Reading "slices" out of a file at known start markers

[hacker]

I have a need to read "slices" out of a text file (a Makefile), based on known values that appear within the file. For example:

 
YACCCOMPILE = $(YACC) $(YFLAGS) $(AM_YFLAGS)    
LTYACCCOMPILE = $(LIBTOOL) $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS)         
+  \
        --mode=compile $(YACC) $(YFLAGS) $(AM_YFLAGS)
YLWRAP = $(top_srcdir)/ylwrap

SOURCES = $(libpiuserland_la_SOURCES) $(pilot_addresses_SOURCES)      
+  \
        $(pilot_clip_SOURCES) $(pilot_csd_SOURCES)                    
+  \
        $(pilot_debugsh_SOURCES) $(pilot_dedupe_SOURCES)              
+  \
        $(pilot_dlpsh_SOURCES) $(pilot_file_SOURCES)                  
+  \
        $(pilot_foto_SOURCES) $(pilot_foto_treo600_SOURCES)           
+  \
        $(pilot_foto_treo650_SOURCES) $(pilot_getram_SOURCES)         
+  \
        $(pilot_getrom_SOURCES) $(pilot_getromtoken_SOURCES)          
+  \
        $(pilot_hinotes_SOURCES) $(pilot_install_datebook_SOURCES)    
+  \
        $(pilot_install_expenses_SOURCES)                             
+  \
        $(pilot_install_hinote_SOURCES) $(pilot_install_memo_SOURCES) 
+  \
        $(pilot_install_netsync_SOURCES) $(pilot_install_todo_SOURCES)
+  \
        $(pilot_install_todos_SOURCES) $(pilot_install_user_SOURCES)  
+  \
        $(pilot_memos_SOURCES) $(pilot_nredir_SOURCES)                
+  \
        $(pilot_read_expenses_SOURCES) $(pilot_read_ical_SOURCES)     
+  \
        $(pilot_read_notepad_SOURCES) $(pilot_read_palmpix_SOURCES)   
+  \
        $(pilot_read_screenshot_SOURCES) $(pilot_read_todos_SOURCES)  
+  \
        $(pilot_read_veo_SOURCES) $(pilot_reminders_SOURCES)          
+  \
        $(pilot_schlep_SOURCES) $(pilot_wav_SOURCES)                  
+  \
        $(pilot_xfer_SOURCES)

RECURSIVE_TARGETS = all-recursive check-recursive dvi-recursive       
+  \
        html-recursive info-recursive install-data-recursive          
+  \
        install-dvi-recursive install-exec-recursive                  
+  \
        install-html-recursive install-info-recursive                 
+  \
        install-pdf-recursive install-ps-recursive install-recursive  
+  \
        installcheck-recursive installdirs-recursive pdf-recursive    
+  \
        ps-recursive uninstall-recursive

In this example, I want everything from ^SOURCES until the beginning of the next "block" that starts with ^RECURSIVE_TARGETS.

I know what my ^MARKERS will be in-advance, but I don't know how many lines will follow them until the next section that begins with another marker I may or may not need.

One of the problems is that there can be any number of spaces/tabs in the middle of, or at the end of each "continuation" line (or no continuation delimiters at all), and the "block" can be continued for anywhere from 1 line to dozens of lines.

Any idea how I would approach this problem in a clean, simplistic way? Is there enough detail provided here to understand my problem?