Make ranged for loops work with STACK_OF(T).
My original plan here was to make STACK_OF(T) expand to a template so
the inner type were extractable. Unfortunately, we cannot sanely make
STACK_OF(T) expand to a different type in C and C++ even across
compilation units because UBSan sometimes explodes. This is nuts, but so
it goes.
Instead, use StackTraits to extract the STACK_OF(T) parameters and
define an iterator type.
Bug: 189
Change-Id: I64f5173b34b723ec471f7a355ff46b04f161386a
Reviewed-on: https://boringssl-review.googlesource.com/18467
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/include/openssl/stack.h b/include/openssl/stack.h
index 8f15ea2..0e59d6a 100644
--- a/include/openssl/stack.h
+++ b/include/openssl/stack.h
@@ -222,21 +222,22 @@
}
}
-#define BORINGSSL_DEFINE_STACK_TRAITS(name, is_const) \
- extern "C++" { \
- namespace bssl { \
- namespace internal { \
- template <> \
- struct StackTraits<STACK_OF(name)> { \
- using Type = name; \
- static constexpr bool kIsConst = is_const; \
- }; \
- } \
- } \
+#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) \
+ extern "C++" { \
+ namespace bssl { \
+ namespace internal { \
+ template <> \
+ struct StackTraits<STACK_OF(name)> { \
+ static constexpr bool kIsStack = true; \
+ using Type = type; \
+ static constexpr bool kIsConst = is_const; \
+ }; \
+ } \
+ } \
}
#else
-#define BORINGSSL_DEFINE_STACK_TRAITS(name, is_const)
+#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const)
#endif
/* Stack functions must be tagged unused to support file-local stack types.
@@ -350,15 +351,15 @@
/* DEFINE_STACK_OF defines |STACK_OF(type)| to be a stack whose elements are
* |type| *. */
-#define DEFINE_STACK_OF(type) \
+#define DEFINE_STACK_OF(type) \
BORINGSSL_DEFINE_STACK_OF_IMPL(type, type *, const type *) \
- BORINGSSL_DEFINE_STACK_TRAITS(type, false)
+ BORINGSSL_DEFINE_STACK_TRAITS(type, type, false)
/* DEFINE_CONST_STACK_OF defines |STACK_OF(type)| to be a stack whose elements
* are const |type| *. */
-#define DEFINE_CONST_STACK_OF(type) \
+#define DEFINE_CONST_STACK_OF(type) \
BORINGSSL_DEFINE_STACK_OF_IMPL(type, const type *, const type *) \
- BORINGSSL_DEFINE_STACK_TRAITS(type, true)
+ BORINGSSL_DEFINE_STACK_TRAITS(type, const type, true)
/* DEFINE_SPECIAL_STACK_OF defines |STACK_OF(type)| to be a stack whose elements
* are |type|, where |type| must be a typedef for a pointer. */
@@ -407,10 +408,62 @@
}
};
+template <typename Stack>
+class StackIteratorImpl {
+ public:
+ using Type = typename StackTraits<Stack>::Type;
+ // Iterators must be default-constructable.
+ StackIteratorImpl() : sk_(nullptr), idx_(0) {}
+ StackIteratorImpl(const Stack *sk, size_t idx) : sk_(sk), idx_(idx) {}
+
+ bool operator==(StackIteratorImpl other) const {
+ return sk_ == other.sk_ && idx_ == other.idx_;
+ }
+ bool operator!=(StackIteratorImpl other) const {
+ return !(*this == other);
+ }
+
+ Type *operator*() const {
+ return reinterpret_cast<Type *>(
+ sk_value(reinterpret_cast<const _STACK *>(sk_), idx_));
+ }
+
+ StackIteratorImpl &operator++(/* prefix */) {
+ idx_++;
+ return *this;
+ }
+
+ StackIteratorImpl operator++(int /* postfix */) {
+ StackIteratorImpl copy(*this);
+ ++(*this);
+ return copy;
+ }
+
+ private:
+ const Stack *sk_;
+ size_t idx_;
+};
+
+template <typename Stack>
+using StackIterator = typename std::enable_if<StackTraits<Stack>::kIsStack,
+ StackIteratorImpl<Stack>>::type;
+
} // namespace internal
} // namespace bssl
+// Define begin() and end() for stack types so C++ range for loops work.
+template <typename Stack>
+static inline bssl::internal::StackIterator<Stack> begin(const Stack *sk) {
+ return bssl::internal::StackIterator<Stack>(sk, 0);
+}
+
+template <typename Stack>
+static inline bssl::internal::StackIterator<Stack> end(const Stack *sk) {
+ return bssl::internal::StackIterator<Stack>(
+ sk, sk_num(reinterpret_cast<const _STACK *>(sk)));
+}
+
} // extern C++
#endif
diff --git a/ssl/ssl_cert.cc b/ssl/ssl_cert.cc
index 0fcf48d..4337ec0 100644
--- a/ssl/ssl_cert.cc
+++ b/ssl/ssl_cert.cc
@@ -721,9 +721,7 @@
return CBB_flush(cbb);
}
- for (size_t i = 0; i < sk_CRYPTO_BUFFER_num(names); i++) {
- const CRYPTO_BUFFER *name = sk_CRYPTO_BUFFER_value(names, i);
-
+ for (const CRYPTO_BUFFER *name : names) {
if (!CBB_add_u16_length_prefixed(&child, &name_cbb) ||
!CBB_add_bytes(&name_cbb, CRYPTO_BUFFER_data(name),
CRYPTO_BUFFER_len(name))) {
