Move the column marking functionality to the Highlighter framework

Summary:
The syntax highlighting feature so far is mutually exclusive with the lldb feature
that marks the current column in the line by underlining it via an ANSI color code.
Meaning that if you enable one, the other is automatically disabled by LLDB.

This was caused by the fact that both features inserted color codes into the the
source code and were likely to interfere with each other (which would result
in a broken source code printout to the user).

This patch moves the cursor code into the highlighting framework, which provides
the same feature to the user in normal non-C source code. For any source code
that is highlighted by Clang, we now also have cursor marking for the whole token
that is under the current source location. E.g., before we underlined only the '!' in the
expression '1 != 2', but now the whole token '!=' is underlined. The same for function
calls and so on. Below you can see two examples where we before only underlined
the first character of the token, but now underline the whole token.

{F7075400}
{F7075414}

It also simplifies the DisplaySourceLines method in the SourceManager as most of
the code in there was essentially just for getting this column marker to work as
a FormatEntity.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D51466

llvm-svn: 341003

1 files changed, 26 insertions, 69 deletions

diff --git a/lldb/source/Core/SourceManager.cpp b/lldb/source/Core/SourceManager.cpp
index c14b72250e7..413505d3ba8 100644
--- a/lldb/source/Core/SourceManager.cpp
+++ b/lldb/source/Core/SourceManager.cpp
@@ -127,11 +127,6 @@ static bool should_show_stop_column_with_ansi(DebuggerSP debugger_sp) {
   if (!debugger_sp->GetUseColor())
     return false;
 
-  // Don't use terminal attributes when we have highlighting enabled. This
-  // can mess up the command line.
-  if (debugger_sp->GetHighlightSource())
-    return false;
-
   // We only use ANSI stop column formatting if we're either supposed to show
   // ANSI where available (which we know we have when we get to this point), or
   // if we're only supposed to use ANSI.
@@ -201,8 +196,16 @@ size_t SourceManager::DisplaySourceLinesWithLineNumbersUsingLastFile(
       return_value +=
           s->Printf("%s%2.2s %-4u\t", prefix,
                     line == curr_line ? current_line_cstr : "", line);
-      size_t this_line_size = m_last_file_sp->DisplaySourceLines(
-          line, line == curr_line ? column : 0, 0, 0, s);
+
+      // So far we treated column 0 as a special 'no column value', but
+      // DisplaySourceLines starts counting columns from 0 (and no column is
+      // expressed by passing an empty optional).
+      llvm::Optional<size_t> columnToHighlight;
+      if (line == curr_line && column)
+        columnToHighlight = column - 1;
+
+      size_t this_line_size =
+          m_last_file_sp->DisplaySourceLines(line, columnToHighlight, 0, 0, s);
       if (column != 0 && line == curr_line &&
           should_show_stop_column_with_caret(m_debugger_wp.lock())) {
         // Display caret cursor.
@@ -521,7 +524,8 @@ void SourceManager::File::UpdateIfNeeded() {
   }
 }
 
-size_t SourceManager::File::DisplaySourceLines(uint32_t line, uint32_t column,
+size_t SourceManager::File::DisplaySourceLines(uint32_t line,
+                                               llvm::Optional<size_t> column,
                                                uint32_t context_before,
                                                uint32_t context_after,
                                                Stream *s) {
@@ -535,15 +539,24 @@ size_t SourceManager::File::DisplaySourceLines(uint32_t line, uint32_t column,
 
   size_t bytes_written = s->GetWrittenBytes();
 
-  std::string previous_content;
+  auto debugger_sp = m_debugger_wp.lock();
+
+  HighlightStyle style;
+  // Use the default Vim style if source highlighting is enabled.
+  if (should_highlight_source(debugger_sp))
+    style = HighlightStyle::MakeVimStyle();
+
+  // If we should mark the stop column with color codes, then copy the prefix
+  // and suffix to our color style.
+  if (should_show_stop_column_with_ansi(debugger_sp))
+    style.selected.Set(debugger_sp->GetStopShowColumnAnsiPrefix(),
+                       debugger_sp->GetStopShowColumnAnsiSuffix());
 
-  HighlightStyle style = HighlightStyle::MakeVimStyle();
   HighlighterManager mgr;
   std::string path = GetFileSpec().GetPath(/*denormalize*/ false);
   // FIXME: Find a way to get the definitive language this file was written in
   // and pass it to the highlighter.
-  auto &highlighter =
-      mgr.getHighlighterFor(lldb::LanguageType::eLanguageTypeUnknown, path);
+  const auto &h = mgr.getHighlighterFor(lldb::eLanguageTypeUnknown, path);
 
   const uint32_t start_line =
       line <= context_before ? 1 : line - context_before;
@@ -560,64 +573,8 @@ size_t SourceManager::File::DisplaySourceLines(uint32_t line, uint32_t column,
       const uint8_t *cstr = m_data_sp->GetBytes() + start_line_offset;
 
       auto ref = llvm::StringRef(reinterpret_cast<const char *>(cstr), count);
-      bool displayed_line = false;
-
-      auto debugger_sp = m_debugger_wp.lock();
-      if (should_highlight_source(debugger_sp)) {
-        highlighter.Highlight(style, ref, previous_content, *s);
-        displayed_line = true;
-        // Add the new line to the previous lines.
-        previous_content += ref.str();
-      }
-
-      if (!displayed_line && column && (column < count)) {
-        if (should_show_stop_column_with_ansi(debugger_sp) && debugger_sp) {
-          // Check if we have any ANSI codes with which to mark this column. If
-          // not, no need to do this work.
-          auto ansi_prefix_entry = debugger_sp->GetStopShowColumnAnsiPrefix();
-          auto ansi_suffix_entry = debugger_sp->GetStopShowColumnAnsiSuffix();
-
-          // We only bother breaking up the line to format the marked column if
-          // there is any marking specified on both sides of the marked column.
-          // In ANSI-terminal-sequence land, there must be a post if there is a
-          // pre format, and vice versa.
-          if (ansi_prefix_entry && ansi_suffix_entry) {
-            // Mark the current column with the desired escape sequence for
-            // formatting the column (e.g. underline, inverse, etc.)
-
-            // First print the part before the column to mark.
-            s->Write(cstr, column - 1);
-
-            // Write the pre escape sequence.
-            const SymbolContext *sc = nullptr;
-            const ExecutionContext *exe_ctx = nullptr;
-            const Address addr = LLDB_INVALID_ADDRESS;
-            ValueObject *valobj = nullptr;
-            const bool function_changed = false;
-            const bool initial_function = false;
-
-            FormatEntity::Format(*ansi_prefix_entry, *s, sc, exe_ctx, &addr,
-                                 valobj, function_changed, initial_function);
-
-            s->Write(cstr + column - 1, 1);
-
-            // Write the post escape sequence.
-            FormatEntity::Format(*ansi_suffix_entry, *s, sc, exe_ctx, &addr,
-                                 valobj, function_changed, initial_function);
-
-            // And finish up with the rest of the line.
-            s->Write(cstr + column, count - column);
-
-            // Keep track of the fact that we just wrote the line.
-            displayed_line = true;
-          }
-        }
-      }
 
-      // If we didn't end up displaying the line with ANSI codes for whatever
-      // reason, display it now sans codes.
-      if (!displayed_line)
-        s->PutCString(ref);
+      h.Highlight(style, ref, column, "", *s);
 
       // Ensure we get an end of line character one way or another.
       if (!is_newline_char(ref.back()))