[review] Style diassembly in the TUI

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b0268e3..b57c699 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,30 @@ 
 2019-10-21  Tom Tromey  <tom@tromey.com>
 
+	* tui/tui-source.h (struct tui_source_window): Inline
+	constructor.  Remove destructor.
+	<style_changed, m_observable>: Move to superclass.
+	* tui/tui-winsource.h (tui_copy_source_line): Declare.
+	(struct tui_source_window_base): Move private members to end.
+	<style_changed, m_observable>: Move from tui_source_window.
+	* tui/tui-winsource.c (tui_copy_source_line): Move from
+	tui-source.c.  Rename from copy_source_line.  Add special handling
+	for negative line number.
+	(tui_source_window_base::style_changed): Move from
+	tui_source_window.
+	(tui_source_window_base): Register observer.
+	(~tui_source_window_base): New.
+	* tui/tui-source.c (copy_source_line): Move to tui-winsource.c;
+	rename.
+	(tui_source_window::set_contents): Use tui_copy_source_line.
+	(tui_source_window::tui_source_window): Move to tui-source.h.
+	(tui_source_window::~tui_source_window): Remove.
+	(tui_source_window::style_changed): Move to superclass.
+	* tui/tui-disasm.c (tui_disassemble): Create string file with
+	styling, when possible.
+	(tui_disasm_window::set_contents): Use tui_copy_source_line.
+
+2019-10-21  Tom Tromey  <tom@tromey.com>
+
 	* tui/tui-winsource.h (struct tui_source_element) <line>: Now a
 	std::string.
 	* tui/tui-winsource.c (tui_show_source_line): Update.
diff --git a/gdb/tui/tui-disasm.c b/gdb/tui/tui-disasm.c
index 91c9845..d27ddb8 100644
--- a/gdb/tui/tui-disasm.c
+++ b/gdb/tui/tui-disasm.c
@@ -39,6 +39,7 @@ 
 #include "tui/tui-source.h"
 #include "progspace.h"
 #include "objfiles.h"
+#include "cli/cli-style.h"
 
 #include "gdb_curses.h"
 
@@ -57,7 +58,8 @@ 
 		 std::vector<tui_asm_line> &asm_lines,
 		 CORE_ADDR pc, int pos, int count)
 {
-  string_file gdb_dis_out;
+  string_file gdb_dis_out (source_styling
+			   && gdb_stdout->can_emit_style_escape ());
 
   /* Now construct each line.  */
   for (int i = 0; i < count; ++i)
@@ -215,11 +217,8 @@ 
 		       - asm_lines[i].addr_string.size ())
 	   + asm_lines[i].insn);
 
-      /* Now copy the line taking the offset into account.  */
-      if (line.size () > offset)
-	src->line = line.substr (offset, line_width);
-      else
-	src->line.clear ();
+      const char *ptr = line.c_str ();
+      src->line = tui_copy_source_line (&ptr, -1, offset, line_width);
 
       src->line_or_addr.loa = LOA_ADDRESS;
       src->line_or_addr.u.addr = asm_lines[i].addr;
diff --git a/gdb/tui/tui-source.c b/gdb/tui/tui-source.c
index f956645..915f9e3 100644
--- a/gdb/tui/tui-source.c
+++ b/gdb/tui/tui-source.c
@@ -37,90 +37,6 @@ 
 #include "tui/tui-source.h"
 #include "gdb_curses.h"
 
-/* A helper function for tui_set_source_content that extracts some
-   source text from PTR.  LINE_NO is the line number; FIRST_COL is the
-   first column to extract, and LINE_WIDTH is the number of characters
-   to display.  Returns a string holding the desired text.  */
-
-static std::string
-copy_source_line (const char **ptr, int line_no, int first_col,
-		  int line_width)
-{
-  const char *lineptr = *ptr;
-
-  /* Init the line with the line number.  */
-  std::string result = string_printf ("%-6d", line_no);
-  int len = result.size ();
-  len = len - ((len / tui_tab_width) * tui_tab_width);
-  result.append (len, ' ');
-
-  int column = 0;
-  char c;
-  do
-    {
-      int skip_bytes;
-
-      c = *lineptr;
-      if (c == '\033' && skip_ansi_escape (lineptr, &skip_bytes))
-	{
-	  /* We always have to preserve escapes.  */
-	  result.append (lineptr, lineptr + skip_bytes);
-	  lineptr += skip_bytes;
-	  continue;
-	}
-
-      ++lineptr;
-      ++column;
-
-      auto process_tab = [&] ()
-	{
-	  int max_tab_len = tui_tab_width;
-
-	  --column;
-	  for (int j = column % max_tab_len;
-	       j < max_tab_len && column < first_col + line_width;
-	       column++, j++)
-	    if (column >= first_col)
-	      result.push_back (' ');
-	};
-
-      /* We have to process all the text in order to pick up all the
-	 escapes.  */
-      if (column <= first_col || column > first_col + line_width)
-	{
-	  if (c == '\t')
-	    process_tab ();
-	  continue;
-	}
-
-      if (c == '\n' || c == '\r' || c == '\0')
-	{
-	  /* Nothing.  */
-	}
-      else if (c < 040 && c != '\t')
-	{
-	  result.push_back ('^');
-	  result.push_back (c + 0100);
-	}
-      else if (c == 0177)
-	{
-	  result.push_back ('^');
-	  result.push_back ('?');
-	}
-      else if (c == '\t')
-	process_tab ();
-      else
-	result.push_back (c);
-    }
-  while (c != '\0' && c != '\n' && c != '\r');
-
-  if (c == '\r' && *lineptr == '\n')
-    ++lineptr;
-  *ptr = lineptr;
-
-  return result;
-}
-
 /* Function to display source in the source window.  */
 enum tui_status
 tui_source_window::set_contents (struct gdbarch *arch,
@@ -171,8 +87,9 @@ 
 
 	      std::string text;
 	      if (*iter != '\0')
-		text = copy_source_line (&iter, cur_line_no, horizontal_offset,
-					 line_width);
+		text = tui_copy_source_line (&iter, cur_line_no,
+					     horizontal_offset,
+					     line_width);
 
 	      /* Set whether element is the execution point
 		 and whether there is a break point on it.  */
@@ -249,26 +166,6 @@ 
     }
 }
 
-tui_source_window::tui_source_window ()
-  : tui_source_window_base (SRC_WIN)
-{
-  gdb::observers::source_styling_changed.attach
-    (std::bind (&tui_source_window::style_changed, this),
-     m_observable);
-}
-
-tui_source_window::~tui_source_window ()
-{
-  gdb::observers::source_styling_changed.detach (m_observable);
-}
-
-void
-tui_source_window::style_changed ()
-{
-  if (tui_active && is_visible ())
-    refill ();
-}
-
 bool
 tui_source_window::location_matches_p (struct bp_location *loc, int line_no)
 {
diff --git a/gdb/tui/tui-source.h b/gdb/tui/tui-source.h
index 3ef737c..a2b7754 100644
--- a/gdb/tui/tui-source.h
+++ b/gdb/tui/tui-source.h
@@ -31,8 +31,10 @@ 
 
 struct tui_source_window : public tui_source_window_base
 {
-  tui_source_window ();
-  ~tui_source_window ();
+  tui_source_window ()
+    : tui_source_window_base (SRC_WIN)
+  {
+  }
 
   DISABLE_COPY_AND_ASSIGN (tui_source_window);
 
@@ -70,17 +72,12 @@ 
 
 private:
 
-  void style_changed ();
-
   /* Answer whether a particular line number or address is displayed
      in the current source window.  */
   bool line_is_displayed (int line) const;
 
   /* It is the resolved form as returned by symtab_to_fullname.  */
   gdb::unique_xmalloc_ptr<char> m_fullname;
-
-  /* A token used to register and unregister an observer.  */
-  gdb::observers::token m_observable;
 };
 
 #endif /* TUI_TUI_SOURCE_H */
diff --git a/gdb/tui/tui-winsource.c b/gdb/tui/tui-winsource.c
index 5d0bcb4..3ca723c 100644
--- a/gdb/tui/tui-winsource.c
+++ b/gdb/tui/tui-winsource.c
@@ -65,7 +65,98 @@ 
     }
 }
 
+/* See tui-winsource.h.  */
 
+std::string
+tui_copy_source_line (const char **ptr, int line_no, int first_col,
+		      int line_width)
+{
+  const char *lineptr = *ptr;
+
+  /* Init the line with the line number.  */
+  std::string result;
+
+  if (line_no > 0)
+    {
+      result = string_printf ("%-6d", line_no);
+      int len = result.size ();
+      len = len - ((len / tui_tab_width) * tui_tab_width);
+      result.append (len, ' ');
+    }
+
+  int column = 0;
+  char c;
+  do
+    {
+      int skip_bytes;
+
+      c = *lineptr;
+      if (c == '\033' && skip_ansi_escape (lineptr, &skip_bytes))
+	{
+	  /* We always have to preserve escapes.  */
+	  result.append (lineptr, lineptr + skip_bytes);
+	  lineptr += skip_bytes;
+	  continue;
+	}
+
+      ++lineptr;
+      ++column;
+
+      auto process_tab = [&] ()
+	{
+	  int max_tab_len = tui_tab_width;
+
+	  --column;
+	  for (int j = column % max_tab_len;
+	       j < max_tab_len && column < first_col + line_width;
+	       column++, j++)
+	    if (column >= first_col)
+	      result.push_back (' ');
+	};
+
+      /* We have to process all the text in order to pick up all the
+	 escapes.  */
+      if (column <= first_col || column > first_col + line_width)
+	{
+	  if (c == '\t')
+	    process_tab ();
+	  continue;
+	}
+
+      if (c == '\n' || c == '\r' || c == '\0')
+	{
+	  /* Nothing.  */
+	}
+      else if (c < 040 && c != '\t')
+	{
+	  result.push_back ('^');
+	  result.push_back (c + 0100);
+	}
+      else if (c == 0177)
+	{
+	  result.push_back ('^');
+	  result.push_back ('?');
+	}
+      else if (c == '\t')
+	process_tab ();
+      else
+	result.push_back (c);
+    }
+  while (c != '\0' && c != '\n' && c != '\r');
+
+  if (c == '\r' && *lineptr == '\n')
+    ++lineptr;
+  *ptr = lineptr;
+
+  return result;
+}
+
+void
+tui_source_window_base::style_changed ()
+{
+  if (tui_active && is_visible ())
+    refill ();
+}
 
 /* Function to display source in the source window.  This function
    initializes the horizontal scroll to 0.  */
@@ -253,8 +344,16 @@ 
   gdb_assert (type == SRC_WIN || type == DISASSEM_WIN);
   start_line_or_addr.loa = LOA_ADDRESS;
   start_line_or_addr.u.addr = 0;
+
+  gdb::observers::source_styling_changed.attach
+    (std::bind (&tui_source_window::style_changed, this),
+     m_observable);
 }
 
+tui_source_window_base::~tui_source_window_base ()
+{
+  gdb::observers::source_styling_changed.detach (m_observable);
+}
 
 /* See tui-data.h.  */
 
diff --git a/gdb/tui/tui-winsource.h b/gdb/tui/tui-winsource.h
index 185d3dd..7c3c626 100644
--- a/gdb/tui/tui-winsource.h
+++ b/gdb/tui/tui-winsource.h
@@ -74,11 +74,9 @@ 
 
 struct tui_source_window_base : public tui_win_info
 {
-private:
-  void show_source_content ();
-
 protected:
   explicit tui_source_window_base (enum tui_win_type type);
+  ~tui_source_window_base ();
 
   DISABLE_COPY_AND_ASSIGN (tui_source_window_base);
 
@@ -140,6 +138,16 @@ 
   struct gdbarch *gdbarch = nullptr;
 
   std::vector<tui_source_element> content;
+
+private:
+
+  void show_source_content ();
+
+  /* Called when the user "set style enabled" setting is changed.  */
+  void style_changed ();
+
+  /* A token used to register and unregister an observer.  */
+  gdb::observers::token m_observable;
 };
 
 
@@ -227,6 +235,16 @@ 
 extern void tui_update_source_windows_with_line (struct symtab *, 
 						 int);
 
+/* Extract some source text from PTR.  LINE_NO is the line number.  If
+   it is positive, it is printed at the start of the line.  FIRST_COL
+   is the first column to extract, and LINE_WIDTH is the number of
+   characters to display.  Returns a string holding the desired text.
+   PTR is updated to point to the start of the next line.  */
+
+extern std::string tui_copy_source_line (const char **ptr,
+					 int line_no, int first_col,
+					 int line_width);
+
 /* Constant definitions. */
 #define SCROLL_THRESHOLD 2	/* Threshold for lazy scroll.  */