fixed #14261 - Regex: added std::regex implementation [skip ci]

Author: firewave

cli/cmdlineparser.cpp

@@ -1375,6 +1375,9 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
                             if (std::strcmp(engine, "pcre") == 0) {
                                 rule.engine = Regex::Engine::Pcre;
                             }
+                            else if (std::strcmp(engine, "std") == 0) {
+                                rule.engine = Regex::Engine::Std;
+                            }
                             else {
                                 mLogger.printError(std::string("unknown regex engine '") + engine + "'.");
                                 return Result::Fail;

lib/regex.cpp

@@ -20,6 +20,7 @@
 
 #include "regex.h"
 
+#include <regex>
 #include <utility>
 
 #ifdef _WIN32
@@ -246,6 +247,51 @@ namespace {
     }
 }
 
+namespace {
+    class StdRegex : public Regex
+    {
+    public:
+        explicit StdRegex(std::string pattern)
+            : mPattern(std::move(pattern))
+        {}
+
+        std::string compile()
+        {
+            if (mCompiled)
+                return "regular expression has already been compiled";
+
+            try {
+                mRegex = std::regex(mPattern);
+            } catch (const std::exception& e) {
+                return e.what();
+            }
+            mCompiled = true;
+            return "";
+        }
+
+        std::string match(const std::string& str, const MatchFn& matchFn) const override
+        {
+            if (!mCompiled)
+                return "regular expression has not been compiled yet";
+
+            auto I = std::sregex_iterator(str.cbegin(), str.cend(), mRegex);
+            const auto E = std::sregex_iterator();
+            while (I != E)
+            {
+                const std::smatch& match = *I;
+                matchFn(match.position(), match.position() + match.length());
+                ++I;
+            }
+            return "";
+        }
+
+    private:
+        std::string mPattern;
+        std::regex mRegex;
+        bool mCompiled{};
+    };
+}
+
 template<typename T>
 static T* createAndCompileRegex(std::string pattern, std::string& err)
 {
@@ -259,6 +305,8 @@ std::shared_ptr<Regex> Regex::create(std::string pattern, Engine engine, std::st
     Regex* regex = nullptr;
     if (engine == Engine::Pcre)
         regex = createAndCompileRegex<PcreRegex>(std::move(pattern), err);
+    else if (engine == Engine::Std)
+        regex = createAndCompileRegex<StdRegex>(std::move(pattern), err);
     else {
         err = "unknown regular expression engine";
     }

lib/regex.h

@@ -41,7 +41,8 @@ class CPPCHECKLIB Regex
     enum class Engine : std::uint8_t
     {
         Unknown = 0,
-        Pcre = 1
+        Pcre = 1,
+        Std = 2
     };
 
     static std::shared_ptr<Regex> create(std::string pattern, Engine engine, std::string& err);

releasenotes.txt

@@ -28,4 +28,6 @@ Other:
 - Moved source code from https://github.com/danmar/cppcheck to https://github.com/cppcheck-opensource/cppcheck
 - The official Windows binary is now built with Visual Studio 2026.
 - Updated simplecpp to 1.7.0.
+- Added support for `std::regex` as the regular engine for rules. It can be specified using `std` in the engine` element in a rule XML.
+-
 -

test/testcmdlineparser.cpp

@@ -2715,6 +2715,7 @@ class TestCmdlineParser : public TestFixture {
                         "</message>\n"
                         "</rule>\n"
                         "<rule>\n"
+                        "<engine>std</engine>\n"
                         "<tokenlist>define</tokenlist>\n"
                         "<pattern>.*</pattern>\n"
                         "<message>\n"
@@ -2735,7 +2736,7 @@ class TestCmdlineParser : public TestFixture {
         ASSERT_EQUALS("ruleId1", it->id);
         ASSERT_EQUALS("ruleSummary1", it->summary);
         ++it;
-        ASSERT_EQUALS_ENUM(Regex::Engine::Pcre, it->engine);
+        ASSERT_EQUALS_ENUM(Regex::Engine::Std, it->engine);
         ASSERT_EQUALS("define", it->tokenlist);
         ASSERT_EQUALS(".*", it->pattern);
         ASSERT_EQUALS_ENUM(Severity::warning, it->severity);

test/testregex.cpp

@@ -85,6 +85,18 @@ class TestRegExBase : public TestFixture {
         std::string exp;
         if (mEngine == Regex::Engine::Pcre)
             exp = "missing terminating ] for character class";
+        else if (mEngine == Regex::Engine::Std)
+        {
+#if defined(_MSC_VER)
+            exp = "regex_error(error_brack): The expression contained mismatched [ and ].";
+#elif defined(_LIBCPP_VERSION)
+            exp = "The expression contained mismatched [ and ].";
+#elif defined(__clang__)
+            exp = "Unexpected character within '[...]' in regular expression";
+#else
+            exp = "Unexpected character in bracket expression.";
+#endif
+        }
 
         (void)assertRegex("[", exp);
     }
@@ -201,6 +213,12 @@ class TestRegExPcre : public TestRegExBase {
     TestRegExPcre() : TestRegExBase("TestRegExPcre", Regex::Engine::Pcre) {}
 };
 
+class TestRegExStd : public TestRegExBase {
+public:
+    TestRegExStd() : TestRegExBase("TestRegExStd", Regex::Engine::Std) {}
+};
+
 REGISTER_TEST(TestRegExPcre)
+REGISTER_TEST(TestRegExStd)
 
 #endif // HAVE_RULES