From: Leonard Chan <leonardchan@google.com>
Date: Tue, 7 Aug 2018 19:43:53 +0000 (+0000)
Subject: [Sema] Fix for crash on conditional operation with address_space pointer
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a6a78706b0c7af354cfb8be5a9aeb410ef2ab67e;p=clang

[Sema] Fix for crash on conditional operation with address_space pointer

Compiling the following causes clang to crash

```
char *cmp(__attribute__((address_space(1))) char *x, __attribute__((address_space(2))) char *y) {
  return x < y ? x : y;
}
```

with the message: "wrong cast for pointers in different address
spaces(must be an address space cast)!"

This is because during IR emission, the source and dest type for a
bitcast should not have differing address spaces.

This fix prints an error since the code shouldn't compile in the first place.

Differential Revision: https://reviews.llvm.org/D50278

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@339167 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 6b4507f7c9..ce0d32b25e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -6460,20 +6460,18 @@ static QualType checkConditionalPointerCompatibility(Sema &S, ExprResult &LHS,
   LangAS ResultAddrSpace = LangAS::Default;
   LangAS LAddrSpace = lhQual.getAddressSpace();
   LangAS RAddrSpace = rhQual.getAddressSpace();
-  if (S.getLangOpts().OpenCL) {
-    // OpenCL v1.1 s6.5 - Conversion between pointers to distinct address
-    // spaces is disallowed.
-    if (lhQual.isAddressSpaceSupersetOf(rhQual))
-      ResultAddrSpace = LAddrSpace;
-    else if (rhQual.isAddressSpaceSupersetOf(lhQual))
-      ResultAddrSpace = RAddrSpace;
-    else {
-      S.Diag(Loc,
-             diag::err_typecheck_op_on_nonoverlapping_address_space_pointers)
-          << LHSTy << RHSTy << 2 << LHS.get()->getSourceRange()
-          << RHS.get()->getSourceRange();
-      return QualType();
-    }
+
+  // OpenCL v1.1 s6.5 - Conversion between pointers to distinct address
+  // spaces is disallowed.
+  if (lhQual.isAddressSpaceSupersetOf(rhQual))
+    ResultAddrSpace = LAddrSpace;
+  else if (rhQual.isAddressSpaceSupersetOf(lhQual))
+    ResultAddrSpace = RAddrSpace;
+  else {
+    S.Diag(Loc, diag::err_typecheck_op_on_nonoverlapping_address_space_pointers)
+        << LHSTy << RHSTy << 2 << LHS.get()->getSourceRange()
+        << RHS.get()->getSourceRange();
+    return QualType();
   }
 
   unsigned MergedCVRQual = lhQual.getCVRQualifiers() | rhQual.getCVRQualifiers();
@@ -6491,16 +6489,12 @@ static QualType checkConditionalPointerCompatibility(Sema &S, ExprResult &LHS,
   // Thus for conditional operator we merge CVR and address space unqualified
   // pointees and if there is a composite type we return a pointer to it with
   // merged qualifiers.
-  if (S.getLangOpts().OpenCL) {
-    LHSCastKind = LAddrSpace == ResultAddrSpace
-                      ? CK_BitCast
-                      : CK_AddressSpaceConversion;
-    RHSCastKind = RAddrSpace == ResultAddrSpace
-                      ? CK_BitCast
-                      : CK_AddressSpaceConversion;
-    lhQual.removeAddressSpace();
-    rhQual.removeAddressSpace();
-  }
+  LHSCastKind =
+      LAddrSpace == ResultAddrSpace ? CK_BitCast : CK_AddressSpaceConversion;
+  RHSCastKind =
+      RAddrSpace == ResultAddrSpace ? CK_BitCast : CK_AddressSpaceConversion;
+  lhQual.removeAddressSpace();
+  rhQual.removeAddressSpace();
 
   lhptee = S.Context.getQualifiedType(lhptee.getUnqualifiedType(), lhQual);
   rhptee = S.Context.getQualifiedType(rhptee.getUnqualifiedType(), rhQual);
@@ -6516,6 +6510,7 @@ static QualType checkConditionalPointerCompatibility(Sema &S, ExprResult &LHS,
         S.Context.getAddrSpaceQualType(S.Context.VoidTy, ResultAddrSpace));
     LHS = S.ImpCastExprToType(LHS.get(), incompatTy, LHSCastKind);
     RHS = S.ImpCastExprToType(RHS.get(), incompatTy, RHSCastKind);
+
     // FIXME: For OpenCL the warning emission and cast to void* leaves a room
     // for casts between types with incompatible address space qualifiers.
     // For the following code the compiler produces casts between global and
@@ -6526,6 +6521,7 @@ static QualType checkConditionalPointerCompatibility(Sema &S, ExprResult &LHS,
     S.Diag(Loc, diag::ext_typecheck_cond_incompatible_pointers)
         << LHSTy << RHSTy << LHS.get()->getSourceRange()
         << RHS.get()->getSourceRange();
+
     return incompatTy;
   }
 
diff --git a/test/Sema/address_spaces.c b/test/Sema/address_spaces.c
index 87707d7deb..9f555a870e 100644
--- a/test/Sema/address_spaces.c
+++ b/test/Sema/address_spaces.c
@@ -71,5 +71,5 @@ __attribute__((address_space("12"))) int *i; // expected-error {{'address_space'
 
 // Clang extension doesn't forbid operations on pointers to different address spaces.
 char* cmp(_AS1 char *x,  _AS2 char *y) {
-  return x < y ? x : y; // expected-warning {{pointer type mismatch ('__attribute__((address_space(1))) char *' and '__attribute__((address_space(2))) char *')}}
+  return x < y ? x : y; // expected-error{{conditional operator with the second and third operands of type  ('__attribute__((address_space(1))) char *' and '__attribute__((address_space(2))) char *') which are pointers to non-overlapping address spaces}}
 }
diff --git a/test/Sema/conditional-expr.c b/test/Sema/conditional-expr.c
index 5ff58a2ec4..6b24ef49b3 100644
--- a/test/Sema/conditional-expr.c
+++ b/test/Sema/conditional-expr.c
@@ -73,10 +73,10 @@ void foo() {
 
   int __attribute__((address_space(2))) *adr2;
   int __attribute__((address_space(3))) *adr3;
-  test0 ? adr2 : adr3; // expected-warning {{pointer type mismatch}} expected-warning {{expression result unused}}
+  test0 ? adr2 : adr3; // expected-error{{conditional operator with the second and third operands of type  ('__attribute__((address_space(2))) int *' and '__attribute__((address_space(3))) int *') which are pointers to non-overlapping address spaces}}
 
   // Make sure address-space mask ends up in the result type
-  (test0 ? (test0 ? adr2 : adr2) : nonconst_int); // expected-warning {{pointer type mismatch}} expected-warning {{expression result unused}}
+  (test0 ? (test0 ? adr2 : adr2) : nonconst_int); // expected-error{{conditional operator with the second and third operands of type  ('__attribute__((address_space(2))) int *' and 'int *') which are pointers to non-overlapping address spaces}}
 }
 
 int Postgresql() {