Modernize configure script.

Add Github Actions CI builds and Coverity scanning.

Add clang and cppcheck scanning.

Add test target.

.cppcheck

@@ -0,0 +1,20 @@
+// Bad CERT recommendation: C memory layout not determined by variable locations
+cert-API01-C
+
+// Cppcheck doesn't know enough about variables to know whether they are 
+// uninitialized...
+uninitvar
+
+// Don't report non-const casts.  Inline suppression comments are not working,
+// otherwise we'd be more selective...
+cert-EXP05-C
+
+// Not handling "(unsigned)~CONSTANT" properly...
+cert-INT31-c
+
+// fopen_s is NOT supported on POSIX platforms and DOES NOT APPLY for reading
+// of files!
+cert-MSC24-C
+
+// Not sure why this is a thing...
+preprocessorErrorDirective

.github/workflows/build.yml

@@ -0,0 +1,59 @@
+name: Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build-linux:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: update build environment
+      run: sudo apt-get update --fix-missing -y
+    - name: install prerequisites
+      run: sudo apt-get install -y cppcheck
+    - name: configure
+      env:
+        CC: /usr/bin/gcc
+      run: ./configure --enable-debug --enable-maintainer
+    - name: make
+      run: make
+    - name: test
+      env:
+        ASAN_OPTIONS: leak_check_at_exit=false
+      run: make test
+    - name: clang static analyzer
+      run: make CC=clang "GHA_ERROR=::error::" clang
+    - name: cppcheck
+      run: make "GHA_ERROR=::error::" cppcheck
+
+  build-macos:
+
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: configure
+      run: ./configure --enable-debug --enable-maintainer
+    - name: make
+      run: make
+    - name: test
+      run: make test
+    - name: clang static analyzer
+      run: make CC=clang "GHA_ERROR=::error::" clang
+
+  build-windows:
+
+    runs-on: windows-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: setup-msbuild
+      uses: microsoft/setup-msbuild@v1.0.2
+    - name: msbuild
+      run: msbuild vcnet\mxml.sln

.github/workflows/coverity.yml

@@ -0,0 +1,39 @@
+name: Coverity Scan
+
+on: workflow_dispatch
+
+jobs:
+  coverity-scan:
+    runs-on: ubuntu-latest
+    environment: Coverity
+    steps:
+      - uses: actions/checkout@v2
+      - name: update build environment
+        run: sudo apt-get update --fix-missing -y
+      - name: Download Coverity Build Tool
+        run: |
+          wget -q https://scan.coverity.com/download/linux64 --post-data token="$TOKEN&project=$GITHUB_REPOSITORY" -O cov-analysis-linux64.tar.gz
+          mkdir cov-analysis-linux64
+          tar xzf cov-analysis-linux64.tar.gz --strip 1 -C cov-analysis-linux64
+        env:
+          TOKEN: ${{ secrets.COVERITY_SCAN_TOKEN }}
+
+      - name: configure
+        run: ./configure --enable-debug --enable-maintainer
+
+      - name: Build with cov-build
+        run: |
+          export PATH=`pwd`/cov-analysis-linux64/bin:$PATH
+          cov-build --dir cov-int make
+      - name: Submit the result to Coverity Scan
+        run: |
+          tar czvf cov.tgz cov-int
+          curl \
+            --form token=$TOKEN \
+            --form email=michael.r.sweet@gmail.com \
+            --form file=@cov.tgz \
+            --form version="$GITHUB_REF" \
+            --form description="$GITHUB_SHA" \
+            "https://scan.coverity.com/builds?project=$GITHUB_REPOSITORY"
+        env:
+          TOKEN: ${{ secrets.COVERITY_SCAN_TOKEN }}

Makefile.in

@@ -3,7 +3,7 @@
 #
 # https://www.msweet.org/mxml
 #
-# Copyright © 2003-2019 by Michael R Sweet.
+# Copyright © 2003-2021 by Michael R Sweet.
 #
 # Licensed under Apache License v2.0.  See the file "LICENSE" for more
 # information.
@@ -17,20 +17,22 @@ AR		=	@AR@
 ARFLAGS		=	@ARFLAGS@
 ARCHFLAGS	=	@ARCHFLAGS@
 CC		=	@CC@
-CFLAGS		=	$(OPTIM) $(ARCHFLAGS) @CFLAGS@ @CPPFLAGS@ @PTHREAD_FLAGS@
+CFLAGS		=	$(OPTIM) $(ARCHFLAGS) @CFLAGS@ $(CPPFLAGS) $(WARNINGS)
 CP		=	@CP@
+CPPFLAGS	=	@CPPFLAGS@
 DSO		=	@DSO@
 DSOFLAGS	=	@DSOFLAGS@
 LDFLAGS		=	$(OPTIM) $(ARCHFLAGS) @LDFLAGS@
 INSTALL		=	@INSTALL@
 LIBMXML		=	@LIBMXML@
-LIBS		=	@LIBS@ @PTHREAD_LIBS@
+LIBS		=	@LIBS@
 LN		=	@LN@ -s
 MKDIR		=	@MKDIR@
 OPTIM		=	@OPTIM@
 RANLIB		=	@RANLIB@
 RM		=	@RM@ -f
 SHELL		=	/bin/sh
+WARNINGS	=	@WARNINGS@
 
 
 #
@@ -201,6 +203,34 @@ uninstall-libmxml.1.dylib:
 	$(RM) $(BUILDROOT)$(libdir)/libmxml.1.dylib
 
 
+#
+# Test everything...
+#
+
+test:	testmxml
+	@echo Testing library...
+	./testmxml test.xml temp1s.xml >temp1.xml
+	./testmxml temp1.xml temp2s.xml >temp2.xml
+	@if cmp temp1.xml temp2.xml; then \
+		echo Stdio file test passed!; \
+		$(RM) temp2.xml temp2s.xml; \
+	else \
+		echo Stdio file test failed!; \
+	fi
+	@if cmp temp1.xml temp1s.xml; then \
+		echo String test passed!; \
+		$(RM) temp1.xml temp1s.xml; \
+	else \
+		echo String test failed!; \
+	fi
+	@if cmp test.xml test.xmlfd; then \
+		echo File descriptor test passed!; \
+		$(RM) test.xmlfd temp1.xmlfd; \
+	else \
+		echo File descriptor test failed!; \
+	fi
+
+
 #
 # Figure out lines-of-code...
 #
@@ -270,27 +300,6 @@ libmxml.1.dylib:	$(LIBOBJS)
 testmxml:	libmxml.a testmxml.o
 	echo Linking $@...
 	$(CC) $(LDFLAGS) -o $@ testmxml.o libmxml.a $(LIBS)
-	@echo Testing library...
-	./testmxml test.xml temp1s.xml >temp1.xml
-	./testmxml temp1.xml temp2s.xml >temp2.xml
-	@if cmp temp1.xml temp2.xml; then \
-		echo Stdio file test passed!; \
-		$(RM) temp2.xml temp2s.xml; \
-	else \
-		echo Stdio file test failed!; \
-	fi
-	@if cmp temp1.xml temp1s.xml; then \
-		echo String test passed!; \
-		$(RM) temp1.xml temp1s.xml; \
-	else \
-		echo String test failed!; \
-	fi
-	@if cmp test.xml test.xmlfd; then \
-		echo File descriptor test passed!; \
-		$(RM) test.xmlfd temp1.xmlfd; \
-	else \
-		echo File descriptor test failed!; \
-	fi
 
 testmxml-vg:	$(LIBOBJS) testmxml.o
 	echo Linking $@...
@@ -299,6 +308,27 @@ testmxml-vg:	$(LIBOBJS) testmxml.o
 testmxml.o:	mxml.h
 
 
+#
+# Analyze code with the Clang static analyzer <https://clang-analyzer.llvm.org>
+#
+
+.PHONY: clang
+clang:
+	clang $(CPPFLAGS) --analyze $(OBJS:.o=.c) 2>clang.log
+	rm -rf $(OBJS:.o=.plist)
+	test -s clang.log && (echo "$(GHA_ERROR)Clang detected issues."; echo ""; cat clang.log; exit 1) || exit 0
+
+
+#
+# Analyze code using Cppcheck <http://cppcheck.sourceforge.net>
+#
+
+.PHONY: cppcheck
+cppcheck:
+	cppcheck $(CPPFLAGS) --template=gcc --addon=cert.py --suppressions-list=.cppcheck $(OBJS:.o=.c) 2>cppcheck.log
+	test -s cppcheck.log && (echo "$(GHA_ERROR)Cppcheck detected issues."; echo ""; cat cppcheck.log; exit 1) || exit 0
+
+
 #
 # Documentation (depends on separate codedoc utility)
 #

configure.ac

@@ -3,20 +3,26 @@ dnl Configuration script for Mini-XML, a small XML-like file parsing library.
 dnl
 dnl https://www.msweet.org/mxml
 dnl
-dnl Copyright © 2003-2020 by Michael R Sweet.
+dnl Copyright © 2003-2021 by Michael R Sweet.
 dnl
 dnl Licensed under Apache License v2.0.  See the file "LICENSE" for more
 dnl information.
 dnl
 
+dnl We need at least autoconf 2.70 for --runstatedir...
+AC_PREREQ([2.70])
+
+
 dnl Package name and version...
-AC_INIT([Mini-XML], [3.2], [https://github.com/michaelrsweet/mxml/issues], [mxml], [https://michaelrsweet.github.io/mxml])
+AC_INIT([Mini-XML], [3.2.1], [https://github.com/michaelrsweet/mxml/issues], [mxml], [https://www.msweet.org/mxml])
+
 
 dnl This line is provided to ensure that you don't run the autoheader program
 dnl against this project.  Doing so is completely unsupported and WILL cause
 dnl problems!
 AH_TOP([#error "Somebody ran autoheader on this project which is unsupported and WILL cause problems."])
 
+
 dnl Get the build and host platforms and split the host_os value
 AC_CANONICAL_BUILD
 AC_CANONICAL_HOST
@@ -24,58 +30,73 @@ AC_CANONICAL_HOST
 [host_os_name=`echo $host_os | sed -e '1,$s/[0-9.]*$//g'`]
 [host_os_version=`echo $host_os | sed -e '1,$s/^[^0-9.]*//g'`]
 
+
 dnl Set the name of the config header file...
-AC_CONFIG_HEADER(config.h)
+AC_CONFIG_HEADERS([config.h])
+
 
 dnl Version number...
 VERSION="AC_PACKAGE_VERSION"
 AC_SUBST(VERSION)
 AC_DEFINE_UNQUOTED(MXML_VERSION, "Mini-XML v$VERSION")
 
+
 dnl Clear default debugging options and set normal optimization by
 dnl default unless the user asks for debugging specifically.
 CFLAGS="${CFLAGS:=}"
-CXXFLAGS="${CXXFLAGS:=}"
+CPPFLAGS="${CPPFLAGS:=}"
 LDFLAGS="${LDFLAGS:=}"
-AC_SUBST(LDFLAGS)
+AC_SUBST([LDFLAGS])
+LIBS="${LIBS:=}"
 
-AC_ARG_WITH(ansi, [  --with-ansi             set full ANSI C mode, default=no],
-	use_ansi="$withval",
-	use_ansi="no")
 
-AC_ARG_WITH(archflags, [  --with-archflags        set additional architecture flags, default=none],
+dnl Options...
-	ARCHFLAGS="$withval",
+AC_ARG_WITH([ansi], AS_HELP_STRING([--with-ansi], [set full ANSI C mode, default=no]), [
-	ARCHFLAGS="")
+    use_ansi="$withval"
-AC_SUBST(ARCHFLAGS)
+], [
+    use_ansi="no"
+])
 
-AC_ARG_WITH(optim,   [  --with-optim            set additional optimization flags, default=none],
+AC_ARG_WITH([archflags], AS_HELP_STRING([--with-archflags], [set additional architecture flags, default=none]), [
-	OPTIM="$withval",
+    ARCHFLAGS="$withval"
-	OPTIM="")
+], [
-AC_SUBST(OPTIM)
+    ARCHFLAGS=""
+])
+AC_SUBST([ARCHFLAGS])
 
-AC_ARG_ENABLE(debug, [  --enable-debug          turn on debugging, default=no],
+AC_ARG_WITH([optim], AS_HELP_STRING([--with-optim], [set additional optimization flags, default=none]), [
-if eval "test x$enable_debug = xyes"; then
+    OPTIM="$withval"
- 	OPTIM="$OPTIM -g"
+], [
-fi)
+    OPTIM=""
+])
+AC_SUBST([OPTIM])
 
-AC_ARG_WITH(docdir, [  --with-docdir           set directory for documentation, default=${prefix}/share/doc/mxml],
+AC_ARG_ENABLE([debug], AS_HELP_STRING([--enable-debug], [turn on debugging, default=no]))
-	docdir="$withval",
+AC_ARG_ENABLE([maintainer], AS_HELP_STRING([--enable-maintainer], [turn on maintainer mode, default=no]))
-	docdir="NONE")
+AC_ARG_ENABLE([sanitizer], AS_HELP_STRING([--enable-sanitizer], [build with AddressSanitizer, default=no]))
 
+AC_ARG_WITH([docdir], AS_HELP_STRING([--with-docdir], [set directory for documentation, default=${prefix}/share/doc/mxml]), [
+    docdir="$withval"
+], [
+    docdir="NONE"
+])
 AC_SUBST(docdir)
 
-AC_ARG_WITH(vsnprintf, [  --with-vsnprintf        use vsnprintf emulation functions, default=auto],
+AC_ARG_WITH([vsnprintf], AS_HELP_STRING([--with-vsnprintf], [use vsnprintf emulation functions, default=auto]), [
-	use_vsnprintf="$withval",
+    use_vsnprintf="$withval"
-	use_vsnprintf="no")
+], [
+    use_vsnprintf="no"
+])
+
 
 dnl Checks for programs...
 AC_PROG_CC
 AC_PROG_CXX
 AC_PROG_INSTALL
-if test "$INSTALL" = "$ac_install_sh"; then
+AS_IF([test "$INSTALL" = "$ac_install_sh"], [
     # Use full path to install-sh script...
     INSTALL="`pwd`/install-sh -c"
-fi
+])
 AC_PROG_RANLIB
 AC_CHECK_TOOL(AR,ar)
 AC_PATH_PROG(CP,cp)
@@ -84,264 +105,270 @@ AC_PATH_PROG(LN,ln)
 AC_PATH_PROG(MKDIR,mkdir)
 AC_PATH_PROG(RM,rm)
 
-dnl Flags for "ar" command...
-case "$host_os_name" in
-        darwin* | *bsd)
-                ARFLAGS="-rcv"
-                ;;
-        *)
-                ARFLAGS="crvs"
-                ;;
-esac
 
+dnl Flags for "ar" command...
+AS_CASE(["$host_os_name"], [darwin* | *bsd], [
+    ARFLAGS="-rcv"
+], [*], [
+    ARFLAGS="crvs"
+])
 AC_SUBST(ARFLAGS)
 
+
 dnl Inline functions...
 AC_C_INLINE
 
-dnl Checks for string functions.
-if test "x$use_ansi" != xyes; then
-	AC_CHECK_FUNCS(strdup strlcat strlcpy)
-fi
 
-if test "x$use_vsnprintf" != xyes; then
+dnl Checks for string functions.
-	AC_CHECK_FUNCS(snprintf vasprintf vsnprintf)
+AS_IF([test "x$use_ansi" != xyes], [
-fi
+    AC_CHECK_FUNCS([strdup strlcat strlcpy])
+])
+
+AS_IF([test "x$use_vsnprintf" != xyes], [
+    AC_CHECK_FUNCS([snprintf vasprintf vsnprintf])
+])
+
 
 dnl Check for "long long" support...
-AC_CACHE_CHECK(for long long int, ac_cv_c_long_long,
+AC_CACHE_CHECK([for long long int], [ac_cv_c_long_long], [
-	[if test "$GCC" = yes; then
+    AS_IF([test "$GCC" = yes], [
 	ac_cv_c_long_long=yes
-	else
+    ], [
-		AC_TRY_COMPILE(,[long long int i;],
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
-			ac_cv_c_long_long=yes,
+	    long long int i;]])
-			ac_cv_c_long_long=no)
+	], [
-	fi])
+	    ac_cv_c_long_long=yes
+	], [
+	    ac_cv_c_long_long=no
+	])
+    ])
+])
+
+AS_IF([test $ac_cv_c_long_long = yes], [
+    AC_DEFINE([HAVE_LONG_LONG], [Have the long long type?])
+])
 
-if test $ac_cv_c_long_long = yes; then
-	AC_DEFINE(HAVE_LONG_LONG)
-fi
 
 dnl Threading support
-AC_ARG_ENABLE(threads, [  --enable-threads        enable multi-threading support])
+AC_ARG_ENABLE([threads], AS_HELP_STRING([--disable-threads], [disable multi-threading support, default=no]))
 
 have_pthread=no
-PTHREAD_FLAGS=""
+AS_IF([test "x$enable_threads" != xno], [
-PTHREAD_LIBS=""
+    AC_CHECK_HEADER([pthread.h], [
+        AC_DEFINE([HAVE_PTHREAD_H], [Have <pthread.h>?])
+    ])
 
-if test "x$enable_threads" != xno; then
+    AS_IF([test x$ac_cv_header_pthread_h = xyes], [
-	AC_CHECK_HEADER(pthread.h, AC_DEFINE(HAVE_PTHREAD_H))
-
-	if test x$ac_cv_header_pthread_h = xyes; then
 	dnl Check various threading options for the platforms we support
 	for flag in -lpthreads -lpthread -pthread; do
 	    AC_MSG_CHECKING([for pthread_create using $flag])
 	    SAVELIBS="$LIBS"
 	    LIBS="$flag $LIBS"
-        		AC_TRY_LINK([#include <pthread.h>],
+	    AC_LANG([C])
-				[pthread_create(0, 0, 0, 0);],
+	    AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>],[pthread_create(0, 0, 0, 0);])], [
-        			have_pthread=yes)
+		have_pthread=yes
-        		AC_MSG_RESULT([$have_pthread])
+	    ], [
 		LIBS="$SAVELIBS"
+	    ])
 
-			if test $have_pthread = yes; then
+	    AS_IF([test x$have_pthread = xyes], [
-				PTHREAD_FLAGS="-D_THREAD_SAFE -D_REENTRANT"
+		AC_MSG_RESULT([yes])
-				PTHREAD_LIBS="$flag"
+		CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE -D_REENTRANT"
-
-				# Solaris requires -D_POSIX_PTHREAD_SEMANTICS to
-				# be POSIX-compliant... :(
-				case "$host_os_name" in
-					sunos)
-					PTHREAD_FLAGS="$PTHREAD_FLAGS -D_POSIX_PTHREAD_SEMANTICS"
-					;;
-				esac
 		break
-			fi
+	    ], [
+		AC_MSG_RESULT([no])
+	    ])
 	done
-	fi
+    ])
-fi
+])
 
-AC_SUBST(PTHREAD_FLAGS)
-AC_SUBST(PTHREAD_LIBS)
 
 dnl Shared library support...
 DSO="${DSO:=:}"
 DSOFLAGS="${DSOFLAGS:=}"
 
-AC_ARG_ENABLE(shared, [  --enable-shared         turn on shared libraries, default=no])
+AC_ARG_ENABLE([shared], AS_HELP_STRING([--disable-shared], [turn off shared libraries, default=no]))
 
-if test x$enable_shared != xno; then
+AS_IF([test x$enable_shared != xno], [
-	AC_MSG_CHECKING(for shared library support)
+    AC_MSG_CHECKING([for shared library support])
     PICFLAG=1
 
-	case "$host_os_name" in
+    AS_CASE(["$host_os_name"], [sunos | unix_s], [
-		sunos | unix_s)
+	AC_MSG_RESULT([yes])
-			AC_MSG_RESULT(yes)
 	LIBMXML="libmxml.so.1.6"
 	DSO="\$(CC)"
 	DSOFLAGS="$DSOFLAGS -Wl,-h,libmxml.so.1 -G -R\$(libdir) \$(OPTIM)"
 	LDFLAGS="$LDFLAGS -R\$(libdir)"
-                	;;
+    ], [linux*], [
-
+	AC_MSG_RESULT([yes])
-		linux*)
-			AC_MSG_RESULT(yes)
 	LIBMXML="libmxml.so.1.6"
 	DSO="\$(CC)"
 	DSOFLAGS="$DSOFLAGS -Wl,-soname,libmxml.so.1 -shared \$(OPTIM)"
-			;;
+    ], [osf | gnu], [
-
+	AC_MSG_RESULT([yes])
-		osf | gnu)
-			AC_MSG_RESULT(yes)
 	LIBMXML="libmxml.so.1.6"
 	DSO="\$(CC)"
 	DSOFLAGS="$DSOFLAGS -Wl,-soname,libmxml.so.1,-rpath,\$(libdir) -shared \$(OPTIM)"
 	LDFLAGS="$LDFLAGS -Wl,-rpath,\$(libdir)"
-			;;
+    ], [*bsd | haiku*], [
-
+	AC_MSG_RESULT([yes])
-		*bsd | haiku*)
-			AC_MSG_RESULT(yes)
 	LIBMXML="libmxml.so.1.6"
 	DSO="\$(CC)"
 	DSOFLAGS="$DSOFLAGS -Wl,-soname,libmxml.so.1,-R\$(libdir) -shared \$(OPTIM)"
 	LDFLAGS="$LDFLAGS -Wl,-R\$(libdir)"
-                        ;;
+    ], [darwin], [
-
+	AC_MSG_RESULT([yes])
-		darwin)
-			AC_MSG_RESULT(yes)
 	LIBMXML="libmxml.1.dylib"
 	DSO="\$(CC)"
 	DSOFLAGS="$DSOFLAGS \$(RC_CFLAGS) -dynamiclib -lc"
-			;;
+    ], [mingw], [
-
+	AC_MSG_RESULT([yes])
-                mingw)
-                        AC_MSG_RESULT(yes)
 	LIBMXML="mxml1.dll"
 	DSO="\$(CC)"
 	DSOFLAGS="$DSOFLAGS -shared -Wl,--out-implib,libmxml1.a,--no-undefined,--enable-runtime-pseudo-reloc"
-                        ;;
+    ], [*], [
-
+	AC_MSG_RESULT([no])
-		*)
+	AC_MSG_WARN([shared libraries not supported on this platform.])
-			AC_MSG_RESULT(no)
-			AC_MSG_WARN(shared libraries not supported on this platform.)
 	PICFLAG=0
 	LIBMXML="libmxml.a"
-			;;
+    ])
-	esac
+], [
-else
     PICFLAG=0
     LIBMXML="libmxml.a"
-fi
+])
 
-AC_SUBST(DSO)
+AC_SUBST([DSO])
-AC_SUBST(DSOFLAGS)
+AC_SUBST([DSOFLAGS])
-AC_SUBST(LIBMXML)
+AC_SUBST([LIBMXML])
-AC_SUBST(PICFLAG)
+AC_SUBST([PICFLAG])
 
-dnl Add -Wall for GCC...
-if test -n "$GCC"; then
-	CFLAGS="-Wall -D_GNU_SOURCE $CFLAGS"
 
-	if test "x$OPTIM" = x; then
+dnl Compiler options...
-		OPTIM="-Os -g"
+WARNINGS=""
-	fi
+AC_SUBST([WARNINGS])
 
-	if test "x$use_ansi" = xyes; then
+AS_IF([test -n "$GCC"], [
+    CFLAGS="-D_GNU_SOURCE $CFLAGS"
+
+    AS_IF([test "x$OPTIM" = x], [
+	AS_IF([test x$enable_debug = xyes], [
+	    OPTIM="-g"
+	], [
+	    OPTIM="-g -Os"
+	])
+    ], [test x$enable_debug = xyes], [
+	OPTIM="$OPTIM -g"
+    ])
+
+    AS_IF([test x$enable_sanitizer = xyes], [
+	# Use -fsanitize=address with debugging...
+	OPTIM="$OPTIM -fsanitize=address"
+    ], [
+	# Otherwise use the Fortify enhancements to catch any unbounded
+	# string operations...
+	CPPFLAGS="$CPPFLAGS -D_FORTIFY_SOURCE=2"
+    ])
+
+    AS_IF([test "x$use_ansi" = xyes], [
 	CFLAGS="-ansi -pedantic $CFLAGS"
-	fi
+    ])
 
-	if test $PICFLAG = 1 -a "$host_os_name" != aix; then
+    dnl Show all standard warnings + unused variables when compiling...
+    WARNINGS="-Wall -Wunused"
+
+    dnl Drop some not-useful/unreliable warnings...
+    for warning in char-subscripts format-truncation format-y2k switch unused-result; do
+	AC_MSG_CHECKING([whether compiler supports -Wno-$warning])
+
+	OLDCFLAGS="$CFLAGS"
+	CFLAGS="$CFLAGS -Wno-$warning -Werror"
+
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM()], [
+	    AC_MSG_RESULT(yes)
+	    WARNINGS="$WARNINGS -Wno-$warning"
+        ], [
+	    AC_MSG_RESULT(no)
+	])
+
+	CFLAGS="$OLDCFLAGS"
+    done
+
+    dnl Maintainer mode enables -Werror...
+    AS_IF([test x$enable_maintainer = xyes], [
+	WARNINGS="$WARNINGS -Werror"
+    ])
+
+    AS_IF([test $PICFLAG = 1 -a "$host_os_name" != aix], [
 	OPTIM="-fPIC $OPTIM"
-	fi
+    ])
-else
+], [
-	case "$host_os_name" in
+    AS_IF([test "x$OPTIM" = x], [
-		hp-ux)
+	AS_IF([test x$enable_debug = xyes], [
-			CFLAGS="-Ae $CFLAGS"
+	    OPTIM="-g"
-
+	], [
-			if test "x$OPTIM" = x; then
 	    OPTIM="-O"
-			fi
+	])
+    ])
+
+    AS_CASE(["$host_os_name"], [hp-ux], [
+	CFLAGS="-Ae $CFLAGS"
 
 	OPTIM="+DAportable $OPTIM"
 
-			if test $PICFLAG = 1; then
+	AS_IF([test $PICFLAG = 1], [
 	    OPTIM="+z $OPTIM"
-			fi
+	])
-			;;
+    ], [unix_svr | sunos], [
-
+	AS_IF([test $PICFLAG = 1], [
-		unix_svr | sunos)
-			if test "x$OPTIM" = x; then
-				OPTIM="-O"
-			fi
-
-			if test $PICFLAG = 1; then
 	    OPTIM="-KPIC $OPTIM"
-			fi
+	])
-			;;
+    ])
+])
 
-		*)
-			if test "x$OPTIM" = x; then
-				OPTIM="-O"
-			fi
-			;;
-	esac
-fi
 
 dnl Determine whether we are cross-compiling...
-if test "$build" = "$host"; then
+AS_IF([test "$build" = "$host"], [
     TARGETS="ALLTARGETS"
-else
+], [
     TARGETS="CROSSTARGETS"
-fi
+])
-AC_SUBST(TARGETS)
+AC_SUBST([TARGETS])
 
-dnl Fix "prefix" variable if it hasn't been specified...
+
-if test "$prefix" = "NONE"; then
+dnl Fix installation directories...
+AS_IF([test "$prefix" = "NONE"], [
     prefix="/usr/local"
-fi
+])
 
-dnl Fix "exec_prefix" variable if it hasn't been specified...
+AS_IF([test "$exec_prefix" = "NONE"], [
-if test "$exec_prefix" = "NONE"; then
     exec_prefix="$prefix"
-fi
+])
 
-dnl Fix "docdir" variable if it hasn't been specified...
+AS_IF([test "$docdir" = "NONE"], [
-if test "$docdir" = "NONE"; then
     docdir="$datadir/doc/mxml"
-fi
+])
 
-dnl Fix "mandir" variable if it hasn't been specified...
+AS_IF([test "$mandir" = "\${prefix}/man" -a "$prefix" = "/usr"], [
-if test "$mandir" = "\${prefix}/man" -a "$prefix" = "/usr"; then
-	case "$host_os_name" in
-        	*bsd | darwin | linux*)
-        		# *BSD, Darwin (macOS), and Linux
     mandir="/usr/share/man"
-        		;;
+])
-        	irix)
+
-        		# SGI IRIX
-        		mandir="/usr/share/catman/u_man"
-        		;;
-        	*)
-        		# All others
-        		mandir="/usr/man"
-        		;;
-	esac
-fi
 
 dnl pkg-config stuff...
-if test "$includedir" != /usr/include; then
+AS_IF([test "$includedir" != /usr/include], [
     PC_CFLAGS="-I$includedir"
-else
+], [
     PC_CFLAGS=""
-fi
+])
+AC_SUBST([PC_CFLAGS])
 
-if test "$libdir" != /usr/lib; then
+AS_IF([test "$libdir" != /usr/lib], [
     PC_LIBS="-L$libdir -lmxml"
-else
+], [
     PC_LIBS="-lmxml"
-fi
+])
+AC_SUBST([PC_LIBS])
 
-AC_SUBST(PC_CFLAGS)
-AC_SUBST(PC_LIBS)
 
 dnl Output the makefile, etc...
-AC_OUTPUT(Makefile mxml.pc)
+AC_CONFIG_FILES([Makefile mxml.pc])
+AC_OUTPUT