Remove GetAt from string classes

This method duplicates the behaviour of the const [] operator and
doesn't offer any additional safety. Folding them into one
implementation.

SetAt is retained, since implementing the non-const [] operator to
replace SetAt has potential performance concerns. Specifically many
non-obvious cases of reading an element using [] will cause a realloc
& copy.

BUG=pdfium:860

Change-Id: I3ef5e5e5a15376f040256b646eb0d90636e24b67
Reviewed-on: https://pdfium-review.googlesource.com/10870
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

3 files changed, 16 insertions, 16 deletions

diff --git a/core/fpdfdoc/cpdf_filespec.cpp b/core/fpdfdoc/cpdf_filespec.cpp
index 5ef6f466c5..e34f54e4e1 100644
--- a/core/fpdfdoc/cpdf_filespec.cpp
+++ b/core/fpdfdoc/cpdf_filespec.cpp
@@ -69,13 +69,13 @@ CFX_WideString CPDF_FileSpec::DecodeFileName(const CFX_WideString& filepath) {
   return ChangeSlashToPlatform(filepath.c_str());
 #elif _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 
-  if (filepath.GetAt(0) != L'/')
+  if (filepath[0] != L'/')
     return ChangeSlashToPlatform(filepath.c_str());
-  if (filepath.GetAt(1) == L'/')
+  if (filepath[1] == L'/')
     return ChangeSlashToPlatform(filepath.c_str() + 1);
-  if (filepath.GetAt(2) == L'/') {
+  if (filepath[2] == L'/') {
     CFX_WideString result;
-    result += filepath.GetAt(1);
+    result += filepath[1];
     result += L':';
     result += ChangeSlashToPlatform(filepath.c_str() + 2);
     return result;
@@ -158,19 +158,19 @@ CFX_WideString CPDF_FileSpec::EncodeFileName(const CFX_WideString& filepath) {
     return CFX_WideString();
 
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
-  if (filepath.GetAt(1) == L':') {
+  if (filepath[1] == L':') {
     CFX_WideString result(L'/');
-    result += filepath.GetAt(0);
-    if (filepath.GetAt(2) != L'\\')
+    result += filepath[0];
+    if (filepath[2] != L'\\')
       result += L'/';
 
     result += ChangeSlashToPDF(filepath.c_str() + 2);
     return result;
   }
-  if (filepath.GetAt(0) == L'\\' && filepath.GetAt(1) == L'\\')
+  if (filepath[0] == L'\\' && filepath[1] == L'\\')
     return ChangeSlashToPDF(filepath.c_str() + 1);
 
-  if (filepath.GetAt(0) == L'\\')
+  if (filepath[0] == L'\\')
     return L'/' + ChangeSlashToPDF(filepath.c_str());
   return ChangeSlashToPDF(filepath.c_str());
 #elif _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
diff --git a/core/fpdfdoc/cpdf_variabletext.cpp b/core/fpdfdoc/cpdf_variabletext.cpp
index 74a5e3adfc..877f8ca01e 100644
--- a/core/fpdfdoc/cpdf_variabletext.cpp
+++ b/core/fpdfdoc/cpdf_variabletext.cpp
@@ -358,11 +358,11 @@ CPVT_WordPlace CPDF_VariableText::InsertText(const CPVT_WordPlace& place,
   CPVT_WordPlace wp = place;
   for (int32_t i = 0, sz = swText.GetLength(); i < sz; i++) {
     CPVT_WordPlace oldwp = wp;
-    uint16_t word = swText.GetAt(i);
+    uint16_t word = swText[i];
     switch (word) {
       case 0x0D:
         if (m_bMultiLine) {
-          if (swText.GetAt(i + 1) == 0x0A)
+          if (swText[i + 1] == 0x0A)
             i += 1;
 
           wp = InsertSection(wp, nullptr, nullptr);
@@ -370,7 +370,7 @@ CPVT_WordPlace CPDF_VariableText::InsertText(const CPVT_WordPlace& place,
         break;
       case 0x0A:
         if (m_bMultiLine) {
-          if (swText.GetAt(i + 1) == 0x0D)
+          if (swText[i + 1] == 0x0D)
             i += 1;
 
           wp = InsertSection(wp, nullptr, nullptr);
@@ -426,11 +426,11 @@ void CPDF_VariableText::SetText(const CFX_WideString& swText) {
     if (m_nCharArray > 0 && nCharCount >= m_nCharArray)
       break;
 
-    uint16_t word = swText.GetAt(i);
+    uint16_t word = swText[i];
     switch (word) {
       case 0x0D:
         if (m_bMultiLine) {
-          if (i + 1 < sz && swText.GetAt(i + 1) == 0x0A)
+          if (i + 1 < sz && swText[i + 1] == 0x0A)
             i++;
           wp.AdvanceSection();
           AddSection(wp, secinfo);
@@ -438,7 +438,7 @@ void CPDF_VariableText::SetText(const CFX_WideString& swText) {
         break;
       case 0x0A:
         if (m_bMultiLine) {
-          if (i + 1 < sz && swText.GetAt(i + 1) == 0x0D)
+          if (i + 1 < sz && swText[i + 1] == 0x0D)
             i++;
           wp.AdvanceSection();
           AddSection(wp, secinfo);
diff --git a/core/fpdfdoc/cpvt_generateap.cpp b/core/fpdfdoc/cpvt_generateap.cpp
index d1abde681d..9b5a82a055 100644
--- a/core/fpdfdoc/cpvt_generateap.cpp
+++ b/core/fpdfdoc/cpvt_generateap.cpp
@@ -123,7 +123,7 @@ bool GenerateWidgetAP(CPDF_Document* pDoc,
       dsBorder = CPVT_Dash(pArray->GetIntegerAt(0), pArray->GetIntegerAt(1),
                            pArray->GetIntegerAt(2));
     }
-    switch (pBSDict->GetStringFor("S").GetAt(0)) {
+    switch (pBSDict->GetStringFor("S")[0]) {
       case 'S':
         nBorderStyle = BorderStyle::SOLID;
         break;