From: Sven van Haastregt <sven.vanhaastregt@arm.com>
Date: Thu, 20 Sep 2018 10:07:27 +0000 (+0000)
Subject: [OpenCL] Diagnose redundant address space conversion
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8141e9ffd63b4473556dce81f900c7eaff65ccc8;p=clang

[OpenCL] Diagnose redundant address space conversion

Add a warning if a parameter with a named address space is passed
to a to_addr builtin.

For example:

  int i;
  to_private(&i); // generate warning as conversion from private to private is redundant.

Patch by Alistair Davies.

Differential Revision: https://reviews.llvm.org/D51411


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@342638 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 5cb037ffc2..9aaa7657d4 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8613,6 +8613,10 @@ def err_opencl_variadic_function : Error<
   "invalid prototype, variadic arguments are not allowed in OpenCL">;
 def err_opencl_requires_extension : Error<
   "use of %select{type|declaration}0 %1 requires %2 extension to be enabled">;
+def warn_opencl_generic_address_space_arg : Warning<
+  "passing non-generic address space pointer to %0"
+  " may cause dynamic conversion affecting performance">,
+  InGroup<Conversion>, DefaultIgnore;
 
 // OpenCL v2.0 s6.13.6 -- Builtin Pipe Functions
 def err_opencl_builtin_pipe_first_arg : Error<
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index a1bfff4fb7..c46468f1c7 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -849,6 +849,13 @@ static bool SemaOpenCLBuiltinToAddr(Sema &S, unsigned BuiltinID,
     return true;
   }
 
+  if (RT->getPointeeType().getAddressSpace() != LangAS::opencl_generic) {
+    S.Diag(Call->getArg(0)->getBeginLoc(),
+           diag::warn_opencl_generic_address_space_arg)
+        << Call->getDirectCallee()->getNameInfo().getAsString()
+        << Call->getArg(0)->getSourceRange();
+  }
+
   RT = RT->getPointeeType();
   auto Qual = RT.getQualifiers();
   switch (BuiltinID) {
diff --git a/test/SemaOpenCL/to_addr_builtin.cl b/test/SemaOpenCL/to_addr_builtin.cl
index 70956f007a..9b95ff4e64 100644
--- a/test/SemaOpenCL/to_addr_builtin.cl
+++ b/test/SemaOpenCL/to_addr_builtin.cl
@@ -1,5 +1,5 @@
 // RUN: %clang_cc1 -verify -fsyntax-only %s
-// RUN: %clang_cc1 -verify -fsyntax-only -cl-std=CL2.0 %s
+// RUN: %clang_cc1 -Wconversion -verify -fsyntax-only -cl-std=CL2.0 %s
 
 void test(void) {
   global int *glob;
@@ -43,6 +43,7 @@ void test(void) {
   // expected-warning@-2{{incompatible integer to pointer conversion assigning to '__local int *' from 'int'}}
 #else
   // expected-error@-4{{assigning '__global int *' to '__local int *' changes address space of pointer}}
+  // expected-warning@-5{{passing non-generic address space pointer to to_global may cause dynamic conversion affecting performance}}
 #endif
 
   global char *glob_c = to_global(loc);
@@ -50,6 +51,7 @@ void test(void) {
   // expected-warning@-2{{incompatible integer to pointer conversion initializing '__global char *' with an expression of type 'int'}}
 #else
   // expected-warning@-4{{incompatible pointer types initializing '__global char *' with an expression of type '__global int *'}}
+  // expected-warning@-5{{passing non-generic address space pointer to to_global may cause dynamic conversion affecting performance}}
 #endif
 
 }