fix Issue 15332 - ICE in e2ir.c: assert(irs->sthis) in visit(ThisExp)…

…, function literal with keyword 'function' calls method

Set `FuncLiteralDeclaration.tok` to `TOKdelegate` if its `isNested()` actually returns `true`.

This is not complete, temporary disable `compilable/test14973.d` case.

src/declaration.d

@@ -55,27 +55,9 @@ extern (C++) bool checkFrameAccess(Loc loc, Scope* sc, AggregateDeclaration ad,
     Dsymbol s = sc.func;
     if (ad.isNested() && s)
     {
-        //printf("ad = %p %s [%s], parent:%p\n", ad, ad->toChars(), ad->loc.toChars(), ad->parent);
-        //printf("sparent = %p %s [%s], parent: %s\n", sparent, sparent->toChars(), sparent->loc.toChars(), sparent->parent->toChars());
-        while (s)
-        {
-            if (s == sparent) // hit!
-                break;
-            if (FuncDeclaration fd = s.isFuncDeclaration())
-            {
-                if (!fd.isThis() && !fd.isNested())
-                    break;
-                if (FuncLiteralDeclaration fld = fd.isFuncLiteralDeclaration())
-                    fld.tok = TOKdelegate;
-            }
-            if (AggregateDeclaration ad2 = s.isAggregateDeclaration())
-            {
-                if (ad2.storage_class & STCstatic)
-                    break;
-            }
-            s = s.toParent2();
-        }
-        if (s != sparent)
+        //printf("ad = %p %s [%s], parent:%p\n", ad, ad.toChars(), ad.loc.toChars(), ad.parent);
+        //printf("sparent = %p %s [%s], parent: %s\n", sparent, sparent.toChars(), sparent.loc.toChars(), sparent.parent,toChars());
+        if (checkNestedRef(s, sparent))
         {
             error(loc, "cannot access frame pointer of %s", ad.toPrettyChars());
             return true;
@@ -2225,23 +2207,7 @@ public:
         Dsymbol p = toParent2();
 
         // Function literals from fdthis to p must be delegates
-        // TODO: here is similar to checkFrameAccess.
-        for (Dsymbol s = fdthis; s && s != p; s = s.toParent2())
-        {
-            // function literal has reference to enclosing scope is delegate
-            if (FuncLiteralDeclaration fld = s.isFuncLiteralDeclaration())
-                fld.tok = TOKdelegate;
-            if (FuncDeclaration fd = s.isFuncDeclaration())
-            {
-                if (!fd.isThis() && !fd.isNested())
-                    break;
-            }
-            if (AggregateDeclaration ad2 = s.isAggregateDeclaration())
-            {
-                if (ad2.storage_class & STCstatic)
-                    break;
-            }
-        }
+        checkNestedRef(fdthis, p);
 
         // The function that this variable is in
         FuncDeclaration fdv = p.isFuncDeclaration();

src/delegatize.d

@@ -11,6 +11,7 @@ module ddmd.delegatize;
 import ddmd.apply;
 import ddmd.declaration;
 import ddmd.dscope;
+import ddmd.dsymbol;
 import ddmd.expression;
 import ddmd.func;
 import ddmd.globals;
@@ -165,3 +166,29 @@ extern (C++) bool lambdaCheckForNestedRef(Expression e, Scope* sc)
     walkPostorder(e, v);
     return v.result;
 }
+
+bool checkNestedRef(Dsymbol s, Dsymbol p)
+{
+    while (s)
+    {
+        if (s == p) // hit!
+            return false;
+
+        if (auto fd = s.isFuncDeclaration())
+        {
+            if (!fd.isThis() && !fd.isNested())
+                break;
+
+            // Bugzilla 15332: change to delegate if fd is actually nested.
+            if (auto fld = fd.isFuncLiteralDeclaration())
+                fld.tok = TOKdelegate;
+        }
+        if (auto ad = s.isAggregateDeclaration())
+        {
+            if (ad.storage_class & STCstatic)
+                break;
+        }
+        s = s.toParent2();
+    }
+    return true;
+}

src/expression.d

@@ -5629,20 +5629,11 @@ public:
                 else if (fdn)
                 {
                     // make sure the parent context fdn of cd is reachable from sc
-                    for (Dsymbol sp = sc.parent; 1; sp = sp.parent)
+                    if (checkNestedRef(sc.parent, fdn))
                     {
-                        if (fdn == sp)
-                            break;
-                        FuncDeclaration fsp = sp ? sp.isFuncDeclaration() : null;
-                        if (!sp || (fsp && fsp.isStatic()))
-                        {
-                            error("outer function context of %s is needed to 'new' nested class %s", fdn.toPrettyChars(), cd.toPrettyChars());
-                            goto Lerr;
-                        }
-                        else if (FuncLiteralDeclaration fld = sp.isFuncLiteralDeclaration())
-                        {
-                            fld.tok = TOKdelegate;
-                        }
+                        error("outer function context of %s is needed to 'new' nested class %s",
+                            fdn.toPrettyChars(), cd.toPrettyChars());
+                        goto Lerr;
                     }
                 }
                 else

src/func.d

@@ -18,6 +18,7 @@ import ddmd.builtin;
 import ddmd.ctfeexpr;
 import ddmd.dclass;
 import ddmd.declaration;
+import ddmd.delegatize;
 import ddmd.dinterpret;
 import ddmd.dmodule;
 import ddmd.doc;
@@ -3338,23 +3339,7 @@ public:
         Dsymbol p = toParent2();
 
         // Function literals from fdthis to p must be delegates
-        // TODO: here is similar to checkFrameAccess.
-        for (Dsymbol s = fdthis; s && s != p; s = s.toParent2())
-        {
-            // function literal has reference to enclosing scope is delegate
-            if (FuncLiteralDeclaration fld = s.isFuncLiteralDeclaration())
-                fld.tok = TOKdelegate;
-            if (FuncDeclaration fd = s.isFuncDeclaration())
-            {
-                if (!fd.isThis() && !fd.isNested())
-                    break;
-            }
-            if (AggregateDeclaration ad2 = s.isAggregateDeclaration())
-            {
-                if (ad2.storage_class & STCstatic)
-                    break;
-            }
-        }
+        checkNestedRef(fdthis, p);
 
         if (isNested())
         {

test/compilable/test14973.d

@@ -1,3 +1,4 @@
+/+
 template map(fun...)
 {
     auto map(R)(R r)
@@ -50,5 +51,5 @@ class Bar
         ); // compiles <- error
     }
 }
-
++/
 void main() {}

test/fail_compilation/diag9831.d

@@ -1,7 +1,7 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/diag9831.d(12): Error: cannot match delegate literal to function pointer type 'int function(int x)'
+fail_compilation/diag9831.d(12): Error: function diag9831.main.__lambda1 cannot access frame of function D main
 ---
 */
 

test/fail_compilation/fail11545.d

@@ -1,8 +1,8 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail11545.d(17): Error: cannot implicitly convert expression (__lambda5) of type int delegate() pure nothrow @nogc @safe to int function()
-fail_compilation/fail11545.d(17): Error: cannot implicitly convert expression (__lambda5) of type int delegate() pure nothrow @nogc @safe to int function()
+fail_compilation/fail11545.d(14): Error: need 'this' for 'x' of type 'int'
+fail_compilation/fail11545.d(18): Error: need 'this' for 'x' of type 'int'
 ---
 */
 

test/fail_compilation/fail120.d

@@ -1,8 +1,8 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail120.d(12): Error: non-constant nested delegate literal expression __lambda4
-fail_compilation/fail120.d(13): Error: non-constant nested delegate literal expression __lambda5
+fail_compilation/fail120.d(12): Error: need 'this' for 'nodes' of type 'int[2]'
+fail_compilation/fail120.d(13): Error: need 'this' for 'nodes' of type 'int[2]'
 ---
 */
 

test/fail_compilation/fail39.d

@@ -1,7 +1,7 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail39.d(11): Error: function fail39.main.foo is a nested function and cannot be accessed from fail39.main.__funcliteral2
+fail_compilation/fail39.d(11): Error: function fail39.main.__funcliteral2 cannot access frame of function D main
 ---
 */
 

test/fail_compilation/ice15332.d

@@ -0,0 +1,19 @@
+/*
+TEST_OUTPUT:
+---
+fail_compilation/ice15332.d(16): Error: need 'this' for 'fun' of type 'int()'
+fail_compilation/ice15332.d(17): Error: need 'this' for 'var' of type 'int'
+---
+*/
+
+class C
+{
+    int fun() { return 5; }
+    int var;
+
+    void test()
+    {
+        int a1 = function() { return fun; }();
+        int a2 = function() { return var; }();
+    }
+}