Fix #718 (# operator drops the space that a comment stands for)

simplecpp.cpp

@@ -1490,8 +1490,12 @@ void simplecpp::TokenList::removeComments()
     while (tok) {
         Token * const tok1 = tok;
         tok = tok->next;
-        if (tok1->comment)
+        if (tok1->comment) {
+            // a comment is replaced by one space character
+            if (tok1->previous)
+                tok1->previous->whitespaceahead = true;
             deleteToken(tok1);
+        }
     }
 }
 
@@ -2187,7 +2191,14 @@ namespace simplecpp {
             if (!parametertokens1.empty())
                 parametertokens1.swap(parametertokens2);
 
-            return functionLike() ? parametertokens2.back()->next : nameTokInst->next;
+            const Token * const callEnd = functionLike() ? parametertokens2.back() : nameTokInst;
+
+            // Whitespace at the end of the replacement list does not count.
+            // The expansion is followed by the whitespace after the macro call.
+            if (output.back() && output.back() != output_end_1)
+                output.back()->whitespaceahead = callEnd->whitespaceahead;
+
+            return callEnd->next;
         }
 
         /** Returns the macro to expand when the last token of @p temp is the name of a

test.cpp

@@ -1731,6 +1731,55 @@ static void hashEscape()
                   "\"L\\\"a\\\\\\\"b\\\"\"", preprocess(code));
 }
 
+static void hashComment()
+{
+    // a comment is replaced by one space character
+    simplecpp::DUI dui;
+    dui.removeComments = true;
+    const char code[] = "#define str(x) #x\n"
+                        "#define xstr(x) str(x)\n"
+                        "str(a/**/b)\n"
+                        "str(a/**/ /**/b)\n"
+                        "str(a/**/)\n"
+                        "xstr(a/**/b)";
+    ASSERT_EQUALS("\n\n"
+                  "\"a b\"\n"
+                  "\"a b\"\n"
+                  "\"a\"\n"
+                  "\"a b\"", preprocess(code, dui));
+
+    // comments are kept in the string when they are not removed, like gcc -C
+    ASSERT_EQUALS("\n\n"
+                  "\"a/**/b\"\n"
+                  "\"a/**/ /**/b\"\n"
+                  "\"a/**/\"\n"
+                  "\"a/**/b\"", preprocess(code));
+}
+
+static void hashMacroTrailingWhitespace()
+{
+    // whitespace at the end of a replacement list does not count
+    simplecpp::DUI dui;
+    dui.removeComments = true;
+    const char code[] = "#define str(x) #x\n"
+                        "#define xstr(x) str(x)\n"
+                        "#define MAJOR 1/*major*/\n"
+                        "#define MINOR 2 \n"
+                        "#define F(x) x\n"
+                        "#define G F(a)\n"
+                        "xstr(MAJOR.MINOR)\n"
+                        "xstr(F(a)b)\n"
+                        "xstr(F(a) b)\n"
+                        "xstr(G.b)\n"
+                        "xstr(G b)";
+    ASSERT_EQUALS("\n\n\n\n\n\n"
+                  "\"1.2\"\n"
+                  "\"ab\"\n"
+                  "\"a b\"\n"
+                  "\"a.b\"\n"
+                  "\"a b\"", preprocess(code, dui));
+}
+
 static void hashEscapeTrailingBackslash()
 {
     // an odd number of trailing backslashes would escape the closing quote,
@@ -4836,6 +4885,8 @@ static void runTests(int argc, char **argv, Input input)
 
     TEST_CASE(hash);
     TEST_CASE(hashEscape);
+    TEST_CASE(hashComment);
+    TEST_CASE(hashMacroTrailingWhitespace);
     TEST_CASE(hashEscapeTrailingBackslash);
     TEST_CASE(hashhash1);
     TEST_CASE(hashhash2);