fix Issue 18708 - Flow analysis in constructors not done correctly fo…

src/dmd/ctorflow.d

@@ -85,6 +85,22 @@ struct CtorFlow
         foreach (ref u; fieldinit)
             u |= csx;
     }
+
+    /******************************
+     * OR CSX bits to `this`
+     * Params:
+     *  ctorflow = bits to OR in
+     */
+    void OR(const ref CtorFlow ctorflow)
+    {
+        callSuper |= ctorflow.callSuper;
+        if (fieldinit.length && ctorflow.fieldinit.length)
+        {
+            assert(fieldinit.length == ctorflow.fieldinit.length);
+            foreach (i, u; ctorflow.fieldinit)
+                fieldinit[i] |= u;
+        }
+    }
 }
 
 

src/dmd/dscope.d

@@ -209,21 +209,11 @@ struct Scope
     extern (C++) Scope* pop()
     {
         //printf("Scope::pop() %p nofree = %d\n", this, nofree);
-        Scope* enc = enclosing;
         if (enclosing)
-        {
-            enclosing.ctorflow.callSuper |= ctorflow.callSuper;
-            if (ctorflow.fieldinit.length)
-            {
-                if (enclosing.ctorflow.fieldinit.length)
-                {
-                    assert(ctorflow.fieldinit.ptr != enclosing.ctorflow.fieldinit.ptr);
-                    foreach (i, u; ctorflow.fieldinit)
-                        enclosing.ctorflow.fieldinit[i] |= u;
-                }
-                ctorflow.freeFieldinit();
-            }
-        }
+            enclosing.ctorflow.OR(ctorflow);
+        ctorflow.freeFieldinit();
+
+        Scope* enc = enclosing;
         if (!nofree)
         {
             enclosing = freelist;

src/dmd/expressionsem.d

@@ -8635,7 +8635,6 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
 
         e1x = resolveProperties(sc, e1x);
         e1x = e1x.toBoolean(sc);
-        CSX cs1 = sc.ctorflow.callSuper;
 
         if (sc.flags & SCOPE.condition)
         {
@@ -8649,8 +8648,10 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
             }
         }
 
+        CtorFlow ctorflow = sc.ctorflow.clone();
         Expression e2x = exp.e2.expressionSemantic(sc);
-        sc.mergeCallSuper(exp.loc, cs1);
+        sc.merge(exp.loc, ctorflow);
+        ctorflow.freeFieldinit();
 
         // for static alias this: https://issues.dlang.org/show_bug.cgi?id=17684
         if (e2x.op == TOK.type)
@@ -9127,6 +9128,7 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
         e2x = resolveProperties(sc, e2x);
 
         sc.merge(exp.loc, ctorflow1);
+        ctorflow1.freeFieldinit();
 
         if (ec.op == TOK.error)
         {

src/dmd/statementsem.d

@@ -2124,9 +2124,6 @@ else
         /* https://dlang.org/spec/statement.html#IfStatement
          */
 
-        // Save 'root' of two branches (then and else)
-        CtorFlow ctorflow_root = sc.ctorflow.clone();
-
         // check in syntax level
         ifs.condition = checkAssignmentAsCondition(ifs.condition);
 
@@ -2181,6 +2178,9 @@ else
         // This feature allows a limited form of conditional compilation.
         ifs.condition = ifs.condition.optimize(WANTvalue);
 
+        // Save 'root' of two branches (then and else) at the point where it forks
+        CtorFlow ctorflow_root = scd.ctorflow.clone();
+
         ifs.ifbody = ifs.ifbody.semanticNoScope(scd);
         scd.pop();
 
@@ -2192,6 +2192,8 @@ else
         // Merge 'then' results into 'else' results
         sc.merge(ifs.loc, ctorflow_then);
 
+        ctorflow_then.freeFieldinit();          // free extra copy of the data
+
         if (ifs.condition.op == TOK.error ||
             (ifs.ifbody && ifs.ifbody.isErrorStatement()) ||
             (ifs.elsebody && ifs.elsebody.isErrorStatement()))

test/fail_compilation/test18708.d

@@ -0,0 +1,64 @@
+/* TEST_OUTPUT:
+---
+fail_compilation/test18708.d(24): Error: one path skips field `s`
+fail_compilation/test18708.d(29): Error: one path skips field `s`
+fail_compilation/test18708.d(34): Error: one path skips field `s`
+fail_compilation/test18708.d(39): Error: one path skips field `s`
+---
+*/
+// https://issues.dlang.org/show_bug.cgi?id=18708
+
+struct S { int y; @disable this(); }
+
+class C
+{
+    S s;
+
+    this(S t)
+    {
+        if (bar(s = t)) foo(); // OK
+    }
+
+    this(S t, int i)
+    {
+        i || bar(s = t);
+    }
+
+    this(S t, int i, int j)
+    {
+        i && bar(s = t);
+    }
+
+    this(S t, int i, long j)
+    {
+        i ? bar(s = t) : i;
+    }
+
+    this(S t, int i, byte j)
+    {
+        i ? i : bar(s = t);
+    }
+}
+
+int bar(S s);
+int foo();
+
+/***********************************/
+
+class E : Exception
+{
+    this(string msg, int line = 0, int pos = 0) pure nothrow @safe
+    {
+        if (line)
+            super("hello");
+        else
+            super(msg);
+    }
+
+    this(string msg, string file, size_t line) pure nothrow @safe
+    {
+        super(msg, file, line);
+    }
+}
+
+