bug#30198: 26.0.91; [PATCH] Fix emacs-module-tests to work with out of tree build directory

[Andy Moreton <andrewjmoreton@gmail.com>]

Currently the emacs module tests fail to build when using an out of tree
build directory. The following patch moves the location of the module
library mod-test.{so,dll} from test/data/emacs-module to
<builddir>/test/data/emacs-module, as build outputs do not belong in the
source tree. It also fixes the test module build to find the module header
at the correct lcoation, namely <builddir>/src/emacs-module.h.

Tested on Windows with the mingw64-x86_64 toolchain (msys2) for both
both in-tree and out-of-tree build directories:


Fix emacs-module-tests to work with an out of tree build directory

* test/Makefile.in(test_module_dir): Build the test module library in
a subdirectory of the build directory (not the source tree).
(MODULE_CFLAGS): Fix location of emacs-module.h header file.
(test_module): Move built library out of the source tree.
* test/src/emacs-module-tests.el(mod-test-file): Locate the test module
library relative to the running emacs executable.

diff --git a/test/Makefile.in b/test/Makefile.in
index 341b09b03f..7c5976435c 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -119,7 +119,7 @@ emacs =
   EMACS_TEST_DIRECTORY=$(abspath $(srcdir)) \
   $(GDB) "$(EMACS)" $(MODULES_EMACSOPT) $(EMACSOPT)

-test_module_dir := $(srcdir)/data/emacs-module
+test_module_dir := data/emacs-module

  .PHONY: all check

@@ -222,12 +222,13 @@ FPIC_CFLAGS =
  FPIC_CFLAGS = -fPIC
  endif

-MODULE_CFLAGS = -I$(srcdir)/../src $(FPIC_CFLAGS) $(PROFILING_CFLAGS) \
+MODULE_CFLAGS = -I../src $(FPIC_CFLAGS) $(PROFILING_CFLAGS) \
    $(WARN_CFLAGS) $(WERROR_CFLAGS) $(CFLAGS)

  test_module = $(test_module_dir)/mod-test${SO}
  src/emacs-module-tests.log: $(test_module)
-$(test_module): $(test_module:${SO}=.c) $(srcdir)/../src/emacs-module.h
+$(test_module): ${srcdir}/$(test_module:${SO}=.c) ../src/emacs-module.h
+    $(AM_V_at)${MKDIR_P} $(dir $@)
      $(AM_V_CCLD)$(CC) -shared $(CPPFLAGS) $(MODULE_CFLAGS) $(LDFLAGS) \
        -o $@ $<
  endif
diff --git a/test/src/emacs-module-tests.el b/test/src/emacs-module-tests.el
index d9406a9609..85d6305386 100644
--- a/test/src/emacs-module-tests.el
+++ b/test/src/emacs-module-tests.el
@@ -25,8 +25,7 @@ mod-test-emacs

  (eval-and-compile
    (defconst mod-test-file
-    (substitute-in-file-name
-     "$EMACS_TEST_DIRECTORY/data/emacs-module/mod-test")
+    (expand-file-name "../test/data/emacs-module/mod-test" 
invocation-directory)
      "File name of the module test file."))

  (require 'mod-test mod-test-file)