Pass target as an actual Make goal to 'make -pq'

.gitignore

@@ -1,3 +1,5 @@
 __pycache__
 build
-*.egg-info
+*.egg-info
+# Regenerated by the test/Makefile's `conditional` regression test fixture
+test/gendep.mk

src/pymakeutils/common.py

@@ -11,11 +11,18 @@
 import sys
 
 
-# Function to parse all rules from 'make -pq' output
+# Function to parse all rules from 'make -pq' output.
+# `goal` is passed as an actual Make goal (rather than only being used to look up its
+# prerequisites in the returned dict), so that MAKECMDGOALS-conditional logic in the
+# Makefile (e.g. `include`s gated on the requested goal) is exercised the same way it
+# would be for a real `make <goal>` invocation, and any prerequisite it generates as a
+# side effect (e.g. an auto-generated dependency file) is reflected in the database.
 @lru_cache(maxsize=4)
-def _parse_makefile(flags=''):
+def _parse_makefile(flags='', goal=None):
     # Run 'make -pq' and capture its output
     cmd = ['make', '-pq']
+    if goal:
+        cmd.append(goal)
     if flags:
         cmd.extend(flags.split())
     result = subprocess.run(
@@ -59,8 +66,8 @@ def _get_prerequisites_recursive(target, targets, recursive=False):
 # Function to list prerequisites, optionally recursively
 def list_prerequisites(target, recursive=False, debug=False):
 
-    # Parse the makefile
-    targets = _parse_makefile()
+    # Parse the makefile, passing `target` as the actual Make goal (see `_parse_makefile`)
+    targets = _parse_makefile(goal=target)
 
     # Handle non-existing target
     if target not in targets:

test/Makefile

@@ -5,4 +5,19 @@ prereq: preprereq1 preprereq2
 	cp $< $@
 	cat preprereq2 >> $@
 
-test2: dirprereq
+test2: dirprereq
+
+# Regression test for passing `target` as an actual Make goal to `make -pq`
+# (rather than only using it to look up its prerequisites in a goal-less
+# database dump). `hiddenprereq` is only a prerequisite of `conditional` once
+# `conditional` is the requested goal, mirroring a common pattern where an
+# auto-generated dependency file is `-include`d only when relevant to
+# MAKECMDGOALS. A tool that queries `make -pq` without passing the goal would
+# never see `hiddenprereq`.
+gendep.mk:
+	echo "conditional: hiddenprereq" > $@
+
+-include $(if $(filter conditional,$(MAKECMDGOALS)),gendep.mk)
+
+conditional: standaloneprereq
+	cp $< $@

test/standaloneprereq

@@ -0,0 +1 @@
+standalone

test/test_cli.py

@@ -38,3 +38,13 @@ def test_list_dependent_targets_non_recursive():
 def test_list_dependent_targets_recursive():
     targets = run_cli('list-dependent-make-targets', 'preprereq1', '--recursive').splitlines()
     assert targets == ['.DEFAULT_GOAL', 'prereq', 'test1']
+
+
+def test_list_prerequisites_with_makecmdgoals_conditional_prerequisite():
+    # `conditional`'s Makefile rule `-include`s a generated dependency file only when
+    # `conditional` itself is passed as an actual Make goal (see test/Makefile). This
+    # guards against a regression where the target was only used to look up its
+    # prerequisites in a goal-less `make -pq` database dump, silently hiding any
+    # prerequisite that depended on MAKECMDGOALS-conditional inclusion logic.
+    prerequisites = run_cli('list-make-prerequisites', 'conditional', '--recursive').splitlines()
+    assert prerequisites == ['hiddenprereq', 'standaloneprereq']