cshtml --diff-base-ignore-checkers: new option for diff scans

For example, if we know that SHELLCHECK_WARNING defects are produced
by different versions of ShellCheck between base and the current scan,
it does not make sense to compare their results with each other.  With
this option, we can make defects produced by certain checkers ignored
in this comparison.

Author: kdudka

cshtml.cc

@@ -55,14 +55,16 @@ int main(int argc, char *argv[])
             + " [options] proj.js, where options are", /* line_length */ 0x80);
 
     typedef std::vector<string> TStringList;
-    string defUrlTemplate, fnBase, plainTextUrl, spPosition;
+    string defUrlTemplate, fnBase, checkerIgnRegex, plainTextUrl, spPosition;
 
     try {
         desc.add_options()
             ("defect-url-template", po::value(&defUrlTemplate),
              "e.g. http://localhost/index.php?proj=%d&defect=%d")
             ("diff-base", po::value(&fnBase),
              "use the given list of defects as diff base")
+            ("diff-base-ignore-checkers", po::value(&checkerIgnRegex),
+             "do not diff base for checkers matching the given regex")
             ("plain-text-url", po::value(&plainTextUrl),
              "generate a link to plain-text version")
             ("scan-props-placement",
@@ -145,7 +147,8 @@ int main(int argc, char *argv[])
 
         if (!fnBase.empty()) {
             const std::string diffTitleFallback = titleFromFileName(fnBase);
-            writer.setDiffBase(&baseLookup, baseProps, diffTitleFallback);
+            writer.setDiffBase(&baseLookup, checkerIgnRegex, baseProps,
+                    diffTitleFallback);
         }
 
         // write HTML

html-writer.cc

@@ -290,6 +290,7 @@ struct HtmlWriter::Private {
     const boost::regex              reEvent;
     unsigned                        defCnt;
     DefLookup                      *baseLookup;
+    boost::regex                    checkerIgnRegex;
     std::string                     newDefMsg;
     std::string                     plainTextUrl;
 
@@ -339,11 +340,13 @@ void HtmlWriter::setScanProps(const TScanProps &scanProps) {
 
 void HtmlWriter::setDiffBase(
         DefLookup                   *baseLookup,
+        const std::string           &checkerIgnRegex,
         const TScanProps            &baseProps,
         const std::string           &baseTitleFallback)
 {
     assert(baseLookup);
     d->baseLookup = baseLookup;
+    d->checkerIgnRegex = checkerIgnRegex;
 
     // TODO: merge with already existing metadata stomping on the same keys
     TScanProps::const_iterator it = baseProps.find("cov-compilation-unit-count");
@@ -401,7 +404,16 @@ void HtmlWriter::Private::writeLinkToDetails(const Defect &def) {
 }
 
 void HtmlWriter::Private::writeNewDefWarning(const Defect &def) {
-    if (!this->baseLookup || this->baseLookup->lookup(def))
+    if (!this->baseLookup)
+        // not lookup set
+        return;
+
+    if (boost::regex_match(def.checker, this->checkerIgnRegex))
+        // user requested to ignore this checker for lookup
+        return;
+
+    if (this->baseLookup->lookup(def))
+        // defect found in the lookup
         return;
 
     // a newly introduced defect

html-writer.hh

@@ -43,6 +43,7 @@ class HtmlWriter: public AbstractWriter {
         /// @attention baseLookup needs to stay valid long enough (no deep copy)
         void setDiffBase(
                 DefLookup                   *baseLookup,
+                const std::string           &checkerIgnRegex,
                 const TScanProps            &baseProps,
                 const std::string           &baseTitleFallback);