Make ANDROID_CC and SDK_BUILD_TOOLS precious variables

* configure.ac (AUTO_DEPEND, ANDROID_STUBIFY, ANDROID_LDFLAGS):
* lib/Makefile.in (ANDROID_CFLAGS, ANDROID_BUILD_CFLAGS)
(ALL_CFLAGS):
* lib/gnulib.mk.in (AM_DEFAULT_VERBOSITY):
* msdos/sed1v2.inp:
* msdos/sedlibmk.inp:
* src/Makefile.in (ANDROID_OBJ, EMACS_CFLAGS): Make those
variables precious.  Rename ANDROID_CFLAGS substitution to
ANDROID_BUILD_CFLAGS.

configure.ac

@@ -174,7 +174,7 @@ if test "$XCONFIGURE" = "android"; then
   with_ndk_path="$android_ndk_path"
   with_ndk_cxx_shared="$android_ndk_cxx_shared"
   with_ndk_cxx="$android_ndk_cxx"
-  ndk_INIT([$android_abi], [$ANDROID_SDK], [cross/ndk-build],\
+  ndk_INIT([$android_abi], [$ANDROID_SDK], [cross/ndk-build],
            [$ANDROID_CFLAGS])
 fi
 
@@ -811,6 +811,8 @@ android_makefiles="lib/Makefile lib/gnulib.mk lib-src/Makefile src/Makefile"
 # This is whether or not to package mailutils into the executable.
 emacs_use_mailutils=
 
+AC_ARG_VAR([SDK_BUILD_TOOLS], [Name of directory holding Android SDK build-tools.])
+AC_ARG_VAR([ANDROID_CFLAGS], [Flags given to the Android C cross-compiler.])
 AC_ARG_VAR([JAVAC], [Java compiler path.  Used for Android.])
 AC_ARG_VAR([JARSIGNER], [Java package signer path.  Used for Android.])
 AC_ARG_VAR([APKSIGNER], [Android package signer path.  Used for Android.])
@@ -2573,7 +2575,9 @@ window_system=none
 
 ANDROID_OBJ=
 ANDROID_LIBS=
-ANDROID_CFLAGS=
+# ANDROID_CFLAGS is a precious variable used to pass information to
+# the cross-compiler.
+ANDROID_BUILD_CFLAGS=
 REALLY_ANDROID=
 CM_OBJ="cm.o"
 
@@ -2602,11 +2606,11 @@ for Android, but all API calls need to be stubbed out])
     # Emacs will be built as a shared library, and a wrapper around it
     # will also be built for the benefit of applications.  This
     # requires Emacs be built as a position independent executable.
-    ANDROID_CFLAGS="-fPIC -fvisibility=hidden"
+    ANDROID_BUILD_CFLAGS="-fPIC -fvisibility=hidden"
 
     # Graphics code in sfntfont-android.c benefits heavily from
     # vectorization.
-    ANDROID_CFLAGS="$ANDROID_CFLAGS -ftree-vectorize"
+    ANDROID_BUILD_CFLAGS="$ANDROID_BUILD_CFLAGS -ftree-vectorize"
 
     # Link with libraries required for Android support.
     # API 9 and later require `-landroid' for the asset manager.
@@ -2638,7 +2642,7 @@ AC_SUBST([ANDROID])
 AC_SUBST([ANDROID_OBJ])
 AC_SUBST([ANDROID_LIBS])
 AC_SUBST([ANDROID_LDFLAGS])
-AC_SUBST([ANDROID_CFLAGS])
+AC_SUBST([ANDROID_BUILD_CFLAGS])
 AC_SUBST([ANDROID_SHARED_USER_ID])
 
 if test "${with_pgtk}" = "yes"; then

lib/Makefile.in

@@ -27,7 +27,7 @@ XCONFIGURE = @XCONFIGURE@
 # This is required to make sure symbol visibility is correct and
 # functions like readlinkat do not end up replacing their OS
 # counterparts.
-ANDROID_CFLAGS = @ANDROID_CFLAGS@
+ANDROID_BUILD_CFLAGS = @ANDROID_BUILD_CFLAGS@
 
 # Variables substituted by 'configure', and not autogenerated in gnulib.mk,
 # or needed before gnulib.mk is included.
@@ -46,7 +46,7 @@ ALL_CFLAGS = \
   $(C_SWITCH_SYSTEM) $(C_SWITCH_MACHINE) $(DEPFLAGS) \
   $(GNULIB_WARN_CFLAGS) $(WERROR_CFLAGS) $(PROFILING_CFLAGS) $(CFLAGS) \
   -I. -I../src -I$(srcdir) -I$(top_srcdir)/src \
-  $(if $(patsubst e-%,,$(notdir $<)),,-Demacs) $(ANDROID_CFLAGS)
+  $(if $(patsubst e-%,,$(notdir $<)),,-Demacs) $(ANDROID_BUILD_CFLAGS)
 
 ifeq ($(HAVE_NATIVE_COMP),yes)
 ALL_CFLAGS += -DGL_COMPILE_CRYPTO_STREAM

lib/gnulib.mk.in

@@ -184,7 +184,7 @@ ALSA_LIBS = @ALSA_LIBS@
 AM_DEFAULT_VERBOSITY = @AM_DEFAULT_VERBOSITY@
 ANDROID = @ANDROID@
 ANDROID_ABI = @ANDROID_ABI@
-ANDROID_CFLAGS = @ANDROID_CFLAGS@
+ANDROID_BUILD_CFLAGS = @ANDROID_BUILD_CFLAGS@
 ANDROID_DEBUGGABLE = @ANDROID_DEBUGGABLE@
 ANDROID_JAR = @ANDROID_JAR@
 ANDROID_LDFLAGS = @ANDROID_LDFLAGS@

msdos/sed1v2.inp

@@ -206,7 +206,7 @@ s/ *@WEBP_LIBS@//
 /^ANDROID_OBJ *=/s/@ANDROID_OBJ@//
 /^ANDROID_LIBS *=/s/@ANDROID_LIBS@//
 /^ANDROID_LDFLAGS *=/s/@ANDROID_LDFLAGS@//
-/^ANDROID_CFLAGS *=/s/@ANDROID_CFLAGS@//
+/^ANDROID_BUILD_CFLAGS *=/s/@ANDROID_CFLAGS@//
 /^LIBGMP_CFLAGS *=/s/@LIBGMP_CFLAGS@//
 /^SQLITE3_CFLAGS *=/s/@SQLITE3_CFLAGS@//
 /^LIBSELINUX_CFLAGS *=/s/@LIBSELINUX_CFLAGS@//

msdos/sedlibmk.inp

@@ -156,7 +156,7 @@ s/@PACKAGE@/emacs/
 /^HYBRID_MALLOC *=/s/@HYBRID_MALLOC@//
 /^WARN_CFLAGS *=/s/@WARN_CFLAGS@//
 /^WERROR_CFLAGS *=/s/@WERROR_CFLAGS@//
-/^ANDROID_CFLAGS *=/s/@ANDROID_CFLAGS@//
+/^ANDROID_BUILD_CFLAGS *=/s/@ANDROID_BUILD_CFLAGS@//
 /^DEFS *=/s/@[^@\n]*@//
 /^DEPDIR *=/s/@[^@\n]*@/deps/
 /^ECHO_N *=/s/@[^@\n]*@/-n/

src/Makefile.in

@@ -391,7 +391,7 @@ HAIKU_CFLAGS = @HAIKU_CFLAGS@
 ANDROID_OBJ = @ANDROID_OBJ@
 ANDROID_LIBS = @ANDROID_LIBS@
 ANDROID_LDFLAGS = @ANDROID_LDFLAGS@
-ANDROID_CFLAGS = @ANDROID_CFLAGS@
+ANDROID_BUILD_CFLAGS = @ANDROID_BUILD_CFLAGS@
 
 LIBGMP_CFLAGS = @LIBGMP_CFLAGS@
 
@@ -437,7 +437,7 @@ EMACS_CFLAGS=-Demacs $(MYCPPFLAGS) -I. -I$(srcdir) \
   $(LIBSYSTEMD_CFLAGS) $(JSON_CFLAGS) $(XSYNC_CFLAGS) $(TREE_SITTER_CFLAGS) \
   $(LIBGNUTLS_CFLAGS) $(NOTIFY_CFLAGS) $(CAIRO_CFLAGS) \
   $(WERROR_CFLAGS) $(HAIKU_CFLAGS) $(XCOMPOSITE_CFLAGS) $(XSHAPE_CFLAGS) \
-  $(ANDROID_CFLAGS) $(GIF_CFLAGS) $(JPEG_CFLAGS) $(SQLITE3_CFLAGS) \
+  $(ANDROID_BUILD_CFLAGS) $(GIF_CFLAGS) $(JPEG_CFLAGS) $(SQLITE3_CFLAGS) \
   $(LIBGMP_CFLAGS) $(TIFF_CFLAGS) $(LIBSELINUX_CFLAGS)
 ALL_CFLAGS = $(EMACS_CFLAGS) $(WARN_CFLAGS) $(CFLAGS)
 ALL_OBJC_CFLAGS = $(EMACS_CFLAGS) \