[lldb] Refactor GetFormatFromCString to always check for partial matches (NFC) (llvm#81018)

Refactors logic in `ParseInternal` that was previously calling
`GetFormatFromCString` twice, once with `partial_match_ok` set to false,
and the second time set to true.

With this change, lldb formats (ie `%@`, `%S`, etc) are checked first.
If a format is not one of those, then `GetFormatFromCString` is called
once, and now always checks for partial matches.

Author: kastiglione

lldb/include/lldb/DataFormatters/FormatManager.h

@@ -138,7 +138,7 @@ class FormatManager : public IFormatChangeListener {
   }
 
   static bool GetFormatFromCString(const char *format_cstr,
-                                   bool partial_match_ok, lldb::Format &format);
+                                   lldb::Format &format);
 
   static char GetFormatAsFormatChar(lldb::Format format);
 

lldb/source/Core/FormatEntity.cpp

@@ -2151,11 +2151,7 @@ static Status ParseInternal(llvm::StringRef &format, Entry &parent_entry,
             if (entry.printf_format.find('%') == std::string::npos) {
               bool clear_printf = false;
 
-              if (FormatManager::GetFormatFromCString(
-                      entry.printf_format.c_str(), false, entry.fmt)) {
-                // We have an LLDB format, so clear the printf format
-                clear_printf = true;
-              } else if (entry.printf_format.size() == 1) {
+              if (entry.printf_format.size() == 1) {
                 switch (entry.printf_format[0]) {
                 case '@': // if this is an @ sign, print ObjC description
                   entry.number = ValueObject::
@@ -2198,20 +2194,20 @@ static Status ParseInternal(llvm::StringRef &format, Entry &parent_entry,
                       eValueObjectRepresentationStyleExpressionPath;
                   clear_printf = true;
                   break;
-                default:
+                }
+              }
+
+              if (entry.number == 0) {
+                if (FormatManager::GetFormatFromCString(
+                        entry.printf_format.c_str(), entry.fmt)) {
+                  clear_printf = true;
+                } else if (entry.printf_format == "tid") {
+                  verify_is_thread_id = true;
+                } else {
                   error.SetErrorStringWithFormat("invalid format: '%s'",
                                                  entry.printf_format.c_str());
                   return error;
                 }
-              } else if (FormatManager::GetFormatFromCString(
-                             entry.printf_format.c_str(), true, entry.fmt)) {
-                clear_printf = true;
-              } else if (entry.printf_format == "tid") {
-                verify_is_thread_id = true;
-              } else {
-                error.SetErrorStringWithFormat("invalid format: '%s'",
-                                               entry.printf_format.c_str());
-                return error;
               }
 
               // Our format string turned out to not be a printf style format

lldb/source/DataFormatters/FormatManager.cpp

@@ -91,7 +91,7 @@ static bool GetFormatFromFormatChar(char format_char, Format &format) {
 }
 
 static bool GetFormatFromFormatName(llvm::StringRef format_name,
-                                    bool partial_match_ok, Format &format) {
+                                    Format &format) {
   uint32_t i;
   for (i = 0; i < g_num_format_infos; ++i) {
     if (format_name.equals_insensitive(g_format_infos[i].format_name)) {
@@ -100,13 +100,11 @@ static bool GetFormatFromFormatName(llvm::StringRef format_name,
     }
   }
 
-  if (partial_match_ok) {
-    for (i = 0; i < g_num_format_infos; ++i) {
-      if (llvm::StringRef(g_format_infos[i].format_name)
-              .starts_with_insensitive(format_name)) {
-        format = g_format_infos[i].format;
-        return true;
-      }
+  for (i = 0; i < g_num_format_infos; ++i) {
+    if (llvm::StringRef(g_format_infos[i].format_name)
+            .starts_with_insensitive(format_name)) {
+      format = g_format_infos[i].format;
+      return true;
     }
   }
   format = eFormatInvalid;
@@ -124,7 +122,6 @@ void FormatManager::Changed() {
 }
 
 bool FormatManager::GetFormatFromCString(const char *format_cstr,
-                                         bool partial_match_ok,
                                          lldb::Format &format) {
   bool success = false;
   if (format_cstr && format_cstr[0]) {
@@ -134,7 +131,7 @@ bool FormatManager::GetFormatFromCString(const char *format_cstr,
         return true;
     }
 
-    success = GetFormatFromFormatName(format_cstr, partial_match_ok, format);
+    success = GetFormatFromFormatName(format_cstr, format);
   }
   if (!success)
     format = eFormatInvalid;

lldb/source/Interpreter/OptionArgParser.cpp

@@ -93,8 +93,7 @@ Status OptionArgParser::ToFormat(const char *s, lldb::Format &format,
         *byte_size_ptr = 0;
     }
 
-    const bool partial_match_ok = true;
-    if (!FormatManager::GetFormatFromCString(s, partial_match_ok, format)) {
+    if (!FormatManager::GetFormatFromCString(s, format)) {
       StreamString error_strm;
       error_strm.Printf(
           "Invalid format character or name '%s'. Valid values are:\n", s);