[lldb] Fix NSURL data formatter truncation issue

Remove hardcoded string prefix length assumption causing issues when
concatenating summary for NSURL in NSURLSummaryProvider. Provider relies
on concatenation of NSStringProvider results for summary, and while the
strings are prefixed with '@' in Objective-C, that is not the case in
Swift causing part of the description to be truncated.

This will be tested in the downstream fork.

Patch by Martin Svensson!

1 files changed, 33 insertions, 21 deletions

diff --git a/lldb/source/Plugins/Language/ObjC/Cocoa.cpp b/lldb/source/Plugins/Language/ObjC/Cocoa.cpp
index ddf3953bb51..8a81abbaedb 100644
--- a/lldb/source/Plugins/Language/ObjC/Cocoa.cpp
+++ b/lldb/source/Plugins/Language/ObjC/Cocoa.cpp
@@ -694,32 +694,44 @@ bool lldb_private::formatters::NSURLSummaryProvider(
   CompilerType type(valobj.GetCompilerType());
   ValueObjectSP text(valobj.GetSyntheticChildAtOffset(offset_text, type, true));
   ValueObjectSP base(valobj.GetSyntheticChildAtOffset(offset_base, type, true));
-  if (!text)
-    return false;
-  if (text->GetValueAsUnsigned(0) == 0)
+  if (!text || text->GetValueAsUnsigned(0) == 0)
     return false;
+
+  StreamString base_summary;
+  if (base && base->GetValueAsUnsigned(0)) {
+    if (!NSURLSummaryProvider(*base, base_summary, options))
+      base_summary.Clear();
+  }
+  if (base_summary.Empty())
+    return NSStringSummaryProvider(*text, stream, options);
+
   StreamString summary;
-  if (!NSStringSummaryProvider(*text, summary, options))
+  if (!NSStringSummaryProvider(*text, summary, options) || summary.Empty())
     return false;
-  if (base && base->GetValueAsUnsigned(0)) {
-    std::string summary_str = summary.GetString();
-
-    if (!summary_str.empty())
-      summary_str.pop_back();
-    summary_str += " -- ";
-    StreamString base_summary;
-    if (NSURLSummaryProvider(*base, base_summary, options) &&
-        !base_summary.Empty()) {
-      llvm::StringRef base_str = base_summary.GetString();
-      if (base_str.size() > 2)
-        base_str = base_str.drop_front(2);
-      summary_str += base_str;
+
+  const char quote_char = '"';
+  std::string prefix, suffix;
+  if (Language *language = Language::FindPlugin(options.GetLanguage())) {
+    if (!language->GetFormatterPrefixSuffix(*text, ConstString("NSString"),
+                                            prefix, suffix)) {
+      prefix.clear();
+      suffix.clear();
     }
-    summary.Clear();
-    summary.PutCString(summary_str);
   }
-  if (!summary.Empty()) {
-    stream.PutCString(summary.GetString());
+  // @"A" -> @"A
+  llvm::StringRef summary_str = summary.GetString();
+  bool back_consumed = summary_str.consume_back(quote_char + suffix);
+  assert(back_consumed);
+  UNUSED_IF_ASSERT_DISABLED(back_consumed);
+  // @"B" -> B"
+  llvm::StringRef base_summary_str = base_summary.GetString();
+  bool front_consumed = base_summary_str.consume_front(prefix + quote_char);
+  assert(front_consumed);
+  UNUSED_IF_ASSERT_DISABLED(front_consumed);
+  // @"A -- B"
+  if (!summary_str.empty() && !base_summary_str.empty()) {
+    stream.Printf("%s -- %s", summary_str.str().c_str(),
+                  base_summary_str.str().c_str());
     return true;
   }