fix issue 6549 - Implement contracts without implementation

dlang · Dec 26, 2017 · c7d0672 · c7d0672
1 parent 5c76d45
commit c7d0672
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Showing 3 changed files with 63 additions and 21 deletions.
diff --git a/src/dmd/dsymbolsem.d b/src/dmd/dsymbolsem.d
@@ -1570,8 +1570,7 @@ extern(C++) final class Semantic3Visitor : Visitor
                 }
 
                 // If declaration has no body, don't set sbody to prevent incorrect codegen.
-                InterfaceDeclaration id = funcdecl.parent.isInterfaceDeclaration();
-                if (funcdecl.fbody || id && (funcdecl.fdensure || funcdecl.fdrequire) && funcdecl.isVirtual())
+                if (funcdecl.fbody || funcdecl.fdensure || funcdecl.fdrequire)
                     funcdecl.fbody = sbody;
             }
 
@@ -4409,11 +4408,6 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
                 funcdecl.error("destructors, postblits and invariants are not allowed in union %s", ud.toChars());
         }
 
-        /* Contracts can only appear without a body when they are virtual interface functions
-         */
-        if (!funcdecl.fbody && (funcdecl.fensure || funcdecl.frequire) && !(id && funcdecl.isVirtual()))
-            funcdecl.error("in and out contracts require function body");
-
         if (StructDeclaration sd = parent.isStructDeclaration())
         {
             if (funcdecl.isCtorDeclaration())
@@ -4786,6 +4780,17 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
         // Reflect this.type to f because it could be changed by findVtblIndex
         f = funcdecl.type.toTypeFunction();
 
+        /* Contracts can only appear without a body when they are virtual interface functions or abstract
+         */
+        if (!funcdecl.fbody && !funcdecl.isAbstract() &&
+            (funcdecl.fensure || funcdecl.frequire) &&
+            !(id && funcdecl.isVirtual()))
+        {
+            auto cd = parent.isClassDeclaration();
+            if (!(cd && cd.isAbstract()))
+                funcdecl.error("in and out contracts on non-virtual/non-abstract functions require function body");
+        }
+
         /* Do not allow template instances to add virtual functions
          * to a class.
          */

diff --git a/test/fail_compilation/fail12901.d b/test/fail_compilation/fail12901.d
diff --git a/test/runnable/testcontracts.d b/test/runnable/testcontracts.d
@@ -421,6 +421,56 @@ void test6417()
     (new Bug6417).bar();
 }
 
+/*******************************************/
+// 6549
+
+class C6549
+{
+    static int ocount = 0;
+    static int icount = 0;
+
+    abstract int foo(int)
+    in { ++icount; }
+    out { ++ocount; }
+}
+
+class CD6549 : C6549
+{
+    override int foo(int)
+    in { assert(false); }
+    do { return 10; }
+}
+
+abstract class D6549
+{
+    static int icount = 0;
+    static int ocount = 0;
+
+    int foo(int)
+    in { ++icount; }
+    out { ++ocount; }
+}
+
+class DD6549 : D6549
+{
+    override int foo(int)
+    in { assert(false); }
+    do { return 10; }
+}
+
+void test6549()
+{
+    auto c = new CD6549;
+    c.foo(10);
+    assert(C6549.icount == 1);
+    assert(C6549.ocount == 1);
+
+    auto d = new DD6549;
+    d.foo(10);
+    assert(D6549.icount == 1);
+    assert(D6549.ocount == 1);
+}
+
 /*******************************************/
 // 7218
 
@@ -1043,6 +1093,7 @@ int main()
     test9();
     test4785();
     test6417();
+    test6549();
     test7218();
     test7517();
     test8073();