3 files changed, 196 insertions, 13 deletions

diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index 835f8034cdf..7a727479e16 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -140,6 +140,24 @@ OptionEnumValueElement g_language_enumerators[] = {
 // {${function.initial-function}{${module.file.basename}`}{${function.name-without-args}}:\n}{${function.changed}\n{${module.file.basename}`}{${function.name-without-args}}:\n}{${current-pc-arrow}
 // }{${addr-file-or-load}}:
 
+#define DEFAULT_STOP_SHOW_COLUMN_ANSI_PREFIX "${ansi.underline}"
+#define DEFAULT_STOP_SHOW_COLUMN_ANSI_SUFFIX "${ansi.normal}"
+
+static OptionEnumValueElement s_stop_show_column_values[] = {
+    {eStopShowColumnAnsiOrCaret, "ansi-or-caret",
+     "Highlight the stop column with ANSI terminal codes when color/ANSI mode "
+     "is enabled; otherwise, fall back to using a text-only caret (^) as if "
+     "\"caret-only\" mode was selected."},
+    {eStopShowColumnAnsi, "ansi", "Highlight the stop column with ANSI "
+                                  "terminal codes when running LLDB with "
+                                  "color/ANSI enabled."},
+    {eStopShowColumnCaret, "caret",
+     "Highlight the stop column with a caret character (^) underneath the stop "
+     "column. This method introduces a new line in source listings that "
+     "display thread stop locations."},
+    {eStopShowColumnNone, "none", "Do not highlight the stop column."},
+    {0, nullptr, nullptr}};
+
 static PropertyDefinition g_properties[] = {
     {"auto-confirm", OptionValue::eTypeBoolean, true, false, nullptr, nullptr,
      "If true all confirmation prompts will receive their default reply."},
@@ -173,6 +191,20 @@ static PropertyDefinition g_properties[] = {
     {"stop-line-count-before", OptionValue::eTypeSInt64, true, 3, nullptr,
      nullptr, "The number of sources lines to display that come before the "
               "current source line when displaying a stopped context."},
+    {"stop-show-column", OptionValue::eTypeEnum, false,
+     eStopShowColumnAnsiOrCaret, nullptr, s_stop_show_column_values,
+     "If true, LLDB will use the column information from the debug info to "
+     "mark the current position when displaying a stopped context."},
+    {"stop-show-column-ansi-prefix", OptionValue::eTypeFormatEntity, true, 0,
+     DEFAULT_STOP_SHOW_COLUMN_ANSI_PREFIX, nullptr,
+     "When displaying the column marker in a color-enabled (i.e. ANSI) "
+     "terminal, use the ANSI terminal code specified in this format at the "
+     "immediately before the column to be marked."},
+    {"stop-show-column-ansi-suffix", OptionValue::eTypeFormatEntity, true, 0,
+     DEFAULT_STOP_SHOW_COLUMN_ANSI_SUFFIX, nullptr,
+     "When displaying the column marker in a color-enabled (i.e. ANSI) "
+     "terminal, use the ANSI terminal code specified in this format "
+     "immediately after the column to be marked."},
     {"term-width", OptionValue::eTypeSInt64, true, 80, nullptr, nullptr,
      "The maximum number of columns to use for displaying text."},
     {"thread-format", OptionValue::eTypeFormatEntity, true, 0,
@@ -210,6 +242,9 @@ enum {
   ePropertyStopDisassemblyDisplay,
   ePropertyStopLineCountAfter,
   ePropertyStopLineCountBefore,
+  ePropertyStopShowColumn,
+  ePropertyStopShowColumnAnsiPrefix,
+  ePropertyStopShowColumnAnsiSuffix,
   ePropertyTerminalWidth,
   ePropertyThreadFormat,
   ePropertyUseExternalEditor,
@@ -371,6 +406,22 @@ bool Debugger::SetUseColor(bool b) {
   return ret;
 }
 
+StopShowColumn Debugger::GetStopShowColumn() const {
+  const uint32_t idx = ePropertyStopShowColumn;
+  return (lldb::StopShowColumn)m_collection_sp->GetPropertyAtIndexAsEnumeration(
+      nullptr, idx, g_properties[idx].default_uint_value);
+}
+
+const FormatEntity::Entry *Debugger::GetStopShowColumnAnsiPrefix() const {
+  const uint32_t idx = ePropertyStopShowColumnAnsiPrefix;
+  return m_collection_sp->GetPropertyAtIndexAsFormatEntity(nullptr, idx);
+}
+
+const FormatEntity::Entry *Debugger::GetStopShowColumnAnsiSuffix() const {
+  const uint32_t idx = ePropertyStopShowColumnAnsiSuffix;
+  return m_collection_sp->GetPropertyAtIndexAsFormatEntity(nullptr, idx);
+}
+
 uint32_t Debugger::GetStopSourceLineCount(bool before) const {
   const uint32_t idx =
       before ? ePropertyStopLineCountBefore : ePropertyStopLineCountAfter;
diff --git a/lldb/source/Core/Disassembler.cpp b/lldb/source/Core/Disassembler.cpp
index a2bbf71d501..5a320d1cd37 100644
--- a/lldb/source/Core/Disassembler.cpp
+++ b/lldb/source/Core/Disassembler.cpp
@@ -289,6 +289,9 @@ Disassembler::GetFunctionDeclLineEntry(const SymbolContext &sc) {
         func_decl_file == prologue_end_line.original_file) {
       decl_line.file = func_decl_file;
       decl_line.line = func_decl_line;
+      // TODO do we care about column on these entries?  If so, we need to
+      // plumb that through GetStartLineSourceInfo.
+      decl_line.column = 0;
     }
   }
   return decl_line;
@@ -448,6 +451,7 @@ bool Disassembler::PrintInstructions(Disassembler *disasm_ptr,
               SourceLine this_line;
               this_line.file = sc.line_entry.file;
               this_line.line = sc.line_entry.line;
+              this_line.column = sc.line_entry.column;
               if (ElideMixedSourceAndDisassemblyLine(exe_ctx, sc, this_line) ==
                   false)
                 AddLineToSourceLineTables(this_line, source_lines_seen);
@@ -613,7 +617,7 @@ bool Disassembler::PrintInstructions(Disassembler *disasm_ptr,
             line_highlight = "**";
           }
           source_manager.DisplaySourceLinesWithLineNumbers(
-              ln.file, ln.line, 0, 0, line_highlight, &strm);
+              ln.file, ln.line, ln.column, 0, 0, line_highlight, &strm);
         }
         if (source_lines_to_display.print_source_context_end_eol)
           strm.EOL();
diff --git a/lldb/source/Core/SourceManager.cpp b/lldb/source/Core/SourceManager.cpp
index 6ecd8da33d8..ff0ee7d8246 100644
--- a/lldb/source/Core/SourceManager.cpp
+++ b/lldb/source/Core/SourceManager.cpp
@@ -22,6 +22,7 @@
 #include "lldb/Symbol/Function.h"
 #include "lldb/Symbol/SymbolContext.h"
 #include "lldb/Target/Target.h"
+#include "lldb/Utility/AnsiTerminal.h"
 
 using namespace lldb;
 using namespace lldb_private;
@@ -71,7 +72,10 @@ SourceManager::FileSP SourceManager::GetFile(const FileSpec &file_spec) {
 
   // If file_sp is no good or it points to a non-existent file, reset it.
   if (!file_sp || !file_sp->GetFileSpec().Exists()) {
-    file_sp.reset(new File(file_spec, target_sp.get()));
+    if (target_sp)
+      file_sp.reset(new File(file_spec, target_sp.get()));
+    else
+      file_sp.reset(new File(file_spec, debugger_sp));
 
     if (debugger_sp)
       debugger_sp->GetSourceFileCache().AddSourceFile(file_sp);
@@ -79,8 +83,44 @@ SourceManager::FileSP SourceManager::GetFile(const FileSpec &file_spec) {
   return file_sp;
 }
 
+static bool should_show_stop_column_with_ansi(DebuggerSP debugger_sp) {
+  // We don't use ANSI stop column formatting if we can't lookup values from
+  // the debugger.
+  if (!debugger_sp)
+    return false;
+
+  // We don't use ANSI stop column formatting if the debugger doesn't think
+  // it should be using color.
+  if (!debugger_sp->GetUseColor())
+    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.
+  const auto value = debugger_sp->GetStopShowColumn();
+  return ((value == eStopShowColumnAnsiOrCaret) ||
+          (value == eStopShowColumnAnsi));
+}
+
+static bool should_show_stop_column_with_caret(DebuggerSP debugger_sp) {
+  // We don't use text-based stop column formatting if we can't lookup values
+  // from the debugger.
+  if (!debugger_sp)
+    return false;
+
+  // If we're asked to show the first available of ANSI or caret, then
+  // we do show the caret when ANSI is not available.
+  const auto value = debugger_sp->GetStopShowColumn();
+  if ((value == eStopShowColumnAnsiOrCaret) && !debugger_sp->GetUseColor())
+    return true;
+
+  // The only other time we use caret is if we're explicitly asked to show
+  // caret.
+  return value == eStopShowColumnCaret;
+}
+
 size_t SourceManager::DisplaySourceLinesWithLineNumbersUsingLastFile(
-    uint32_t start_line, uint32_t count, uint32_t curr_line,
+    uint32_t start_line, uint32_t count, uint32_t curr_line, uint32_t column,
     const char *current_line_cstr, Stream *s,
     const SymbolContextList *bp_locs) {
   if (count == 0)
@@ -123,7 +163,20 @@ 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, 0, 0, s);
+      size_t this_line_size = m_last_file_sp->DisplaySourceLines(
+          line, line == curr_line ? column : 0, 0, 0, s);
+      if (column != 0 && line == curr_line &&
+          should_show_stop_column_with_caret(m_debugger_wp.lock())) {
+        // Display caret cursor.
+        std::string src_line;
+        m_last_file_sp->GetLine(line, src_line);
+        return_value += s->Printf("    \t");
+        // Insert a space for every non-tab character in the source line.
+        for (int i = 0; i < column - 1 && i < src_line.length(); ++i)
+          return_value += s->PutChar(src_line[i] == '\t' ? '\t' : ' ');
+        // Now add the caret.
+        return_value += s->Printf("^\n");
+      }
       if (this_line_size == 0) {
         m_last_line = UINT32_MAX;
         break;
@@ -135,8 +188,9 @@ size_t SourceManager::DisplaySourceLinesWithLineNumbersUsingLastFile(
 }
 
 size_t SourceManager::DisplaySourceLinesWithLineNumbers(
-    const FileSpec &file_spec, uint32_t line, uint32_t context_before,
-    uint32_t context_after, const char *current_line_cstr, Stream *s,
+    const FileSpec &file_spec, uint32_t line, uint32_t column,
+    uint32_t context_before, uint32_t context_after,
+    const char *current_line_cstr, Stream *s,
     const SymbolContextList *bp_locs) {
   FileSP file_sp(GetFile(file_spec));
 
@@ -153,7 +207,7 @@ size_t SourceManager::DisplaySourceLinesWithLineNumbers(
     m_last_file_sp = file_sp;
   }
   return DisplaySourceLinesWithLineNumbersUsingLastFile(
-      start_line, count, line, current_line_cstr, s, bp_locs);
+      start_line, count, line, column, current_line_cstr, s, bp_locs);
 }
 
 size_t SourceManager::DisplayMoreWithLineNumbers(
@@ -193,8 +247,9 @@ size_t SourceManager::DisplayMoreWithLineNumbers(
     } else
       m_last_line = 1;
 
+    const uint32_t column = 0;
     return DisplaySourceLinesWithLineNumbersUsingLastFile(
-        m_last_line, m_last_count, UINT32_MAX, "", s, bp_locs);
+        m_last_line, m_last_count, UINT32_MAX, column, "", s, bp_locs);
   }
   return 0;
 }
@@ -272,10 +327,27 @@ void SourceManager::FindLinesMatchingRegex(FileSpec &file_spec,
                                          match_lines);
 }
 
+SourceManager::File::File(const FileSpec &file_spec,
+                          lldb::DebuggerSP debugger_sp)
+    : m_file_spec_orig(file_spec), m_file_spec(file_spec),
+      m_mod_time(file_spec.GetModificationTime()), m_source_map_mod_id(0),
+      m_data_sp(), m_offsets(), m_debugger_wp(debugger_sp) {
+  CommonInitializer(file_spec, nullptr);
+}
+
 SourceManager::File::File(const FileSpec &file_spec, Target *target)
     : m_file_spec_orig(file_spec), m_file_spec(file_spec),
       m_mod_time(file_spec.GetModificationTime()), m_source_map_mod_id(0),
-      m_data_sp(), m_offsets() {
+      m_data_sp(), m_offsets(),
+      m_debugger_wp(target ? target->GetDebugger().shared_from_this()
+                           : DebuggerSP()) {
+  CommonInitializer(file_spec, target);
+}
+
+SourceManager::File::~File() {}
+
+void SourceManager::File::CommonInitializer(const FileSpec &file_spec,
+                                            Target *target) {
   if (!m_mod_time.IsValid()) {
     if (target) {
       m_source_map_mod_id = target->GetSourcePathMap().GetModificationID();
@@ -337,8 +409,6 @@ SourceManager::File::File(const FileSpec &file_spec, Target *target)
     m_data_sp = m_file_spec.ReadFileContents();
 }
 
-SourceManager::File::~File() {}
-
 uint32_t SourceManager::File::GetLineOffset(uint32_t line) {
   if (line == 0)
     return UINT32_MAX;
@@ -418,10 +488,14 @@ void SourceManager::File::UpdateIfNeeded() {
   }
 }
 
-size_t SourceManager::File::DisplaySourceLines(uint32_t line,
+size_t SourceManager::File::DisplaySourceLines(uint32_t line, uint32_t column,
                                                uint32_t context_before,
                                                uint32_t context_after,
                                                Stream *s) {
+  // Nothing to write if there's no stream.
+  if (!s)
+    return 0;
+
   // Sanity check m_data_sp before proceeding.
   if (!m_data_sp)
     return 0;
@@ -440,7 +514,61 @@ size_t SourceManager::File::DisplaySourceLines(uint32_t line,
     if (start_line_offset < end_line_offset) {
       size_t count = end_line_offset - start_line_offset;
       const uint8_t *cstr = m_data_sp->GetBytes() + start_line_offset;
-      bytes_written = s->Write(cstr, count);
+
+      bool displayed_line = false;
+
+      if (column && (column < count)) {
+        auto debugger_sp = m_debugger_wp.lock();
+        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.
+            bytes_written = 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);
+
+            // Write the marked column.
+            bytes_written += 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.
+            bytes_written += 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)
+        bytes_written = s->Write(cstr, count);
+
+      // Ensure we get an end of line character one way or another.
       if (!is_newline_char(cstr[count - 1]))
         bytes_written += s->EOL();
     }