Adding a checker (cert-err52-cpp) that detects use of setjmp or longjmp in C++ code. Corresponds to the CERT C++ secure coding rule: https://www.securecoding.cert.org/confluence/pages/viewpage.action?pageId=1834

llvm-svn: 249727

1 files changed, 77 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/cert/SetLongJmpCheck.cpp b/clang-tools-extra/clang-tidy/cert/SetLongJmpCheck.cpp
new file mode 100644
index 00000000000..bc5b35341f2
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/cert/SetLongJmpCheck.cpp
@@ -0,0 +1,77 @@
+//===--- SetLongJmpCheck.cpp - clang-tidy----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SetLongJmpCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Preprocessor.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+
+const char SetLongJmpCheck::DiagWording[] =
+    "do not call %0; consider using exception handling instead";
+
+namespace {
+class SetJmpMacroCallbacks : public PPCallbacks {
+  SetLongJmpCheck &Check;
+
+public:
+  explicit SetJmpMacroCallbacks(SetLongJmpCheck &Check) : Check(Check) {}
+
+  void MacroExpands(const Token &MacroNameTok, const MacroDefinition &MD,
+                    SourceRange Range, const MacroArgs *Args) override {
+    const auto *II = MacroNameTok.getIdentifierInfo();
+    if (!II)
+      return;
+
+    if (II->getName() == "setjmp")
+      Check.diag(Range.getBegin(), Check.DiagWording) << II;
+  }
+};
+} // namespace
+
+void SetLongJmpCheck::registerPPCallbacks(CompilerInstance &Compiler) {
+  // This checker only applies to C++, where exception handling is a superior
+  // solution to setjmp/longjmp calls.
+  if (!getLangOpts().CPlusPlus)
+    return;
+
+  // Per [headers]p5, setjmp must be exposed as a macro instead of a function,
+  // despite the allowance in C for setjmp to also be an extern function.
+  Compiler.getPreprocessor().addPPCallbacks(
+      llvm::make_unique<SetJmpMacroCallbacks>(*this));
+}
+
+void SetLongJmpCheck::registerMatchers(MatchFinder *Finder) {
+  // This checker only applies to C++, where exception handling is a superior
+  // solution to setjmp/longjmp calls.
+  if (!getLangOpts().CPlusPlus)
+    return;
+
+  // In case there is an implementation that happens to define setjmp as a
+  // function instead of a macro, this will also catch use of it. However, we
+  // are primarily searching for uses of longjmp.
+  Finder->addMatcher(callExpr(callee(functionDecl(anyOf(hasName("setjmp"),
+                                                        hasName("longjmp")))))
+                         .bind("expr"),
+                     this);
+}
+
+void SetLongJmpCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *E = Result.Nodes.getNodeAs<CallExpr>("expr");
+  diag(E->getExprLoc(), DiagWording) << cast<NamedDecl>(E->getCalleeDecl());
+}
+
+} // namespace tidy
+} // namespace clang