[lldb] Add a setting to customize the prompt color

lldb/include/lldb/Core/Debugger.h

@@ -289,6 +289,10 @@ class Debugger : public std::enable_shared_from_this<Debugger>,
 
   llvm::StringRef GetPrompt() const;
 
+  llvm::StringRef GetPromptAnsiPrefix() const;
+
+  llvm::StringRef GetPromptAnsiSuffix() const;
+
   void SetPrompt(llvm::StringRef p);
   void SetPrompt(const char *) = delete;
 

lldb/include/lldb/Host/Editline.h

@@ -211,6 +211,14 @@ class Editline {
     m_fix_indentation_callback_chars = indent_chars;
   }
 
+  void SetPromptAnsiPrefix(std::string prefix) {
+    m_prompt_ansi_prefix = std::move(prefix);
+  }
+
+  void SetPromptAnsiSuffix(std::string suffix) {
+    m_prompt_ansi_suffix = std::move(suffix);
+  }
+
   void SetSuggestionAnsiPrefix(std::string prefix) {
     m_suggestion_ansi_prefix = std::move(prefix);
   }
@@ -398,6 +406,8 @@ class Editline {
   CompleteCallbackType m_completion_callback;
   SuggestionCallbackType m_suggestion_callback;
 
+  std::string m_prompt_ansi_prefix;
+  std::string m_prompt_ansi_suffix;
   std::string m_suggestion_ansi_prefix;
   std::string m_suggestion_ansi_suffix;
 

lldb/source/Core/CoreProperties.td

@@ -65,6 +65,14 @@ let Definition = "debugger" in {
     DefaultEnumValue<"OptionValueString::eOptionEncodeCharacterEscapeSequences">,
     DefaultStringValue<"(lldb) ">,
     Desc<"The debugger command line prompt displayed for the user.">;
+  def PromptAnsiPrefix: Property<"prompt-ansi-prefix", "String">,
+    Global,
+    DefaultStringValue<"${ansi.faint}">,
+    Desc<"When in a color-enabled terminal, use the ANSI terminal code specified in this format immediately before the prompt.">;
+  def PromptAnsiSuffix: Property<"prompt-ansi-suffix", "String">,
+    Global,
+    DefaultStringValue<"${ansi.normal}">,
+    Desc<"When in a color-enabled terminal, use the ANSI terminal code specified in this format immediately after the prompt.">;
   def ScriptLanguage: Property<"script-lang", "Enum">,
     Global,
     DefaultEnumValue<"eScriptLanguagePython">,

lldb/source/Core/Debugger.cpp

@@ -235,6 +235,13 @@ Status Debugger::SetPropertyValue(const ExecutionContext *exe_ctx,
       // use-color changed. Ping the prompt so it can reset the ansi terminal
       // codes.
       SetPrompt(GetPrompt());
+    } else if (property_path ==
+                   g_debugger_properties[ePropertyPromptAnsiPrefix].name ||
+               property_path ==
+                   g_debugger_properties[ePropertyPromptAnsiSuffix].name) {
+      // Prompt colors changed. Ping the prompt so it can reset the ansi
+      // terminal codes.
+      SetPrompt(GetPrompt());
     } else if (property_path ==
                g_debugger_properties[ePropertyUseSourceCache].name) {
       // use-source-cache changed. Wipe out the cache contents if it was
@@ -301,6 +308,18 @@ llvm::StringRef Debugger::GetPrompt() const {
       idx, g_debugger_properties[idx].default_cstr_value);
 }
 
+llvm::StringRef Debugger::GetPromptAnsiPrefix() const {
+  const uint32_t idx = ePropertyPromptAnsiPrefix;
+  return GetPropertyAtIndexAs<llvm::StringRef>(
+      idx, g_debugger_properties[idx].default_cstr_value);
+}
+
+llvm::StringRef Debugger::GetPromptAnsiSuffix() const {
+  const uint32_t idx = ePropertyPromptAnsiSuffix;
+  return GetPropertyAtIndexAs<llvm::StringRef>(
+      idx, g_debugger_properties[idx].default_cstr_value);
+}
+
 void Debugger::SetPrompt(llvm::StringRef p) {
   constexpr uint32_t idx = ePropertyPrompt;
   SetPropertyAtIndex(idx, p);

lldb/source/Core/IOHandler.cpp

@@ -474,8 +474,15 @@ bool IOHandlerEditline::SetPrompt(llvm::StringRef prompt) {
   m_prompt = std::string(prompt);
 
 #if LLDB_ENABLE_LIBEDIT
-  if (m_editline_up)
+  if (m_editline_up) {
     m_editline_up->SetPrompt(m_prompt.empty() ? nullptr : m_prompt.c_str());
+    if (m_debugger.GetUseColor()) {
+      m_editline_up->SetPromptAnsiPrefix(
+          ansi::FormatAnsiTerminalCodes(m_debugger.GetPromptAnsiPrefix()));
+      m_editline_up->SetPromptAnsiSuffix(
+          ansi::FormatAnsiTerminalCodes(m_debugger.GetPromptAnsiSuffix()));
+    }
+  }
 #endif
   return true;
 }

lldb/source/Host/common/Editline.cpp

@@ -53,10 +53,6 @@ int setupterm(char *term, int fildes, int *errret);
 
 /// https://www.ecma-international.org/publications/files/ECMA-ST/Ecma-048.pdf
 #define ESCAPE "\x1b"
-/// Faint, decreased intensity or second colour.
-#define ANSI_FAINT ESCAPE "[2m"
-/// Normal colour or normal intensity (neither bold nor faint).
-#define ANSI_UNFAINT ESCAPE "[0m"
 #define ANSI_CLEAR_BELOW ESCAPE "[J"
 #define ANSI_CLEAR_RIGHT ESCAPE "[K"
 #define ANSI_SET_COLUMN_N ESCAPE "[%dG"
@@ -431,15 +427,13 @@ void Editline::MoveCursor(CursorLocation from, CursorLocation to) {
 void Editline::DisplayInput(int firstIndex) {
   fprintf(m_output_file, ANSI_SET_COLUMN_N ANSI_CLEAR_BELOW, 1);
   int line_count = (int)m_input_lines.size();
-  const char *faint = m_color_prompts ? ANSI_FAINT : "";
-  const char *unfaint = m_color_prompts ? ANSI_UNFAINT : "";
-
   for (int index = firstIndex; index < line_count; index++) {
-    fprintf(m_output_file, "%s"
-                           "%s"
-                           "%s" EditLineStringFormatSpec " ",
-            faint, PromptForIndex(index).c_str(), unfaint,
-            m_input_lines[index].c_str());
+    fprintf(m_output_file,
+            "%s"
+            "%s"
+            "%s" EditLineStringFormatSpec " ",
+            m_prompt_ansi_prefix.c_str(), PromptForIndex(index).c_str(),
+            m_prompt_ansi_suffix.c_str(), m_input_lines[index].c_str());
     if (index < line_count - 1)
       fprintf(m_output_file, "\n");
   }
@@ -548,14 +542,16 @@ unsigned char Editline::RecallHistory(HistoryOperation op) {
 int Editline::GetCharacter(EditLineGetCharType *c) {
   const LineInfoW *info = el_wline(m_editline);
 
-  // Paint a faint version of the desired prompt over the version libedit draws
-  // (will only be requested if colors are supported)
+  // Paint a ANSI formatted version of the desired prompt over the version
+  // libedit draws. (will only be requested if colors are supported)
   if (m_needs_prompt_repaint) {
     MoveCursor(CursorLocation::EditingCursor, CursorLocation::EditingPrompt);
-    fprintf(m_output_file, "%s"
-                           "%s"
-                           "%s",
-            ANSI_FAINT, Prompt(), ANSI_UNFAINT);
+    fprintf(m_output_file,
+            "%s"
+            "%s"
+            "%s",
+            m_prompt_ansi_prefix.c_str(), Prompt(),
+            m_prompt_ansi_suffix.c_str());
     MoveCursor(CursorLocation::EditingPrompt, CursorLocation::EditingCursor);
     m_needs_prompt_repaint = false;
   }

lldb/test/API/terminal/TestEditline.py

@@ -55,3 +55,27 @@ def test_prompt_unicode(self):
         # Prompt: 🐛 _
         # Column: 1..4
         self.child.expect(re.escape("🐛 \x1b[0m\x1b[4G"))
+
+    @skipIfAsan
+    @skipIfEditlineSupportMissing
+    def test_prompt_color(self):
+        """Test that we can change the prompt color with prompt-ansi-prefix."""
+        self.launch(use_colors=True)
+        self.child.send('settings set prompt-ansi-prefix "${ansi.fg.red}"\n')
+        # Make sure this change is reflected immediately. Check that the color
+        # is set (31) and the cursor position (8) is correct.
+        # Prompt: (lldb) _
+        # Column: 1....6.8
+        self.child.expect(re.escape("\x1b[31m(lldb) \x1b[0m\x1b[8G"))
+
+    @skipIfAsan
+    @skipIfEditlineSupportMissing
+    def test_prompt_no_color(self):
+        """Test that prompt-ansi-prefix doesn't color the prompt when colors are off."""
+        self.launch(use_colors=False)
+        self.child.send('settings set prompt-ansi-prefix "${ansi.fg.red}"\n')
+        # Send foo so we can match the newline before the prompt and the foo
+        # after the prompt.
+        self.child.send("foo")
+        # Check that there are no escape codes.
+        self.child.expect(re.escape("\n(lldb) foo"))