Fix OutOfMemoryDeathTest.ViaSharedLibraries.

This test was invalid on modern glibc:
asprintf errors EOVERFLOW without attempting an allocation
when the size is at least INT_MAX - 32. INT_MAX - 33 is the
largest size that can attempt to trigger allocation failure,
and will not necessarily accomplish that on some systems.

Create a library that is specified to wrap malloc trivially,
to accomplish the goal of the test without external dependencies
or inconsistently implemented behavior.

BUG=428211

Review URL: https://codereview.chromium.org/1064793002

Cr-Commit-Position: refs/heads/master@{#324092}

base/BUILD.gn

@@ -1348,6 +1348,8 @@ test("base_unittests") {
   if (is_linux) {
     sources -= [ "file_version_info_unittest.cc" ]
     sources += [ "nix/xdg_util_unittest.cc" ]
+    deps += [ "//base/test:malloc_wrapper" ]
+
     if (use_glib) {
       configs += [ "//build/config/linux:glib" ]
     }

base/base.gyp

@@ -758,11 +758,17 @@
             'message_loop/message_pump_glib_unittest.cc',
           ]
         }],
-        ['OS == "linux" and use_allocator!="none"', {
-            'dependencies': [
-              'allocator/allocator.gyp:allocator',
-            ],
-          },
+        ['OS == "linux"', {
+          'dependencies': [
+            'malloc_wrapper',
+          ],
+          'conditions': [
+            ['use_allocator!="none"', {
+              'dependencies': [
+                'allocator/allocator.gyp:allocator',
+              ],
+            }],
+          ]},
         ],
         ['OS == "win"', {
           'sources!': [
@@ -1327,6 +1333,20 @@
         },
       ],
     }],
+    ['OS == "linux"', {
+      'targets': [
+        {
+          'target_name': 'malloc_wrapper',
+          'type': 'shared_library',
+          'dependencies': [
+            'base',
+          ],
+          'sources': [
+            'test/malloc_wrapper.cc',
+          ],
+        }
+      ],
+    }],
     ['OS == "android"', {
       'targets': [
         {

base/base_unittests.isolate

@@ -50,6 +50,13 @@
         'read_only': 1,
       },
     }],
+    ['OS=="linux"', {
+      'variables': {
+        'files': [
+          '<(PRODUCT_DIR)/lib/libmalloc_wrapper.so',
+        ],
+      },
+    }],
     ['OS=="mac" and asan==1 and fastbuild==0', {
       'variables': {
         'files': [

base/process/memory_unittest.cc

@@ -26,6 +26,7 @@
 #endif
 #if defined(OS_LINUX)
 #include <malloc.h>
+#include "base/test/malloc_wrapper.h"
 #endif
 
 #if defined(OS_WIN)
@@ -234,13 +235,11 @@ TEST_F(OutOfMemoryDeathTest, Memalign) {
 
 TEST_F(OutOfMemoryDeathTest, ViaSharedLibraries) {
   // This tests that the run-time symbol resolution is overriding malloc for
-  // shared libraries (including libc itself) as well as for our code.
-  std::string format = base::StringPrintf("%%%zud", test_size_);
-  char *value = NULL;
+  // shared libraries as well as for our code.
   ASSERT_DEATH({
-      SetUpInDeathAssert();
-      EXPECT_EQ(-1, asprintf(&value, format.c_str(), 0));
-    }, "");
+    SetUpInDeathAssert();
+    value_ = MallocWrapper(test_size_);
+  }, "");
 }
 #endif  // OS_LINUX
 

base/test/BUILD.gn

@@ -183,6 +183,18 @@ source_set("run_all_unittests") {
   ]
 }
 
+if (is_linux) {
+  shared_library("malloc_wrapper") {
+    testonly = true
+    sources = [
+      "malloc_wrapper.cc",
+    ]
+    deps = [
+      "//base",
+    ]
+  }
+}
+
 if (is_android) {
   generate_jni("base_unittests_jni_headers") {
     sources = [

base/test/malloc_wrapper.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "malloc_wrapper.h"
+
+#include <stdlib.h>
+
+void* MallocWrapper(size_t size) {
+  return malloc(size);
+}

base/test/malloc_wrapper.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_TEST_MALLOC_WRAPPER_H_
+#define BASE_TEST_MALLOC_WRAPPER_H_
+
+#include "base/basictypes.h"
+
+// BASE_EXPORT depends on COMPONENT_BUILD.
+// This will always be a separate shared library, so don't use BASE_EXPORT here.
+#if defined(WIN32)
+#define MALLOC_WRAPPER_EXPORT __declspec(dllexport)
+#else
+#define MALLOC_WRAPPER_EXPORT __attribute__((visibility("default")))
+#endif  // defined(WIN32)
+
+// Calls malloc directly.
+MALLOC_WRAPPER_EXPORT void* MallocWrapper(size_t size);
+
+#endif  // BASE_TEST_MALLOC_WRAPPER_H_