Suppression file name cache.

Implement a file name cache per suppression to avoid calling PathMatch::match
again and again for the same suppression and file name combination.

Author: MartinBP

lib/suppressions.cpp

@@ -420,7 +420,7 @@ SuppressionList::Suppression::Result SuppressionList::Suppression::isSuppressed(
             if (!thisAndNextLine || lineNumber + 1 != errmsg.lineNumber)
                 return Result::None;
         }
-        if (!fileName.empty() && !PathMatch::match(fileName, errmsg.getFileName()))
+        if (!fileName.empty() && !isFileNameMatch(errmsg.getFileName()))
             return Result::None;
         if (hash > 0 && hash != errmsg.hash)
             return Result::Checked;
@@ -453,6 +453,21 @@ SuppressionList::Suppression::Result SuppressionList::Suppression::isSuppressed(
     return Result::Matched;
 }
 
+bool SuppressionList::Suppression::isFileNameMatch(const std::string &errorFileName) const
+{
+    const auto it = mFileNameMatchCache.find(errorFileName);
+    if (it != mFileNameMatchCache.end())
+        return it->second;
+
+    const bool isMatch = PathMatch::match(fileName, errorFileName);
+
+    if (mFileNameMatchCache.size() >= FileNameMatchCacheMaxEntries)
+        mFileNameMatchCache.clear();
+
+    mFileNameMatchCache.emplace(errorFileName, isMatch);
+    return isMatch;
+}
+
 bool SuppressionList::Suppression::isMatch(const SuppressionList::ErrorMessage &errmsg)
 {
     switch (isSuppressed(errmsg)) {

lib/suppressions.h

@@ -168,6 +168,12 @@ class CPPCHECKLIB SuppressionList {
         bool isPolyspace{};
 
         enum : std::int8_t { NO_LINE = -1 };
+
+    private:
+        bool isFileNameMatch(const std::string &errorFileName) const;
+
+        static constexpr std::size_t FileNameMatchCacheMaxEntries = 256;
+        mutable std::map<std::string, bool> mFileNameMatchCache;
     };
 
     /**