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
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
use rustc_ast as ast;
use rustc_ast::{ptr::P, tokenstream::TokenStream};
use rustc_errors::Applicability;
use rustc_expand::base::{self, DummyResult};
use rustc_session::errors::report_lit_error;
use rustc_span::Span;
/// Emits errors for literal expressions that are invalid inside and outside of an array.
fn invalid_type_err(
cx: &mut base::ExtCtxt<'_>,
token_lit: ast::token::Lit,
span: Span,
is_nested: bool,
) {
match ast::LitKind::from_token_lit(token_lit) {
Ok(ast::LitKind::Char(_)) => {
let mut err = cx.struct_span_err(span, "cannot concatenate character literals");
if let Ok(snippet) = cx.sess.source_map().span_to_snippet(span) {
err.span_suggestion(
span,
"try using a byte character",
format!("b{}", snippet),
Applicability::MachineApplicable,
)
.emit();
}
}
Ok(ast::LitKind::Str(_, _)) => {
let mut err = cx.struct_span_err(span, "cannot concatenate string literals");
// suggestion would be invalid if we are nested
if !is_nested {
if let Ok(snippet) = cx.sess.source_map().span_to_snippet(span) {
err.span_suggestion(
span,
"try using a byte string",
format!("b{}", snippet),
Applicability::MachineApplicable,
);
}
}
err.emit();
}
Ok(ast::LitKind::Float(_, _)) => {
cx.span_err(span, "cannot concatenate float literals");
}
Ok(ast::LitKind::Bool(_)) => {
cx.span_err(span, "cannot concatenate boolean literals");
}
Ok(ast::LitKind::Err) => {}
Ok(ast::LitKind::Int(_, _)) if !is_nested => {
let mut err = cx.struct_span_err(span, "cannot concatenate numeric literals");
if let Ok(snippet) = cx.sess.source_map().span_to_snippet(span) {
err.span_suggestion(
span,
"try wrapping the number in an array",
format!("[{}]", snippet),
Applicability::MachineApplicable,
);
}
err.emit();
}
Ok(ast::LitKind::Int(
val,
ast::LitIntType::Unsuffixed | ast::LitIntType::Unsigned(ast::UintTy::U8),
)) => {
assert!(val > u8::MAX.into()); // must be an error
cx.span_err(span, "numeric literal is out of bounds");
}
Ok(ast::LitKind::Int(_, _)) => {
cx.span_err(span, "numeric literal is not a `u8`");
}
Ok(ast::LitKind::ByteStr(_) | ast::LitKind::Byte(_)) => unreachable!(),
Err(err) => {
report_lit_error(&cx.sess.parse_sess, err, token_lit, span);
}
}
}
fn handle_array_element(
cx: &mut base::ExtCtxt<'_>,
has_errors: &mut bool,
missing_literals: &mut Vec<rustc_span::Span>,
expr: &P<rustc_ast::Expr>,
) -> Option<u8> {
match expr.kind {
ast::ExprKind::Array(_) | ast::ExprKind::Repeat(_, _) => {
if !*has_errors {
cx.span_err(expr.span, "cannot concatenate doubly nested array");
}
*has_errors = true;
None
}
ast::ExprKind::Lit(token_lit) => match ast::LitKind::from_token_lit(token_lit) {
Ok(ast::LitKind::Int(
val,
ast::LitIntType::Unsuffixed | ast::LitIntType::Unsigned(ast::UintTy::U8),
)) if val <= u8::MAX.into() => Some(val as u8),
Ok(ast::LitKind::Byte(val)) => Some(val),
Ok(ast::LitKind::ByteStr(_)) => {
if !*has_errors {
cx.struct_span_err(expr.span, "cannot concatenate doubly nested array")
.note("byte strings are treated as arrays of bytes")
.help("try flattening the array")
.emit();
}
*has_errors = true;
None
}
_ => {
if !*has_errors {
invalid_type_err(cx, token_lit, expr.span, true);
}
*has_errors = true;
None
}
},
ast::ExprKind::IncludedBytes(..) => {
if !*has_errors {
cx.struct_span_err(expr.span, "cannot concatenate doubly nested array")
.note("byte strings are treated as arrays of bytes")
.help("try flattening the array")
.emit();
}
*has_errors = true;
None
}
_ => {
missing_literals.push(expr.span);
None
}
}
}
pub fn expand_concat_bytes(
cx: &mut base::ExtCtxt<'_>,
sp: rustc_span::Span,
tts: TokenStream,
) -> Box<dyn base::MacResult + 'static> {
let Some(es) = base::get_exprs_from_tts(cx, sp, tts) else {
return DummyResult::any(sp);
};
let mut accumulator = Vec::new();
let mut missing_literals = vec![];
let mut has_errors = false;
for e in es {
match &e.kind {
ast::ExprKind::Array(exprs) => {
for expr in exprs {
if let Some(elem) =
handle_array_element(cx, &mut has_errors, &mut missing_literals, expr)
{
accumulator.push(elem);
}
}
}
ast::ExprKind::Repeat(expr, count) => {
if let ast::ExprKind::Lit(token_lit) = count.value.kind
&& let Ok(ast::LitKind::Int(count_val, _)) =
ast::LitKind::from_token_lit(token_lit)
{
if let Some(elem) =
handle_array_element(cx, &mut has_errors, &mut missing_literals, expr)
{
for _ in 0..count_val {
accumulator.push(elem);
}
}
} else {
cx.span_err(count.value.span, "repeat count is not a positive number");
}
}
&ast::ExprKind::Lit(token_lit) => match ast::LitKind::from_token_lit(token_lit) {
Ok(ast::LitKind::Byte(val)) => {
accumulator.push(val);
}
Ok(ast::LitKind::ByteStr(ref bytes)) => {
accumulator.extend_from_slice(&bytes);
}
_ => {
if !has_errors {
invalid_type_err(cx, token_lit, e.span, false);
}
has_errors = true;
}
},
ast::ExprKind::IncludedBytes(bytes) => {
accumulator.extend_from_slice(bytes);
}
ast::ExprKind::Err => {
has_errors = true;
}
_ => {
missing_literals.push(e.span);
}
}
}
if !missing_literals.is_empty() {
let mut err = cx.struct_span_err(missing_literals.clone(), "expected a byte literal");
err.note("only byte literals (like `b\"foo\"`, `b's'`, and `[3, 4, 5]`) can be passed to `concat_bytes!()`");
err.emit();
return base::MacEager::expr(DummyResult::raw_expr(sp, true));
} else if has_errors {
return base::MacEager::expr(DummyResult::raw_expr(sp, true));
}
let sp = cx.with_def_site_ctxt(sp);
base::MacEager::expr(cx.expr_byte_str(sp, accumulator))
}
|
