Simplify find_first_of & find_last_of on single char.

[brucem]

Summary

When calling find_first_of and find_last_of on a single character,
we can instead just call find / rfind and make our intent more
clear.

[brucem]

This touches random files across the tree, including lldb-mi. I wasn't sure how best this should be reviewed or by who (despite it being pretty mechanical).

source/Core/FormatEntity.cpp

 
 Error
 FormatEntity::ExtractVariableInfo (llvm::StringRef &format_str, llvm::StringRef &variable_name, llvm::StringRef &variable_format)
 {
     Error error;
     variable_name = llvm::StringRef();
     variable_format = llvm::StringRef();
 
-    const size_t paren_pos = format_str.find_first_of('}');
+    const size_t paren_pos = format_str.find('}');
     if (paren_pos != llvm::StringRef::npos)
     {
-        const size_t percent_pos = format_str.find_first_of('%');
+        const size_t percent_pos = format_str.find('%');
         if (percent_pos < paren_pos)
         {
             if (percent_pos > 0)
             {
                 if (percent_pos > 1)
                     variable_name = format_str.substr(0, percent_pos);
                 variable_format = format_str.substr(percent_pos + 1, paren_pos - (percent_pos + 1));
             }

source/Host/common/FileSpec.cpp

 void
 FileSpec::ResolveUsername (llvm::SmallVectorImpl<char> &path)
 {
 #if LLDB_CONFIG_TILDE_RESOLVES_TO_USER
     if (path.empty() || path[0] != '~')
         return;
     
     llvm::StringRef path_str(path.data(), path.size());
-    size_t slash_pos = path_str.find_first_of("/", 1);
+    size_t slash_pos = path_str.find('/', 1);
     if (slash_pos == 1 || path.size() == 1)
     {
         // A path of ~/ resolves to the current user's home dir
         llvm::SmallString<64> home_dir;
         if (!llvm::sys::path::home_directory(home_dir))
             return;
         
         // Overwrite the ~ with the first character of the homedir, and insert

source/Host/common/ThisThread.cpp

ThisThread::SetName(llvm::StringRef name, int max_length)
     {
         // First see if we can get lucky by removing any initial or final braces.
         std::string::size_type begin = truncated_name.find_first_not_of("(<");
         std::string::size_type end = truncated_name.find_last_not_of(")>.");
         if (end - begin > static_cast<size_t>(max_length))
         {
             // We're still too long.  Since this is a dotted component, use everything after the last
             // dot, up to a maximum of |length| characters.
-            std::string::size_type last_dot = truncated_name.find_last_of(".");
+            std::string::size_type last_dot = truncated_name.rfind('.');
             if (last_dot != std::string::npos)
                 begin = last_dot + 1;
 
             end = std::min(end, begin + max_length);
         }
 
         std::string::size_type count = end - begin + 1;
         truncated_name = truncated_name.substr(begin, count);
     }
 
     SetName(truncated_name.c_str());
 }

source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTypeEncodingParser.cpp

if (type.NextIf('"'))
         else
         {
             // the quoted string is a class name – see the rule
         }
     }
     
     if (for_expression && !name.empty())
     {
-        size_t less_than_pos = name.find_first_of('<');
+        size_t less_than_pos = name.find('<');
         
         if (less_than_pos != std::string::npos)
         {
             if (less_than_pos == 0)
                 return ast_ctx.getObjCIdType();
             else
                 name.erase(less_than_pos);
         }

source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp

if (info_sym)
         DataBufferSP buffer = fs.ReadFileContents(addr, size);
 
         if (!buffer)
             return false;
 
         std::string info((const char *)buffer->GetBytes());
 
         std::vector<std::string> info_lines;
-        size_t lpos = info.find_first_of("\n");
+        size_t lpos = info.find('\n');
         while (lpos != std::string::npos)
         {
             info_lines.push_back(info.substr(0, lpos));
             info = info.substr(lpos + 1);
-            lpos = info.find_first_of("\n");
+            lpos = info.find('\n');
         }
         size_t offset = 0;
         while (offset < info_lines.size())
         {
             std::string line = info_lines[offset];
             // Parse directives
             uint32_t numDefns = 0;
             if (sscanf(line.c_str(), "exportVarCount: %u", &numDefns) == 1)

source/Utility/UriParser.cpp

UriParser::Parse(const std::string& uri,
     static const char* kSchemeSep = "://";
     auto pos = uri.find(kSchemeSep);
     if (pos == std::string::npos)
         return false;
 
     // Extract path.
     tmp_scheme = uri.substr(0, pos);
     auto host_pos = pos + strlen(kSchemeSep);
-    auto path_pos = uri.find_first_of("/", host_pos);
+    auto path_pos = uri.find('/', host_pos);
     if (path_pos != std::string::npos)
         tmp_path = uri.substr(path_pos);
     else
         tmp_path = "/";
 
     auto host_port = uri.substr(
         host_pos, ((path_pos != std::string::npos) ? path_pos  : uri.size()) - host_pos);
 

tools/lldb-mi/MICmdArgValFile.cpp

 // Throws:  None.
 //--
 bool
 CMICmdArgValFile::IsFilePath(const CMIUtilString &vrFileNamePath) const
 {
     if (vrFileNamePath.empty())
         return false;
 
-    const bool bHavePosSlash = (vrFileNamePath.find_first_of("/") != std::string::npos);
-    const bool bHaveBckSlash = (vrFileNamePath.find_first_of("\\") != std::string::npos);
+    const bool bHavePosSlash = (vrFileNamePath.find('/') != std::string::npos);
+    const bool bHaveBckSlash = (vrFileNamePath.find('\\') != std::string::npos);
 
     // Look for --someLongOption
     size_t nPos = vrFileNamePath.find("--");
     const bool bLong = (nPos == 0);
     if (bLong)
         return false;
 
     // Look for -f type short parameters
-    nPos = vrFileNamePath.find_first_of("-");
+    nPos = vrFileNamePath.find('-');
     const bool bShort = (nPos == 0);
     if (bShort)
         return false;
 
     // Look for i1 i2 i3....
-    nPos = vrFileNamePath.find_first_of("i");
+    nPos = vrFileNamePath.find('i');
     const bool bFoundI1 = ((nPos == 0) && (::isdigit(vrFileNamePath[1])));
     if (bFoundI1)
         return false;
 
     const bool bValidChars = IsValidChars(vrFileNamePath);
     if (bValidChars || bHavePosSlash || bHaveBckSlash)
         return true;
 

tools/lldb-mi/MICmdArgValOptionLong.cpp

 // Type:    Method.
 // Args:    vrTxt   - (R) Some text.
 // Return:  bool    - True = yes valid arg, false = no.
 // Throws:  None.
 //--
 bool
 CMICmdArgValOptionLong::IsArgLongOption(const CMIUtilString &vrTxt) const
 {
-    const bool bHavePosSlash = (vrTxt.find_first_of("/") != std::string::npos);
-    const bool bHaveBckSlash = (vrTxt.find_first_of("\\") != std::string::npos);
+    const bool bHavePosSlash = (vrTxt.find('/') != std::string::npos);
+    const bool bHaveBckSlash = (vrTxt.find('\\') != std::string::npos);
     if (bHavePosSlash || bHaveBckSlash)
         return false;
 
     const size_t nPos = vrTxt.find("--");
     if (nPos != 0)
         return false;
 
     if (vrTxt.length() < 3)

tools/lldb-mi/MICmdArgValString.cpp

 // Throws:  None.
 //--
 bool
 CMICmdArgValString::IsStringArgSingleText(const CMIUtilString &vrTxt) const
 {
     if (!m_bHandleDirPaths)
     {
         // Look for directory file paths, if found reject
-        const bool bHavePosSlash = (vrTxt.find_first_of("/") != std::string::npos);
-        const bool bHaveBckSlash = (vrTxt.find_first_of("\\") != std::string::npos);
+        const bool bHavePosSlash = (vrTxt.find('/') != std::string::npos);
+        const bool bHaveBckSlash = (vrTxt.find('\\') != std::string::npos);
         if (bHavePosSlash || bHaveBckSlash)
             return false;
     }
 
     // Look for --someLongOption, if found reject
     if (0 == vrTxt.find("--"))
         return false;
 

tools/lldb-mi/MICmdArgValThreadGrp.cpp

 // Args:    vrTxt   - (R) Some text.
 // Return:  bool    - True = yes valid arg, false = no.
 // Throws:  None.
 //--
 bool
 CMICmdArgValThreadGrp::IsArgThreadGrp(const CMIUtilString &vrTxt) const
 {
     // Look for i1 i2 i3....
-    const MIint nPos = vrTxt.find_first_of("i");
+    const MIint nPos = vrTxt.find('i');
     if (nPos != 0)
         return false;
 
     const CMIUtilString strNum = vrTxt.substr(1).c_str();
     if (!strNum.IsNumber())
         return false;
 
     return true;

tools/lldb-mi/MICmdCmdBreak.cpp

 // Given a string, return the position of the ':' separator in 'file:func'
 // or 'file:line', if any.  If not found, return npos.  For example, return
 // 5 for 'foo.c:std::string'.
 //--
 static size_t findFileSeparatorPos(const std::string& x)
 {
     // Full paths in windows can have ':' after a drive letter, so we
     // search backwards, taking care to skip C++ namespace tokens '::'.
-    size_t n = x.find_last_of(':');
+    size_t n = x.rfind(':');
     while (n != std::string::npos && n > 1 && x[n-1] == ':')
     {
-        n = x.find_last_of(':', n - 2);
+        n = x.rfind(':', n - 2);
     }
     return n;
 }
 
 //++ ------------------------------------------------------------------------------------
 // Details: The invoker requires this function. The command does work in this function.
 //          The command is likely to communicate with the LLDB SBDebugger in here.
 // Type:    Overridden.