Re-enable all the windows warnings except 4267

The code is changed or had been changed to no longer generate these
warnings. It is safe to re-enabled these warnings.

In this code change, we fixed some code which generates warnings 4018
(signed/unsigned mismatch) and 4146 (unary minus operator applied to
unsigned type, result still unsigned).

Warning 4333 (right shift by too large amount, data loss) and 4345
(an object of POD type constructed with an initializer of the form ()
will be default-initialized) are no longer generated.

The same setting is applied and verified for GN build as well.

BUG=pdfium:29

Review URL: https://codereview.chromium.org/1849443003

9 files changed, 25 insertions, 36 deletions

diff --git a/BUILD.gn b/BUILD.gn
index b0ab4e1940..ad12068ad3 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -43,24 +43,7 @@ config("pdfium_config") {
 
   if (is_win) {
     cflags += [
-      "/wd4005",
-      "/wd4018",
-      "/wd4146",
-      "/wd4333",
-      "/wd4345",
       "/wd4267",
-
-      # TODO(ochang): Investigate if this can be fixed properly.
-      "/wd4201",
-
-      # TODO(thestig): Fix all instances, remove this, pdfium:29
-      "/wd4245",
-      "/wd4310",
-      "/wd4389",
-      "/wd4701",
-      "/wd4702",
-      "/wd4706",
-      "/wd4800",
     ]
   }
 
diff --git a/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp b/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp
index a4b85a34fa..15f98b26b9 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp
@@ -716,10 +716,10 @@ FX_BOOL CPDF_DataAvail::CheckFirstPage(IPDF_DataAvail::DownloadHints* pHints) {
 FX_BOOL CPDF_DataAvail::IsDataAvail(FX_FILESIZE offset,
                                     uint32_t size,
                                     IPDF_DataAvail::DownloadHints* pHints) {
-  if (offset > m_dwFileLen)
+  if (offset < 0 || offset > m_dwFileLen)
     return TRUE;
 
-  FX_SAFE_DWORD safeSize = pdfium::base::checked_cast<uint32_t>(offset);
+  FX_SAFE_FILESIZE safeSize = offset;
   safeSize += size;
   safeSize += 512;
   if (!safeSize.IsValid() || safeSize.ValueOrDie() > m_dwFileLen)
diff --git a/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.h b/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.h
index 26b6a8d3df..04fe6f4fec 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.h
+++ b/core/fpdfapi/fpdf_parser/cpdf_syntax_parser.h
@@ -83,7 +83,7 @@ class CPDF_SyntaxParser {
   FX_FILESIZE m_Pos;
   int m_MetadataObjnum;
   IFX_FileRead* m_pFileAccess;
-  uint32_t m_HeaderOffset;
+  FX_FILESIZE m_HeaderOffset;
   FX_FILESIZE m_FileLen;
   uint8_t* m_pFileBuf;
   uint32_t m_BufSize;
diff --git a/core/fxcrt/fx_basic_gcc.cpp b/core/fxcrt/fx_basic_gcc.cpp
index 1b2f01ec89..c3afe1115b 100644
--- a/core/fxcrt/fx_basic_gcc.cpp
+++ b/core/fxcrt/fx_basic_gcc.cpp
@@ -39,7 +39,10 @@ IntType FXSYS_StrToInt(const CharType* str) {
     num = num * 10 + val;
     str++;
   }
-  return neg ? -num : num;
+  // When it is a negative value, -num should be returned. Since num may be of
+  // unsigned type, use ~num + 1 to avoid the warning of applying unary minus
+  // operator to unsigned type.
+  return neg ? ~num + 1 : num;
 }
 
 template <typename T, typename UT, typename STR_T>
diff --git a/core/fxcrt/fx_basic_gcc_unittest.cpp b/core/fxcrt/fx_basic_gcc_unittest.cpp
index c6913cfd82..73e7446de0 100644
--- a/core/fxcrt/fx_basic_gcc_unittest.cpp
+++ b/core/fxcrt/fx_basic_gcc_unittest.cpp
@@ -16,15 +16,16 @@ TEST(fxcrt, FXSYS_atoi) {
   EXPECT_EQ(2345, FXSYS_atoi("+2345"));
   // The max value.
   EXPECT_EQ(2147483647, FXSYS_atoi("2147483647"));
-  // The min value.
-  EXPECT_EQ(-2147483648, FXSYS_atoi("-2147483648"));
+  // The min value. Written in -1 format to avoid "unary minus operator applied
+  // to unsigned type" warning.
+  EXPECT_EQ(-2147483647 - 1, FXSYS_atoi("-2147483648"));
   // With invalid char.
   EXPECT_EQ(9, FXSYS_atoi("9x9"));
 
   // Out of range values.
   EXPECT_EQ(2147483647, FXSYS_atoi("2147483623423412348"));
   EXPECT_EQ(2147483647, FXSYS_atoi("2147483648"));
-  EXPECT_EQ(-2147483648, FXSYS_atoi("-2147483650"));
+  EXPECT_EQ(-2147483647 - 1, FXSYS_atoi("-2147483650"));
 }
 
 TEST(fxcrt, FXSYS_atoi64) {
@@ -58,13 +59,13 @@ TEST(fxcrt, FXSYS_wtoi) {
   // The max value.
   EXPECT_EQ(2147483647, FXSYS_wtoi(L"2147483647"));
   // The min value.
-  EXPECT_EQ(-2147483648, FXSYS_wtoi(L"-2147483648"));
+  EXPECT_EQ(-2147483647 - 1, FXSYS_wtoi(L"-2147483648"));
   EXPECT_EQ(9, FXSYS_wtoi64(L"9x9"));
 
   // Out of range values.
   EXPECT_EQ(2147483647, FXSYS_wtoi(L"2147483623423412348"));
   EXPECT_EQ(2147483647, FXSYS_wtoi(L"2147483648"));
-  EXPECT_EQ(-2147483648, FXSYS_wtoi(L"-2147483652"));
+  EXPECT_EQ(-2147483647 - 1, FXSYS_wtoi(L"-2147483652"));
 }
 
 TEST(fxcrt, FXSYS_wtoi64) {
diff --git a/core/fxge/ge/fx_ge_fontmap.cpp b/core/fxge/ge/fx_ge_fontmap.cpp
index c6a6c5c003..c6b208c624 100644
--- a/core/fxge/ge/fx_ge_fontmap.cpp
+++ b/core/fxge/ge/fx_ge_fontmap.cpp
@@ -681,15 +681,17 @@ void CFX_FontMapper::SetSystemFontInfo(IFX_SystemFontInfo* pFontInfo) {
   }
   m_pFontInfo = pFontInfo;
 }
+
 static CFX_ByteString GetStringFromTable(const uint8_t* string_ptr,
                                          uint32_t string_ptr_length,
                                          uint16_t offset,
                                          uint16_t length) {
-  if (string_ptr_length < offset + length) {
+  if (string_ptr_length < static_cast<uint32_t>(offset + length)) {
     return CFX_ByteString();
   }
   return CFX_ByteStringC(string_ptr + offset, length);
 }
+
 CFX_ByteString GetNameFromTT(const uint8_t* name_table,
                              uint32_t name_table_size,
                              uint32_t name_id) {
diff --git a/fpdfsdk/fpdfformfill.cpp b/fpdfsdk/fpdfformfill.cpp
index 9230910a1f..ed6279a2c6 100644
--- a/fpdfsdk/fpdfformfill.cpp
+++ b/fpdfsdk/fpdfformfill.cpp
@@ -480,13 +480,13 @@ DLLEXPORT void STDCALL FPDF_Widget_Copy(FPDF_DOCUMENT document,
   pXFAMenuHander->Copy((IXFA_Widget*)hWidget, wsCpText);
 
   CFX_ByteString bsCpText = wsCpText.UTF16LE_Encode();
-  int len = bsCpText.GetLength() / sizeof(unsigned short);
+  uint32_t len = bsCpText.GetLength() / sizeof(unsigned short);
   if (wsText == NULL) {
     *size = len;
     return;
   }
 
-  int real_size = len < *size ? len : *size;
+  uint32_t real_size = len < *size ? len : *size;
   if (real_size > 0) {
     FXSYS_memcpy((void*)wsText,
                  bsCpText.GetBuffer(real_size * sizeof(unsigned short)),
@@ -516,13 +516,13 @@ DLLEXPORT void STDCALL FPDF_Widget_Cut(FPDF_DOCUMENT document,
   pXFAMenuHander->Cut((IXFA_Widget*)hWidget, wsCpText);
 
   CFX_ByteString bsCpText = wsCpText.UTF16LE_Encode();
-  int len = bsCpText.GetLength() / sizeof(unsigned short);
+  uint32_t len = bsCpText.GetLength() / sizeof(unsigned short);
   if (wsText == NULL) {
     *size = len;
     return;
   }
 
-  int real_size = len < *size ? len : *size;
+  uint32_t real_size = len < *size ? len : *size;
   if (real_size > 0) {
     FXSYS_memcpy((void*)wsText,
                  bsCpText.GetBuffer(real_size * sizeof(unsigned short)),
@@ -625,13 +625,13 @@ FPDF_StringHandleGetStringByIndex(FPDF_STRINGHANDLE sHandle,
     return FALSE;
 
   std::vector<CFX_ByteString>* sSuggestWords = FromFPDFStringHandle(sHandle);
-  int len = (*sSuggestWords)[index].GetLength();
+  uint32_t len = (*sSuggestWords)[index].GetLength();
   if (!bsText) {
     *size = len;
     return TRUE;
   }
 
-  int real_size = len < *size ? len : *size;
+  uint32_t real_size = len < *size ? len : *size;
   if (real_size > 0)
     FXSYS_memcpy((void*)bsText, (const FX_CHAR*)(*sSuggestWords)[index],
                  real_size);
diff --git a/fpdfsdk/fpdfview.cpp b/fpdfsdk/fpdfview.cpp
index 9183b4073b..3a3449745c 100644
--- a/fpdfsdk/fpdfview.cpp
+++ b/fpdfsdk/fpdfview.cpp
@@ -391,7 +391,7 @@ class CMemFile final : public IFX_FileRead {
     FX_SAFE_FILESIZE newPos =
         pdfium::base::checked_cast<FX_FILESIZE, size_t>(size);
     newPos += offset;
-    if (!newPos.IsValid() || newPos.ValueOrDie() > (uint32_t)m_size) {
+    if (!newPos.IsValid() || newPos.ValueOrDie() > m_size) {
       return FALSE;
     }
     FXSYS_memcpy(buffer, m_pBuf + offset, size);
@@ -1155,7 +1155,7 @@ DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDest(FPDF_DOCUMENT document,
 
   CFX_WideString wsName = PDF_DecodeText(bsName);
   CFX_ByteString utf16Name = wsName.UTF16LE_Encode();
-  unsigned int len = utf16Name.GetLength();
+  int len = utf16Name.GetLength();
   if (!buffer) {
     *buflen = len;
   } else if (*buflen >= len) {
diff --git a/pdfium.gyp b/pdfium.gyp
index 63d0c03404..ed6003ed81 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -93,7 +93,7 @@
       }],
     ],
     'msvs_disabled_warnings': [
-      4018, 4146, 4333, 4345, 4267,
+      4267,
     ],
     'variables': {
       'clang_warning_flags': [