Support attributes on array members

Array members are allow to have attributes such as `#[cfg]`.

This is a bit tricky as we don't know if the first expression is an
initializer or a member until we encounter a `;`. This reuses a trick
from `stmt` where we remember if we saw an attribute and then raise an
error if the first expression ends up being an initializer.

This isn't perfect as the error isn't correctly located on the attribute
or initializer; it ends up immediately after the `;`.
This commit is contained in:
Ryan Cumming 2019-06-30 17:59:26 +10:00
parent 27df89f47d
commit b01496538c
7 changed files with 205 additions and 0 deletions

View file

@ -170,8 +170,28 @@ fn array_expr(p: &mut Parser) -> CompletedMarker {
if p.eat(T![']']) {
return m.complete(p, ARRAY_EXPR);
}
// test first_array_member_attributes
// pub const A: &[i64] = &[
// #[cfg(test)]
// 1,
// 2,
// ];
let first_member_has_attrs = p.at(T![#]);
attributes::outer_attributes(p);
expr(p);
if p.eat(T![;]) {
if first_member_has_attrs {
// test_err array_length_attributes
// pub const A: &[i64] = &[
// #[cfg(test)]
// 1;
// 2,
// ];
p.error("removing an expression is not supported in this position");
}
expr(p);
p.expect(T![']']);
return m.complete(p, ARRAY_EXPR);
@ -181,6 +201,14 @@ fn array_expr(p: &mut Parser) -> CompletedMarker {
if p.at(T![']']) {
break;
}
// test subsequent_array_member_attributes
// pub const A: &[i64] = &[
// 1,
// #[cfg(test)]
// 2,
// ];
attributes::outer_attributes(p);
if !p.at_ts(EXPR_FIRST) {
p.error("expected expression");
break;

View file

@ -0,0 +1,5 @@
pub const A: &[i64] = &[
#[cfg(test)]
1;
2,
];

View file

@ -0,0 +1,60 @@
SOURCE_FILE@[0; 53)
CONST_DEF@[0; 48)
VISIBILITY@[0; 3)
PUB_KW@[0; 3) "pub"
WHITESPACE@[3; 4) " "
CONST_KW@[4; 9) "const"
WHITESPACE@[9; 10) " "
NAME@[10; 11)
IDENT@[10; 11) "A"
COLON@[11; 12) ":"
WHITESPACE@[12; 13) " "
REFERENCE_TYPE@[13; 19)
AMP@[13; 14) "&"
SLICE_TYPE@[14; 19)
L_BRACK@[14; 15) "["
PATH_TYPE@[15; 18)
PATH@[15; 18)
PATH_SEGMENT@[15; 18)
NAME_REF@[15; 18)
IDENT@[15; 18) "i64"
R_BRACK@[18; 19) "]"
WHITESPACE@[19; 20) " "
EQ@[20; 21) "="
WHITESPACE@[21; 22) " "
REF_EXPR@[22; 48)
AMP@[22; 23) "&"
ARRAY_EXPR@[23; 48)
L_BRACK@[23; 24) "["
WHITESPACE@[24; 27) "\n "
ATTR@[27; 39)
POUND@[27; 28) "#"
TOKEN_TREE@[28; 39)
L_BRACK@[28; 29) "["
IDENT@[29; 32) "cfg"
TOKEN_TREE@[32; 38)
L_PAREN@[32; 33) "("
IDENT@[33; 37) "test"
R_PAREN@[37; 38) ")"
R_BRACK@[38; 39) "]"
WHITESPACE@[39; 42) "\n "
LITERAL@[42; 43)
INT_NUMBER@[42; 43) "1"
SEMI@[43; 44) ";"
WHITESPACE@[44; 47) "\n "
LITERAL@[47; 48)
INT_NUMBER@[47; 48) "2"
ERROR@[48; 49)
COMMA@[48; 49) ","
WHITESPACE@[49; 50) "\n"
ERROR@[50; 51)
R_BRACK@[50; 51) "]"
ERROR@[51; 52)
SEMI@[51; 52) ";"
WHITESPACE@[52; 53) "\n"
error 44: removing an expression is not supported in this position
error 48: expected R_BRACK
error 48: expected SEMI
error 48: expected an item
error 50: expected an item
error 51: expected an item

View file

@ -0,0 +1,5 @@
pub const A: &[i64] = &[
#[cfg(test)]
1,
2,
];

View file

@ -0,0 +1,51 @@
SOURCE_FILE@[0; 56)
CONST_DEF@[0; 55)
VISIBILITY@[0; 3)
PUB_KW@[0; 3) "pub"
WHITESPACE@[3; 4) " "
CONST_KW@[4; 9) "const"
WHITESPACE@[9; 10) " "
NAME@[10; 11)
IDENT@[10; 11) "A"
COLON@[11; 12) ":"
WHITESPACE@[12; 13) " "
REFERENCE_TYPE@[13; 19)
AMP@[13; 14) "&"
SLICE_TYPE@[14; 19)
L_BRACK@[14; 15) "["
PATH_TYPE@[15; 18)
PATH@[15; 18)
PATH_SEGMENT@[15; 18)
NAME_REF@[15; 18)
IDENT@[15; 18) "i64"
R_BRACK@[18; 19) "]"
WHITESPACE@[19; 20) " "
EQ@[20; 21) "="
WHITESPACE@[21; 22) " "
REF_EXPR@[22; 54)
AMP@[22; 23) "&"
ARRAY_EXPR@[23; 54)
L_BRACK@[23; 24) "["
WHITESPACE@[24; 28) "\n "
ATTR@[28; 40)
POUND@[28; 29) "#"
TOKEN_TREE@[29; 40)
L_BRACK@[29; 30) "["
IDENT@[30; 33) "cfg"
TOKEN_TREE@[33; 39)
L_PAREN@[33; 34) "("
IDENT@[34; 38) "test"
R_PAREN@[38; 39) ")"
R_BRACK@[39; 40) "]"
WHITESPACE@[40; 44) "\n "
LITERAL@[44; 45)
INT_NUMBER@[44; 45) "1"
COMMA@[45; 46) ","
WHITESPACE@[46; 50) "\n "
LITERAL@[50; 51)
INT_NUMBER@[50; 51) "2"
COMMA@[51; 52) ","
WHITESPACE@[52; 53) "\n"
R_BRACK@[53; 54) "]"
SEMI@[54; 55) ";"
WHITESPACE@[55; 56) "\n"

View file

@ -0,0 +1,5 @@
pub const A: &[i64] = &[
1,
#[cfg(test)]
2,
];

View file

@ -0,0 +1,51 @@
SOURCE_FILE@[0; 56)
CONST_DEF@[0; 55)
VISIBILITY@[0; 3)
PUB_KW@[0; 3) "pub"
WHITESPACE@[3; 4) " "
CONST_KW@[4; 9) "const"
WHITESPACE@[9; 10) " "
NAME@[10; 11)
IDENT@[10; 11) "A"
COLON@[11; 12) ":"
WHITESPACE@[12; 13) " "
REFERENCE_TYPE@[13; 19)
AMP@[13; 14) "&"
SLICE_TYPE@[14; 19)
L_BRACK@[14; 15) "["
PATH_TYPE@[15; 18)
PATH@[15; 18)
PATH_SEGMENT@[15; 18)
NAME_REF@[15; 18)
IDENT@[15; 18) "i64"
R_BRACK@[18; 19) "]"
WHITESPACE@[19; 20) " "
EQ@[20; 21) "="
WHITESPACE@[21; 22) " "
REF_EXPR@[22; 54)
AMP@[22; 23) "&"
ARRAY_EXPR@[23; 54)
L_BRACK@[23; 24) "["
WHITESPACE@[24; 28) "\n "
LITERAL@[28; 29)
INT_NUMBER@[28; 29) "1"
COMMA@[29; 30) ","
WHITESPACE@[30; 34) "\n "
ATTR@[34; 46)
POUND@[34; 35) "#"
TOKEN_TREE@[35; 46)
L_BRACK@[35; 36) "["
IDENT@[36; 39) "cfg"
TOKEN_TREE@[39; 45)
L_PAREN@[39; 40) "("
IDENT@[40; 44) "test"
R_PAREN@[44; 45) ")"
R_BRACK@[45; 46) "]"
WHITESPACE@[46; 50) "\n "
LITERAL@[50; 51)
INT_NUMBER@[50; 51) "2"
COMMA@[51; 52) ","
WHITESPACE@[52; 53) "\n"
R_BRACK@[53; 54) "]"
SEMI@[54; 55) ";"
WHITESPACE@[55; 56) "\n"