SERVER-78007 Move rand check to clang-tidy

.clang-tidy.in

@@ -43,6 +43,7 @@ Checks:          '-*,
                   mongo-macro-definition-leaks-check,
                   mongo-mutex-check,
                   mongo-assert-check,
+                  mongo-rand-check,
                   mongo-std-optional-check,
                   mongo-uninterruptible-lock-guard-check,
                   mongo-unstructured-log-check,

buildscripts/linter/simplecpplint.py

@@ -52,9 +52,7 @@ def _make_polyfill_regex():
 
 _RE_LINT = re.compile("//.*NOLINT")
 _RE_COMMENT_STRIP = re.compile("//.*")
-
 _RE_PATTERN_MONGO_POLYFILL = _make_polyfill_regex()
-_RE_RAND = re.compile(r'\b(srand\(|rand\(\))')
 
 _RE_GENERIC_FCV_COMMENT = re.compile(r'\(Generic FCV reference\):')
 GENERIC_FCV = [
@@ -147,7 +145,6 @@ class Linter:
                 continue
 
             self._check_for_mongo_polyfill(linenum)
-            self._check_for_rand(linenum)
             self._check_for_c_stdlib_headers(linenum)
 
             # Relax the rule of commenting generic FCV references for files directly related to FCV
@@ -215,12 +212,6 @@ class Linter:
                 'Illegal use of banned name from std::/boost:: for "%s", use mongo::stdx:: variant instead'
                 % (match.group(0)))
 
-    def _check_for_rand(self, linenum):
-        line = self.clean_lines[linenum]
-        if _RE_RAND.search(line):
-            self._error(linenum, 'mongodb/rand',
-                        'Use of rand or srand, use <random> or PseudoRandom instead.')
-
     def _license_error(self, linenum, msg, category='legal/license'):
         style_url = 'https://github.com/mongodb/mongo/wiki/Server-Code-Style'
         self._error(linenum, category, '{} See {}'.format(msg, style_url))

src/mongo/tools/mongo_tidy_checks/MongoRandCheck.cpp

@@ -0,0 +1,54 @@
+/**
+ *    Copyright (C) 2023-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program 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
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "MongoRandCheck.h"
+
+namespace mongo::tidy {
+
+using namespace clang;
+using namespace clang::ast_matchers;
+
+MongoRandCheck::MongoRandCheck(StringRef Name, clang::tidy::ClangTidyContext* Context)
+    : ClangTidyCheck(Name, Context) {}
+
+void MongoRandCheck::registerMatchers(ast_matchers::MatchFinder* Finder) {
+    // Matcher for srand and sand functions
+    Finder->addMatcher(
+        callExpr(callee(functionDecl(hasAnyName("::srand", "::rand")))).bind("callExpr"), this);
+}
+
+void MongoRandCheck::check(const ast_matchers::MatchFinder::MatchResult& Result) {
+    // Get the matched check
+    const auto* CallExpr = Result.Nodes.getNodeAs<clang::CallExpr>("callExpr");
+    if (CallExpr) {
+        diag(CallExpr->getBeginLoc(),
+             "Use of rand or srand, use <random> or PseudoRandom instead.");
+    }
+}
+}  // namespace mongo::tidy

src/mongo/tools/mongo_tidy_checks/MongoRandCheck.h

@@ -0,0 +1,53 @@
+/**
+ *    Copyright (C) 2023-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program 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
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+#pragma once
+
+#include <clang-tidy/ClangTidy.h>
+#include <clang-tidy/ClangTidyCheck.h>
+
+namespace mongo::tidy {
+
+/**
+ * MongoRandCheck is a custom clang-tidy check for detecting
+ * the usage of 'rand' and 'srand' functions in the source code.
+ *
+ * It extends ClangTidyCheck and overrides the registerMatchers
+ * and check functions. The registerMatchers function adds matchers
+ * to identify the usage of 'rand' and 'srand',
+ * while the check function flags the matched occurrences.
+ */
+class MongoRandCheck : public clang::tidy::ClangTidyCheck {
+
+public:
+    MongoRandCheck(clang::StringRef Name, clang::tidy::ClangTidyContext* Context);
+    void registerMatchers(clang::ast_matchers::MatchFinder* Finder) override;
+    void check(const clang::ast_matchers::MatchFinder::MatchResult& Result) override;
+};
+
+}  // namespace mongo::tidy

src/mongo/tools/mongo_tidy_checks/MongoTidyModule.cpp

@@ -37,6 +37,7 @@
 #include "MongoHeaderBracketCheck.h"
 #include "MongoMacroDefinitionLeaksCheck.h"
 #include "MongoMutexCheck.h"
+#include "MongoRandCheck.h"
 #include "MongoStdAtomicCheck.h"
 #include "MongoStdOptionalCheck.h"
 #include "MongoTraceCheck.h"
@@ -75,6 +76,7 @@ public:
             "mongo-collection-sharding-runtime-check");
         CheckFactories.registerCheck<MongoMacroDefinitionLeaksCheck>(
             "mongo-macro-definition-leaks-check");
+        CheckFactories.registerCheck<MongoRandCheck>("mongo-rand-check");
     }
 };
 

src/mongo/tools/mongo_tidy_checks/SConscript

@@ -138,6 +138,7 @@ mongo_custom_check = env.SharedLibrary(
         "MongoUnstructuredLogCheck.cpp",
         "MongoCollectionShardingRuntimeCheck.cpp",
         "MongoMacroDefinitionLeaksCheck.cpp",
+        "MongoRandCheck.cpp",
     ],
     LIBDEPS_NO_INHERIT=[
         '$BUILD_DIR/third_party/shim_allocator',

src/mongo/tools/mongo_tidy_checks/tests/MongoTidyCheck_unittest.py

@@ -338,6 +338,20 @@ class MongoTidyTests(unittest.TestCase):
         self.run_clang_tidy()
 
 
+    def test_MongoRandCheck(self):
+        self.write_config(
+            textwrap.dedent("""\
+                Checks: '-*,mongo-rand-check'
+                WarningsAsErrors: '*'
+                """))
+
+        self.expected_output =[
+            "error: Use of rand or srand, use <random> or PseudoRandom instead. [mongo-rand-check,-warnings-as-errors]\n    srand(time(0));",
+            "error: Use of rand or srand, use <random> or PseudoRandom instead. [mongo-rand-check,-warnings-as-errors]\n    int random_number = rand();",
+        ]
+
+        self.run_clang_tidy()
+
 if __name__ == '__main__':
 
     parser = argparse.ArgumentParser()

src/mongo/tools/mongo_tidy_checks/tests/SConscript

@@ -41,6 +41,7 @@ if env.GetOption('ninja') == 'disabled':
         'test_MongoUnstructuredLogCheck.cpp',
         'test_MongoCollectionShardingRuntimeCheck.cpp',
         'test_MongoMacroDefinitionLeaksCheck.cpp',
+        'test_MongoRandCheck.cpp',
     ]
 
     # So that we can do fast runs, we will generate a separate compilation database file for each

src/mongo/tools/mongo_tidy_checks/tests/test_MongoRandCheck.cpp

@@ -0,0 +1,8 @@
+#include <cstdlib>
+#include <ctime>
+namespace mongo {
+void mongoRandCheck() {
+    srand(time(0));
+    int random_number = rand();
+}
+}  // namespace mongo