diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py index 8c1328928..9c2a74c79 100644 --- a/mesonbuild/interpreter.py +++ b/mesonbuild/interpreter.py @@ -1323,6 +1323,8 @@ class Interpreter(): return self.evaluate_plusassign(cur) elif isinstance(cur, mparser.IndexNode): return self.evaluate_indexing(cur) + elif isinstance(cur, mparser.TernaryNode): + return self.evaluate_ternary(cur) elif self.is_elementary_type(cur): return cur else: @@ -2402,6 +2404,16 @@ class Interpreter(): if not isinstance(node.elseblock, mparser.EmptyNode): self.evaluate_codeblock(node.elseblock) + def evaluate_ternary(self, node): + assert(isinstance(node, mparser.TernaryNode)) + result = self.evaluate_statement(node.condition) + if not isinstance(result, bool): + raise InterpreterException('Ternary condition is not boolean.') + if result: + return self.evaluate_statement(node.trueblock) + else: + return self.evaluate_statement(node.falseblock) + def evaluate_foreach(self, node): assert(isinstance(node, mparser.ForeachClauseNode)) varname = node.varname.value diff --git a/mesonbuild/mparser.py b/mesonbuild/mparser.py index fd720fbdd..2f0eb2de1 100644 --- a/mesonbuild/mparser.py +++ b/mesonbuild/mparser.py @@ -67,6 +67,7 @@ class Lexer: ('lt', re.compile(r'<')), ('ge', re.compile(r'>=')), ('gt', re.compile(r'>')), + ('questionmark', re.compile(r'\?')), ] def lex(self, code): @@ -282,6 +283,14 @@ class IfNode(): self.condition = condition self.block = block +class TernaryNode(): + def __init__(self, lineno, colno, condition, trueblock, falseblock): + self.lineno = lineno + self.colno = colno + self.condition = condition + self.trueblock = trueblock + self.falseblock = falseblock + class ArgumentNode(): def __init__(self, token): self.lineno = token.lineno @@ -344,6 +353,7 @@ class Parser: def __init__(self, code): self.stream = Lexer().lex(code) self.getsym() + self.in_ternary = False def getsym(self): try: @@ -383,6 +393,16 @@ class Parser: raise ParseException('Assignment target must be an id.', left.lineno, left.colno) return AssignmentNode(left.lineno, left.colno, left.value, value) + elif self.accept('questionmark'): + if self.in_ternary: + raise ParseException('Nested ternary operators are not allowed.', + left.lineno, left.colno) + self.in_ternary = True + trueblock = self.e1() + self.expect('colon') + falseblock = self.e1() + self.in_ternary = False + return TernaryNode(left.lineno, left.colno, left, trueblock, falseblock) return left def e2(self): diff --git a/test cases/common/116 ternary/meson.build b/test cases/common/116 ternary/meson.build new file mode 100644 index 000000000..3e650463f --- /dev/null +++ b/test cases/common/116 ternary/meson.build @@ -0,0 +1,7 @@ +project('ternary operator', 'c') + +one = true ? 1 : error('False branch should not be evaluated') +two = false ? error('True branch should not be evaluated.') : 2 + +assert(one == 1, 'Return value from ternary true is wrong.') +assert(two == 2, 'Return value from ternary false is wrong.') diff --git a/test cases/failing/30 nested ternary/meson.build b/test cases/failing/30 nested ternary/meson.build new file mode 100644 index 000000000..f9c2e5f8a --- /dev/null +++ b/test cases/failing/30 nested ternary/meson.build @@ -0,0 +1,3 @@ +project('nested ternary', 'c') + +x = true ? (false ? 1 : 0) : 2