Add initial implementation of checking for uses of floating point as a loop counter.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76833 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CheckSecuritySyntaxOnly.cpp b/lib/Analysis/CheckSecuritySyntaxOnly.cpp
new file mode 100644
index 0000000..f29a8cc
--- /dev/null
+++ b/lib/Analysis/CheckSecuritySyntaxOnly.cpp
@@ -0,0 +1,122 @@
+//==- CheckSecuritySyntaxOnly.cpp - Basic security checks --------*- C++ -*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a set of flow-insensitive security checks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/PathSensitive/BugReporter.h"
+#include "clang/Analysis/LocalCheckers.h"
+#include "clang/AST/StmtVisitor.h"
+#include "llvm/Support/Compiler.h"
+
+using namespace clang;
+
+namespace {
+class VISIBILITY_HIDDEN WalkAST : public StmtVisitor<WalkAST> {
+ BugReporter &BR;
+public:
+ WalkAST(BugReporter &br) : BR(br) {}
+
+ // Statement visitor methods.
+ void VisitDoStmt(DoStmt *S);
+ void VisitWhileStmt(WhileStmt *S);
+ void VisitForStmt(ForStmt *S);
+
+ void VisitChildren(Stmt *S);
+ void VisitStmt(Stmt *S) { VisitChildren(S); }
+
+ // Checker-specific methods.
+ void CheckLoopConditionForFloat(Stmt *Loop, Expr *Condition);
+};
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// AST walking.
+//===----------------------------------------------------------------------===//
+
+void WalkAST::VisitChildren(Stmt *S) {
+ for (Stmt::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
+ if (Stmt *child = *I)
+ Visit(child);
+}
+
+void WalkAST::VisitDoStmt(DoStmt *S) {
+ CheckLoopConditionForFloat(S, S->getCond());
+ VisitChildren(S);
+}
+
+void WalkAST::VisitForStmt(ForStmt *S) {
+ if (Expr *Cond = S->getCond())
+ CheckLoopConditionForFloat(S, Cond);
+
+ VisitChildren(S);
+}
+
+void WalkAST::VisitWhileStmt(WhileStmt *S) {
+ CheckLoopConditionForFloat(S, S->getCond());
+ VisitChildren(S);
+}
+
+//===----------------------------------------------------------------------===//
+// Checking logic.
+//===----------------------------------------------------------------------===//
+
+static Expr* IsFloatCondition(Expr *Condition) {
+ while (Condition) {
+ Condition = Condition->IgnoreParenCasts();
+
+ if (Condition->getType()->isFloatingType())
+ return Condition;
+
+ switch (Condition->getStmtClass()) {
+ case Stmt::BinaryOperatorClass: {
+ BinaryOperator *B = cast<BinaryOperator>(Condition);
+
+ Expr *LHS = B->getLHS();
+ if (LHS->getType()->isFloatingType())
+ return LHS;
+
+ Expr *RHS = B->getRHS();
+ if (RHS->getType()->isFloatingType())
+ return RHS;
+
+ return NULL;
+ }
+ case Stmt::UnaryOperatorClass: {
+ UnaryOperator *U = cast<UnaryOperator>(Condition);
+ if (U->isArithmeticOp()) {
+ Condition = U->getSubExpr();
+ continue;
+ }
+ return NULL;
+ }
+ default:
+ break;
+ }
+ }
+ return NULL;
+}
+
+void WalkAST::CheckLoopConditionForFloat(Stmt *Loop, Expr *Condition) {
+ if ((Condition = IsFloatCondition(Condition))) {
+ const char *bugType = "Floating point value used in loop condition";
+ SourceRange R = Condition->getSourceRange();
+ BR.EmitBasicReport(bugType, "Security", bugType, Loop->getLocStart(),&R, 1);
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Entry point for check.
+//===----------------------------------------------------------------------===//
+
+void clang::CheckSecuritySyntaxOnly(Decl *D, BugReporter &BR) {
+ WalkAST walker(BR);
+ walker.Visit(D->getBody());
+}