BLI: improve exception safety of memory utils

Even if we do not use exception in many places in Blender, our core C++ library
should become exception safe. Otherwise, we don't even have the option
to work with exceptions if we decide to do so.

4 files changed, 125 insertions, 4 deletions

diff --git a/tests/gtests/blenlib/BLI_memory_utils_test.cc b/tests/gtests/blenlib/BLI_memory_utils_test.cc
new file mode 100644
index 00000000000..aec57d02819
--- /dev/null
+++ b/tests/gtests/blenlib/BLI_memory_utils_test.cc
@@ -0,0 +1,120 @@
+#include "BLI_memory_utils.hh"
+#include "BLI_strict_flags.h"
+#include "testing/testing.h"
+
+namespace blender {
+
+struct MyValue {
+  static inline int alive = 0;
+
+  MyValue()
+  {
+    if (alive == 15) {
+      throw std::exception();
+    }
+
+    alive++;
+  }
+
+  MyValue(const MyValue &other)
+  {
+    if (alive == 15) {
+      throw std::exception();
+    }
+
+    alive++;
+  }
+
+  ~MyValue()
+  {
+    alive--;
+  }
+};
+
+TEST(memory_utils, DefaultConstructN_ActuallyCallsConstructor)
+{
+  constexpr int amount = 10;
+  TypedBuffer<MyValue, amount> buffer;
+
+  EXPECT_EQ(MyValue::alive, 0);
+  default_construct_n(buffer.ptr(), amount);
+  EXPECT_EQ(MyValue::alive, amount);
+  destruct_n(buffer.ptr(), amount);
+  EXPECT_EQ(MyValue::alive, 0);
+}
+
+TEST(memory_utils, DefaultConstructN_StrongExceptionSafety)
+{
+  constexpr int amount = 20;
+  TypedBuffer<MyValue, amount> buffer;
+
+  EXPECT_EQ(MyValue::alive, 0);
+  EXPECT_THROW(default_construct_n(buffer.ptr(), amount), std::exception);
+  EXPECT_EQ(MyValue::alive, 0);
+}
+
+TEST(memory_utils, UninitializedCopyN_ActuallyCopies)
+{
+  constexpr int amount = 5;
+  TypedBuffer<MyValue, amount> buffer1;
+  TypedBuffer<MyValue, amount> buffer2;
+
+  EXPECT_EQ(MyValue::alive, 0);
+  default_construct_n(buffer1.ptr(), amount);
+  EXPECT_EQ(MyValue::alive, amount);
+  uninitialized_copy_n(buffer1.ptr(), amount, buffer2.ptr());
+  EXPECT_EQ(MyValue::alive, 2 * amount);
+  destruct_n(buffer1.ptr(), amount);
+  EXPECT_EQ(MyValue::alive, amount);
+  destruct_n(buffer2.ptr(), amount);
+  EXPECT_EQ(MyValue::alive, 0);
+}
+
+TEST(memory_utils, UninitializedCopyN_StrongExceptionSafety)
+{
+  constexpr int amount = 10;
+  TypedBuffer<MyValue, amount> buffer1;
+  TypedBuffer<MyValue, amount> buffer2;
+
+  EXPECT_EQ(MyValue::alive, 0);
+  default_construct_n(buffer1.ptr(), amount);
+  EXPECT_EQ(MyValue::alive, amount);
+  EXPECT_THROW(uninitialized_copy_n(buffer1.ptr(), amount, buffer2.ptr()), std::exception);
+  EXPECT_EQ(MyValue::alive, amount);
+  destruct_n(buffer1.ptr(), amount);
+  EXPECT_EQ(MyValue::alive, 0);
+}
+
+TEST(memory_utils, UninitializedFillN_ActuallyCopies)
+{
+  constexpr int amount = 10;
+  TypedBuffer<MyValue, amount> buffer;
+
+  EXPECT_EQ(MyValue::alive, 0);
+  {
+    MyValue value;
+    EXPECT_EQ(MyValue::alive, 1);
+    uninitialized_fill_n(buffer.ptr(), amount, value);
+    EXPECT_EQ(MyValue::alive, 1 + amount);
+    destruct_n(buffer.ptr(), amount);
+    EXPECT_EQ(MyValue::alive, 1);
+  }
+  EXPECT_EQ(MyValue::alive, 0);
+}
+
+TEST(memory_utils, UninitializedFillN_StrongExceptionSafety)
+{
+  constexpr int amount = 20;
+  TypedBuffer<MyValue, amount> buffer;
+
+  EXPECT_EQ(MyValue::alive, 0);
+  {
+    MyValue value;
+    EXPECT_EQ(MyValue::alive, 1);
+    EXPECT_THROW(uninitialized_fill_n(buffer.ptr(), amount, value), std::exception);
+    EXPECT_EQ(MyValue::alive, 1);
+  }
+  EXPECT_EQ(MyValue::alive, 0);
+}
+
+}  // namespace blender
diff --git a/tests/gtests/blenlib/BLI_vector_test.cc b/tests/gtests/blenlib/BLI_vector_test.cc
index ea4711ca015..bd72a67746a 100644
--- a/tests/gtests/blenlib/BLI_vector_test.cc
+++ b/tests/gtests/blenlib/BLI_vector_test.cc
@@ -499,7 +499,7 @@ class TypeConstructMock {
   {
   }
 
-  TypeConstructMock(TypeConstructMock &&other) : move_constructed(true)
+  TypeConstructMock(TypeConstructMock &&other) noexcept : move_constructed(true)
   {
   }
 
@@ -513,7 +513,7 @@ class TypeConstructMock {
     return *this;
   }
 
-  TypeConstructMock &operator=(TypeConstructMock &&other)
+  TypeConstructMock &operator=(TypeConstructMock &&other) noexcept
   {
     if (this == &other) {
       return *this;
diff --git a/tests/gtests/blenlib/CMakeLists.txt b/tests/gtests/blenlib/CMakeLists.txt
index ba493b22b42..0831024556b 100644
--- a/tests/gtests/blenlib/CMakeLists.txt
+++ b/tests/gtests/blenlib/CMakeLists.txt
@@ -63,6 +63,7 @@ BLENDER_TEST(BLI_math_geom "bf_blenlib")
 BLENDER_TEST(BLI_math_matrix "bf_blenlib")
 BLENDER_TEST(BLI_math_vector "bf_blenlib")
 BLENDER_TEST(BLI_memiter "bf_blenlib")
+BLENDER_TEST(BLI_memory_utils "bf_blenlib")
 BLENDER_TEST(BLI_path_util "${BLI_path_util_extra_libs}")
 BLENDER_TEST(BLI_polyfill_2d "bf_blenlib")
 BLENDER_TEST(BLI_set "bf_blenlib")
diff --git a/tests/gtests/functions/FN_cpp_type_test.cc b/tests/gtests/functions/FN_cpp_type_test.cc
index f6ae0877ed1..1297ca471b7 100644
--- a/tests/gtests/functions/FN_cpp_type_test.cc
+++ b/tests/gtests/functions/FN_cpp_type_test.cc
@@ -50,7 +50,7 @@ struct TestType {
     other.value = copy_constructed_from_value;
   }
 
-  TestType(TestType &&other)
+  TestType(TestType &&other) noexcept
   {
     value = move_constructed_value;
     other.value = move_constructed_from_value;
@@ -63,7 +63,7 @@ struct TestType {
     return *this;
   }
 
-  TestType &operator=(TestType &&other)
+  TestType &operator=(TestType &&other) noexcept
   {
     value = move_assigned_value;
     other.value = move_assigned_from_value;