Add safe cstring rules (#250)

Author: lucic71

cpp2rust/converter/models/converter_refcount.cpp

@@ -1169,6 +1169,9 @@ bool ConverterRefCount::VisitImplicitCastExpr(clang::ImplicitCastExpr *expr) {
 
   if (expr->getCastKind() == clang::CastKind::CK_BitCast) {
     if (expr->getType()->isVoidPointerType()) {
+      if (sub_expr->getType()->isVoidPointerType()) {
+        return Convert(sub_expr);
+      }
       PushConversionKind push(*this, ConversionKind::Unboxed);
       if (sub_expr->getType()->isPointerType() &&
           sub_expr->getType()->getPointeeType()->isArrayType()) {

libcc2rs/src/rc.rs

@@ -1010,6 +1010,16 @@ impl Ptr<u8> {
 
     #[allow(clippy::explicit_counter_loop)]
     pub fn memcpy(&self, src: &Self, len: usize) {
+        if *self > *src {
+            let mut dst = self.offset(len);
+            let mut s = src.offset(len);
+            for _ in 0..len {
+                dst -= 1;
+                s -= 1;
+                dst.write(s.read());
+            }
+            return;
+        }
         let mut dst = self.clone();
         let mut i: usize = 0;
         for value in src {

rule-preprocessor/src/semantic.rs

@@ -406,10 +406,10 @@ impl<'a, 'tcx> AstVisitor<'a, 'tcx> {
             rustc_hir::ExprKind::Lit(_)
             | rustc_hir::ExprKind::Path(_)
             | rustc_hir::ExprKind::Ret(None)
-            | rustc_hir::ExprKind::Break(_, _)
+            | rustc_hir::ExprKind::Break(_, None)
             | rustc_hir::ExprKind::Continue(_) => {}
 
-            rustc_hir::ExprKind::Ret(Some(e)) => {
+            rustc_hir::ExprKind::Ret(Some(e)) | rustc_hir::ExprKind::Break(_, Some(e)) => {
                 self.visit_expr(e, Access::Read);
             }