maintainer/syntax-checks.mk

   1 # Maintainer checks for Automake.  Requires GNU make.
   2
   3 # Copyright (C) 2012-2024 Free Software Foundation, Inc.
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2, or (at your option)
   8 # any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  17
  18 # We also have to take into account VPATH builds (where some generated
  19 # tests might be in '$(builddir)' rather than in '$(srcdir)'), TAP-based
  20 # tests script (which have a '.tap' extension) and helper scripts used
  21 # by other test cases (which have a '.sh' extension).
  22 xtests := $(shell \
  23   if test $(srcdir) = .; then \
  24      dirs=.; \
  25    else \
  26      dirs='$(srcdir) .'; \
  27    fi; \
  28    for d in $$dirs; do \
  29      for s in tap sh; do \
  30        ls $$d/t/ax/*.$$s $$d/t/*.$$s $$d/contrib/t/*.$$s 2>/dev/null; \
  31      done; \
  32    done | sort)
  33
  34 xdefs = \
  35   $(srcdir)/t/ax/am-test-lib.sh \
  36   $(srcdir)/t/ax/test-lib.sh \
  37   $(srcdir)/t/ax/test-defs.in
  38
  39 # Must prune test dirs since some are intentionally unreadable.
  40 ams := $(shell find $(srcdir) -name '*.dir' -prune -o -name '*.am' -print)
  41
  42 # Some simple checks, and then ordinary checks.  These are only really
  43 # guaranteed to work on my machine.
  44 syntax_check_rules = \
  45 $(sc_tests_plain_check_rules) \
  46 sc_diff_automake \
  47 sc_diff_aclocal \
  48 sc_no_brace_variable_expansions \
  49 sc_rm_minus_f \
  50 sc_no_for_variable_in_macro \
  51 sc_mkinstalldirs \
  52 sc_pre_normal_post_install_uninstall \
  53 sc_perl_no_undef \
  54 sc_perl_no_split_regex_space \
  55 sc_perl_protos \
  56 sc_cd_in_backquotes \
  57 sc_cd_relative_dir \
  58 sc_perl_at_uscore_in_scalar_context \
  59 sc_perl_local \
  60 sc_AMDEP_TRUE_in_automake_in \
  61 sc_make_without_am_makeflags \
  62 sc_tests_no_source_defs \
  63 sc_tests_obsolete_variables \
  64 sc_tests_here_document_format \
  65 sc_tests_command_subst \
  66 sc_tests_no_run_make_redirect \
  67 sc_tests_exit_not_Exit \
  68 sc_tests_automake_fails \
  69 sc_tests_overriding_macros_on_cmdline \
  70 sc_tests_no_make_e \
  71 sc_tests_plain_sleep \
  72 sc_tests_ls_t \
  73 sc_m4_am_plain_egrep_fgrep \
  74 sc_tests_no_configure_in \
  75 sc_tests_PATH_SEPARATOR \
  76 sc_tests_logs_duplicate_prefixes \
  77 sc_tests_makefile_variable_order \
  78 sc_perl_at_substs \
  79 sc_unquoted_DESTDIR \
  80 sc_tabs_in_texi \
  81 sc_at_in_texi
  82
  83 $(syntax_check_rules): bin/automake bin/aclocal
  84 maintainer-check syntax-check: $(syntax_check_rules)
  85 .PHONY: maintainer-check syntax-check $(syntax_check_rules)
  86
  87 # Check that the list of tests given in the Makefile is equal to the
  88 # list of all test scripts in the Automake testsuite.
  89 maintainer-check: maintainer-check-list-of-tests
  90
  91 # I'm a lazy typist.
  92 lint: maintainer-check
  93 .PHONY: lint
  94
  95 # The recipes of syntax checks require a modern GNU grep.
  96 sc_sanity_gnu_grep:
  97         $(AM_V_GEN)grep --version | grep 'GNU grep' >/dev/null 2>&1 \
  98           && ab=$$(printf 'a\nb') \
  99           && test "$$(printf 'xa\nb\nc' | grep -Pzo 'a\nb' | tr -d '\0')" \
 100                = "$$ab" \
 101           || { \
 102             echo "Syntax checks recipes require a modern GNU grep" >&2; \
 103             exit 1; \
 104           }
 105 .PHONY: sc_sanity_gnu_grep
 106 $(syntax_check_rules): sc_sanity_gnu_grep
 107
 108 # Check that every subroutine in perl scripts has a corresponding
 109 # prototype.
 110 sc_perl_protos:
 111         $(AM_V_GEN)$(srcdir)/maintainer/check-perl-protos \
 112           <$(srcdir)/bin/aclocal.in && \
 113         $(srcdir)/maintainer/check-perl-protos <$(srcdir)/bin/automake.in
 114
 115 # These check avoids accidental configure substitutions in the source.
 116 # There are exactly 7 lines that should be modified from automake.in to
 117 # automake, and 8 lines that should be modified from aclocal.in to
 118 # aclocal.
 119 automake_diff_no = 7
 120 aclocal_diff_no = 8
 121 sc_diff_automake sc_diff_aclocal: in=$($*_in)
 122 sc_diff_automake sc_diff_aclocal: out=$($*_script)
 123 sc_diff_automake sc_diff_aclocal: sc_diff_% :
 124         @set +e; \
 125         in=$*-in.tmp out=$*-out.tmp diffs=$*-diffs.tmp \
 126           && sed '/^#!.*[pP]rototypes/d' $(in) > $$in \
 127           && sed '/^# BEGIN.* PROTO/,/^# END.* PROTO/d' $(out) > $$out \
 128           && { diff -u $$in $$out > $$diffs; test $$? -eq 1; } \
 129           && added=`grep -v '^+++ ' $$diffs | grep -c '^+'` \
 130           && removed=`grep -v '^--- ' $$diffs | grep -c '^-'` \
 131           && test $$added,$$removed = $($*_diff_no),$($*_diff_no) \
 132           || { \
 133             echo "Found unexpected diffs between $(in) and $(out)"; \
 134             echo "Lines added:   $$added"  ; \
 135             echo "Lines removed: $$removed"; \
 136             cat $$diffs; \
 137             exit 1; \
 138           } >&2; \
 139         rm -f $$in $$out $$diffs
 140
 141 # Expect no instances of '${...}'.  However, $${...} is ok, since that
 142 # is a shell construct, not a Makefile construct.
 143 sc_no_brace_variable_expansions:
 144         @if grep -v '^ *#' $(ams) | grep -F '$${' | grep -F -v '$$$$'; then \
 145           echo "Found too many uses of '\$${' in the lines above." 1>&2; \
 146           exit 1; \
 147         else :; fi
 148
 149 # Make sure 'rm' is called with '-f'.
 150 sc_rm_minus_f:
 151         @if grep -v '^#' $(ams) $(xtests) \
 152            | grep -vE '/(rm-f-probe\.sh|spy-rm\.tap|subobj-clean.*-pr10697\.sh):' \
 153            | grep -E '\<rm ([^-]|-[^f ]*\>)'; \
 154         then \
 155           echo "Suspicious 'rm' invocation." 1>&2; \
 156           exit 1; \
 157         else :; fi
 158
 159 # Never use something like "for file in $(FILES)", this doesn't work
 160 # if FILES is empty or if it contains shell meta characters (e.g. $ is
 161 # commonly used in Java filenames).
 162 sc_no_for_variable_in_macro:
 163         @if grep 'for .* in \$$(' $(ams) | grep -v '/Makefile\.am:'; then \
 164           echo 'Use "list=$$(mumble); for var in $$$$list".' 1>&2 ; \
 165           exit 1; \
 166         else :; fi
 167
 168 # Make sure all invocations of mkinstalldirs are correct.
 169 sc_mkinstalldirs:
 170         @if grep -n 'mkinstalldirs' $(ams) \
 171               | grep -F -v '$$(mkinstalldirs)' \
 172               | grep -v '^\./Makefile.am:[0-9][0-9]*:  *lib/mkinstalldirs \\$$'; \
 173         then \
 174           echo "Found incorrect use of mkinstalldirs in the lines above" 1>&2; \
 175           exit 1; \
 176         else :; fi
 177
 178 # Make sure all calls to PRE/NORMAL/POST_INSTALL/UNINSTALL
 179 sc_pre_normal_post_install_uninstall:
 180         @if grep -E -n '\((PRE|NORMAL|POST)_(|UN)INSTALL\)' $(ams) | \
 181               grep -v ':##' | grep -v ':        @\$$('; then \
 182           echo "Found incorrect use of PRE/NORMAL/POST_INSTALL/UNINSTALL in the lines above" 1>&2; \
 183           exit 1; \
 184         else :; fi
 185
 186 # We never want to use "undef", only "delete", but for $/.
 187 sc_perl_no_undef:
 188         @if grep -n -w 'undef ' $(automake_in) | \
 189               grep -F -v 'undef $$/'; then \
 190           echo "Found 'undef' in the lines above; use 'delete' instead" 1>&2; \
 191           exit 1; \
 192         fi
 193
 194 # We never want split (/ /,...), only split (' ', ...).
 195 sc_perl_no_split_regex_space:
 196         @if grep -n 'split (/ /' $(automake_in) $(acloca_in); then \
 197           echo "Found bad split in the lines above." 1>&2; \
 198           exit 1; \
 199         fi
 200
 201 # Look for cd within backquotes
 202 sc_cd_in_backquotes:
 203         @if grep -n '^[^#]*` *cd ' $(automake_in) $(ams); then \
 204           echo "Consider using \$$(am__cd) in the lines above." 1>&2; \
 205           exit 1; \
 206         fi
 207
 208 # Look for cd to a relative directory (may be influenced by CDPATH).
 209 # Skip some known directories that are OK.
 210 sc_cd_relative_dir:
 211         @if grep -n '^[^#]*cd ' $(automake_in) $(ams) | \
 212               grep -v 'echo.*cd ' | \
 213               grep -v 'am__cd =' | \
 214               grep -v '^[^#]*cd [./]' | \
 215               grep -v '^[^#]*cd \$$(top_builddir)' | \
 216               grep -v '^[^#]*cd "\$$\$$am__cwd' | \
 217               grep -v '^[^#]*cd \$$(abs' | \
 218               grep -v '^[^#]*cd "\$$(DESTDIR)'; then \
 219           echo "Consider using \$$(am__cd) in the lines above." 1>&2; \
 220           exit 1; \
 221         fi
 222
 223 # Using @_ in a scalar context is most probably a programming error.
 224 sc_perl_at_uscore_in_scalar_context:
 225         @if grep -Hn '[^%@_A-Za-z0-9][_A-Za-z0-9]*[^) ] *= *@_' \
 226             $(automake_in) $(aclocal_in); then \
 227           echo "Using @_ in a scalar context in the lines above." 1>&2; \
 228           exit 1; \
 229         fi
 230
 231 ## Allow only few variables to be localized in automake and aclocal.
 232 sc_perl_local:
 233         @if grep -Ev '^[ \t]*local \$$[_~]( *=|;)' \
 234               $(automake_in) $(aclocal_in) | \
 235             grep '^[ \t]*local [^*]'; then \
 236           echo "Please avoid 'local'." 1>&2; \
 237           exit 1; \
 238         fi
 239
 240 # Don't let AMDEP_TRUE substitution appear in automake.in.
 241 sc_AMDEP_TRUE_in_automake_in:
 242         @if grep '@AMDEP''_TRUE@' $(automake_in); then \
 243           echo "Don't put AMDEP_TRUE substitution in automake.in" 1>&2; \
 244           exit 1; \
 245         fi
 246
 247 # Recursive make invocations should always pass $(AM_MAKEFLAGS)
 248 # to $(MAKE), for portability to non-GNU make.
 249 sc_tests_make_without_am_makeflags:
 250         @if grep '^[^#].*(MAKE) ' $(ams) $(automake_in) \
 251             | grep -Fv '$$(AM_MAKEFLAGS)'; \
 252         then \
 253           echo 'Use $$(MAKE) $$(AM_MAKEFLAGS).' 1>&2; \
 254           exit 1; \
 255         fi
 256
 257 # Look out for some obsolete variables.
 258 sc_tests_obsolete_variables:
 259         @vars=" \
 260           using_tap \
 261           am_using_tap \
 262           test_prefer_config_shell \
 263           original_AUTOMAKE \
 264           original_ACLOCAL \
 265           parallel_tests \
 266           am_parallel_tests \
 267         "; \
 268         seen=""; \
 269         for v in $$vars; do \
 270           if grep -E "\b$$v\b" $(xtests) $(xdefs); then \
 271             seen="$$seen $$v"; \
 272           fi; \
 273         done; \
 274         if test -n "$$seen"; then \
 275           for v in $$seen; do \
 276             case $$v in \
 277               parallel_tests|am_parallel_tests) v2=am_serial_tests;; \
 278               *) v2=am_$$v;; \
 279             esac; \
 280             echo "Variable '$$v' is obsolete, use '$$v2' instead." 1>&2; \
 281           done; \
 282           exit 1; \
 283         else :; fi
 284
 285 # Tests should never call some programs directly, but only through the
 286 # corresponding variable (e.g., '$MAKE', not 'make').  This will allow
 287 # the programs to be overridden at configure time (for less brittleness)
 288 # or by the user at make time (to allow better testsuite coverage).
 289 sc_tests_plain_check_rules = \
 290   sc_tests_plain_egrep \
 291   sc_tests_plain_fgrep \
 292   sc_tests_plain_make \
 293   sc_tests_plain_perl \
 294   sc_tests_plain_automake \
 295   sc_tests_plain_aclocal \
 296   sc_tests_plain_autoconf \
 297   sc_tests_plain_autoupdate \
 298   sc_tests_plain_autom4te \
 299   sc_tests_plain_autoheader \
 300   sc_tests_plain_autoreconf
 301
 302 toupper = $(shell echo $(1) | LC_ALL=C tr '[a-z]' '[A-Z]')
 303
 304 $(sc_tests_plain_check_rules): sc_tests_plain_% :
 305         @# The leading ':' in the grep below is what is printed by the
 306         @# preceding 'grep -v' after the file name.
 307         @# It works here as a poor man's substitute for beginning-of-line
 308         @# marker.
 309         @if grep -v '^[         ]*#' $(xtests) \
 310            | $(EGREP) '(:|\bif|\bnot|[;!{\|\(]|&&|\|\|)[        ]*?$*\b'; \
 311          then \
 312            echo 'Do not run "$*" in the above tests.' \
 313                 'Use "$$$(call toupper,$*)" instead.' 1>&2; \
 314            exit 1; \
 315         fi
 316
 317 # Tests should only use END and EOF for here documents
 318 # (so that the next test is effective).
 319 sc_tests_here_document_format:
 320         @if grep '<<' $(xtests) | grep -Ev '\b(END|EOF)\b|\bcout <<'; then \
 321           echo 'Use here documents with "END" and "EOF" only, for greppability.' 1>&2; \
 322           exit 1; \
 323         fi
 324
 325 # Our test case should use the $(...) POSIX form for command substitution,
 326 # rather than the older `...` form.
 327 # The point of ignoring text on here-documents is that we want to exempt
 328 # Makefile.am rules, configure.ac code and helper shell script created and
 329 # used by out shell scripts, because Autoconf (as of version 2.69) does not
 330 # yet ensure that $CONFIG_SHELL will be set to a proper POSIX shell.
 331 sc_tests_command_subst:
 332         @found=false; \
 333         scan () { \
 334           sed -n -e '/^#/d' \
 335                  -e '/<<.*END/,/^END/b' -e '/<<.*EOF/,/^EOF/b' \
 336                  -e 's/\\`/\\{backtick}/' \
 337                  -e "s/[^\\]'\([^']*\`[^']*\)*'/'{quoted-text}'/g" \
 338                  -e '/`/p' $$*; \
 339         }; \
 340         for file in $(xtests); do \
 341           res=`scan $$file`; \
 342           if test -n "$$res"; then \
 343             echo "$$file:$$res"; \
 344             found=true; \
 345           fi; \
 346         done; \
 347         if $$found; then \
 348           echo 'Use $$(...), not `...`, for command substitutions.' >&2; \
 349           exit 1; \
 350         fi
 351
 352 # Tests should no longer call 'Exit', just 'exit'.  That's because we
 353 # now have in place a better workaround to ensure the exit status is
 354 # transported correctly across the exit trap.
 355 sc_tests_exit_not_Exit:
 356         @if grep 'Exit' $(xtests) $(xdefs) | grep -Ev '^[^:]+: *#' | grep .; then \
 357           echo "Use 'exit', not 'Exit'; it's obsolete now." 1>&2; \
 358           exit 1; \
 359         fi
 360
 361 # Guard against obsolescent uses of ./defs in tests.  Now,
 362 # 'test-init.sh' should be used instead.
 363 sc_tests_no_source_defs:
 364         @if grep -E '\. .*defs($$| )' $(xtests); then \
 365           echo "Source 'test-init.sh', not './defs'." 1>&2; \
 366           exit 1; \
 367         fi
 368
 369 # Invocation of 'run_make' should not have output redirections.
 370 sc_tests_no_run_make_redirect:
 371         @if grep -Pzo '.*(\$$MAKE|\brun_make)\b(.*(\\\n))*.*>.*' $(xtests); \
 372         then \
 373           echo 'Do not redirect stdout/stderr in "run_make" or "$$MAKE"' \
 374                'invocations,' >&2; \
 375           echo 'use "run_make {-E|-O|-M}" instead.' >&2; \
 376           exit 1; \
 377         fi
 378
 379 # Use AUTOMAKE_fails when appropriate
 380 sc_tests_automake_fails:
 381         @if grep -v '^#' $(xtests) | grep '\$$AUTOMAKE.*&&.*exit'; then \
 382           echo 'Use AUTOMAKE_fails + grep to catch automake failures in the above tests.' 1>&2;  \
 383           exit 1; \
 384         fi
 385
 386 # "make -e" is brittle and unsafe, since it let *all* the environment
 387 # win over the macro definitions in the Makefiles.  Since we offer
 388 # AM_MAKEFLAGS to allow the user to portably override macro definitions
 389 # from the command line in a safe way, we should encourage users to use
 390 # it.
 391 sc_tests_no_make_e:
 392         @if grep -E '\$$MAKE\b.* -[a-zA-Z0-9]*e' $(xtests); then \
 393           echo '"make -e" is brittle, use "run_make" instead.' 1>&2; \
 394           exit 1; \
 395         fi
 396
 397 # Overriding a Makefile macro on the command line is not portable when
 398 # recursive targets are used.  Better use an envvar.  SHELL is an
 399 # exception, POSIX says it can't come from the environment.  V, DESTDIR,
 400 # DISTCHECK_CONFIGURE_FLAGS and DISABLE_HARD_ERRORS are exceptions, too,
 401 # as package authors are urged not to initialize them anywhere.
 402 # Finally, 'exp' is used by some ad-hoc checks, where we ensure it's
 403 # ok to override it from the command line.
 404 sc_tests_overriding_macros_on_cmdline:
 405 # The first s/// tries to account for usages like "$MAKE || st=$?".
 406 # 'DISTCHECK_CONFIGURE_FLAGS' and 'exp' are allowed to contain whitespace in
 407 # their definitions, hence the more complex last three substitutions below.
 408         @if sed -e 's/ || .*//' -e 's/ && .*//' \
 409                 -e 's/ DESTDIR=[^ ]*/ /' -e 's/ SHELL=[^ ]*/ /' \
 410                 -e 's/ V=[^ ]*/ /' -e 's/ DISABLE_HARD_ERRORS=[^ ]*/ /' \
 411                 -e "s/ DISTCHECK_CONFIGURE_FLAGS='[^']*'/ /" \
 412                 -e 's/ DISTCHECK_CONFIGURE_FLAGS="[^"]*"/ /' \
 413                 -e 's/ DISTCHECK_CONFIGURE_FLAGS=[^ ]/ /' \
 414                 -e "s/ exp='[^']*'/ /" \
 415                 -e 's/ exp="[^"]*"/ /' \
 416                 -e 's/ exp=[^ ]/ /' \
 417               $(filter-out %/am-test-lib.sh,$(xtests)) \
 418                 | grep -E '\$$MAKE .*\S+='; then \
 419           echo 'Rewrite "$$MAKE foo=bar" as "run_make foo=bar" in the lines above,'; \
 420           echo 'it is more portable.'; \
 421           exit 1; \
 422         fi >&2
 423         @if grep 'SHELL=.*\$$MAKE' $(xtests); then \
 424           echo '$$MAKE ignores the SHELL envvar, use "run_make SHELL=$$SHELL"'; \
 425           echo 'in the above lines.'; \
 426           exit 1; \
 427         fi >&2
 428
 429 # Prefer use of our 'is_newest' auxiliary script over the more hacky
 430 # idiom "test $(ls -1t new old | sed 1q) = new", which is both more
 431 # cumbersome and more fragile.
 432 sc_tests_ls_t:
 433         @if LC_ALL=C grep -E '\bls(\s+-[a-zA-Z0-9]+)*\s+-[a-zA-Z0-9]*t' \
 434             $(xtests); then \
 435           echo "Use 'is_newest' rather than hacks based on 'ls -t'" 1>&2; \
 436           exit 1; \
 437         fi
 438
 439 # Never use 'sleep 1' to create files with different timestamps.
 440 # Use '$sleep' instead.  Some file systems (e.g., Windows) have only
 441 # a 2sec resolution.
 442 sc_tests_plain_sleep:
 443         @if grep -vE '^[        ]*#' $(xtests) \
 444               | grep -E '\bsleep +[12345]\b' | grep .; then \
 445           echo 'Do not use "sleep x" in the above tests.  Use "$$sleep" instead.' 1>&2; \
 446           exit 1; \
 447         fi
 448
 449 # fgrep and egrep are not required by POSIX.
 450 sc_m4_am_plain_egrep_fgrep:
 451         @if grep -E '\b[ef]grep\b' $(ams) $(srcdir)/m4/*.m4; then \
 452           echo 'Do not use egrep or fgrep in the above files,' \
 453                'they are not portable.' 1>&2; \
 454           exit 1; \
 455         fi
 456
 457 # Prefer 'configure.ac' over the obsolescent 'configure.in' as the name
 458 # for configure input files in our testsuite.  The latter  has been
 459 # deprecated for several years (at least since autoconf 2.50).
 460 sc_tests_no_configure_in:
 461         @if grep -E '\bconfigure\\*\.in\b' $(xtests) $(xdefs) \
 462               | grep -Ev '/backcompat.*\.(sh|tap):' \
 463               | grep -Ev '/autodist-configure-no-subdir\.sh:' \
 464               | grep -Ev '/(configure|help)\.sh:' \
 465               | grep .; \
 466         then \
 467           echo "Use 'configure.ac', not 'configure.in', as the name" >&2; \
 468           echo "for configure input files in the test cases above." >&2; \
 469           exit 1; \
 470         fi
 471
 472 # Rule to ensure that the testsuite has been run before.  We don't depend
 473 # on 'check' here, because that would be very wasteful in the common case.
 474 # We could run "make check RECHECK_LOGS=" and avoid toplevel races with
 475 # AM_RECURSIVE_TARGETS.  Suggest keeping test directories around for
 476 # greppability of the Makefile.in files.
 477 sc_ensure_testsuite_has_run:
 478         @if test ! -f '$(TEST_SUITE_LOG)'; then \
 479           echo 'Run "env keep_testdirs=yes make check" before' \
 480                'running "make maintainer-check"' >&2; \
 481           exit 1; \
 482         fi
 483 .PHONY: sc_ensure_testsuite_has_run
 484
 485 # Ensure our warning and error messages do not contain duplicate 'warning:' prefixes.
 486 # This test actually depends on the testsuite having been run before.
 487 sc_tests_logs_duplicate_prefixes: sc_ensure_testsuite_has_run
 488         @if grep -E '(warning|error):.*(warning|error):' t/*.log; then \
 489           echo 'Duplicate warning/error message prefixes seen in above tests.' >&2; \
 490           exit 1; \
 491         fi
 492
 493 # Ensure variables are listed before rules in Makefile.in files we generate.
 494 # (Do not descend into test dirs that are unreadable.)
 495 sc_tests_makefile_variable_order: sc_ensure_testsuite_has_run
 496         @st=0; \
 497         for file in `find t ! -perm -o+r -prune -o -name Makefile.in -print`; \
 498         do \
 499           latevars=`sed -n \
 500             -e :x -e 's/#.*//' \
 501             -e '/\\\\$$/{' -e N -e 'b x' -e '}' \
 502             -e '# Literal TAB.' \
 503             -e '1,/^    /d' \
 504             -e '# Allow @ so we match conditionals.' \
 505             -e '/^ *[a-zA-Z_@]\{1,\} *=/p' $$file`; \
 506           if test -n "$$latevars"; then \
 507             echo "Variables are expanded too late in $$file:" >&2; \
 508             echo "$$latevars" | sed 's/^/  /' >&2; \
 509             st=1; \
 510           fi; \
 511         done; \
 512         test $$st -eq 0 || { \
 513           echo 'Ensure variables are expanded before rules' >&2; \
 514           exit 1; \
 515         }
 516
 517 # Using ':' as a PATH separator is not portable.
 518 sc_tests_PATH_SEPARATOR:
 519         @if grep -E '\bPATH=.*:.*' $(xtests) ; then \
 520           echo "Use '\$$PATH_SEPARATOR', not ':', in PATH definitions" \
 521                "above." 1>&2; \
 522           exit 1; \
 523         fi
 524
 525 # Try to make sure all @...@ substitutions are covered by our
 526 # substitution rule.
 527 sc_perl_at_substs:
 528         @if test `grep -E '^[^#]*@[A-Za-z_0-9]+@' bin/aclocal | wc -l` -ne 0; then \
 529           echo "Unresolved @...@ substitution in aclocal" 1>&2; \
 530           exit 1; \
 531         fi
 532         @if test `grep -E '^[^#]*@[A-Za-z_0-9]+@' bin/automake | wc -l` -ne 0; then \
 533           echo "Unresolved @...@ substitution in automake" 1>&2; \
 534           exit 1; \
 535         fi
 536
 537 sc_unquoted_DESTDIR:
 538         @if grep -E "[^\'\"]\\\$$\(DESTDIR" $(ams); then \
 539           echo 'Suspicious unquoted DESTDIR uses.' 1>&2 ; \
 540           exit 1; \
 541         fi
 542
 543 sc_tabs_in_texi:
 544         @if grep '      ' $(srcdir)/doc/automake.texi; then \
 545           echo 'Do not use tabs in the manual.' 1>&2; \
 546           exit 1; \
 547         fi
 548
 549 sc_at_in_texi:
 550         @if grep -E '([^@]|^)@([         ][^@]|$$)' $(srcdir)/doc/automake.texi; \
 551         then \
 552           echo 'Unescaped @.' 1>&2; \
 553           exit 1; \
 554         fi