Add nullability annotations

PiperOrigin-RevId: 589842893
Change-Id: I9657761d1f71c665582406f278c6605f6d382f6d

4 files changed, 16 insertions, 8 deletions

diff --git a/absl/types/BUILD.bazel b/absl/types/BUILD.bazel
index 31a5daa2..ce8f605b 100644
--- a/absl/types/BUILD.bazel
+++ b/absl/types/BUILD.bazel
@@ -118,6 +118,7 @@ cc_library(
     deps = [
         "//absl/algorithm",
         "//absl/base:core_headers",
+        "//absl/base:nullability",
         "//absl/base:throw_delegate",
         "//absl/meta:type_traits",
     ],
@@ -154,6 +155,7 @@ cc_library(
         "//absl/base:base_internal",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/base:nullability",
         "//absl/memory",
         "//absl/meta:type_traits",
         "//absl/utility",
diff --git a/absl/types/CMakeLists.txt b/absl/types/CMakeLists.txt
index 024c2c39..92b4ae49 100644
--- a/absl/types/CMakeLists.txt
+++ b/absl/types/CMakeLists.txt
@@ -115,6 +115,7 @@ absl_cc_library(
   DEPS
     absl::algorithm
     absl::core_headers
+    absl::nullability
     absl::throw_delegate
     absl::type_traits
   PUBLIC
@@ -175,6 +176,7 @@ absl_cc_library(
     absl::config
     absl::core_headers
     absl::memory
+    absl::nullability
     absl::type_traits
     absl::utility
   PUBLIC
diff --git a/absl/types/optional.h b/absl/types/optional.h
index 0a8080dc..395fe62f 100644
--- a/absl/types/optional.h
+++ b/absl/types/optional.h
@@ -61,6 +61,7 @@ ABSL_NAMESPACE_END
 #include <utility>
 
 #include "absl/base/attributes.h"
+#include "absl/base/nullability.h"
 #include "absl/base/internal/inline_variable.h"
 #include "absl/meta/type_traits.h"
 #include "absl/types/bad_optional_access.h"
@@ -415,11 +416,11 @@ class optional : private optional_internal::optional_data<T>,
   // `optional` is empty, behavior is undefined.
   //
   // If you need myOpt->foo in constexpr, use (*myOpt).foo instead.
-  const T* operator->() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
+  absl::Nonnull<const T*> operator->() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
     ABSL_HARDENING_ASSERT(this->engaged_);
     return std::addressof(this->data_);
   }
-  T* operator->() ABSL_ATTRIBUTE_LIFETIME_BOUND {
+  absl::Nonnull<T*> operator->() ABSL_ATTRIBUTE_LIFETIME_BOUND {
     ABSL_HARDENING_ASSERT(this->engaged_);
     return std::addressof(this->data_);
   }
diff --git a/absl/types/span.h b/absl/types/span.h
index 70ed8eb6..7d1d0166 100644
--- a/absl/types/span.h
+++ b/absl/types/span.h
@@ -63,6 +63,7 @@
 #include "absl/base/attributes.h"
 #include "absl/base/internal/throw_delegate.h"
 #include "absl/base/macros.h"
+#include "absl/base/nullability.h"
 #include "absl/base/optimization.h"
 #include "absl/base/port.h"    // TODO(strel): remove this include
 #include "absl/meta/type_traits.h"
@@ -172,8 +173,8 @@ class Span {
  public:
   using element_type = T;
   using value_type = absl::remove_cv_t<T>;
-  using pointer = T*;
-  using const_pointer = const T*;
+  using pointer = absl::Nullable<T*>;
+  using const_pointer = absl::Nullable<const T*>;
   using reference = T&;
   using const_reference = const T&;
   using iterator = pointer;
@@ -679,12 +680,12 @@ bool operator>=(Span<T> a, const U& b) {
 //   }
 //
 template <int&... ExplicitArgumentBarrier, typename T>
-constexpr Span<T> MakeSpan(T* ptr, size_t size) noexcept {
+constexpr Span<T> MakeSpan(absl::Nullable<T*> ptr, size_t size) noexcept {
   return Span<T>(ptr, size);
 }
 
 template <int&... ExplicitArgumentBarrier, typename T>
-Span<T> MakeSpan(T* begin, T* end) noexcept {
+Span<T> MakeSpan(absl::Nullable<T*> begin, absl::Nullable<T*> end) noexcept {
   return ABSL_HARDENING_ASSERT(begin <= end),
          Span<T>(begin, static_cast<size_t>(end - begin));
 }
@@ -725,12 +726,14 @@ constexpr Span<T> MakeSpan(T (&array)[N]) noexcept {
 //   ProcessInts(absl::MakeConstSpan(std::vector<int>{ 0, 0, 0 }));
 //
 template <int&... ExplicitArgumentBarrier, typename T>
-constexpr Span<const T> MakeConstSpan(T* ptr, size_t size) noexcept {
+constexpr Span<const T> MakeConstSpan(absl::Nullable<T*> ptr,
+                                      size_t size) noexcept {
   return Span<const T>(ptr, size);
 }
 
 template <int&... ExplicitArgumentBarrier, typename T>
-Span<const T> MakeConstSpan(T* begin, T* end) noexcept {
+Span<const T> MakeConstSpan(absl::Nullable<T*> begin,
+                            absl::Nullable<T*> end) noexcept {
   return ABSL_HARDENING_ASSERT(begin <= end), Span<const T>(begin, end - begin);
 }