Added support for __VA_OPT__ expansion (#329)

Author: JohnSiegel

simplecpp.cpp

@@ -1959,6 +1959,24 @@ namespace simplecpp {
             // Macro parameter..
             {
                 TokenList temp(files);
+                if (tok->str() == "__VA_OPT__") {
+                    if (sameline(tok, tok->next) && tok->next->str() == "(") {
+                        tok = tok->next;
+                        int paren = 1;
+                        while (sameline(tok, tok->next)) {
+                            if (tok->next->str() == "(")
+                              ++paren;
+                            else if (tok->next->str() == ")")
+                              --paren;                            
+                            if (paren == 0)
+                              return tok->next->next;
+                            tok = tok->next;
+                            if (parametertokens.front()->next->str() != ")" && parametertokens.size() > args.size())
+                              tok = expandToken(output, loc, tok, macros, expandedmacros, parametertokens)->previous;
+                        }
+                    }
+                    throw Error(tok->location, "Missing parenthesis for __VA_OPT__(content)");
+                }
                 if (expandArg(&temp, tok, loc, macros, expandedmacros, parametertokens)) {
                     if (tok->str() == "__VA_ARGS__" && temp.empty() && output->cback() && output->cback()->str() == "," &&
                         tok->nextSkipComments() && tok->nextSkipComments()->str() == ")")

test.cpp

@@ -820,6 +820,88 @@ static void define_va_args_4() // cppcheck trac #9754
     ASSERT_EQUALS("\nprintf ( 1 , 2 )", preprocess(code));
 }
 
+static void define_va_opt_1() 
+{
+    const char code[] = "#define p1(fmt, args...) printf(fmt __VA_OPT__(,) args)\n"
+                        "p1(\"hello\");\n"
+                        "p1(\"%s\", \"hello\");\n";
+
+    ASSERT_EQUALS("\nprintf ( \"hello\" ) ;\n"
+        "printf ( \"%s\" , \"hello\" ) ;",
+        preprocess(code));
+}
+
+static void define_va_opt_2() 
+{
+    const char code[] = "#define err(...)\\\n"
+                        "__VA_OPT__(\\\n"
+                        "printf(__VA_ARGS__);\\\n"
+                        ")\n"
+                        "#define err2(something, ...) __VA_OPT__(err(__VA_ARGS__))\n"
+                        "err2(test)\n"
+                        "err2(test, \"%d\", 2)\n";
+
+    ASSERT_EQUALS("\n\n\n\n\n\nprintf ( \"%d\" , 2 ) ;", preprocess(code));
+}
+
+static void define_va_opt_3()
+{
+    // non-escaped newline without closing parenthesis
+    const char code1[] = "#define err(...) __VA_OPT__(printf( __VA_ARGS__);\n"
+                         ")\n"
+                         "err()";
+
+    simplecpp::OutputList outputList;
+    ASSERT_EQUALS("", preprocess(code1, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to expand 'err', Missing parenthesis for __VA_OPT__(content)\n",
+        toString(outputList));
+
+    outputList.clear();
+
+    // non-escaped newline without open parenthesis
+    const char code2[] = "#define err(...) __VA_OPT__\n"
+                         "(something)\n"
+                         "err()";
+
+    ASSERT_EQUALS("", preprocess(code2, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to expand 'err', Missing parenthesis for __VA_OPT__(content)\n",
+        toString(outputList));
+}
+
+static void define_va_opt_4() 
+{
+    // missing parenthesis
+    const char code1[] = "#define err(...) __VA_OPT__ something\n"
+                         "err()";
+
+    simplecpp::OutputList outputList;
+    ASSERT_EQUALS("", preprocess(code1, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to expand 'err', Missing parenthesis for __VA_OPT__(content)\n",
+        toString(outputList));
+
+    outputList.clear();
+
+    // missing open parenthesis
+    const char code2[] = "#define err(...) __VA_OPT__ something)\n"
+                         "err()";
+
+    ASSERT_EQUALS("", preprocess(code2, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to expand 'err', Missing parenthesis for __VA_OPT__(content)\n",
+        toString(outputList));
+}
+
+static void define_va_opt_5()
+{
+    // parenthesis not directly proceeding __VA_OPT__
+    const char code[] = "#define err(...) __VA_OPT__ something (something)\n"
+                        "err()";
+
+    simplecpp::OutputList outputList;
+    ASSERT_EQUALS("", preprocess(code, &outputList));
+    ASSERT_EQUALS("file0,1,syntax_error,failed to expand 'err', Missing parenthesis for __VA_OPT__(content)\n",
+        toString(outputList));
+}
+
 static void define_ifdef()
 {
     const char code[] = "#define A(X) X\n"
@@ -2694,6 +2776,11 @@ int main(int argc, char **argv)
     TEST_CASE(define_va_args_2);
     TEST_CASE(define_va_args_3);
     TEST_CASE(define_va_args_4);
+    TEST_CASE(define_va_opt_1);
+    TEST_CASE(define_va_opt_2);
+    TEST_CASE(define_va_opt_3);
+    TEST_CASE(define_va_opt_4);
+    TEST_CASE(define_va_opt_5);
 
     // UB: #ifdef as macro parameter
     TEST_CASE(define_ifdef);