More detailed spec and tests for parse limits. (#148)

doc/langdef.md

@@ -51,8 +51,19 @@ FieldInits     = IDENT ":" Expr {"," IDENT ":" Expr} ;
 MapInits       = Expr ":" Expr {"," Expr ":" Expr} ;
 ```
 
-Implementations are required to support at least 250 levels of recursion in
-parsing, but may reject programs that exceed that limit.
+Implementations are required to support at least:
+
+*   32 levels of nested expressions;
+*   32 repetitions of self-recursive or repetitive rules, i.e.:
+    *   32 terms separated by `||` in a row;
+    *   32 terms separated by `&&` in a row;
+    *   32 relations in a row;
+    *   32 binary arithmetic operators of the same precedence in a row;
+    *   32 selection (`.`) operators in a row;
+    *   32 indexing (`[_]`) operators in a row;
+    *   32 function call arguments;
+    *   list literals with 32 elements;
+    *   map or message literals with 32 fields.
 
 This grammar corresponds to the following operator precedence and associativity:
 

tests/simple/testdata/parse.textproto

@@ -1,11 +1,129 @@
 name: "parse"
 description: "End-to-end parsing tests."
 section {
-  name: "depth"
+  name: "nest"
   description: "Deep parse trees which all implementations must support."
+  test {
+    name: "list_index"
+    description: "Member = Member '[' Expr ']'"
+    expr: "a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[a[0]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]"
+    type_env {
+      name: "a"
+      ident { type { list_type { elem_type { primitive: INT64 } } } }
+    }
+    bindings {
+      key: "a"
+      value { value { list_value { values { int64_value: 0 } } } }
+    }
+    value { int64_value: 0 }
+  }
+  test {
+    name: "message_literal"
+    description: "Member = Member '{' [FieldInits] '}'"
+    container: "google.api.expr.test.v1.proto3"
+    expr: "NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{child: NestedTestAllTypes{payload: TestAllTypes{single_int64: 137}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}.payload.single_int64"
+    value { int64_value: 0 }
+  }
+  test {
+    name: "funcall"
+    description: "Primary = ['.'] IDENT ['(' [ExprList] ')']"
+    expr: "int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(int(uint(7))))))))))))))))))))))))))))))))"
+    value { int64_value: 7 }
+  }
+  test {
+    name: "parens"
+    description: "Primary = '(' Expr ')'"
+    expr: "((((((((((((((((((((((((((((((((7))))))))))))))))))))))))))))))))"
+    value { int64_value: 7 }
+  }
   test {
     name: "list_literal"
-    expr: "size([[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[['just fine'],[1],[2],[3],[4],[5]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]])"
+    description: "Primary = '[' [ExprList] ']'"
+    expr: "size([[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[0]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]])"
     value { int64_value: 1 }
   }
+  test {
+    name: "map_literal"
+    description: "Primary = '{' [MapInits] '}'"
+    expr: "size({0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: {0: 'foo'}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}})"
+    value { int64_value: 1 }
+  }
+}
+section {
+  name: "repeat"
+  description: "Repetitive parse trees which all implementations must support."
+  test {
+    name: "conditional"
+    description: "Expr = ConditionalOr ['?' ConditionalOr ':' Expr]"
+    expr: "true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : true ? true : false"
+    value { bool_value: true }
+  }
+  test {
+    name: "or"
+    description: "ConditionalOr = [ConditionalOr '||'] ConditionalAnd"
+    expr: "false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || false || true"
+    value { bool_value: true }
+  }
+  test {
+    name: "and"
+    description: "ConditionalAnd = [ConditionalAnd '&&'] Relation"
+    expr: "true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && true && false"
+    value { bool_value: false }
+  }
+  test {
+    name: "add_sub"
+    description: "Addition = [Addition ('+' | '-')] Multiplication"
+    expr: "3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3 - 3 + 3"
+    value { int64_value: 3 }
+  }
+  test {
+    name: "mul_div"
+    description: "Multiplication = [Multiplication ('*' | '/' | '%')] Unary"
+    expr: "4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4 * 4 / 4"
+    value { int64_value: 4 }
+  }
+  test {
+    name: "not"
+    description: "Unary = '!' {'!'} Member"
+    expr: "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!true"
+    value { bool_value: true }
+  }
+  test {
+    name: "unary_neg"
+    description: "Unary = '-' {'-'} Member"
+    expr: "--------------------------------19"
+    value { int64_value: 19 }
+  }
+  test {
+    name: "select"
+    description: "Member = Member '.' IDENT ['(' [ExprList] ')']"
+    container: "google.api.expr.test.v1.proto3"
+    expr: "NestedTestAllTypes{}.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.child.payload.single_int32"
+    value { int64_value: 0 }
+  }
+  test {
+    name: "index"
+    description: "Member = Member '[' Expr ']'"
+    expr: "[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[['foo']]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0][0]"
+    value { string_value: "foo" }
+  }
+  test {
+    name: "list_literal"
+    description: "Primary = '[' [ExprList] ']'"
+    expr: "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31][17]"
+    value { int64_value: 17 }
+  }
+  test {
+    name: "map_literal"
+    description: "Primary = '{' [MapInits] '}'"
+    expr: "{0: 'zero', 1: 'one', 2: 'two', 3: 'three', 4: 'four', 5: 'five', 6: 'six', 7: 'seven', 8: 'eight', 9: 'nine', 10: 'ten', 11: 'eleven', 12: 'twelve', 13: 'thirteen', 14: 'fourteen', 15: 'fifteen', 16: 'sixteen', 17: 'seventeen', 18: 'eighteen', 19: 'nineteen', 20: 'twenty', 21: 'twenty-one', 22: 'twenty-two', 23: 'twenty-three', 24: 'twenty-four', 25: 'twenty-five', 26: 'twenty-six', 27: 'twenty-seven', 28: 'twenty-eight', 29: 'twenty-nine', 30: 'thirty', 31: 'thirty-one'}[17]"
+    value { string_value: 'seventeen' }
+  }
+  test {
+    name: "message_literal"
+    description: "Member = Member '{' [FieldInits] '}'"
+    container: "google.api.expr.test.v1.proto3"
+    expr: "TestAllTypes{single_int32: 5, single_int64: 10, single_uint32: 15u, single_uint64: 20u, single_sint32: 25, single_sint64: 30, single_fixed32: 35u, single_fixed64: 40u, single_float: 45.0, single_double: 50.0, single_bool: true, single_string: 'sixty', single_bytes: b'sixty-five', single_value: 70.0, single_int64_wrapper: 75, single_int32_wrapper: 80, single_double_wrapper: 85.0, single_float_wrapper: 90.0, single_uint64_wrapper: 95u, single_uint32_wrapper: 100u, single_string_wrapper: 'one hundred five', single_bool_wrapper: true, repeated_int32: [115], repeated_int64: [120], repeated_uint32: [125u], repeated_uint64: [130u], repeated_sint32: [135], repeated_sint64: [140], repeated_fixed32: [145u], repeated_fixed64: [150u], repeated_sfixed32: [155], repeated_float: [160.0]}.single_sint64"
+    value { int64_value: 30 }
+  }
 }