[OpenCL][PR42031] Prevent deducing addr space in type alias.

[Anastasia]

Summary

Similar to typedefs we shouldn't deduce addr space in type alias.

[mantognini]

lib/Sema/SemaType.cpp

7355 ↗

(On Diff #201905)

I think this should also check for !IsPointee as it breaks the following example with error: cannot initialize a variable of type 'c_ptr' (aka 'c1 *') with an rvalue of type 'c1 *'.

struct c1 { int x; };
using c_ptr = c1*;

__kernel void test2() {
  c1 x = { 0 };
  c1* y = &x; // okay
  c_ptr z = &x; // fails
}

test/SemaOpenCLCXX/address-space-deduction.cl

1 ↗

(On Diff #201905)

I guess it's an oversight from previous reviews, but FileCheck is not called here.

5 ↗

(On Diff #201905)

The pattern should probably be:

//CHECK: |-VarDecl {{.*}} foo 'const __global int' constexpr cinit

(i.e. move the {{.*}} before foo).

10 ↗

(On Diff #201905)

This check fails for me because inline is "missing" between static and constexpr. Not sure if it makes sense for foo2 to be inline or not, but that's a different story.

[Anastasia]

• Exclude pointee from early return in addr space deduction
• Improved testing: added FileCheck and avoid testing unnecessary bits

[Anastasia]

@mantognini Good spot! Thanks!

[mantognini]

LGTM

cfe/trunk/lib/Sema/SemaType.cpp

static void deduceOpenCLImplicitAddrSpace(TypeProcessingState &State,
   if ( // Do not deduce addr space for function return type and function type,
        // otherwise it will fail some sema check.
       IsFuncReturnType || IsFuncType ||
       // Do not deduce addr space for member types of struct, except the pointee
       // type of a pointer member type or static data members.
       (D.getContext() == DeclaratorContext::MemberContext &&
        (!IsPointee &&
         D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static)) ||
+      // Do not deduce addr space of non-pointee in type alias because it
+      // doesn't define any object.
+      (D.getContext() == DeclaratorContext::AliasDeclContext && !IsPointee) ||
       // Do not deduce addr space for types used to define a typedef and the
       // typedef itself, except the pointee type of a pointer type which is used
       // to define the typedef.
       (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef &&
        !IsPointee) ||
       // Do not deduce addr space of the void type, e.g. in f(void), otherwise
       // it will fail some sema check.
       (T->isVoidType() && !IsPointee) ||

cfe/trunk/test/SemaOpenCLCXX/address-space-deduction.cl

-//RUN: %clang_cc1 %s -cl-std=c++ -pedantic -ast-dump -verify
+//RUN: %clang_cc1 %s -cl-std=c++ -pedantic -ast-dump -verify | FileCheck %s
 
 //expected-no-diagnostics
 
-//CHECK: |-VarDecl  foo {{.*}} 'const __global int' constexpr cinit
+//CHECK: |-VarDecl {{.*}} foo 'const __global int'
 constexpr int foo = 0;
 
 class c {
 public:
-  //CHECK: `-VarDecl {{.*}} foo2 'const __global int' static constexpr cinit
+  //CHECK: `-VarDecl {{.*}} foo2 'const __global int'
   static constexpr int foo2 = 0;
 };
+
+struct c1 {};
+
+// We only deduce addr space in type alias in pointer types.
+//CHECK: TypeAliasDecl {{.*}} alias_c1 'c1'
+using alias_c1 = c1;
+//CHECK: TypeAliasDecl {{.*}} alias_c1_ptr '__generic c1 *'
+using alias_c1_ptr = c1 *;
+
+struct c2 {
+  alias_c1 y;
+  alias_c1_ptr ptr = &y;
+};
+