Make sure we don't mangle roxygen comments when parsing; add a unit test

Author: kevinushey

inst/unitTests/cpp/attributes.cpp

@@ -0,0 +1,12 @@
+#include <Rcpp.h>
+using namespace Rcpp;
+
+//' @param foo // don't do anything to this
+//'     // or this
+//' @param bar " // or this guy "
+// [[Rcpp::export]] // this comment marks the following function for export
+std::string comments_test( /// // "\""" some '"// more / // ///garbge"
+    std::string msg = "Start a C++ line comment with the characters \"//\"" // "" \" ""
+) { // """
+    return msg;
+}

inst/unitTests/runit.attributes.R

@@ -0,0 +1,33 @@
+#!/usr/bin/r -t
+# -*- mode: R; tab-width: 4; -*-
+#
+# Copyright (C) 2014  Dirk Eddelbuettel, Romain Francois, and Kevin Ushey
+#
+# This file is part of Rcpp.
+#
+# Rcpp is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# Rcpp is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Rcpp.  If not, see <http://www.gnu.org/licenses/>.
+
+.runThisTest <- Sys.getenv("RunAllRcppTests") == "yes"
+
+if (.runThisTest) {
+
+    .setUp <- Rcpp:::unitTestSetup("attributes.cpp")
+    test.attributes <- function() {
+        checkEquals(
+            comments_test(),
+            "Start a C++ line comment with the characters \"//\""
+        )
+    }
+
+}

src/attributes.cpp

@@ -74,7 +74,7 @@ namespace attributes {
 
     // Trim a string
     void trimWhitespace(std::string* pStr);
-    
+
     // Strip trailing line comments
     void stripTrailingLineComments(std::string* pStr);
 
@@ -87,6 +87,9 @@ namespace attributes {
     // show a warning message
     void showWarning(const std::string& msg);
 
+    // is the line a C++ roxygen comment? (started with //')
+    bool isRoxygenCpp(const std::string& str);
+
 } // namespace attributes
 } // namespace Rcpp
 
@@ -961,7 +964,7 @@ namespace attributes {
             // trim before we do this just in case someone updates the regex
             // to allow for whitespace around the call
             trimWhitespace(&paramsText);
-            
+
             paramsText = paramsText.substr(1, paramsText.size()-2);
 
             // parse the parameters
@@ -1012,7 +1015,7 @@ namespace attributes {
                                                     const std::string& input) {
 
         const std::string delimiters(" ,");
-        
+
         std::vector<Param> params;
         std::string::size_type current;
         std::string::size_type next = -1;
@@ -2348,33 +2351,42 @@ namespace attributes {
     bool isWhitespace(char ch) {
         return std::strchr(kWhitespaceChars, ch) != NULL;
     }
-    
+
     // Remove trailing line comments -- ie, find comments that don't begin
     // a line, and remove them. We avoid stripping attributes.
     void stripTrailingLineComments(std::string* pStr) {
-        
+
         if (pStr->empty()) return;
-        
+
         size_t len = pStr->length();
         bool inString = false;
         size_t idx = 0;
-        
+
+        // if this is an roxygen comment, then bail
+        if (isRoxygenCpp(*pStr)) return;
+
         // skip over initial whitespace
         idx = pStr->find_first_not_of(kWhitespaceChars);
         if (idx == std::string::npos) return;
-        
+
         // skip over a first comment
         if (idx + 1 < len && pStr->at(idx) == '/' && pStr->at(idx + 1) == '/') {
             idx = idx + 2;
         }
-        
+
         // since we are searching for "//", we iterate up to 2nd last character
         while (idx < len - 1) {
-            
-            if (pStr->at(idx) == '"') {
-                inString = !inString;
+
+            if (inString) {
+                if (pStr->at(idx) == '"' && pStr->at(idx - 1) != '\\') {
+                    inString = false;
+                }
+            } else {
+                if (pStr->at(idx) == '"') {
+                    inString = true;
+                }
             }
-            
+
             if (!inString &&
                 pStr->at(idx) == '/' &&
                 pStr->at(idx + 1) == '/') {
@@ -2425,6 +2437,25 @@ namespace attributes {
         warning(msg, Rcpp::Named("call.") = false);
     }
 
+    bool isRoxygenCpp(const std::string& str) {
+        size_t len = str.length();
+        if (len < 3) return false;
+        size_t idx = str.find_first_not_of(kWhitespaceChars);
+        if (idx == std::string::npos) return false;
+
+        // make sure there are characters to check
+        if (len - 2 < idx) return false;
+
+        if (str[idx] == '/' &&
+            str[idx + 1] == '/' &&
+            str[idx + 2] == '\'') {
+            return true;
+        }
+
+        return false;
+
+    }
+
 } // namespace attributes
 } // namespace Rcpp