --git a/clang/test/CodeGenSYCL/int_header1.cpp b/clang/test/CodeGenSYCL/int_header1.cpp
@@ -15,7 +15,7 @@
 // CHECK-NEXT:struct IsThisValid;
 // CHECK-NEXT:}}
 
-// CHECK:template <> struct KernelInfo<class KernelName> {
+// CHECK:template <> struct KernelInfo<KernelName> {
 // CHECK:template <> struct KernelInfo<::nm1::nm2::KernelName0> {
 // CHECK:template <> struct KernelInfo<::nm1::KernelName1> {
 // CHECK:template <> struct KernelInfo<::nm1::KernelName3<::nm1::nm2::KernelName0>> {
diff --git a/clang/test/CodeGenSYCL/int_header_esimd.cpp b/clang/test/CodeGenSYCL/int_header_esimd.cpp
@@ -19,7 +19,7 @@ void testA() {
     h.single_task<class KernelA>([=]() __attribute__((sycl_explicit_simd)){});
   });
 }
-// CHECK-LABEL: template <> struct KernelInfo<class KernelA> {
+// CHECK-LABEL: template <> struct KernelInfo<KernelA> {
 // CHECK:   static constexpr bool isESIMD() { return 1; }
 
 // --  ESIMD Functor object kernel.
@@ -46,7 +46,7 @@ void testNA() {
     h.single_task<class KernelNA>([=]() {});
   });
 }
-// CHECK-LABEL: template <> struct KernelInfo<class KernelNA> {
+// CHECK-LABEL: template <> struct KernelInfo<KernelNA> {
 // CHECK:   static constexpr bool isESIMD() { return 0; }
 
 // --  Non-ESIMD Functor object kernel.
diff --git a/clang/test/CodeGenSYCL/integration_header.cpp b/clang/test/CodeGenSYCL/integration_header.cpp
@@ -50,7 +50,7 @@
 // CHECK-EMPTY:
 // CHECK-NEXT: };
 //
-// CHECK: template <> struct KernelInfo<class first_kernel> {
+// CHECK: template <> struct KernelInfo<first_kernel> {
 // CHECK: template <> struct KernelInfo<::second_namespace::second_kernel<char>> {
 // CHECK: template <> struct KernelInfo<::fourth_kernel<::template_arg_ns::namespaced_arg<1>>> {
 
diff --git a/clang/test/CodeGenSYCL/kernel-param-acc-array-ih.cpp b/clang/test/CodeGenSYCL/kernel-param-acc-array-ih.cpp
@@ -25,7 +25,7 @@
 // CHECK-EMPTY:
 // CHECK-NEXT: };
 
-// CHECK: template <> struct KernelInfo<class kernel_A> {
+// CHECK: template <> struct KernelInfo<kernel_A> {
 
 #include "Inputs/sycl.hpp"
 
diff --git a/clang/test/CodeGenSYCL/kernel-param-member-acc-array-ih.cpp b/clang/test/CodeGenSYCL/kernel-param-member-acc-array-ih.cpp
@@ -25,7 +25,7 @@
 // CHECK-EMPTY:
 // CHECK-NEXT: };
 
-// CHECK: template <> struct KernelInfo<class kernel_C> {
+// CHECK: template <> struct KernelInfo<kernel_C> {
 
 #include "Inputs/sycl.hpp"
 
diff --git a/clang/test/CodeGenSYCL/kernel-param-pod-array-ih.cpp b/clang/test/CodeGenSYCL/kernel-param-pod-array-ih.cpp
@@ -31,9 +31,9 @@
 // CHECK-EMPTY:
 // CHECK-NEXT: };
 
-// CHECK: template <> struct KernelInfo<class kernel_B> {
-// CHECK: template <> struct KernelInfo<class kernel_C> {
-// CHECK: template <> struct KernelInfo<class kernel_D> {
+// CHECK: template <> struct KernelInfo<kernel_B> {
+// CHECK: template <> struct KernelInfo<kernel_C> {
+// CHECK: template <> struct KernelInfo<kernel_D> {
 
 #include "Inputs/sycl.hpp"
 
diff --git a/clang/test/CodeGenSYCL/parallel_for_this_item.cpp b/clang/test/CodeGenSYCL/parallel_for_this_item.cpp
@@ -18,7 +18,7 @@
 // CHECK-NEXT:   "_ZTSZZ4mainENKUlRN2cl4sycl7handlerEE_clES2_E3BEE"
 // CHECK-NEXT: };
 
-// CHECK:template <> struct KernelInfo<class GNU> {
+// CHECK:template <> struct KernelInfo<GNU> {
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr const char* getName() { return "_ZTSZZ4mainENKUlRN2cl4sycl7handlerEE_clES2_E3GNU"; }
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
@@ -34,7 +34,7 @@
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:  static constexpr bool callsAnyThisFreeFunction() { return 0; }
 // CHECK-NEXT:};
-// CHECK-NEXT:template <> struct KernelInfo<class EMU> {
+// CHECK-NEXT:template <> struct KernelInfo<EMU> {
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr const char* getName() { return "_ZTSZZ4mainENKUlRN2cl4sycl7handlerEE_clES2_E3EMU"; }
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
@@ -50,7 +50,7 @@
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr bool callsAnyThisFreeFunction() { return 1; }
 // CHECK-NEXT:};
-// CHECK-NEXT:template <> struct KernelInfo<class OWL> {
+// CHECK-NEXT:template <> struct KernelInfo<OWL> {
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr const char* getName() { return "_ZTSZZ4mainENKUlRN2cl4sycl7handlerEE_clES2_E3OWL"; }
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
@@ -66,7 +66,7 @@
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr bool callsAnyThisFreeFunction() { return 0; }
 // CHECK-NEXT:};
-// CHECK-NEXT:template <> struct KernelInfo<class RAT> {
+// CHECK-NEXT:template <> struct KernelInfo<RAT> {
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr const char* getName() { return "_ZTSZZ4mainENKUlRN2cl4sycl7handlerEE_clES2_E3RAT"; }
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
@@ -82,7 +82,7 @@
 // CHECK-NEXT: __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr bool callsAnyThisFreeFunction() { return 1; }
 // CHECK-NEXT:};
-// CHECK-NEXT:template <> struct KernelInfo<class FOX> {
+// CHECK-NEXT:template <> struct KernelInfo<FOX> {
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr const char* getName() { return "_ZTSZZ4mainENKUlRN2cl4sycl7handlerEE_clES2_E3FOX"; }
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
@@ -98,7 +98,7 @@
 // CHECK-NEXT: __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr bool callsAnyThisFreeFunction() { return 1; }
 // CHECK-NEXT:};
-// CHECK-NEXT:template <> struct KernelInfo<class BEE> {
+// CHECK-NEXT:template <> struct KernelInfo<BEE> {
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
 // CHECK-NEXT:    static constexpr const char* getName() { return "_ZTSZZ4mainENKUlRN2cl4sycl7handlerEE_clES2_E3BEE"; }
 // CHECK-NEXT:  __SYCL_DLL_LOCAL
diff --git a/clang/test/CodeGenSYCL/union-kernel-param-ih.cpp b/clang/test/CodeGenSYCL/union-kernel-param-ih.cpp
@@ -24,7 +24,7 @@
 // CHECK-EMPTY:
 // CHECK-NEXT:};
 
-// CHECK: template <> struct KernelInfo<class kernel_A> {
+// CHECK: template <> struct KernelInfo<kernel_A> {
 
 union MyUnion {
   int FldInt;
diff --git a/clang/test/CodeGenSYCL/wrapped-accessor.cpp b/clang/test/CodeGenSYCL/wrapped-accessor.cpp
@@ -21,7 +21,7 @@
 // CHECK-EMPTY:
 // CHECK-NEXT: };
 
-// CHECK: template <> struct KernelInfo<class wrapped_access> {
+// CHECK: template <> struct KernelInfo<wrapped_access> {
 
 #include "Inputs/sycl.hpp"
 
