qb: Refactor how config.h and config.mk are created.

This is a potential security issue.

The problem is that config.h and config.mk are populated with
all variables prefixed with 'HAVE_' from the user's environment.

Example:

  $ HAVE_FOO=yes ./configure
  $ grep FOO config.mk
  HAVE_FOO = 1
  $ grep FOO config.h
  #define HAVE_FOO 1

After this commit these files will only use variables set by
qb configure process and not from the user's environment. This
issue could result in hard to diagnose undefined behavior or
maybe worse?

The user should experience no change in behavior, but
developers should be more careful about setting 'HAVE_'
variables manually.

Unless the FOO variable is used by check_enabled ($2 only),
check_platform, check_lib, check_pkgconf, check_header,
check_macro or check_switch functions it should be set at
least once by the new add_opt function. The first argument
should be 'FOO' which matches the HAVE_FOO variable and the
second argument should contain 'auto', 'no' or 'yes'.

Example:

  add_opt FOO yes

When in doubt its safe to use add_opt. This will also fix a
few potential issues where configure arguments used by the
user are ignored.

When the second argument is not set the FOO variable will only
be used to populate config.h and config.mk with its current
value. This should only be done in qb/qb.libs.sh in functions
that set 'HAVE_' variables.

qb/config.libs.sh

@@ -1,3 +1,9 @@
+# Use add_opt to set HAVE_FOO variables the first time
+# example: add_opt FOO no
+#
+# Only needed when check_enabled ($2), check_platform, check_lib, check_pkgconf,
+# check_header, check_macro and check_switch are not used.
+
 check_switch '' C99 -std=gnu99 "Cannot find C99 compatible compiler."
 check_switch '' NOUNUSED -Wno-unused-result
 add_define MAKEFILE NOUNUSED "$HAVE_NOUNUSED"
@@ -59,7 +65,7 @@ if [ "$HAVE_VIDEOCORE" != "no" ]; then
       [ -d /opt/vc/lib ] && add_dirs LIBRARY /opt/vc/lib /opt/vc/lib/GL
       check_lib '' VIDEOCORE -lbcm_host bcm_host_init "-lvcos -lvchiq_arm"
    else
-      HAVE_VIDEOCORE="$HAVE_VC_TEST"
+      add_opt VIDEOCORE "$HAVE_VC_TEST"
    fi
 fi
 
@@ -115,7 +121,7 @@ check_pkgconf EXYNOS libdrm_exynos
 
 if [ "$LIBRETRO" ]; then
    die : 'Notice: Explicit libretro used, disabling dynamic libretro loading ...'
-   HAVE_DYNAMIC='no'
+   add_opt DYNAMIC no
 else
    LIBRETRO="-lretro"
 fi
@@ -144,7 +150,7 @@ fi
 check_platform 'Linux Win32' CDROM 'CD-ROM is' user
 
 if [ "$OS" = 'Win32' ]; then
-   HAVE_DYLIB=yes
+   add_opt DYLIB yes
 else
    check_lib '' DYLIB "$DYLIB" dlopen
 fi
@@ -152,8 +158,8 @@ fi
 check_lib '' NETWORKING "$SOCKETLIB" socket "" "$SOCKETHEADER"
 
 if [ "$HAVE_NETWORKING" != 'no' ]; then
-   HAVE_GETADDRINFO=auto
-   HAVE_SOCKET_LEGACY=no
+   add_opt GETADDRINFO auto
+   add_opt SOCKET_LEGACY no
 
    # WinXP+ implements getaddrinfo()
    if [ "$OS" = 'Win32' ]; then
@@ -166,9 +172,9 @@ if [ "$HAVE_NETWORKING" != 'no' ]; then
       fi
    fi
 
-   HAVE_NETWORK_CMD=yes
+   add_opt NETWORK_CMD yes
 else
-   HAVE_NETWORK_CMD=no
+   add_opt NETWORK_CMD no
 fi
 
 check_enabled NETWORKING CHEEVOS cheevos 'Networking is' false
@@ -184,9 +190,9 @@ check_lib '' MINIUPNPC '-lminiupnpc'
 check_lib '' STDIN_CMD "$CLIB" fcntl
 
 if [ "$HAVE_NETWORK_CMD" = "yes" ] || [ "$HAVE_STDIN_CMD" = "yes" ]; then
-   HAVE_COMMAND='yes'
+   add_opt COMMAND yes
 else
-   HAVE_COMMAND='no'
+   add_opt COMMAND no
 fi
 
 check_lib '' GETOPT_LONG "$CLIB" getopt_long
@@ -348,7 +354,7 @@ if [ "$HAVE_OPENGL" != 'no' ] && [ "$HAVE_OPENGLES" != 'yes' ]; then
       check_pkgconf OSMESA osmesa
    fi
 else
-   HAVE_OPENGL='no'
+   add_opt OPENGL no
 fi
 
 check_enabled EGL OPENGLES OpenGLES 'EGL is' false
@@ -505,13 +511,13 @@ if [ "$HAVE_MENU" != 'no' ]; then
       else
          if [ "$HAVE_CACA" != 'yes' ] && [ "$HAVE_SIXEL" != 'yes' ] &&
             [ "$HAVE_SDL" != 'yes' ] && [ "$HAVE_SDL2" != 'yes' ]; then
-            HAVE_RGUI=no
+            add_opt RGUI no
          fi
-         HAVE_MATERIALUI=no
-         HAVE_OZONE=no
-         HAVE_XMB=no
-         HAVE_STRIPES=no
-         HAVE_MENU_WIDGETS=no
+         add_opt MATERIALUI no
+         add_opt OZONE no
+         add_opt XMB no
+         add_opt STRIPES no
+         add_opt MENU_WIDGETS no
       fi
       die : 'Notice: Hardware rendering context not available.'
    fi

qb/qb.comp.sh

@@ -16,7 +16,7 @@ int main(void) { puts("Hai world!"); return 0; }
 EOF
 
 cc_works=0
-HAVE_CC=no
+add_opt CC no
 if [ "$CC" ]; then
 	"$CC" -o "$TEMP_EXE" "$TEMP_C" >/dev/null 2>&1 && cc_works=1
 else
@@ -53,7 +53,7 @@ int main() { std::cout << "Hai guise" << std::endl; return 0; }
 EOF
 
 cxx_works=0
-HAVE_CXX=no
+add_opt CXX no
 if [ "$CXX" ]; then
 	"$CXX" -o "$TEMP_EXE" "$TEMP_CXX" >/dev/null 2>&1 && cxx_works=1
 else

qb/qb.libs.sh

@@ -16,7 +16,7 @@ SHARE_DIR="${SHARE_DIR:-${PREFIX}/share}"
 # $2 = define
 # $3 = value
 add_define()
-{ eval "${1}_DEFINES=\"\${${1}_DEFINES} $2=$3\""; }
+{ 	eval "${1}_DEFINES=\"\${${1}_DEFINES} $2=$3\""; }
 
 # add_dirs:
 # $1 = INCLUDE or LIBRARY
@@ -54,7 +54,8 @@ check_compiler()
 # $4 = feature
 # $5 = enable lib when true, disable errors with 'user' [checked only if non-empty]
 check_enabled()
-{	setval="$(eval "printf %s \"\$HAVE_$2\"")"
+{	add_opt "$2"
+	setval="$(eval "printf %s \"\$HAVE_$2\"")"
 
 	for val in $(printf %s "$1"); do
 		tmpvar="$(eval "printf %s \"\$HAVE_$val\"")"
@@ -89,7 +90,8 @@ check_enabled()
 # $3 = feature
 # $4 = enable feature when 'true', disable errors with 'user' [checked only if non-empty]
 check_platform()
-{	tmpval="$(eval "printf %s \"\$HAVE_$2\"")"
+{	add_opt "$2"
+	tmpval="$(eval "printf %s \"\$HAVE_$2\"")"
 	[ "$tmpval" = 'no' ] && return 0
 
 	error=
@@ -137,7 +139,8 @@ check_platform()
 # $7 = include directory [checked only if non-empty]
 # $8 = critical error message [checked only if non-empty]
 check_lib()
-{	tmpval="$(eval "printf %s \"\$HAVE_$2\"")"
+{	add_opt "$2"
+	tmpval="$(eval "printf %s \"\$HAVE_$2\"")"
 	[ "$tmpval" = 'no' ] && return 0
 
 	check_compiler "$1" "$4"
@@ -203,7 +206,8 @@ check_lib()
 # $4 = critical error message [checked only if non-empty]
 # $5 = force check_lib when true [checked only if non-empty, set by check_val]
 check_pkgconf()
-{	tmpval="$(eval "printf %s \"\$HAVE_$1\"")"
+{	add_opt "$1"
+	tmpval="$(eval "printf %s \"\$HAVE_$1\"")"
 	eval "TMP_$1=\$tmpval"
 	[ "$tmpval" = 'no' ] && return 0
 
@@ -263,7 +267,8 @@ check_pkgconf()
 # $1 = HAVE_$1
 # $@ = header files
 check_header()
-{	tmpval="$(eval "printf %s \"\$HAVE_$1\"")"
+{	add_opt "$1"
+	tmpval="$(eval "printf %s \"\$HAVE_$1\"")"
 	[ "$tmpval" = 'no' ] && return 0
 	rm -f -- "$TEMP_C"
 	val="$1"
@@ -292,7 +297,8 @@ check_header()
 # $2 = macro name
 # $3 = header name [included only if non-empty]
 check_macro()
-{	tmpval="$(eval "printf %s \"\$HAVE_$1\"")"
+{	add_opt "$1"
+	tmpval="$(eval "printf %s \"\$HAVE_$1\"")"
 	[ "$tmpval" = 'no' ] && return 0
 	header_include=''
 	ECHOBUF=''
@@ -328,7 +334,8 @@ EOF
 # $3 = switch
 # $4 = critical error message [checked only if non-empty]
 check_switch()
-{	check_compiler "$1" ''
+{	add_opt "$2"
+	check_compiler "$1" ''
 
 	printf %s\\n 'int main(void) { return 0; }' > "$TEMP_CODE"
 	answer='no'

qb/qb.make.sh

@@ -1,7 +1,7 @@
 # Creates config.mk and config.h.
 vars=''
 add_define MAKEFILE GLOBAL_CONFIG_DIR "$GLOBAL_CONFIG_DIR"
-set -- $(set | grep ^HAVE_)
+eval "set -- $CONFIG_OPTS"
 while [ $# -gt 0 ]; do
 	tmpvar="${1%=*}"
 	shift 1

qb/qb.moc.sh

@@ -16,7 +16,7 @@ public:
 };
 EOF
 
-HAVE_MOC=no
+add_opt MOC no
 if [ "$HAVE_QT" = "yes" ]; then
 	moc_works=0
 	if [ "$MOC" ]; then

qb/qb.params.sh

@@ -1,4 +1,23 @@
-print_help_option() # $1 = option $@ = description
+# add_opt
+# $1 = HAVE_$1
+# $2 = value ['auto', 'no' or 'yes', checked only if non-empty]
+add_opt()
+{	setval="$(eval "printf %s \"\$USER_$1\"")"
+	[ "${2:-}" ] && ! match "$setval" no yes && eval "HAVE_$1=\"$2\""
+
+	for opt in $(printf %s "$CONFIG_OPTS"); do
+		case "$opt" in
+			"$1") return 0 ;;
+		esac
+	done
+
+	CONFIG_OPTS="${CONFIG_OPTS} $1"
+}
+
+# print_help_option
+# $1 = option
+# $@ = description
+print_help_option()
 {
 	_opt="$1"
 	shift 1
@@ -68,12 +87,17 @@ opt_exists() # $opt is returned if exists in OPTS
 parse_input() # Parse stuff :V
 {	BUILD=''
 	OPTS=''
+	CONFIG_OPTS=''
 	config_opts='./configure'
 
 	while read -r VAR _; do
 		TMPVAR="${VAR%=*}"
 		NEWVAR="${TMPVAR##HAVE_}"
-		OPTS="$OPTS $NEWVAR"
+		OPTS="${OPTS} $NEWVAR"
+		case "$NEWVAR" in
+			C89_*|CXX_*) : ;;
+			*) CONFIG_OPTS="${CONFIG_OPTS} $NEWVAR" ;;
+		esac
 		eval "USER_$NEWVAR=auto"
 	done < 'qb/config.params.sh'
 	#OPTS contains all available options in config.params.sh - used to speedup