Use separate module for printf checks.

1 files changed, 114 insertions, 0 deletions

diff --git a/clang-plugin/printf_check.cc b/clang-plugin/printf_check.cc
new file mode 100644
index 000000000..4c0e8edd8
--- /dev/null
+++ b/clang-plugin/printf_check.cc
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2015, Vsevolod Stakhov
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *	 * Redistributions of source code must retain the above copyright
+ *	   notice, this list of conditions and the following disclaimer.
+ *	 * Redistributions in binary form must reproduce the above copyright
+ *	   notice, this list of conditions and the following disclaimer in the
+ *	   documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR ''AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "printf_check.h"
+#include "clang/AST/AST.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include <unordered_map>
+
+using namespace clang;
+
+namespace rspamd {
+	class PrintfCheckVisitor::impl {
+		std::unordered_map<std::string, int> printf_functions;
+		ASTContext *pcontext;
+
+	public:
+		impl (ASTContext *_ctx) : pcontext(_ctx)
+		{
+			/* name -> format string position */
+			printf_functions = {
+					{"rspamd_printf",               0},
+					{"rspamd_default_log_function", 4},
+					{"rspamd_snprintf",             2},
+					{"rspamd_fprintf",              1}
+			};
+		};
+
+		bool VisitCallExpr (CallExpr *E)
+		{
+			auto callee = dyn_cast<NamedDecl> (E->getCalleeDecl ());
+			if (callee == NULL) {
+				llvm::errs () << "Bad callee\n";
+				return false;
+			}
+
+			auto fname = callee->getNameAsString ();
+
+			auto pos_it = printf_functions.find (fname);
+
+			if (pos_it != printf_functions.end ()) {
+				const auto args = E->getArgs ();
+				auto pos = pos_it->second;
+				auto query = args[pos];
+
+				if (!query->isEvaluatable (*pcontext)) {
+					llvm::errs () << "Cannot evaluate query\n";
+					return false;
+				}
+
+				clang::Expr::EvalResult r;
+
+				if (!query->EvaluateAsRValue (r, *pcontext)) {
+					llvm::errs () << "Cannot evaluate query\n";
+					return false;
+				}
+
+				auto qval = dyn_cast<StringLiteral> (
+						r.Val.getLValueBase ().get<const Expr *> ());
+				if (qval) {
+					llvm::errs () << "query string: "
+							<< qval->getString () << "\n";
+				}
+
+				for (auto i = pos + 1; i < E->getNumArgs (); i++) {
+					auto arg = args[i];
+
+					if (arg) {
+						auto type = arg->getType ().split ().Ty;
+						type->dump ();
+					}
+				}
+			}
+
+			return true;
+		}
+	};
+
+	PrintfCheckVisitor::PrintfCheckVisitor (ASTContext *ctx) :
+		pimpl { new impl(ctx) }
+	{
+	}
+
+	PrintfCheckVisitor::~PrintfCheckVisitor ()
+	{
+	}
+
+	bool PrintfCheckVisitor::VisitCallExpr (clang::CallExpr *E)
+	{
+		return pimpl->VisitCallExpr (E);
+	}
+};