add stop column highlighting support

This change introduces optional marking of the column within a source
line where a thread is stopped.  This marking will show up when the
source code for a thread stop is displayed, when the debug info
knows the column information, and if the optional column marking is
enabled.

There are two separate methods for handling the marking of the stop
column:

* via ANSI terminal codes, which are added inline to the source line
  display.  The default ANSI mark-up is to underline the column.

* via a pure text-based caret that is added in the appropriate column
  in a newly-inserted blank line underneath the source line in
  question.

There are some new options that control how this all works.

* settings set stop-show-column

  This takes one of 4 values:

  * ansi-or-caret: use the ANSI terminal code mechanism if LLDB
    is running with color enabled; if not, use the caret-based,
    pure text method (see the "caret" mode below).

  * ansi: only use the ANSI terminal code mechanism to highlight
    the stop line.  If LLDB is running with color disabled, no
    stop column marking will occur.

  * caret: only use the pure text caret method, which introduces
    a newly-inserted line underneath the current line, where
    the only character in the new line is a caret that highlights
    the stop column in question.

  * none: no stop column marking will be attempted.

* settings set stop-show-column-ansi-prefix

  This is a text format that indicates the ANSI formatting
  code to insert into the stream immediately preceding the
  column where the stop column character will be marked up.
  It defaults to ${ansi.underline}; however, it can contain
  any valid LLDB format codes, e.g.

      ${ansi.fg.red}${ansi.bold}${ansi.underline}

* settings set stop-show-column-ansi-suffix

  This is the text format that specifies the ANSI terminal
  codes to end the markup that was started with the prefix
  described above.  It defaults to: ${ansi.normal}.  This
  should be sufficient for the common cases.

Significant leg-work was done by Adrian Prantl.  (Thanks, Adrian!)

differential review: https://reviews.llvm.org/D20835

reviewers: clayborg, jingham
llvm-svn: 282105

1 files changed, 7 insertions, 0 deletions

diff --git a/lldb/scripts/interface/SBSourceManager.i b/lldb/scripts/interface/SBSourceManager.i
index 09cd449149d..10fa7a68550 100644
--- a/lldb/scripts/interface/SBSourceManager.i
+++ b/lldb/scripts/interface/SBSourceManager.i
@@ -49,6 +49,13 @@ public:
                                        uint32_t context_after,
                                        const char* current_line_cstr,
                                        lldb::SBStream &s);
+    size_t
+    DisplaySourceLinesWithLineNumbersAndColumn (const lldb::SBFileSpec &file,
+                                                uint32_t line, uint32_t column,
+                                                uint32_t context_before,
+                                                uint32_t context_after,
+                                                const char* current_line_cstr,
+                                                lldb::SBStream &s);
 };
 
 } // namespace lldb