build: use unified dependency expressions instead of weird fields

Instead of "deps", "deps_neg", and "deps_any" fields, just have a single
"deps" field, which changes from an array to a string. The string is now
an expression, which can contain the operators &&, ||, !, and allows
grouping with ( ).

It's probably overkill. If it gets a maintenance burden, we can switch
to specifiying the dep expressions as ASTs (or maybe eval()-able Python
expressions), and we could simplify the code that determines the reason
why a dependency is not fulfilled. The latter involves a complicated
conversion of the expression AST to DNF.

The parser is actually pretty simple, and pretty much follows:
https://en.wikipedia.org/wiki/Shunting_yard_algorithm

3 files changed, 323 insertions, 132 deletions

diff --git a/waftools/dependencies.py b/waftools/dependencies.py
index 994e1d10b2..3cef6a3562 100644
--- a/waftools/dependencies.py
+++ b/waftools/dependencies.py
@@ -2,6 +2,7 @@ from waflib.Errors import ConfigurationError, WafError
 from waflib.Configure import conf
 from waflib.Build import BuildContext
 from waflib.Logs import pprint
+import deps_parser
 import inflector
 
 class DependencyError(Exception):
@@ -16,11 +17,9 @@ class Dependency(object):
         self.attributes = self.__parse_attributes__(dependency)
 
         known_deps.add(self.identifier)
-        for dep_key in ['deps', 'deps_any', 'deps_neg']:
-            if dep_key in self.attributes:
-                deps = self.attributes[dep_key]
-                self.ctx.ensure_dependency_is_known(*deps)
 
+        if 'deps' in self.attributes:
+            self.ctx.ensure_dependency_is_known(self.attributes['deps'])
 
     def __parse_attributes__(self, dependency):
         if 'os_specific_checks' in dependency:
@@ -36,9 +35,7 @@ class Dependency(object):
         try:
             self.check_group_disabled()
             self.check_disabled()
-            self.check_any_dependencies()
             self.check_dependencies()
-            self.check_negative_dependencies()
         except DependencyError:
             # No check was run, since the prerequisites of the dependency are
             # not satisfied. Make sure the define is 'undefined' so that we
@@ -67,27 +64,12 @@ class Dependency(object):
             self.attributes['fmsg'] = "You manually enabled the feature '{0}', but \
 the autodetection check failed.".format(self.identifier)
 
-    def check_any_dependencies(self):
-        if 'deps_any' in self.attributes:
-            deps = set(self.attributes['deps_any'])
-            if len(deps & self.satisfied_deps) == 0:
-                self.skip("not found any of {0}".format(", ".join(deps)))
-                raise DependencyError
-
     def check_dependencies(self):
         if 'deps' in self.attributes:
-            deps = set(self.attributes['deps'])
-            if not deps <= self.satisfied_deps:
-                missing_deps = deps - self.satisfied_deps
-                self.skip("{0} not found".format(", ".join(missing_deps)))
-                raise DependencyError
-
-    def check_negative_dependencies(self):
-        if 'deps_neg' in self.attributes:
-            deps = set(self.attributes['deps_neg'])
-            conflicting_deps = deps & self.satisfied_deps
-            if len(conflicting_deps) > 0:
-                self.skip("{0} found".format(", ".join(conflicting_deps)), 'CYAN')
+            ok, why = deps_parser.check_dependency_expr(self.attributes['deps'],
+                                                        self.satisfied_deps)
+            if not ok:
+                self.skip(why)
                 raise DependencyError
 
     def check_autodetect_func(self):
@@ -145,13 +127,19 @@ def configure(ctx):
     __detect_target_os_dependency__(ctx)
 
 @conf
-def ensure_dependency_is_known(ctx, *depnames):
-    deps = set([d for d in depnames if not d.startswith('os-')])
-    if not deps <= ctx.known_deps:
-        raise ConfigurationError(
-            "error in dependencies definition: some dependencies in"
-            " {0} are unknown.".format(deps))
-
+def ensure_dependency_is_known(ctx, depnames):
+    def check(ast):
+        if isinstance(ast, deps_parser.AstSym):
+            if (not ast.name.startswith('os-')) and ast.name not in ctx.known_deps:
+                raise ConfigurationError(
+                    "error in dependencies definition: dependency {0} in"
+                    " {1} is unknown.".format(ast.name, depnames))
+        elif isinstance(ast, deps_parser.AstOp):
+            for sub in ast.sub:
+                check(sub)
+        else:
+            assert False
+    check(deps_parser.parse_expr(depnames))
 
 @conf
 def mark_satisfied(ctx, dependency_identifier):
@@ -174,7 +162,9 @@ def parse_dependencies(ctx, dependencies):
 @conf
 def dependency_satisfied(ctx, dependency_identifier):
     ctx.ensure_dependency_is_known(dependency_identifier)
-    return dependency_identifier in ctx.satisfied_deps
+    ok, _ = deps_parser.check_dependency_expr(dependency_identifier,
+                                              ctx.satisfied_deps)
+    return ok
 
 @conf
 def store_dependencies_lists(ctx):
@@ -194,13 +184,7 @@ def filtered_sources(ctx, sources):
             return source
 
     def __check_filter__(dependency):
-        if dependency.find('!') == 0:
-            dependency = dependency.lstrip('!')
-            ctx.ensure_dependency_is_known(dependency)
-            return dependency not in ctx.satisfied_deps
-        else:
-            ctx.ensure_dependency_is_known(dependency)
-            return dependency in ctx.satisfied_deps
+        return dependency_satisfied(ctx, dependency)
 
     def __unpack_and_check_filter__(source):
         try:
diff --git a/waftools/deps_parser.py b/waftools/deps_parser.py
new file mode 100644
index 0000000000..ef7888da30
--- /dev/null
+++ b/waftools/deps_parser.py
@@ -0,0 +1,218 @@
+
+class ParseError(Exception):
+    pass
+
+class AstOp(object):
+    def __init__(self, op, sub):
+        self.op = op
+        self.sub = sub
+
+    def __repr__(self):
+        if len(self.sub) == 1:
+            return self.op + str(self.sub[0])
+        return "(" + (" " + self.op + " ").join([str(x) for x in self.sub]) + ")"
+
+class AstSym(object):
+    def __init__(self, name):
+        assert type(name) is type("")
+        self.name = name
+
+    def __repr__(self):
+        return self.name
+
+Arity = { "!": 1, "&&": 2, "||": 2 }
+Precedence = { "!": 3, "&&": 2, "||": 1 }
+Tokens = list(Arity.keys()) + ["(", ")"]
+
+# return (token, rest), or (None, "") if nothing left
+def read_tok(expr):
+    expr = expr.strip()
+    for t in Tokens:
+        if expr.startswith(t):
+            return (t, expr[len(t):])
+    if expr == "":
+        return (None, "")
+    sym = ""
+    while len(expr) and ((expr[0].lower() >= 'a' and expr[0].lower() <= 'z') or
+                         (expr[0] >= '0' and expr[0] <= '9') or
+                         (expr[0] in ["_", "-", "."])):
+        sym += expr[0]
+        expr = expr[1:]
+    if len(sym):
+        return sym, expr
+    raise ParseError("unknown token in '%s'" % expr)
+
+def parse_expr(expr):
+    opstack = []
+    outstack = []
+    def out(sym):
+        if sym in Arity:
+            sub = []
+            for i in range(Arity[sym]):
+                if len(outstack) == 0:
+                    raise ParseError("missing operator argument")
+                sub.insert(0, outstack.pop())
+            outstack.append(AstOp(sym, sub))
+        elif sym == "(":
+            raise ParseError("missing closing ')'")
+        elif not isinstance(sym, AstSym):
+            raise ParseError("bogus symbol '%s'" % sym)
+        else:
+            outstack.append(sym)
+    while True:
+        tok, expr = read_tok(expr)
+        if tok is None:
+            break
+        if tok in Arity:
+            while len(opstack) and opstack[-1] != '(' and \
+                  Precedence[opstack[-1]] > Precedence[tok]:
+                out(opstack.pop())
+            opstack.append(tok)
+        elif tok == "(":
+            opstack.append(tok)
+        elif tok == ")":
+            while True:
+                if not len(opstack):
+                    raise ParseError("missing '(' for ')'")
+                sym = opstack.pop()
+                if sym == "(":
+                    break
+                out(sym)
+        else:
+            out(AstSym(tok)) # Assume a terminal
+    while len(opstack):
+        out(opstack.pop())
+    if len(outstack) != 1:
+        raise ParseError("empty expression or extra symbols (%s)" % outstack)
+    return outstack.pop()
+
+def convert_dnf(ast):
+
+    # no nested ! (negation normal form)
+    def simplify_negation(ast):
+        if isinstance(ast, AstOp):
+            if ast.op == "!":
+                sub = ast.sub[0]
+                if isinstance(sub, AstOp):
+                    if sub.op == "!":
+                        return sub.sub[0]
+                    elif sub.op in ["&&", "||"]:
+                        sub.op = "||" if sub.op == "&&" else "&&"
+                        sub.sub = [AstOp("!", [x]) for x in sub.sub]
+                        return simplify_negation(sub)
+            else:
+                ast.sub = [simplify_negation(x) for x in ast.sub]
+        return ast
+
+    # a && (b && c) => a && b && c
+    def flatten(ast):
+        if isinstance(ast, AstOp):
+            can_flatten = ast.op in ["&&", "||"]
+            nsub = []
+            for sub in ast.sub:
+                sub = flatten(sub)
+                if isinstance(sub, AstOp) and sub.op == ast.op and can_flatten:
+                    nsub.extend(sub.sub)
+                else:
+                    nsub.append(sub)
+            ast.sub = nsub
+            if len(ast.sub) == 1 and can_flatten:
+                return ast.sub[0]
+        return ast
+
+    # a && (b || c) && d => (a && d && b) || (a && d && c)
+    def redist(ast):
+        def recombine(a, stuff):
+            return AstOp("||", [AstOp("&&", [a, n]) for n in stuff])
+        if isinstance(ast, AstOp):
+            ast.sub = [flatten(redist(x)) for x in ast.sub]
+            if ast.op == "&&":
+                for sub in ast.sub:
+                    if isinstance(sub, AstOp) and sub.op == "||":
+                        if len(ast.sub) == 1:
+                            return redist(sub)
+                        other = None
+                        for n in ast.sub:
+                            if n is not sub:
+                                if other is None:
+                                    other = n
+                                else:
+                                    other = flatten(AstOp("&&", [other, n]))
+                        return flatten(redist(recombine(other, sub.sub)))
+        return ast
+
+    return redist(flatten(simplify_negation(ast)))
+
+# Returns (success_as_bool, failure_reason_as_string)
+def check_dependency_expr(expr, deps):
+    ast = parse_expr(expr)
+    def eval_ast(ast):
+        if isinstance(ast, AstSym):
+            return ast.name in deps
+        elif isinstance(ast, AstOp):
+            vals = [eval_ast(x) for x in ast.sub]
+            if ast.op == "&&":
+                return vals[0] and vals[1]
+            elif ast.op == "||":
+                return vals[0] or vals[1]
+            elif ast.op == "!":
+                return not vals[0]
+        assert False
+    if eval_ast(ast):
+        return True, None
+
+    # Now the same thing again, but more complicated, and informing what is
+    # missing.
+    ast = convert_dnf(ast)
+
+    # ast now is a or-combined list of and-combined deps. Each dep can have a
+    # negation (marking a conflict). Each case of and-combined deps is a way
+    # to satisfy the deps expression. Instead of dumping full information,
+    # distinguish the following cases, and only mention the one that applies,
+    # in order:
+    #   1. the first missing dep of a case that has missing deps only
+    #   2. the first conflicting dep at all
+
+    def do_op(ast, op, cb):
+        if isinstance(ast, AstOp) and ast.op == op:
+            for sub in ast.sub:
+                cb(sub)
+        else:
+            cb(ast)
+
+    def get_sub_list(node, op):
+        if isinstance(node, AstOp) and node.op == op:
+            return node.sub
+        else:
+            return [node]
+
+    conflict_dep = None
+    missing_dep = None
+
+    for group in get_sub_list(ast, "||"):
+        group_conflict = None
+        group_missing_dep = None
+        for elem in get_sub_list(group, "&&"):
+            neg = False
+            if isinstance(elem, AstOp) and elem.op == "!":
+                neg = True
+                elem = elem.sub[0]
+            if not isinstance(elem, AstSym):
+                continue # broken DNF?
+            name = elem.name
+            present = name in deps
+            if (not present) and (not neg) and (group_missing_dep is None):
+                group_missing_dep = name
+            if present and neg and (group_conflict is None):
+                group_conflict = name
+        if (missing_dep is None) and (group_conflict is None):
+            missing_dep = group_missing_dep
+        if conflict_dep is None:
+            conflict_dep = group_conflict
+
+    reason = "unknown"
+    if missing_dep is not None:
+        reason = "%s not found" % (missing_dep)
+    elif conflict_dep is not None:
+        reason = "%s found" % (conflict_dep)
+    return False, reason
diff --git a/wscript b/wscript
index 9fe5b0bc8a..2aa5681641 100644
--- a/wscript
+++ b/wscript
@@ -14,7 +14,7 @@ c_preproc.standard_includes.append('/usr/local/include')
 
 """
 Dependency identifiers (for win32 vs. Unix):
-    wscript / C source      meaning
+    wscript / C source                  meaning
     --------------------------------------------------------------------------
     posix / HAVE_POSIX:                 defined on Linux, OSX, Cygwin
                                         (Cygwin emulates POSIX APIs on Windows)
@@ -40,7 +40,7 @@ build_options = [
         'name': '--libmpv-static',
         'desc': 'static library',
         'default': 'disable',
-        'deps_neg': [ 'libmpv-shared' ],
+        'deps': '!libmpv-shared',
         'func': check_true
     }, {
         'name': '--static-build',
@@ -83,8 +83,7 @@ build_options = [
     }, {
         'name': '--cplugins',
         'desc': 'C plugins',
-        'deps': [ 'libdl' ],
-        'deps_neg': [ 'os-win32' ],
+        'deps': 'libdl && !os-win32',
         'func': check_cc(linkflags=['-rdynamic']),
     }, {
         'name': '--zsh-comp',
@@ -127,7 +126,7 @@ main_dependencies = [
     }, {
         'name': 'mingw',
         'desc': 'MinGW',
-        'deps': [ 'os-win32' ],
+        'deps': 'os-win32',
         'func': check_statement('stdlib.h', 'int x = __MINGW32__;'
                                             'int y = __MINGW64_VERSION_MAJOR'),
     }, {
@@ -143,7 +142,7 @@ main_dependencies = [
     }, {
         'name': 'posix-or-mingw',
         'desc': 'development environment',
-        'deps_any': [ 'posix', 'mingw' ],
+        'deps': 'posix || mingw',
         'func': check_true,
         'req': True,
         'fmsg': 'Unable to find either POSIX or MinGW-w64 environment, ' \
@@ -152,20 +151,17 @@ main_dependencies = [
         'name': '--uwp',
         'desc': 'Universal Windows Platform',
         'default': 'disable',
-        'deps': [ 'os-win32', 'mingw' ],
-        'deps_neg': [ 'cplayer' ],
+        'deps': 'os-win32 && mingw && !cplayer',
         'func': check_cc(lib=['windowsapp']),
     }, {
         'name': 'win32-desktop',
         'desc': 'win32 desktop APIs',
-        'deps_any': [ 'os-win32', 'os-cygwin' ],
-        'deps_neg': [ 'uwp' ],
+        'deps': '(os-win32 || os-cygwin) && !uwp',
         'func': check_cc(lib=['winmm', 'gdi32', 'ole32', 'uuid', 'avrt', 'dwmapi']),
     }, {
         'name': '--win32-internal-pthreads',
         'desc': 'internal pthread wrapper for win32 (Vista+)',
-        'deps_neg': [ 'posix' ],
-        'deps': [ 'os-win32' ],
+        'deps': 'os-win32 && !posix',
         'func': check_true,
     }, {
         'name': 'pthreads',
@@ -189,11 +185,11 @@ main_dependencies = [
         'desc': 'stdatomic.h support or slow emulation',
         'func': check_true,
         'req': True,
-        'deps_any': ['stdatomic', 'gnuc'],
+        'deps': 'stdatomic || gnuc',
     }, {
         'name': 'librt',
         'desc': 'linking with -lrt',
-        'deps': [ 'pthreads' ],
+        'deps': 'pthreads',
         'func': check_cc(lib='rt')
     }, {
         'name': '--iconv',
@@ -206,7 +202,7 @@ iconv support use --disable-iconv.",
     }, {
         'name': 'dos-paths',
         'desc': 'w32/dos paths',
-        'deps_any': [ 'os-win32', 'os-cygwin' ],
+        'deps': 'os-win32 || os-cygwin',
         'func': check_true
     }, {
         'name': '--termios',
@@ -226,28 +222,26 @@ iconv support use --disable-iconv.",
         'desc': 'POSIX spawnp()/kill()',
         'func': check_statement(['spawn.h', 'signal.h'],
             'posix_spawnp(0,0,0,0,0,0); kill(0,0)'),
-        'deps_neg': ['mingw'],
+        'deps': '!mingw',
     }, {
         'name': 'win32-pipes',
         'desc': 'Windows pipe support',
         'func': check_true,
-        'deps': [ 'win32-desktop' ],
-        'deps_neg': [ 'posix' ],
+        'deps': 'win32-desktop && !posix',
     }, {
         'name': 'glob-posix',
         'desc': 'glob() POSIX support',
-        'deps_neg': [ 'os-win32', 'os-cygwin' ],
+        'deps': '!(os-win32 || os-cygwin)',
         'func': check_statement('glob.h', 'glob("filename", 0, 0, 0)'),
     }, {
         'name': 'glob-win32',
         'desc': 'glob() win32 replacement',
-        'deps_neg': [ 'posix' ],
-        'deps_any': [ 'os-win32', 'os-cygwin' ],
+        'deps': '!posix && (os-win32 || os-cygwin)',
         'func': check_true
     }, {
         'name': 'glob',
         'desc': 'any glob() support',
-        'deps_any': [ 'glob-posix', 'glob-win32' ],
+        'deps': 'glob-posix || glob-win32',
         'func': check_true,
     }, {
         'name': 'fchmod',
@@ -271,13 +265,13 @@ iconv support use --disable-iconv.",
     }, {
         'name': 'osx-thread-name',
         'desc': 'OSX API for setting thread name',
-        'deps_neg': [ 'glibc-thread-name' ],
+        'deps': '!glibc-thread-name',
         'func': check_statement('pthread.h',
                                 'pthread_setname_np("ducks")', use=['pthreads']),
     }, {
         'name': 'bsd-thread-name',
         'desc': 'BSD API for setting thread name',
-        'deps_neg': [ 'glibc-thread-name', 'osx-thread-name' ],
+        'deps': '!(glibc-thread-name || osx-thread-name)',
         'func': check_statement('pthread.h',
                                 'pthread_set_name_np(pthread_self(), "ducks")',
                                 use=['pthreads']),
@@ -289,13 +283,13 @@ iconv support use --disable-iconv.",
     }, {
         'name': 'linux-fstatfs',
         'desc': "Linux's fstatfs()",
-        'deps': [ 'os-linux' ],
+        'deps': 'os-linux',
         'func': check_statement('sys/vfs.h',
                                 'struct statfs fs; fstatfs(0, &fs); fs.f_namelen')
     }, {
         'name': '--libsmbclient',
         'desc': 'Samba support (makes mpv GPLv3)',
-        'deps': [ 'libdl' ],
+        'deps': 'libdl',
         'func': check_pkg_config('smbclient'),
         'default': 'disable',
         'module': 'input',
@@ -318,12 +312,12 @@ iconv support use --disable-iconv.",
     }, {
         'name': '--libass-osd',
         'desc': 'libass OSD support',
-        'deps': [ 'libass' ],
+        'deps': 'libass',
         'func': check_true,
     }, {
         'name': 'dummy-osd',
         'desc': 'dummy OSD support',
-        'deps_neg': [ 'libass-osd' ],
+        'deps': '!libass-osd',
         'func': check_true,
     } , {
         'name': '--zlib',
@@ -355,7 +349,7 @@ iconv support use --disable-iconv.",
     }, {
         'name': 'dvdread-common',
         'desc': 'DVD/IFO support',
-        'deps_any': [ 'dvdread', 'dvdnav' ],
+        'deps': 'dvdread || dvdnav',
         'func': check_true,
     }, {
         'name': '--cdda',
@@ -365,7 +359,7 @@ iconv support use --disable-iconv.",
     }, {
         'name': '--uchardet',
         'desc': 'uchardet support',
-        'deps': [ 'iconv' ],
+        'deps': 'iconv',
         'func': check_pkg_config('uchardet'),
     }, {
         'name': '--rubberband',
@@ -383,12 +377,12 @@ iconv support use --disable-iconv.",
     }, {
         'name': '--vapoursynth-lazy',
         'desc': 'VapourSynth filter bridge (Lazy Lua)',
-        'deps': ['lua'],
+        'deps': 'lua',
         'func': check_pkg_config('vapoursynth',        '>= 24'),
     }, {
         'name': 'vapoursynth-core',
         'desc': 'VapourSynth filter bridge (core)',
-        'deps_any': ['vapoursynth', 'vapoursynth-lazy'],
+        'deps': 'vapoursynth || vapoursynth-lazy',
         'func': check_true,
     }, {
         'name': '--libarchive',
@@ -454,7 +448,7 @@ libav_dependencies = [
     }, {
         'name': 'libav',
         'desc': 'Libav/FFmpeg library versions',
-        'deps_any': [ 'is_ffmpeg', 'is_libav' ],
+        'deps': 'is_ffmpeg || is_libav',
         'func': check_ffmpeg_or_libav_versions(),
         'req': True,
         'fmsg': "Unable to find development files for some of the required \
@@ -499,14 +493,14 @@ audio_output_features = [
     }, {
         'name': '--sdl1',
         'desc': 'SDL (1.x)',
-        'deps_neg': [ 'sdl2' ],
+        'deps': '!sdl2',
         'func': check_pkg_config('sdl'),
         'default': 'disable'
     }, {
         'name': '--oss-audio',
         'desc': 'OSS',
         'func': check_cc(header_name='sys/soundcard.h'),
-        'deps': [ 'posix' ],
+        'deps': 'posix',
     }, {
         'name': '--rsound',
         'desc': 'RSound audio output',
@@ -547,14 +541,14 @@ audio_output_features = [
     }, {
         'name': '--audiounit',
         'desc': 'AudioUnit output for iOS',
-        'deps': ['atomics'],
+        'deps': 'atomics',
         'func': check_cc(
             fragment=load_fragment('audiounit.c'),
             framework_name=['Foundation', 'AudioToolbox'])
     }, {
         'name': '--wasapi',
         'desc': 'WASAPI audio output',
-        'deps_any': ['os-win32', 'os-cygwin'],
+        'deps': 'os-win32 || os-cygwin',
         'func': check_cc(fragment=load_fragment('wasapi.c')),
     }
 ]
@@ -567,12 +561,12 @@ video_output_features = [
     }, {
         'name': '--drm',
         'desc': 'DRM',
-        'deps': [ 'vt.h' ],
+        'deps': 'vt.h',
         'func': check_pkg_config('libdrm'),
     }, {
         'name': '--gbm',
         'desc': 'GBM',
-        'deps': [ 'gbm.h' ],
+        'deps': 'gbm.h',
         'func': check_pkg_config('gbm'),
     } , {
         'name': '--wayland',
@@ -591,12 +585,12 @@ video_output_features = [
     } , {
         'name': '--xv',
         'desc': 'Xv video output',
-        'deps': [ 'x11' ],
+        'deps': 'x11',
         'func': check_pkg_config('xv'),
     } , {
         'name': '--gl-cocoa',
         'desc': 'OpenGL Cocoa Backend',
-        'deps': [ 'cocoa' ],
+        'deps': 'cocoa',
         'groups': [ 'gl' ],
         'func': check_statement('IOSurface/IOSurface.h',
                                 'IOSurfaceRef surface;',
@@ -604,7 +598,7 @@ video_output_features = [
     } , {
         'name': '--gl-x11',
         'desc': 'OpenGL X11 Backend',
-        'deps': [ 'x11' ],
+        'deps': 'x11',
         'groups': [ 'gl' ],
         'func': check_libs(['GL', 'GL Xdamage'],
                    check_cc(fragment=load_fragment('gl_x11.c'),
@@ -612,33 +606,33 @@ video_output_features = [
     } , {
         'name': '--egl-x11',
         'desc': 'OpenGL X11 EGL Backend',
-        'deps': [ 'x11' ],
+        'deps': 'x11',
         'groups': [ 'gl' ],
         'func': check_pkg_config('egl'),
     } , {
         'name': '--egl-drm',
         'desc': 'OpenGL DRM EGL Backend',
-        'deps': [ 'drm', 'gbm' ],
+        'deps': 'drm && gbm',
         'groups': [ 'gl' ],
         'func': check_pkg_config('egl'),
     } , {
         'name': '--gl-wayland',
         'desc': 'OpenGL Wayland Backend',
-        'deps': [ 'wayland' ],
+        'deps': 'wayland',
         'groups': [ 'gl' ],
         'func': check_pkg_config('wayland-egl', '>= 9.0.0',
                                  'egl',         '>= 9.0.0')
     } , {
         'name': '--gl-win32',
         'desc': 'OpenGL Win32 Backend',
-        'deps': [ 'win32-desktop' ],
+        'deps': 'win32-desktop',
         'groups': [ 'gl' ],
         'func': check_statement('windows.h', 'wglCreateContext(0)',
                                 lib='opengl32')
     } , {
         'name': '--gl-dxinterop',
         'desc': 'OpenGL/DirectX Interop Backend',
-        'deps': [ 'gl-win32' ],
+        'deps': 'gl-win32',
         'groups': [ 'gl' ],
         'func': compose_checks(
             check_statement(['GL/gl.h', 'GL/wglext.h'], 'int i = WGL_ACCESS_WRITE_DISCARD_NV'),
@@ -646,14 +640,14 @@ video_output_features = [
     } , {
         'name': '--egl-angle',
         'desc': 'OpenGL ANGLE headers',
-        'deps_any': [ 'os-win32', 'os-cygwin' ],
+        'deps': 'os-win32 || os-cygwin',
         'groups': [ 'gl' ],
         'func': check_statement(['EGL/egl.h', 'EGL/eglext.h'],
                                 'int x = EGL_D3D_TEXTURE_2D_SHARE_HANDLE_ANGLE')
     } , {
         'name': '--egl-angle-lib',
         'desc': 'OpenGL Win32 ANGLE Library',
-        'deps': [ 'egl-angle' ],
+        'deps': 'egl-angle',
         'groups': [ 'gl' ],
         'func': check_statement(['EGL/egl.h'],
                                 'eglCreateWindowSurface(0, 0, 0, 0)',
@@ -664,54 +658,53 @@ video_output_features = [
     }, {
         'name': '--egl-angle-win32',
         'desc': 'OpenGL Win32 ANGLE Backend',
-        'deps': [ 'egl-angle', 'win32-desktop' ],
+        'deps': 'egl-angle && win32-desktop',
         'groups': [ 'gl' ],
         'func': check_true,
     } , {
         'name': '--vdpau',
         'desc': 'VDPAU acceleration',
-        'deps': [ 'x11' ],
+        'deps': 'x11',
         'func': check_pkg_config('vdpau', '>= 0.2'),
     } , {
         'name': '--vdpau-gl-x11',
         'desc': 'VDPAU with OpenGL/X11',
-        'deps': [ 'vdpau', 'gl-x11' ],
+        'deps': 'vdpau && gl-x11',
         'func': check_true,
     }, {
         'name': '--vaapi',
         'desc': 'VAAPI acceleration',
-        'deps': [ 'libdl' ],
-        'deps_any': [ 'x11', 'wayland', 'egl-drm' ],
+        'deps': 'libdl && (x11 || wayland || egl-drm)',
         'func': check_pkg_config('libva', '>= 0.36.0'),
     }, {
         'name': '--vaapi-x11',
         'desc': 'VAAPI (X11 support)',
-        'deps': [ 'vaapi', 'x11' ],
+        'deps': 'vaapi && x11',
         'func': check_pkg_config('libva-x11', '>= 0.36.0'),
     }, {
         'name': '--vaapi-wayland',
         'desc': 'VAAPI (Wayland support)',
-        'deps': [ 'vaapi', 'gl-wayland' ],
+        'deps': 'vaapi && gl-wayland',
         'func': check_pkg_config('libva-wayland', '>= 0.36.0'),
     }, {
         'name': '--vaapi-drm',
         'desc': 'VAAPI (DRM/EGL support)',
-        'deps': [ 'vaapi', 'egl-drm' ],
+        'deps': 'vaapi && egl-drm',
         'func': check_pkg_config('libva-drm', '>= 0.36.0'),
     }, {
         'name': '--vaapi-glx',
         'desc': 'VAAPI GLX',
-        'deps': [ 'vaapi-x11', 'gl-x11' ],
+        'deps': 'vaapi-x11 && gl-x11',
         'func': check_true,
     }, {
         'name': '--vaapi-x-egl',
         'desc': 'VAAPI EGL on X11',
-        'deps': [ 'vaapi-x11', 'egl-x11' ],
+        'deps': 'vaapi-x11 && egl-x11',
         'func': check_true,
     }, {
         'name': 'vaapi-egl',
         'desc': 'VAAPI EGL',
-        'deps_any': [ 'vaapi-x-egl', 'vaapi-wayland' ],
+        'deps': 'vaapi-x-egl || vaapi-wayland',
         'func': check_true,
     }, {
         'name': '--caca',
@@ -725,7 +718,7 @@ video_output_features = [
     }, {
         'name': '--direct3d',
         'desc': 'Direct3D support',
-        'deps': [ 'win32-desktop' ],
+        'deps': 'win32-desktop',
         'func': check_cc(header_name='d3d9.h'),
     }, {
         # We need MMAL/bcm_host/dispmanx APIs. Also, most RPI distros require
@@ -754,12 +747,12 @@ video_output_features = [
     } , {
         'name': '--plain-gl',
         'desc': 'OpenGL without platform-specific code (e.g. for libmpv)',
-        'deps_any': [ 'libmpv-shared', 'libmpv-static' ],
+        'deps': 'libmpv-shared || libmpv-static',
         'func': check_true,
     }, {
         'name': '--mali-fbdev',
         'desc': 'MALI via Linux fbdev',
-        'deps': ['libdl'],
+        'deps': 'libdl',
         'func': compose_checks(
             check_cc(lib="EGL"),
             check_statement('EGL/fbdev_window.h', 'struct fbdev_window test'),
@@ -768,9 +761,9 @@ video_output_features = [
     }, {
         'name': '--gl',
         'desc': 'OpenGL video outputs',
-        'deps_any': [ 'gl-cocoa', 'gl-x11', 'egl-x11', 'egl-drm',
-                      'gl-win32', 'gl-wayland', 'rpi', 'mali-fbdev',
-                      'plain-gl' ],
+        'deps': 'gl-cocoa || gl-x11 || egl-x11 || egl-drm || '
+                 + 'gl-win32 || gl-wayland || rpi || mali-fbdev || '
+                 + 'plain-gl',
         'func': check_true,
         'req': True,
         'fmsg': "No OpenGL video output found or enabled. " +
@@ -779,8 +772,8 @@ video_output_features = [
     }, {
         'name': 'egl-helpers',
         'desc': 'EGL helper functions',
-        'deps_any': [ 'egl-x11', 'mali-fbdev', 'rpi', 'gl-wayland', 'egl-drm',
-                      'egl-angle-win32' ],
+        'deps': 'egl-x11 || mali-fbdev || rpi || gl-wayland || egl-drm || ' +
+                'egl-angle-win32',
         'func': check_true
     }
 ]
@@ -789,7 +782,7 @@ hwaccel_features = [
     {
         'name': '--vaapi-hwaccel',
         'desc': 'libavcodec VAAPI hwaccel (FFmpeg 3.3 API)',
-        'deps': [ 'vaapi' ],
+        'deps': 'vaapi',
         'func': check_statement('libavcodec/version.h',
             'int x[(LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 26, 0) && '
             '       LIBAVCODEC_VERSION_MICRO < 100) ||'
@@ -800,7 +793,7 @@ hwaccel_features = [
     }, {
         'name': '--videotoolbox-hwaccel-new',
         'desc': 'libavcodec videotoolbox hwaccel (new API)',
-        'deps_any': [ 'gl-cocoa', 'ios-gl' ],
+        'deps': 'gl-cocoa || ios-gl',
         'func': check_statement('libavcodec/version.h',
             'int x[(LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 96, 100) && '
             '       LIBAVCODEC_VERSION_MICRO >= 100)'
@@ -809,8 +802,7 @@ hwaccel_features = [
     }, {
         'name': '--videotoolbox-hwaccel-old',
         'desc': 'libavcodec videotoolbox hwaccel (old API)',
-        'deps_any': [ 'gl-cocoa', 'ios-gl' ],
-        'deps_neg': [ 'videotoolbox-hwaccel-new' ],
+        'deps': '(gl-cocoa || ios-gl) && !videotoolbox-hwaccel-new',
         'func': compose_checks(
             check_headers('VideoToolbox/VideoToolbox.h'),
             check_statement('libavcodec/videotoolbox.h',
@@ -819,17 +811,17 @@ hwaccel_features = [
     }, {
         'name': 'videotoolbox-hwaccel',
         'desc': 'libavcodec videotoolbox hwaccel',
-        'deps_any': [ 'videotoolbox-hwaccel-new', 'videotoolbox-hwaccel-old' ],
+        'deps': 'videotoolbox-hwaccel-new || videotoolbox-hwaccel-old',
         'func': check_true,
     }, {
         'name': '--videotoolbox-gl',
         'desc': 'Videotoolbox with OpenGL',
-        'deps': [ 'gl-cocoa', 'videotoolbox-hwaccel' ],
+        'deps': 'gl-cocoa && videotoolbox-hwaccel',
         'func': check_true
     }, {
         'name': '--vdpau-hwaccel',
         'desc': 'libavcodec VDPAU hwaccel (FFmpeg 3.3 API)',
-        'deps': [ 'vdpau' ],
+        'deps': 'vdpau',
         'func': check_statement('libavcodec/version.h',
             'int x[(LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 37, 1) && '
             '       LIBAVCODEC_VERSION_MICRO < 100) ||'
@@ -841,7 +833,7 @@ hwaccel_features = [
         # (conflated with ANGLE for easier deps)
         'name': '--d3d-hwaccel',
         'desc': 'D3D11VA hwaccel (plus ANGLE)',
-        'deps': [ 'os-win32', 'egl-angle' ],
+        'deps': 'os-win32 && egl-angle',
         'func': check_true,
     }, {
         'name': '--d3d-hwaccel-new',
@@ -853,29 +845,28 @@ hwaccel_features = [
             '       LIBAVCODEC_VERSION_MICRO >= 100)'
             '      ? 1 : -1]',
             use='libav'),
-        'deps': [ 'd3d-hwaccel' ],
+        'deps': 'd3d-hwaccel',
     }, {
         'name': '--d3d9-hwaccel',
         'desc': 'DXVA2 hwaccel (plus ANGLE)',
-        'deps': [ 'd3d-hwaccel', 'egl-angle-win32' ],
+        'deps': 'd3d-hwaccel && egl-angle-win32',
         'func': check_true,
     }, {
         'name': '--gl-dxinterop-d3d9',
         'desc': 'OpenGL/DirectX Interop Backend DXVA2 interop',
-        'deps': [ 'gl-dxinterop', 'd3d9-hwaccel' ],
+        'deps': 'gl-dxinterop && d3d9-hwaccel',
         'groups': [ 'gl' ],
         'func': check_true,
     }, {
         'name': '--cuda-hwaccel',
         'desc': 'CUDA hwaccel',
-        'deps': [ 'gl' ],
+        'deps': 'gl',
         'func': check_cc(fragment=load_fragment('cuda.c'),
                          use='libav'),
     }, {
         'name': 'sse4-intrinsics',
         'desc': 'GCC SSE4 intrinsics for GPU memcpy',
-        'deps_any': [ 'd3d-hwaccel' ],
-        'deps_neg': [ 'd3d-hwaccel-new' ],
+        'deps': 'd3d-hwaccel && !d3d-hwaccel-new',
         'func': check_cc(fragment=load_fragment('sse.c')),
     }
 ]
@@ -890,28 +881,26 @@ radio_and_tv_features = [
         'name': 'sys_videoio_h',
         'desc': 'videoio.h',
         'func': check_cc(header_name=['sys/time.h', 'sys/videoio.h']),
-        'deps': [ 'tv' ],
+        'deps': 'tv',
     }, {
         'name': 'videodev',
         'desc': 'videodev2.h',
         'func': check_cc(header_name=['sys/time.h', 'linux/videodev2.h']),
-        'deps': [ 'tv' ],
-        'deps_neg': [ 'sys_videoio_h' ],
+        'deps': 'tv && !sys_videoio_h',
     }, {
         'name': '--tv-v4l2',
         'desc': 'Video4Linux2 TV interface',
-        'deps': [ 'tv' ],
-        'deps_any': [ 'sys_videoio_h', 'videodev' ],
+        'deps': 'tv && (sys_videoio_h || videodev)',
         'func': check_true,
     }, {
         'name': '--libv4l2',
         'desc': 'libv4l2 support',
         'func': check_pkg_config('libv4l2'),
-        'deps': [ 'tv-v4l2' ],
+        'deps': 'tv-v4l2',
     }, {
         'name': '--audio-input',
         'desc': 'audio input support',
-        'deps_any': [ 'tv-v4l2' ],
+        'deps': 'tv-v4l2',
         'func': check_true
     } , {
         'name': '--dvbin',
@@ -925,17 +914,17 @@ standalone_features = [
     {
         'name': 'win32-executable',
         'desc': 'w32 executable',
-        'deps_any': [ 'os-win32', 'os-cygwin'],
+        'deps': 'os-win32 || !(!(os-cygwin))',
         'func': check_ctx_vars('WINDRES')
     }, {
         'name': '--apple-remote',
         'desc': 'Apple Remote support',
-        'deps': [ 'cocoa' ],
+        'deps': 'cocoa',