From 34f5c8c5aea5822fde4c5e162d7b019ed9182dde Mon Sep 17 00:00:00 2001
From: Kim Grasman <kim.grasman@gmail.com>
Date: Sun, 12 Apr 2020 22:39:42 +0200
Subject: [PATCH] Add more complete testing for operator new

This replaces builtins_new_included.cc with operator_new.cc, and covers
all variants of operator new that do _not_ require <new> to be
included:

- Raw explicit ::operator new/::operator delete calls
- New expressions, both of builtin and user-defined types
- Aligned allocation (currently disabled, as we misdiagnose it,
  see PR #777).
---
 run_iwyu_tests.py                  |  2 +
 tests/cxx/builtins_new_included.cc | 31 -----------
 tests/cxx/operator_new.cc          | 85 ++++++++++++++++++++++++++++++
 3 files changed, 87 insertions(+), 31 deletions(-)
 delete mode 100644 tests/cxx/builtins_new_included.cc
 create mode 100644 tests/cxx/operator_new.cc

diff --git a/run_iwyu_tests.py b/run_iwyu_tests.py
index f312a4438..c3ebf3ea9 100755
--- a/run_iwyu_tests.py
+++ b/run_iwyu_tests.py
@@ -113,6 +113,7 @@ def setUp(self):
           self.Include('macro_defined_by_includer-prefix.h')],
       'macro_location.cc': ['-Wno-sizeof-pointer-div'],
       'ms_inline_asm.cc': ['-fms-extensions'],
+      'operator_new.cc': ['-std=c++17'],
       'placement_new.cc': ['-std=c++17'],
       'prefix_header_attribution.cc': [self.Include('prefix_header_attribution-d1.h')],
       'prefix_header_includes_add.cc': prefix_headers,
@@ -181,6 +182,7 @@ def setUp(self):
       'no_fwd_decls.cc': ['.'],
       'no_h_includes_cc.cc': ['.'],
       'non_transitive_include.cc': ['.'],
+      'operator_new.cc': ['.'],
       'overloaded_class.cc': ['.'],
       'pch_in_code.cc': ['.'],
       'pointer_arith.cc': ['.'],
diff --git a/tests/cxx/builtins_new_included.cc b/tests/cxx/builtins_new_included.cc
deleted file mode 100644
index 76efc7b2c..000000000
--- a/tests/cxx/builtins_new_included.cc
+++ /dev/null
@@ -1,31 +0,0 @@
-//===--- builtins_new_included.cc - test input file for iwyu --------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-// Test that iwyu suggests the include for <new> be removed if only
-// built-in functions are used.
-
-#include <new>
-
-void foo() {
-  char* ch = new char;
-  delete ch;
-  int* int_array = new int[10];
-  delete[] int_array;
-}
-
-/**** IWYU_SUMMARY
-
-tests/cxx/builtins_new_included.cc should add these lines:
-
-tests/cxx/builtins_new_included.cc should remove these lines:
-- #include <new>  // lines XX-XX
-
-The full include-list for tests/cxx/builtins_new_included.cc:
-
-***** IWYU_SUMMARY */
diff --git a/tests/cxx/operator_new.cc b/tests/cxx/operator_new.cc
new file mode 100644
index 000000000..b6676cb5a
--- /dev/null
+++ b/tests/cxx/operator_new.cc
@@ -0,0 +1,85 @@
+//===--- operator_new.cc - test input file for iwyu -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// Test that iwyu suggests the include for <new> be removed if only
+// built-in functions are used.
+
+#include <new>
+#include "tests/cxx/direct.h"
+
+// The most primitive ::operator new/delete are builtins, and are basically
+// wrappers around malloc.
+void ExplicitOperators() {
+  // IWYU: IndirectClass needs a declaration
+  // IWYU: IndirectClass is...*indirect.h
+  IndirectClass* elem = (IndirectClass*)::operator new(sizeof(IndirectClass));
+  ::operator delete(elem);
+
+  // IWYU: IndirectClass needs a declaration
+  // IWYU: IndirectClass is...*indirect.h
+  IndirectClass* arr = (IndirectClass*)::operator new[](4 * sizeof(IndirectClass));
+  ::operator delete[](arr);
+}
+
+// New- and delete-expressions, unless using placement syntax, only use builtin
+// operators. They're equivalent with the above, but also run ctors/dtors.
+// For placement syntax, see tests/cxx/placement_new.cc
+void ExpressionsBuiltinTypes() {
+  char* elem = new char;
+  delete elem;
+
+  int* arr = new int[4];
+  delete[] arr;
+}
+
+// New- and delete-expressions with user-defined types.
+void ExpressionsUserTypes() {
+  // IWYU: IndirectClass needs a declaration
+  // IWYU: IndirectClass is...*indirect.h
+  IndirectClass* elem = new IndirectClass;
+  // IWYU: IndirectClass is...*indirect.h
+  delete elem;
+
+  // IWYU: IndirectClass needs a declaration
+  // IWYU: IndirectClass is...*indirect.h
+  IndirectClass* arr = new IndirectClass[4];
+  // IWYU: IndirectClass is...*indirect.h
+  delete[] arr;
+}
+
+#if 0
+// Aligned allocation uses operator new(size_t, std::align_val_t) under the
+// hood in C++17, but does not require <new> to be included for it. Pre-C++17,
+// the alignment is just ignored.
+void ImplicitAlignedAllocation() {
+  struct alignas(32) Aligned {
+    float value[8];
+  };
+
+  Aligned* elem = new Aligned;
+  delete elem;
+  
+  Aligned* arr = new Aligned[10];
+  delete[] arr;
+}
+#endif
+
+/**** IWYU_SUMMARY
+
+tests/cxx/operator_new.cc should add these lines:
+#include "tests/cxx/indirect.h"
+
+tests/cxx/operator_new.cc should remove these lines:
+- #include <new>  // lines XX-XX
+- #include "tests/cxx/direct.h"  // lines XX-XX
+
+The full include-list for tests/cxx/operator_new.cc:
+#include "tests/cxx/indirect.h"  // for IndirectClass
+
+***** IWYU_SUMMARY */