add MAKELEVEL built-in variable

"As a special feature, the variable MAKELEVEL is changed when it is passed down from level to level. This variable’s value is a string which is the depth of the level as a decimal number. The value is ‘0’ for the top-level make; ‘1’ for a sub-make, ‘2’ for a sub-sub-make, and so on. The incrementation happens when make sets up the environment for a recipe. "

GNU Make Manual https://www.gnu.org/software/make/manual/make.html

pymake/pymake.py

@@ -277,7 +277,7 @@ def _execute_statement_list(stmt_list, curr_rules, rulesdb, symtable):
     # bottom of loop
     return exit_code
 
-def execute_recipe(rule, recipe, symtable):
+def execute_recipe(rule, recipe, symtable, dry_run=False):
     def remove_duplicates(s_list):
         # the $^ variable removes duplicates but must must must preserve order
         seen_list = []
@@ -333,6 +333,8 @@ def check_prefixes(s):
 
         return s, ignore_failure, silent
 
+    makelevel = int(symtable.fetch("MAKELEVEL"))
+
     # TODO many more automatic variables
     symtable.push("@")
     symtable.push("^")
@@ -373,6 +375,11 @@ def check_prefixes(s):
 
         s, ignore_failure, silent = check_prefixes(s)
 
+        if dry_run:
+            # TODO submakes
+            print(s)
+            continue
+
         if not silent:
             print(s)
 
@@ -391,7 +398,7 @@ def check_prefixes(s):
             args = pargs.parse_args(submake_argv[1:])
 #            breakpoint()
             currwd = os.getcwd()
-            exit_code = _run_it(args)
+            exit_code = _run_it(args, makelevel+1)
             os.chdir(currwd)
             # clean up the output from the submake helper
             ret.stdout = ""
@@ -408,7 +415,7 @@ def check_prefixes(s):
 
     return exit_status["error"] if exit_code else exit_status["success"] 
 
-def execute(makefile, args):
+def execute(makefile, args, makelevel):
     # ha ha type checking
     assert isinstance(args, pargs.Args)
 
@@ -429,6 +436,8 @@ def execute(makefile, args):
     # The -C option will be handled before this function is called.
     symtable.add("CURDIR", os.getcwd())
 
+    symtable.add("MAKELEVEL", str(makelevel))
+
     target_list = []
 
     # GNU Make allows passing assignment statements on the command line.
@@ -496,7 +505,7 @@ def execute(makefile, args):
         # walk a dependency tree
         for rule in rulesdb.walk_tree(target):
             for recipe in rule.recipe_list:
-                exit_code = execute_recipe(rule, recipe, symtable)
+                exit_code = execute_recipe(rule, recipe, symtable, args.dry_run)
                 if exit_code != 0:
                     break
 
@@ -505,7 +514,7 @@ def execute(makefile, args):
 
     return exit_status["error"] if exit_code else exit_status["success"] 
 
-def _run_it(args):
+def _run_it(args, makelevel):
     # -C option
     if args.directory:
         os.chdir(os.path.join(*args.directory))
@@ -534,7 +543,7 @@ def _run_it(args):
             print(makefile.makefile(), file=outfile)
         print("# end makefile %s" % args.output)
 
-    exit_code = execute(makefile, args)
+    exit_code = execute(makefile, args, makelevel)
     return exit_code
 
 # FIXME ugly hack dependency injection to solve problems with circular imports
@@ -553,7 +562,7 @@ def main():
 #        usage()
 #        sys.exit(1)
 
-    sys.exit(_run_it(args))
+    sys.exit(_run_it(args,0))
 
 if __name__=='__main__':
     main()

tests/submake.mk

@@ -2,20 +2,31 @@
 
 $(info CURDIR=$(CURDIR))
 
+# check on MAKELEVEL value
+$(if $(MAKELEVEL),,$(error MAKELEVEL is missing))
+
 all:
 	@echo hello from make pid=$$$$
 	$(MAKE) -f $(CURDIR)/tests/submake.mk submake A=B B=C C=D
+
+# we should ignore this error and continue
 	-$(MAKE) -f $(CURDIR)/tests/submake.mk submake-error
 
 # adding a shell expression to verify we go through the shell
 	@$(MAKE) -f $(CURDIR)/tests/submake.mk hello-world NUM=$$((10+20)) a={1,2,3}
 
+	if [ -z '$(MAKELEVEL)' ] ; then echo missing MAKELEVEL && exit 1 ; fi
+	if [ ! $(MAKELEVEL) -eq 0 ] ; then echo MAKELEVEL should be zero && exit 1 ; fi
+
 submake:
 	@echo hello from submake pid=$$$$
+	if [ ! $(MAKELEVEL) -eq 1 ] ; then echo MAKELEVEL should be value 1 && exit 1 ; fi
 
 hello-world:
+	if [ ! $(MAKELEVEL) -eq 1 ] ; then echo MAKELEVEL should be value 1 && exit 1 ; fi
 	@echo hello, world NUM=$(NUM) a=$(a)
 
 submake-error:
+	if [ ! $(MAKELEVEL) -eq 1 ] ; then echo MAKELEVEL should be value 1 && exit 1 ; fi
 	@echo error && exit 1