[PATCH] - Make - print rule with -d flag

[Duane Ellis]

I often debug Makefiles and often ask: where did that command (rule) 
come from?

My solution has always been to use combinations of "-d" and "-p" and  
attempt to sort through the copious output.

With "-p" - make prints the resulting makefile.
With "-d" - make tells you what it is doing.

With *LARGE* makefiles {for example GCC}...
Or Makefile systems that make heavy use of  "include  make-fragment"
(Did you know GCC uses that feature?)

Debugging becomes 'a maze of twisty passages all alike'

Attached is a *simple* ( 9 line ) patch that greatly simplifies the way 
through the maze
(and to the battery/lamp-oil vending machine in the middle of the maze)

here is an example [snip] from the NEW -d output of make while building g++
The _*OLD*_  "make -d" output is available with:  make -d

>> Finished prerequisites of target file `g++'.
>> Must remake target `g++'.
>> Execute:
>> #  commands to execute (from `../.././gcc/cp/Make-lang.in', line 65):
>>     $(CC) $(ALL_CFLAGS) $(LDFLAGS) -o $@ \
>>     $(GXX_OBJS) $(EXTRA_GCC_OBJS) $(LIBS)
>> gcc   -g -DIN_GCC -DCROSS_COMPILE  .. [SNIP] ...

--Duane

====================================






diff -Naur make-3.81/commands.c make-3.81-patch-location-print/commands.c
--- make-3.81/commands.c        2006-02-20 02:14:01.000000000 +0000
+++ make-3.81-patch-location-print/commands.c   2007-04-14 15:47:53.000000000 
+0000
@@ -27,6 +27,7 @@
 #include "w32err.h"
 #endif
 
+#include "debug.h"
 #if VMS
 # define FILE_LIST_SEPARATOR ','
 #else
@@ -372,6 +373,10 @@
   /* Don't go through all the preparations if
      the commands are nothing but whitespace.  */
 
+  if( ISDB( DB_LOCATION ) ){
+    printf( _("Execute:\n") );
+    print_commands( file->cmds );
+  }
   for (p = file->cmds->commands; *p != '\0'; ++p)
     if (!isspace ((unsigned char)*p) && *p != '-' && *p != '@')
       break;
diff -Naur make-3.81/debug.h make-3.81-patch-location-print/debug.h
--- make-3.81/debug.h   2006-02-11 22:16:04.000000000 +0000
+++ make-3.81-patch-location-print/debug.h      2007-04-14 15:39:16.000000000 
+0000
@@ -20,6 +20,7 @@
 #define DB_VERBOSE      (0x002)
 #define DB_JOBS         (0x004)
 #define DB_IMPLICIT     (0x008)
+#define DB_LOCATION     (0x010)
 #define DB_MAKEFILES    (0x100)
 
 #define DB_ALL          (0xfff)
diff -Naur make-3.81/main.c make-3.81-patch-location-print/main.c
--- make-3.81/main.c    2006-03-20 02:36:37.000000000 +0000
+++ make-3.81-patch-location-print/main.c       2007-04-14 15:40:22.000000000 
+0000
@@ -623,6 +623,9 @@
             case 'm':
               db_level |= DB_BASIC | DB_MAKEFILES;
               break;
+           case 'p': /* as in the -p flag */
+             db_level |= DB_LOCATION;
+             break;
             case 'v':
               db_level |= DB_BASIC | DB_VERBOSE;
               break;