Fix FXSYS_itoa() implementation.

core/src/fxcrt/fx_system_unittest.cpp

Index: core/src/fxcrt/fx_system_unittest.cpp
diff --git a/core/src/fxcrt/fx_system_unittest.cpp b/core/src/fxcrt/fx_system_unittest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f1a4aee6bdab82ebfa85c0222c4fb8138737a807
--- /dev/null
+++ b/core/src/fxcrt/fx_system_unittest.cpp
@@ -0,0 +1,212 @@
+// Copyright 2015 PDFium 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 <string>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "../../../testing/fx_string_testhelpers.h"
+#include "../../include/fxcrt/fx_system.h"
+
+// Unit test covering cases where PDFium replaces well-known library
+// functionality on any given platformn.
+
+TEST(fxcrt, FXSYS_itoa) {
+  const size_t kBase2SentinelLocation = 34;  // "-" + 32 digits + null == 34.

[brucedawson, 2015/08/07 20:55:49]

I think that the preferred abbreviation for the null character is NUL. This name
helps to distinguish it from NULL (the pointer) or nullptr.

But, although a quick wikipedia search supports this it also suggests that it is
not universal and not important, so feel free to ignore.

+  const size_t kBase10SentinelLocation = 12;  // "-" + 10 digits + null == 12.
+  const size_t kBase16SentinelLocation = 10;  // "-" + 8 digits + null == 10.
+  const size_t kBufLen = 35;
+  const FX_CHAR kSentinel = 0x7f;
+
+  FX_CHAR buf[kBufLen];
+
+  FXSYS_itoa(42, buf, 17);
+  EXPECT_EQ(std::string(""), buf);
+
+  FXSYS_itoa(42, buf, 1);
+  EXPECT_EQ(std::string(""), buf);
+
+  FXSYS_itoa(42, buf, 0);
+  EXPECT_EQ(std::string(""), buf);
+
+  FXSYS_itoa(42, buf, -1);
+  EXPECT_EQ(std::string(""), buf);
+
+  buf[kBase16SentinelLocation] = kSentinel;

[Lei Zhang, 2015/08/07 20:50:12]

Maybe write CheckBase16ItoA(int32_t input, const char* expected_output) rather
than repeating the same 4 lines over and over? Similarly for Base10 and Base2.

[Tom Sepez, 2015/08/07 21:58:14]

Done.

+  FXSYS_itoa(std::numeric_limits<int32_t>::min(), buf, 16);
+  EXPECT_EQ(std::string("-80000000"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_itoa(std::numeric_limits<int32_t>::min(), buf, 10);
+  EXPECT_EQ(std::string("-2147483648"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_itoa(std::numeric_limits<int32_t>::min(), buf, 2);
+  EXPECT_EQ(std::string("-10000000000000000000000000000000"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);

[Lei Zhang, 2015/08/07 20:50:12]

Repeat of last line?

[Tom Sepez, 2015/08/07 21:58:14]

Done.

+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_itoa(-1, buf, 16);
+  EXPECT_EQ(std::string("-1"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_itoa(-1, buf, 10);
+  EXPECT_EQ(std::string("-1"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_itoa(-1, buf, 2);
+  EXPECT_EQ(std::string("-1"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_itoa(0, buf, 16);
+  EXPECT_EQ(std::string("0"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_itoa(0, buf, 10);
+  EXPECT_EQ(std::string("0"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_itoa(0, buf, 2);
+  EXPECT_EQ(std::string("0"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_itoa(42, buf, 16);
+  EXPECT_EQ(std::string("2a"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_itoa(42, buf, 10);
+  EXPECT_EQ(std::string("42"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_itoa(42, buf, 2);
+  EXPECT_EQ(std::string("101010"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_itoa(std::numeric_limits<int32_t>::max(), buf, 16);
+  EXPECT_EQ(std::string("7fffffff"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_itoa(std::numeric_limits<int32_t>::max(), buf, 10);
+  EXPECT_EQ(std::string("2147483647"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_itoa(std::numeric_limits<int32_t>::max(), buf, 2);
+  EXPECT_EQ(std::string("1111111111111111111111111111111"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+}
+
+TEST(fxcrt, FXSYS_i64toa) {
+  const size_t kBufLen = 67;
+  const size_t kBase2SentinelLocation = 66;  // "-" + 64 digits + null.
+  const size_t kBase10SentinelLocation = 21;  // "-" + 19 digits + null.
+  const size_t kBase16SentinelLocation = 18;  // "-" + 16 digits + null.
+  const FX_CHAR kSentinel = 0x7f;
+
+  FX_CHAR buf[kBufLen];
+
+  FXSYS_i64toa(42, buf, 17);
+  EXPECT_EQ(std::string(""), buf);
+
+  FXSYS_i64toa(42, buf, 1);
+  EXPECT_EQ(std::string(""), buf);
+
+  FXSYS_i64toa(42, buf, 0);
+  EXPECT_EQ(std::string(""), buf);
+
+  FXSYS_i64toa(42, buf, -1);
+  EXPECT_EQ(std::string(""), buf);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_i64toa(std::numeric_limits<int64_t>::min(), buf, 16);
+  EXPECT_EQ(std::string("-8000000000000000"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_i64toa(std::numeric_limits<int64_t>::min(), buf, 10);
+  EXPECT_EQ(std::string("-9223372036854775808"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_i64toa(std::numeric_limits<int64_t>::min(), buf, 2);
+  EXPECT_EQ(std::string(
+      "-1000000000000000000000000000000000000000000000000000000000000000"),
+            buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_i64toa(-1, buf, 16);
+  EXPECT_EQ(std::string("-1"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_i64toa(-1, buf, 10);
+  EXPECT_EQ(std::string("-1"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_i64toa(-1, buf, 2);
+  EXPECT_EQ(std::string("-1"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_i64toa(0, buf, 16);
+  EXPECT_EQ(std::string("0"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_i64toa(0, buf, 10);
+  EXPECT_EQ(std::string("0"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_i64toa(0, buf, 2);
+  EXPECT_EQ(std::string("0"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_i64toa(42, buf, 16);
+  EXPECT_EQ(std::string("2a"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_i64toa(42, buf, 10);
+  EXPECT_EQ(std::string("42"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_i64toa(42, buf, 2);
+  EXPECT_EQ(std::string("101010"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+
+  buf[kBase16SentinelLocation] = kSentinel;
+  FXSYS_i64toa(std::numeric_limits<int64_t>::max(), buf, 16);
+  EXPECT_EQ(std::string("7fffffffffffffff"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase16SentinelLocation]);
+
+  buf[kBase10SentinelLocation] = kSentinel;
+  FXSYS_i64toa(std::numeric_limits<int64_t>::max(), buf, 10);
+  EXPECT_EQ(std::string("9223372036854775807"), buf);
+  EXPECT_EQ(kSentinel, buf[kBase10SentinelLocation]);
+
+  buf[kBase2SentinelLocation] = kSentinel;
+  FXSYS_i64toa(std::numeric_limits<int64_t>::max(), buf, 2);
+  EXPECT_EQ(std::string(
+      "111111111111111111111111111111111111111111111111111111111111111"),
+            buf);
+  EXPECT_EQ(kSentinel, buf[kBase2SentinelLocation]);
+}