mk/subst.mk: evaluate SUBST_MESSAGE only once, and late

The default value of SUBST_MESSAGE is based on SUBST_FILES, and that
variable may use the :sh modifier to list files from WRKSRC, which may
not exist at load time.

1 files changed, 49 insertions, 3 deletions

diff --git a/regress/infra-unittests/subst.sh b/regress/infra-unittests/subst.sh
index d96ce2e7adb..8091bdc9d77 100644
--- a/regress/infra-unittests/subst.sh
+++ b/regress/infra-unittests/subst.sh
@@ -379,9 +379,55 @@ EOF
 	test_case_end
 fi
 
-# TODO: Add test that ensures SUBST_FILES is evaluated as late as possible.
-# Evaluating it early breaks cases like _pkglocaledir where the list of files
-# is generated by a shell command. See mk/configure/replace-localedir.mk.
+
+if test_case_begin "late evaluation of SUBST_FILES"; then
+
+	# Ensure that SUBST_FILES is evaluated as late as possible.
+	# Evaluating it early breaks cases like pkglocaledir where the
+	# list of files is generated by a shell command.
+	# See mk/configure/replace-localedir.mk.
+
+	create_file "testcase.mk" <<EOF
+REPLACE_FILES_CMD.class= \
+	cd \${WRKSRC} && echo *r*
+
+SUBST_CLASSES+=		class
+SUBST_STAGE.class=	pre-configure
+SUBST_FILES.class=	first third # \${REPLACE_FILES_CMD.class:sh}
+SUBST_SED.class=	-e 's,from,to,'
+
+.include "prepare-subst.mk"
+RUN=		@set -e;
+WRKSRC=		\${WRKDIR}/package-1.0
+.include "mk/subst.mk"
+
+# It is tricky that the dependency must use an internal implementation
+# detail, but that's the only way to guarantee the correct ordering.
+\${_SUBST_COOKIE.class}: prepare-subst-class
+prepare-subst-class:
+	\${RUN} \${MKDIR} \${WRKSRC}
+	\${RUN} \${ECHO} "from" > "\${WRKSRC}/first"
+	\${RUN} \${ECHO} "from" > "\${WRKSRC}/second"
+	\${RUN} \${ECHO} "from" > "\${WRKSRC}/third"
+EOF
+
+	test_file "testcase.mk" "subst-class" \
+		1> "$tmpdir/actual-output" \
+		2> "$tmpdir/actual-stderr" \
+	&& exitcode=0 || exitcode=$?
+
+	create_file_lines "expected-output" \
+		'=> Substituting "class" in first third'
+	assert_that "actual-output" --file-equals "expected-output"
+	assert_that "actual-stderr" --file-is-empty
+	assert_that "package-1.0/first" --file-contains-exactly "to"
+	assert_that "package-1.0/second" --file-contains-exactly "from"
+	assert_that "package-1.0/third" --file-contains-exactly "to"
+	assert_that "$exitcode" --equals "0"
+
+	test_case_end
+fi
+
 
 # TODO: Add tests for files having special characters, like space, dollar,
 # backticks, basically every ASCII character.