fix Issue 22102 - importC: Error: function is used as a type

src/dmd/cparse.d

@@ -163,6 +163,19 @@ final class CParser(AST) : Parser!AST
                 case TOK.rightShiftAssign:
                     goto Lexp;
 
+                case TOK.leftParenthesis:
+                {
+                    /* Ambiguous cases arise for declarations in the style:
+                     *      typedef-name ( identifier ) ;
+                     * As type-name won't be resolved until semantic, prefer
+                     * to first assume it is a call expression, and rewrite later.
+                     */
+                    auto tk = &token;
+                    if (isFunctionCall(tk))
+                        goto Lexp;
+                    goto default;
+                }
+
                 default:
                 {
                     /* If tokens look like a declaration, assume it is one
@@ -3208,6 +3221,46 @@ final class CParser(AST) : Parser!AST
         return true;
     }
 
+    /********************************
+     * See if match for:
+     *    postfix-expression ( argument-expression-list(opt) )
+     * Params:
+     *  pt = starting token, updated to one past end of initializer if true
+     * Returns:
+     *  true if function call
+     */
+    private bool isFunctionCall(ref Token* pt)
+    {
+        //printf("isFunctionCall()\n");
+        auto t = pt;
+
+        if (!isPrimaryExpression(t))
+            return false;
+        if (t.value != TOK.leftParenthesis)
+            return false;
+        t = peek(t);
+        while (1)
+        {
+            if (!isAssignmentExpression(t))
+                return false;
+            if (t.value == TOK.comma)
+            {
+                t = peek(t);
+                continue;
+            }
+            if (t.value == TOK.rightParenthesis)
+            {
+                t = peek(t);
+                break;
+            }
+            return false;
+        }
+        if (t.value != TOK.semicolon)
+            return false;
+        pt = t;
+        return true;
+    }
+
     /********************************
      * See if match for assignment-expression.
      * Params:

src/dmd/expressionsem.d

@@ -4463,6 +4463,40 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
                 // Rewrite (*fp)(arguments) to fp(arguments)
                 exp.e1 = (cast(PtrExp)exp.e1).e1;
             }
+            else if (exp.e1.op == TOK.type && (sc && sc.flags & SCOPE.Cfile))
+            {
+                /* Ambiguous cases arise from CParser where there is not enough
+                 * information to determine if we have a function call or declaration.
+                 *   type-name ( identifier ) ;
+                 *   identifier ( identifier ) ;
+                 * If exp.e1 is a type-name, then this is a declaration. C11 does not
+                 * have type construction syntax, so don't convert this to a cast().
+                 */
+                if (exp.arguments && exp.arguments.dim == 1)
+                {
+                    Expression arg = (*exp.arguments)[0];
+                    if (auto ie = (*exp.arguments)[0].isIdentifierExp())
+                    {
+                        TypeExp te = cast(TypeExp)exp.e1;
+                        auto initializer = new VoidInitializer(ie.loc);
+                        Dsymbol s = new VarDeclaration(ie.loc, te.type, ie.ident, initializer);
+                        auto decls = new Dsymbols(1);
+                        (*decls)[0] = s;
+                        s = new LinkDeclaration(s.loc, LINK.c, decls);
+                        result = new DeclarationExp(exp.loc, s);
+                        result = result.expressionSemantic(sc);
+                    }
+                    else
+                    {
+                        arg.error("identifier or `(` expected");
+                        result = ErrorExp.get();
+                    }
+                    return;
+                }
+                exp.error("identifier or `(` expected before `)`");
+                result = ErrorExp.get();
+                return;
+            }
         }
 
         Type t1 = exp.e1.type ? exp.e1.type.toBasetype() : null;

test/compilable/testcstuff2.c

@@ -228,8 +228,8 @@ void test22063()
 
 void test22066()
 {
-  int var = 0;
-  (var)++;
+    int var = 0;
+    (var)++;
 }
 
 /***************************************************/
@@ -320,6 +320,18 @@ void test22088()
     c = ld;
 }
 
+/***************************************************/
+// https://issues.dlang.org/show_bug.cgi?id=22102
+
+void fun22102(int var);
+typedef int int22102;
+
+void test22102()
+{
+    int22102(var);
+    fun22102(var);
+}
+
 /***************************************************/
 // https://issues.dlang.org/show_bug.cgi?id=22103
 

test/fail_compilation/failcstuff1.c

@@ -40,6 +40,12 @@ fail_compilation/failcstuff1.c(460): Error: variable length arrays are not suppo
 fail_compilation/failcstuff1.c(460): Error: variable length array used outside of function prototype
 fail_compilation/failcstuff1.c(461): Error: array type has incomplete element type `int[]`
 fail_compilation/failcstuff1.c(462): Error: `=`, `;` or `,` expected
+fail_compilation/failcstuff1.c(502): Error: identifier or `(` expected
+fail_compilation/failcstuff1.c(502): Error: found `;` when expecting `)`
+fail_compilation/failcstuff1.c(503): Error: `=`, `;` or `,` expected
+fail_compilation/failcstuff1.c(504): Error: identifier or `(` expected
+fail_compilation/failcstuff1.c(504): Error: found `;` when expecting `)`
+fail_compilation/failcstuff1.c(505): Error: `=`, `;` or `,` expected
 ---
 */
 
@@ -132,3 +138,13 @@ void test22103e()
     int array4[][];
     int array4[4] const;
 }
+
+// https://issues.dlang.org/show_bug.cgi?id=22102
+#line 500
+void test22102()
+{
+    int(0);
+    int var1;
+    int();
+    int var2;
+}

test/fail_compilation/failcstuff2.c

@@ -28,6 +28,8 @@ fail_compilation/failcstuff2.c(204): Error: variable `var` is used as a type
 fail_compilation/failcstuff2.c(203):        variable `var` is declared here
 fail_compilation/failcstuff2.c(205): Error: variable `var` is used as a type
 fail_compilation/failcstuff2.c(203):        variable `var` is declared here
+fail_compilation/failcstuff2.c(254): Error: identifier or `(` expected before `)`
+fail_compilation/failcstuff2.c(255): Error: identifier or `(` expected
 ---
 */
 
@@ -97,3 +99,14 @@ void test21992(int var)
     var = (var) ~ 1234;
     var = (var) ! 1234;
 }
+
+/***************************************************/
+// https://issues.dlang.org/show_bug.cgi?id=22102
+#line 250
+typedef int int22102;
+
+void test22102()
+{
+    int22102();
+    int22102(0);
+}