[Sema][RISCV][SVE] Allow ?: to select Typedef BuiltinType in C

[arcbbb]

Summary

This patch solves an error such as:

incompatible operand types ('vbool4_t' (aka '__rvv_bool4_t') and '__rvv_bool4_t')

when one of the value is a TypedefType of the other value in ?:.

[kito-cheng]

Testcase for AArch64/SVE:

#include <arm_sve.h>

svint8_t a();
__SVInt8_t b();

svint8_t foo(int cond){
  return cond ? a(): b();
}

[kito-cheng]

The testcase I provided in last comment could be compile successfully with aarch64-gcc, but failed on clang.

[rsandifo-arm]

Thanks for the fix. I agree this is the right behaviour FWIW. I held off approving it in case there's another idiom that's preferred when comparing canonical types.

[frasercrmck]

In D103603#2795899, @kito-cheng wrote:

Testcase for AArch64/SVE:

#include <arm_sve.h>

svint8_t a();
__SVInt8_t b();

svint8_t foo(int cond){
  return cond ? a(): b();
}

Could that AArch64 test also be part of this patch?

[jrtc27]

clang/lib/Sema/SemaExpr.cpp

8397

This is Context.hasSameType, and the braces are unnecessary.

[arcbbb]

Add a case in AArch64 test and address review comments.

[rjmccall]

LGTM

clang/lib/Sema/SemaExpr.cpp

if (checkPointerIntegerMismatch(*this, LHS, RHS.get(), QuestionLoc,
       /*IsIntFirstExpr=*/true))
     return RHSTy;
   if (checkPointerIntegerMismatch(*this, RHS, LHS.get(), QuestionLoc,
       /*IsIntFirstExpr=*/false))
     return LHSTy;
 
   // Allow ?: operations in which both operands have the same
   // built-in sizeless type.
-  if (LHSTy->isSizelessBuiltinType() && LHSTy == RHSTy)
+  if (LHSTy->isSizelessBuiltinType() &&
+      (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy))) {
     return LHSTy;
+  }
 
   // Emit a better diagnostic if one of the expressions is a null pointer
   // constant and the other is not a pointer type. In this case, the user most
   // likely forgot to take the address of the other expression.
   if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
     return QualType();
 
   // Otherwise, the operands are not compatible.

clang/test/Sema/riscv-types.c

void bar(void) {
   __rvv_int8mf8_t x41;
 
   // CHECK: __rvv_int8mf4_t x42;
   __rvv_int8mf4_t x42;
 
   // CHECK: __rvv_int8mf2_t x43;
   __rvv_int8mf2_t x43;
 }
+
+typedef __rvv_bool4_t vbool4_t;
+__rvv_bool4_t get_rvv_bool4();
+vbool4_t get_vbool4_t();
+
+void func1(int sel) {
+  // CHECK: vbool4_t t0 = sel ? get_rvv_bool4() : get_vbool4_t();
+  vbool4_t t0 = sel ? get_rvv_bool4() : get_vbool4_t();
+}