build: quote 'like this', not `like this'

As per updated GCS recommendations.

* Makefile.am, configure.ac, lib/m4sugar/Makefile.am,
tests/Makefile.am, m4/m4.m4: Here.

Signed-off-by: Stefano Lattarini <[email protected]>

Makefile.am

@@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # bin/ must be run first, as it builds executables needed for tests.
-# autom4te uses autotest.m4f to generate `testsuite', so build tests last.
+# autom4te uses autotest.m4f to generate 'testsuite', so build tests last.
 # Rules in man/ use scripts from both bin/ and tests/, so *it* goes last.
 SUBDIRS = bin . lib doc tests man
 
@@ -114,8 +114,8 @@ check-coverage-run: all
 
 check-coverage-report:
 	@if test ! -d $(PERL_COVERAGE_DB); then \
-	  echo "No coverage database found in \`$(PERL_COVERAGE_DB)'." >&2; \
-	  echo "Please run \`make check-coverage' first" >&2; \
+	  echo "No coverage database found in '$(PERL_COVERAGE_DB)'." >&2; \
+	  echo "Please run 'make check-coverage' first" >&2; \
 	  exit 1; \
 	fi
 	$(PERL_COVER) $(PERL_COVERAGE_DB) $(PERL_COVER_FLAGS)

configure.ac

@@ -30,9 +30,9 @@ AM_INIT_AUTOMAKE([1.11 dist-xz readme-alpha no-texinfo.tex std-options])
 
 AB_INIT
 
-# We use `/bin/sh -n script' to check that there are no syntax errors
+# We use '/bin/sh -n script' to check that there are no syntax errors
 # in the scripts.  Although incredible, there are /bin/sh that go into
-# endless loops with `-n', e.g., SunOS's:
+# endless loops with '-n', e.g., SunOS's:
 #
 #   $ uname -a
 #   SunOS ondine 4.1.3 2 sun4m unknown
@@ -50,8 +50,8 @@ AB_INIT
 # Also, some implementations of /bin/sh (e.g., Solaris 8) are soooo slow
 # that they are unusable on large scripts like our testsuite.
 
-# So before using `/bin/sh -n' to check our scripts, we first check
-# that `/bin/sh -n' is known to not have these problems.
+# So before using '/bin/sh -n' to check our scripts, we first check
+# that '/bin/sh -n' is known to not have these problems.
 
 AC_CACHE_CHECK([whether /bin/sh -n is known to work], [ac_cv_sh_n_works],
 [if (

lib/m4sugar/Makefile.am

@@ -28,7 +28,7 @@ RELEASE_YEAR = \
 ## version.m4.  ##
 ## ------------ ##
 
-# The `:;' works around a redirected compound command bash exit status bug.
+# The ':;' works around a redirected compound command bash exit status bug.
 version.m4: Makefile
 	:;{ \
 	  echo '# This file is part of -*- Autoconf -*-.' && \

m4/m4.m4

@@ -18,7 +18,7 @@
 # Also avoid versions of m4 that trigger strstr bugs.
 AC_DEFUN([AC_PROG_GNU_M4],
   [AC_ARG_VAR([M4], [Location of GNU M4 1.4.6 or later.  Defaults to the first
-    program of `m4', `gm4', or `gnum4' on PATH that meets Autoconf needs.])
+    program of 'm4', 'gm4', or 'gnum4' on PATH that meets Autoconf needs.])
   AC_CACHE_CHECK([for GNU M4 that supports accurate traces], [ac_cv_path_M4],
     [rm -f conftest.m4f
 ac_had_posixly_correct=${POSIXLY_CORRECT:+yes}

tests/Makefile.am

@@ -22,7 +22,7 @@
 EXTRA_DIST = $(TESTSUITE_AT) local.at mktests.sh \
 	     atlocal.in wrapper.as statesave.m4
 
-# Running the uninstalled scripts.  Build them upon `all', for the manpages.
+# Running the uninstalled scripts.  Build them upon 'all', for the manpages.
 noinst_SCRIPTS = $(wrappers)
 DISTCLEANFILES = atconfig atlocal $(TESTSUITE)
 MAINTAINERCLEANFILES = Makefile.in
@@ -35,7 +35,7 @@ include ../lib/freeze.mk
 ## package.m4.  ##
 ## ------------ ##
 
-# The `:;' works around a redirected compound command bash exit status bug.
+# The ':;' works around a redirected compound command bash exit status bug.
 package.m4: Makefile
 	:;{ \
 	  echo '# Signature of the current package.' && \
@@ -109,7 +109,7 @@ TESTSUITE_AT = $(TESTSUITE_GENERATED_AT) $(TESTSUITE_HAND_AT)
 TESTSUITE = ./testsuite
 
 # Run the non installed autom4te.
-# Don't use AUTOM4TE since `make alpha' makes it unavailable although
+# Don't use AUTOM4TE since 'make alpha' makes it unavailable although
 # we are allowed to use it (since we ship it).
 AUTOTEST = $(MY_AUTOM4TE) --language=autotest
 $(TESTSUITE): package.m4 \
@@ -158,7 +158,7 @@ MAINTAINERCLEANFILES += $(TESTSUITE_GENERATED_AT)
 
 # The files which contain macros we check for syntax.  Use $(top_srcdir)
 # for the benefit of non-GNU make.  Fix the names in the rule below
-# where we `cd' to $srcdir.
+# where we 'cd' to $srcdir.
 autoconfdir = $(top_srcdir)/lib/autoconf
 AUTOCONF_FILES = $(autoconfdir)/general.m4 \
 		 $(autoconfdir)/status.m4 \