build: prohibit cross-inclusion

Make it easier to detect invalid cross-directory includes, by
adding a syntax check.  The check is designed to be extensible:
the default case lists only the non-driver directories, and
specific directories can list a different set (for example,
util/ can only use itself, network/ can only use itself, util/,
or conf/).

* .gnulib: Update to latest, for syntax check improvment.
* cfg.mk (sc_prohibit_cross_inclusion): New check.
(sc_prohibit_strncmp, sc_libvirt_unmarked_diagnostics): Simplify.

diff --git a/.gnulib b/.gnulib
index b856fadc1c8dcb53e7efcbb2d0ae7edc022fdb6a..d5612c714c87555f1059d71d347e20271dced322 160000 (submodule)
--- a/.gnulib
+++ b/.gnulib
@@ -1 +1 @@
-Subproject commit b856fadc1c8dcb53e7efcbb2d0ae7edc022fdb6a
+Subproject commit d5612c714c87555f1059d71d347e20271dced322

diff --git a/cfg.mk b/cfg.mk
index ac6c527891e2cee4d82873030f5172caf3a4f361..95994df1ec116368a050e917aca18a769e16fde9 100644 (file)
--- a/cfg.mk
+++ b/cfg.mk
@@ -348,11 +348,10 @@ sc_prohibit_access_xok:
 # Use STREQLEN or STRPREFIX rather than comparing strncmp == 0, or != 0.
 snp_ = strncmp *\(.+\)
 sc_prohibit_strncmp:
-       @grep -nE '! *strncmp *\(|\<$(snp_) *[!=]=|[!=]= *$(snp_)'      \
-           $$($(VC_LIST_EXCEPT))                                       \
-         | grep -vE ':# *define STR(N?EQLEN|PREFIX)\(' &&              \
-         { echo '$(ME): use STREQLEN or STRPREFIX instead of str''ncmp' \
-               1>&2; exit 1; } || :
+       @prohibit='! *strncmp *\(|\<$(snp_) *[!=]=|[!=]= *$(snp_)'      \
+       exclude=':# *define STR(N?EQLEN|PREFIX)\('                      \
+       halt='$(ME): use STREQLEN or STRPREFIX instead of str''ncmp'    \
+         $(_sc_search_regexp)
 
 # Use virAsprintf rather than as'printf since *strp is undefined on error.
 sc_prohibit_asprintf:
@@ -569,11 +568,10 @@ func_re := ($(func_or))
 #    _("...: "
 #    "%s", _("no storage vol w..."
 sc_libvirt_unmarked_diagnostics:
-       @grep -nE                                                       \
-           '\<$(func_re) *\([^"]*"[^"]*[a-z]{3}' $$($(VC_LIST_EXCEPT)) \
-         | grep -v '_''(' &&                                           \
-         { echo '$(ME): found unmarked diagnostic(s)' 1>&2;            \
-           exit 1; } || :
+       @prohibit='\<$(func_re) *\([^"]*"[^"]*[a-z]{3}'                 \
+       exclude='_\('                                                   \
+       halt='$(ME): found unmarked diagnostic(s)'                      \
+         $(_sc_search_regexp)
        @{ grep     -nE '\<$(func_re) *\(.*;$$' $$($(VC_LIST_EXCEPT));   \
           grep -A1 -nE '\<$(func_re) *\(.*,$$' $$($(VC_LIST_EXCEPT)); } \
           | sed 's/_("[^"][^"]*"//;s/[  ]"%s"//'                       \
@@ -624,6 +622,26 @@ sc_prohibit_gettext_markup:
        halt='do not mark these strings for translation'                \
          $(_sc_search_regexp)
 
+# Our code is divided into modular subdirectories for a reason, and
+# lower-level code must not include higher-level headers.
+cross_dirs=$(patsubst $(srcdir)/src/%.,%,$(wildcard $(srcdir)/src/*/.))
+cross_dirs_re=($(subst / ,/|,$(cross_dirs)))
+sc_prohibit_cross_inclusion:
+       @for dir in $(cross_dirs); do                                   \
+         case $$dir in                                                 \
+           util/) safe="util";;                                        \
+           cpu/ | locking/ | network/ | rpc/ | security/)              \
+             safe="($$dir|util|conf)";;                                \
+           xenapi/ | xenxs/ ) safe="($$dir|util|conf|xen)";;           \
+           *) safe="($$dir|util|conf|cpu|network|locking|rpc|security)";; \
+         esac;                                                         \
+         in_vc_files="^src/$$dir"                                      \
+         prohibit='^# *include .$(cross_dirs_re)'                      \
+         exclude="# *include .$$safe"                                  \
+         halt='unsafe cross-directory include'                         \
+           $(_sc_search_regexp)                                        \
+       done
+
 # When converting an enum to a string, make sure that we track any new
 # elements added to the enum by using a _LAST marker.
 sc_require_enum_last_marker: