Reduce signed/unsigned comparison warnings

The warnings generated by Clang. This is part 1 for some simple cases.

BUG=pdfium:29
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1840483003 .

6 files changed, 25 insertions, 27 deletions

diff --git a/core/fpdfapi/fpdf_page/cpdf_colorspace.cpp b/core/fpdfapi/fpdf_page/cpdf_colorspace.cpp
index 3add21cfed..213d777ecb 100644
--- a/core/fpdfapi/fpdf_page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_colorspace.cpp
@@ -467,7 +467,7 @@ void CPDF_ColorSpace::GetDefaultColor(FX_FLOAT* buf) const {
     return;
   }
   FX_FLOAT min, max;
-  for (int i = 0; i < m_nComponents; i++) {
+  for (uint32_t i = 0; i < m_nComponents; i++) {
     GetDefaultValue(i, buf[i], min, max);
   }
 }
@@ -490,7 +490,7 @@ void CPDF_ColorSpace::TranslateImageLine(uint8_t* dest_buf,
   FX_FLOAT* src = srcbuf;
   FX_FLOAT R, G, B;
   for (int i = 0; i < pixels; i++) {
-    for (int j = 0; j < m_nComponents; j++)
+    for (uint32_t j = 0; j < m_nComponents; j++)
       if (m_Family == PDFCS_INDEXED) {
         src[j] = (FX_FLOAT)(*src_buf++);
       } else {
@@ -842,7 +842,7 @@ FX_BOOL CPDF_ICCBasedCS::v_Load(CPDF_Document* pDoc, CPDF_Array* pArray) {
   }
   CPDF_Array* pRanges = pDict->GetArrayBy("Range");
   m_pRanges = FX_Alloc2D(FX_FLOAT, m_nComponents, 2);
-  for (int i = 0; i < m_nComponents * 2; i++) {
+  for (uint32_t i = 0; i < m_nComponents * 2; i++) {
     if (pRanges)
       m_pRanges[i] = pRanges->GetNumberAt(i);
     else if (i % 2)
@@ -918,7 +918,7 @@ void CPDF_ICCBasedCS::TranslateImageLine(uint8_t* pDestBuf,
     ReverseRGB(pDestBuf, pSrcBuf, pixels);
   } else if (m_pProfile->m_pTransform) {
     int nMaxColors = 1;
-    for (int i = 0; i < m_nComponents; i++) {
+    for (uint32_t i = 0; i < m_nComponents; i++) {
       nMaxColors *= 52;
     }
     if (m_nComponents > 3 || image_width * image_height < nMaxColors * 3 / 2) {
@@ -932,7 +932,7 @@ void CPDF_ICCBasedCS::TranslateImageLine(uint8_t* pDestBuf,
         for (int i = 0; i < nMaxColors; i++) {
           uint32_t color = i;
           uint32_t order = nMaxColors / 52;
-          for (int c = 0; c < m_nComponents; c++) {
+          for (uint32_t c = 0; c < m_nComponents; c++) {
             *pSrc++ = (uint8_t)(color / order * 5);
             color %= order;
             order /= 52;
@@ -944,7 +944,7 @@ void CPDF_ICCBasedCS::TranslateImageLine(uint8_t* pDestBuf,
       }
       for (int i = 0; i < pixels; i++) {
         int index = 0;
-        for (int c = 0; c < m_nComponents; c++) {
+        for (uint32_t c = 0; c < m_nComponents; c++) {
           index = index * 52 + (*pSrcBuf) / 5;
           pSrcBuf++;
         }
diff --git a/core/fpdfapi/fpdf_page/cpdf_textobject.cpp b/core/fpdfapi/fpdf_page/cpdf_textobject.cpp
index 7ca03b4f05..444101fb9e 100644
--- a/core/fpdfapi/fpdf_page/cpdf_textobject.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_textobject.cpp
@@ -28,7 +28,7 @@ void CPDF_TextObject::GetItemInfo(int index, CPDF_TextObjectItem* pInfo) const {
       m_nChars == 1 ? (uint32_t)(uintptr_t)m_pCharCodes : m_pCharCodes[index];
   pInfo->m_OriginX = index ? m_pCharPos[index - 1] : 0;
   pInfo->m_OriginY = 0;
-  if (pInfo->m_CharCode == -1) {
+  if (pInfo->m_CharCode == CPDF_Font::kInvalidCharCode) {
     return;
   }
   CPDF_Font* pFont = m_TextState.GetFont();
@@ -54,7 +54,7 @@ int CPDF_TextObject::CountChars() const {
   }
   int count = 0;
   for (int i = 0; i < m_nChars; ++i)
-    if (m_pCharCodes[i] != (uint32_t)-1) {
+    if (m_pCharCodes[i] != CPDF_Font::kInvalidCharCode) {
       ++count;
     }
   return count;
@@ -70,10 +70,11 @@ void CPDF_TextObject::GetCharInfo(int index,
   }
   int count = 0;
   for (int i = 0; i < m_nChars; ++i) {
-    if (m_pCharCodes[i] != (uint32_t)-1) {
+    if (m_pCharCodes[i] != CPDF_Font::kInvalidCharCode) {
       if (count == index) {
         charcode = m_pCharCodes[i];
-        if (i == m_nChars - 1 || m_pCharCodes[i + 1] != (uint32_t)-1) {
+        if (i == m_nChars - 1 ||
+            m_pCharCodes[i + 1] != CPDF_Font::kInvalidCharCode) {
           kerning = 0;
         } else {
           kerning = m_pCharPos[i];
@@ -93,7 +94,7 @@ void CPDF_TextObject::GetCharInfo(int index, CPDF_TextObjectItem* pInfo) const {
   int count = 0;
   for (int i = 0; i < m_nChars; ++i) {
     uint32_t charcode = m_pCharCodes[i];
-    if (charcode == (uint32_t)-1) {
+    if (charcode == CPDF_Font::kInvalidCharCode) {
       continue;
     }
     if (count == index) {
@@ -156,7 +157,7 @@ void CPDF_TextObject::SetSegments(const CFX_ByteString* pStrs,
       }
       if (i != nsegs - 1) {
         m_pCharPos[index - 1] = pKerning[i];
-        m_pCharCodes[index++] = (uint32_t)-1;
+        m_pCharCodes[index++] = CPDF_Font::kInvalidCharCode;
       }
     }
   } else {
@@ -206,7 +207,7 @@ void CPDF_TextObject::CalcPositionData(FX_FLOAT* pTextAdvanceX,
     uint32_t charcode =
         m_nChars == 1 ? (uint32_t)(uintptr_t)m_pCharCodes : m_pCharCodes[i];
     if (i > 0) {
-      if (charcode == (uint32_t)-1) {
+      if (charcode == CPDF_Font::kInvalidCharCode) {
         curpos -= (m_pCharPos[i - 1] * fontsize) / 1000;
         continue;
       }
diff --git a/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp b/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
index f2b7582a01..8bff5445ff 100644
--- a/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
+++ b/core/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
@@ -48,7 +48,7 @@ uint32_t DecodeAllScanlines(ICodec_ScanlineDecoder* pDecoder,
                             uint8_t*& dest_buf,
                             uint32_t& dest_size) {
   if (!pDecoder) {
-    return static_cast<uint32_t>(-1);
+    return FX_INVALID_OFFSET;
   }
   int ncomps = pDecoder->CountComps();
   int bpc = pDecoder->GetBPC();
@@ -57,7 +57,7 @@ uint32_t DecodeAllScanlines(ICodec_ScanlineDecoder* pDecoder,
   int pitch = (width * ncomps * bpc + 7) / 8;
   if (height == 0 || pitch > (1 << 30) / height) {
     delete pDecoder;
-    return static_cast<uint32_t>(-1);
+    return FX_INVALID_OFFSET;
   }
   dest_buf = FX_Alloc2D(uint8_t, pitch, height);
   dest_size = pitch * height;  // Safe since checked alloc returned.
diff --git a/core/fpdfapi/fpdf_parser/cpdf_array.cpp b/core/fpdfapi/fpdf_parser/cpdf_array.cpp
index 69de5bbc26..544469916b 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_array.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_array.cpp
@@ -47,7 +47,7 @@ const CPDF_Array* CPDF_Array::AsArray() const {
 
 CPDF_Object* CPDF_Array::Clone(FX_BOOL bDirect) const {
   CPDF_Array* pCopy = new CPDF_Array();
-  for (int i = 0; i < GetCount(); i++) {
+  for (size_t i = 0; i < GetCount(); i++) {
     CPDF_Object* value = m_Objects.GetAt(i);
     pCopy->m_Objects.Add(value->Clone(bDirect));
   }
diff --git a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp
index dd2be01311..147ae37ed0 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp
@@ -185,7 +185,7 @@ FX_BOOL CPDF_HintTables::ReadPageHintTable(CFX_BitStream* hStream) {
     if (!CanReadFromBitStream(hStream, required_bits))
       return FALSE;
 
-    for (int j = 0; j < m_dwNSharedObjsArray[i]; j++)
+    for (uint32_t j = 0; j < m_dwNSharedObjsArray[i]; j++)
       m_dwIdentifierArray.Add(hStream->GetBits(dwSharedIdBits));
   }
   hStream->ByteAlign();
@@ -385,7 +385,7 @@ IPDF_DataAvail::DocAvailStatus CPDF_HintTables::CheckPage(
 
   uint32_t dwIndex = 0;
   uint32_t dwObjNum = 0;
-  for (int j = 0; j < m_dwNSharedObjsArray[index]; ++j) {
+  for (uint32_t j = 0; j < m_dwNSharedObjsArray[index]; ++j) {
     dwIndex = m_dwIdentifierArray[offset + j];
     if (dwIndex >= m_dwSharedObjNumArray.GetSize())
       return IPDF_DataAvail::DataNotAvailable;
diff --git a/core/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp b/core/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
index 219a72507b..346476b62b 100644
--- a/core/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
+++ b/core/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
@@ -176,24 +176,21 @@ uint32_t RunLengthDecode(const uint8_t* src_buf,
     if (src_buf[i] < 128) {
       old = dest_size;
       dest_size += src_buf[i] + 1;
-      if (dest_size < old) {
-        return static_cast<uint32_t>(-1);
-      }
+      if (dest_size < old)
+        return FX_INVALID_OFFSET;
       i += src_buf[i] + 2;
     } else if (src_buf[i] > 128) {
       old = dest_size;
       dest_size += 257 - src_buf[i];
-      if (dest_size < old) {
-        return static_cast<uint32_t>(-1);
-      }
+      if (dest_size < old)
+        return FX_INVALID_OFFSET;
       i += 2;
     } else {
       break;
     }
   }
-  if (dest_size >= _STREAM_MAX_SIZE_) {
-    return static_cast<uint32_t>(-1);
-  }
+  if (dest_size >= _STREAM_MAX_SIZE_)
+    return FX_INVALID_OFFSET;
   dest_buf = FX_Alloc(uint8_t, dest_size);
   i = 0;
   int dest_count = 0;