Re-fix Issue 12901 in/out contracts on struct constructor must requir…

…e function body
dlang · Dec 29, 2017 · f8b5246 · f8b5246
1 parent a6d8665
commit f8b5246
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Showing 3 changed files with 40 additions and 12 deletions.
diff --git a/src/dmd/dsymbolsem.d b/src/dmd/dsymbolsem.d
@@ -151,6 +151,28 @@ const(char)* getMessage(DeprecatedDeclaration dd)
     return dd.msgstr;
 }
 
+// Returns true if a contract can appear without a function body.
+package bool allowsContractWithoutBody(FuncDeclaration funcdecl)
+{
+    assert(!funcdecl.fbody);
+
+    /* Contracts can only appear without a body when they are virtual
+     * interface functions or abstract.
+     */
+    Dsymbol parent = funcdecl.toParent();
+    InterfaceDeclaration id = parent.isInterfaceDeclaration();
+
+    if (!funcdecl.isAbstract() &&
+        (funcdecl.fensure || funcdecl.frequire) &&
+        !(id && funcdecl.isVirtual()))
+    {
+        auto cd = parent.isClassDeclaration();
+        if (!(cd && cd.isAbstract()))
+            return false;
+    }
+    return true;
+}
+
 private extern(C++) final class DsymbolSemanticVisitor : Visitor
 {
     alias visit = Visitor.visit;
@@ -3149,16 +3171,9 @@ 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");
-        }
+    Ldone:
+        if (!funcdecl.fbody && !funcdecl.allowsContractWithoutBody())
+            funcdecl.error("in and out contracts can only appear without a body when they are virtual interface functions or abstract");
 
         /* Do not allow template instances to add virtual functions
          * to a class.
@@ -3189,7 +3204,6 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
         if (funcdecl.isMain())
             funcdecl.checkDmain();       // Check main() parameters and return type
 
-    Ldone:
         /* Purity and safety can be inferred for some functions by examining
          * the function body.
          */

diff --git a/src/dmd/semantic3.d b/src/dmd/semantic3.d
@@ -1074,7 +1074,7 @@ extern(C++) final class Semantic3Visitor : Visitor
                 }
 
                 // If declaration has no body, don't set sbody to prevent incorrect codegen.
-                if (funcdecl.fbody || funcdecl.fdensure || funcdecl.fdrequire)
+                if (funcdecl.fbody || funcdecl.allowsContractWithoutBody())
                     funcdecl.fbody = sbody;
             }
 

diff --git a/test/fail_compilation/fail12901.d b/test/fail_compilation/fail12901.d
@@ -0,0 +1,14 @@
+/*
+TEST_OUTPUT:
+---
+fail_compilation/fail12901.d(11): Error: constructor fail12901.S.this in and out contracts can only appear without a body when they are virtual interface functions or abstract
+---
+*/
+
+struct S
+{
+    int a;
+    this(int n)
+    in { a = n; }
+    // no body
+}