Linenoise for a better debugger experience 🍒

doc/src/appendix.adoc

@@ -36,3 +36,34 @@ Copyright (c) 2013-2022 Niels Lohmann
 https://github.com/edwardtufte/tufte-css[Tufte CSS]::
 Copyright (c) Dave Liepmann, Edward Tufte, et al. The documentation style is
 based on this CSS.
+
+== BSD-2 License
+
+```
+BSD-2 License
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice,
+  this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+```
+
+https://github.com/antirez/linenoise[Linenoise, a minimal readline replacement]::
+Copyright (c) 2010-2014, Salvatore Sanfilippo
+Copyright (c) 2010-2013, Pieter Noordhuis

doc/src/history.adoc

@@ -10,6 +10,10 @@
 * *New*: Add reading/parsing of property database from JSON data to base CPS
   support from.
   -- _René Ferdinand Rivera Morell_
+* *New*: Added readline capabilities, command history, cmdline editing, etc,
+  to internal debugger (not on Windows), thanks to *linenoise* by
+  _Salvatore Sanfilippo_ (repo at https://github.com/antirez/linenoise.)
+  -- _Paolo Pastori_
 * Fix Jam/{CPP} bind definitions of 4 or more values in a single
   declared argument not actually adding all the definitions.
   -- _Paolo Pastori_

src/engine/build.sh

@@ -486,6 +486,7 @@ mod_string.cpp \
 mod_summary.cpp \
 mod_sysinfo.cpp \
 mod_version.cpp \
+ext_linenoise.cpp \
  "
 
     if test_true ${B2_DEBUG_OPT} ; then B2_CXXFLAGS="${B2_CXXFLAGS_DEBUG}"

src/engine/debugger.cpp

@@ -8,6 +8,10 @@
 #include "jam.h"
 #include "debugger.h"
 
+#ifndef NT
+#include "ext_linenoise.h"
+#endif
+
 #include "constants.h"
 #include "cwd.h"
 #include "function.h"
@@ -908,7 +912,7 @@ static void debug_parent_child_exited( int pid, int exit_code )
     }
 }
 
-#if !NT
+#ifndef NT
 
 static void debug_parent_child_signalled( int pid, int id )
 {
@@ -1740,21 +1744,21 @@ static void debug_mi_interpreter_exec( int argc, const char * * argv );
 
 static struct command_elem parent_commands[] =
 {
-    { "run", &debug_parent_run },
-    { "continue", &debug_parent_continue },
-    { "kill", &debug_parent_kill },
-    { "step", &debug_parent_step },
-    { "next", &debug_parent_next },
-    { "finish", &debug_parent_finish },
+    { "backtrace", &debug_parent_backtrace },
     { "break", &debug_parent_break },
+    { "clear", &debug_parent_clear },
+    { "continue", &debug_parent_continue },
+    { "delete", &debug_parent_delete },
     { "disable", &debug_parent_disable },
     { "enable", &debug_parent_enable },
-    { "delete", &debug_parent_delete },
-    { "clear", &debug_parent_clear },
+    { "finish", &debug_parent_finish },
+    { "help", &debug_parent_help },
+    { "kill", &debug_parent_kill },
+    { "next", &debug_parent_next },
     { "print", &debug_parent_print },
-    { "backtrace", &debug_parent_backtrace },
     { "quit", &debug_parent_quit },
-    { "help", &debug_parent_help },
+    { "run", &debug_parent_run },
+    { "step", &debug_parent_step },
     { "-break-insert", &debug_mi_break_insert },
     { "-break-delete", &debug_mi_break_delete },
     { "-break-disable", &debug_mi_break_disable },
@@ -2602,6 +2606,19 @@ static void debug_mi_interpreter_exec( int argc, const char * * argv )
     process_command( (char *)argv[ 2 ] );
 }
 
+#ifndef NT
+/* for Linenoise command completion using TAB */
+void completion( const char *cmdbuf, linenoiseCompletions *lc ) {
+    size_t buflen = strlen( cmdbuf );
+    for ( struct command_elem & pci : parent_commands )
+    {
+        if ( pci.key[0] == '-' ) break; /* end of user commands reached */
+        if ( !buflen || !strncmp(cmdbuf, pci.key, buflen) )
+            linenoiseAddCompletion( lc, pci.key );
+    }
+}
+#endif
+
 /* The debugger's main loop. */
 int debugger( void )
 {
@@ -2611,10 +2628,35 @@ int debugger( void )
         printf( "=thread-group-added,id=\"i1\"\n(gdb) \n" );
     while ( 1 )
     {
+#ifdef NT
         if ( globs.debug_interface == DEBUG_INTERFACE_CONSOLE )
             printf("(b2db) ");
         fflush( stdout );
         read_command();
+#else
+        if ( globs.debug_interface == DEBUG_INTERFACE_CONSOLE )
+        {
+            /* Add support for command history, command line
+             * editing, command completion, and more, see
+             * https://github.com/antirez/linenoise
+             */
+            linenoiseSetCompletionCallback( completion );
+
+            char *cmdline = linenoise( "(b2db) " );
+            if ( cmdline == NULL ) break; /* CTRL-C, CTRL-D, out of memory.. */
+
+            linenoiseHistoryAdd( cmdline );
+
+            process_command( cmdline );
+
+            linenoiseFree( cmdline );
+        }
+        else
+        {
+            fflush( stdout );
+            read_command();
+        }
+#endif
     }
     return 0;
 }