From: Aaron Ballman <aaron@aaronballman.com>
Date: Thu, 31 Jul 2014 20:44:26 +0000 (+0000)
Subject: Implemented a diagnostic to handle multiple, distinct ownership_return attributes... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e3faa8fffecf47d58aee102668c46d7b70038e6e;p=clang

Implemented a diagnostic to handle multiple, distinct ownership_return attributes on the same declaration. This removes a FIXME from the code.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214436 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 87032b8a5c..24145317c9 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1949,6 +1949,10 @@ def err_attribute_invalid_implicit_this_argument : Error<
   "%0 attribute is invalid for the implicit this argument">;
 def err_ownership_type : Error<
   "%0 attribute only applies to %select{pointer|integer}1 arguments">;
+def err_ownership_returns_index_mismatch : Error<
+  "'ownership_returns' attribute index does not match; here it is %0">;
+def note_ownership_returns_index_mismatch : Note<
+  "declared with index %0 here">;
 def err_format_strftime_third_parameter : Error<
   "strftime format attribute requires 3rd parameter to be 0">;
 def err_format_attribute_requires_variadic : Error<
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index b7ca9924ef..ff4192e91d 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -1292,13 +1292,26 @@ static void handleOwnershipAttr(Sema &S, Decl *D, const AttributeList &AL) {
 
     // Check we don't have a conflict with another ownership attribute.
     for (const auto *I : D->specific_attrs<OwnershipAttr>()) {
-      // FIXME: A returns attribute should conflict with any returns attribute
-      // with a different index too.
+      // Cannot have two ownership attributes of different kinds for the same
+      // index.
       if (I->getOwnKind() != K && I->args_end() !=
           std::find(I->args_begin(), I->args_end(), Idx)) {
         S.Diag(AL.getLoc(), diag::err_attributes_are_not_compatible)
           << AL.getName() << I;
         return;
+      } else if (K == OwnershipAttr::Returns &&
+                 I->getOwnKind() == OwnershipAttr::Returns) {
+        // A returns attribute conflicts with any other returns attribute using
+        // a different index. Note, diagnostic reporting is 1-based, but stored
+        // argument indexes are 0-based.
+        if (std::find(I->args_begin(), I->args_end(), Idx) == I->args_end()) {
+          S.Diag(I->getLocation(), diag::err_ownership_returns_index_mismatch)
+              << *(I->args_begin()) + 1;
+          if (I->args_size())
+            S.Diag(AL.getLoc(), diag::note_ownership_returns_index_mismatch)
+                << (unsigned)Idx + 1 << Ex->getSourceRange();
+          return;
+        }
       }
     }
     OwnershipArgs.push_back(Idx);
diff --git a/test/Sema/attr-ownership.c b/test/Sema/attr-ownership.c
index 2aa9f9f27c..d2e48c65a2 100644
--- a/test/Sema/attr-ownership.c
+++ b/test/Sema/attr-ownership.c
@@ -17,3 +17,8 @@ void *f12(float i, int k, int f, int *j) __attribute__((ownership_returns(foo, 4
 
 void f13(int *i, int *j) __attribute__((ownership_holds(foo, 1))) __attribute__((ownership_takes(foo, 2)));
 void f14(int i, int j, int *k) __attribute__((ownership_holds(foo, 3))) __attribute__((ownership_takes(foo, 3)));  // expected-error {{'ownership_holds' and 'ownership_takes' attributes are not compatible}}
+
+void f15(int, int)
+  __attribute__((ownership_returns(foo, 1)))  // expected-note {{declared with index 1 here}}
+  __attribute__((ownership_returns(foo, 2))); // expected-error {{'ownership_returns' attribute index does not match; here it is 2}}
+void f16(int *i, int *j) __attribute__((ownership_holds(foo, 1))) __attribute__((ownership_holds(foo, 1))); // OK, same index