From 87fed9778e3d7d4e1a9c4ff9ff7d3aede639f761 Mon Sep 17 00:00:00 2001
From: asquared31415 <34665709+asquared31415@users.noreply.github.com>
Date: Thu, 21 Dec 2023 17:32:58 +0000
Subject: [PATCH] Make named_asm_labels lint not trigger on unicode and trigger
on format args
---
compiler/rustc_lint/src/builtin.rs | 62 ++++++++++++----
tests/ui/asm/named-asm-labels.rs | 21 ++++++
tests/ui/asm/named-asm-labels.stderr | 103 ++++++++++++++++++++++++---
3 files changed, 162 insertions(+), 24 deletions(-)
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 045ff38c0568c..34994ca2e8fc1 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -2734,10 +2734,13 @@ impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels {
#[allow(rustc::diagnostic_outside_of_impl)]
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>) {
if let hir::Expr {
- kind: hir::ExprKind::InlineAsm(hir::InlineAsm { template_strs, .. }),
+ kind: hir::ExprKind::InlineAsm(hir::InlineAsm { template_strs, options, .. }),
..
} = expr
{
+ // asm with `options(raw)` does not do replacement with `{` and `}`.
+ let raw = options.contains(InlineAsmOptions::RAW);
+
for (template_sym, template_snippet, template_span) in template_strs.iter() {
let template_str = template_sym.as_str();
let find_label_span = |needle: &str| -> Option<Span> {
@@ -2763,24 +2766,57 @@ impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels {
for statement in statements {
// If there's a comment, trim it from the statement
let statement = statement.find("//").map_or(statement, |idx| &statement[..idx]);
+
+ // In this loop, if there is ever a non-label, no labels can come after it.
let mut start_idx = 0;
- for (idx, _) in statement.match_indices(':') {
+ 'label_loop: for (idx, _) in statement.match_indices(':') {
let possible_label = statement[start_idx..idx].trim();
let mut chars = possible_label.chars();
- let Some(c) = chars.next() else {
- // Empty string means a leading ':' in this section, which is not a label
- break;
+
+ let Some(start) = chars.next() else {
+ // Empty string means a leading ':' in this section, which is not a label.
+ break 'label_loop;
};
- // A label starts with an alphabetic character or . or _ and continues with alphanumeric characters, _, or $
- if (c.is_alphabetic() || matches!(c, '.' | '_'))
- && chars.all(|c| c.is_alphanumeric() || matches!(c, '_' | '$'))
- {
- found_labels.push(possible_label);
- } else {
- // If we encounter a non-label, there cannot be any further labels, so stop checking
- break;
+
+ // Whether a { bracket has been seen and its } hasn't been found yet.
+ let mut in_bracket = false;
+
+ // A label starts with an ASCII alphabetic character or . or _
+ // A label can also start with a format arg, if it's not a raw asm block.
+ if !raw && start == '{' {
+ in_bracket = true;
+ } else if !(start.is_ascii_alphabetic() || matches!(start, '.' | '_')) {
+ break 'label_loop;
+ }
+
+ // Labels continue with ASCII alphanumeric characters, _, or $
+ for c in chars {
+ // Inside a template format arg, any character is permitted for the puproses of label detection
+ // because we assume that it can be replaced with some other valid label string later.
+ // `options(raw)` asm blocks cannot have format args, so they are excluded from this special case.
+ if !raw && in_bracket {
+ if c == '{' {
+ // Nested brackets are not allowed in format args, this cannot be a label.
+ break 'label_loop;
+ }
+
+ if c == '}' {
+ // The end of the format arg.
+ in_bracket = false;
+ }
+ } else if !raw && c == '{' {
+ // Start of a format arg.
+ in_bracket = true;
+ } else {
+ if !(c.is_ascii_alphanumeric() || matches!(c, '_' | '$')) {
+ // The potential label had an invalid character inside it, it cannot be a label.
+ break 'label_loop;
+ }
+ }
}
+ // If all characters passed the label checks, this is likely a label.
+ found_labels.push(possible_label);
start_idx = idx + 1;
}
}
diff --git a/tests/ui/asm/named-asm-labels.rs b/tests/ui/asm/named-asm-labels.rs
index 160dbf617c4f6..24586b39aacc0 100644
--- a/tests/ui/asm/named-asm-labels.rs
+++ b/tests/ui/asm/named-asm-labels.rs
@@ -120,6 +120,27 @@ fn main() {
// is there an example that is valid x86 for this test?
asm!(":bbb nop");
+ // non-ascii characters are not allowed in labels, so should not trigger the lint
+ asm!("Ù: nop");
+ asm!("testÙ: nop");
+ asm!("_Ù_: nop");
+
+ // Format arguments should be conservatively assumed to be valid characters in labels
+ // Would emit `test_rax:` or similar
+ #[allow(asm_sub_register)]
+ {
+ asm!("test_{}: nop", in(reg) 10); //~ ERROR avoid using named labels
+ }
+ asm!("test_{}: nop", const 10); //~ ERROR avoid using named labels
+ asm!("test_{}: nop", sym main); //~ ERROR avoid using named labels
+ asm!("{}_test: nop", const 10); //~ ERROR avoid using named labels
+ asm!("test_{}_test: nop", const 10); //~ ERROR avoid using named labels
+ asm!("{}: nop", const 10); //~ ERROR avoid using named labels
+
+ asm!("{uwu}: nop", uwu = const 10); //~ ERROR avoid using named labels
+ asm!("{0}: nop", const 10); //~ ERROR avoid using named labels
+ asm!("{1}: nop", "/* {0} */", const 10, const 20); //~ ERROR avoid using named labels
+
// Test include_str in asm
asm!(include_str!("named-asm-labels.s")); //~ ERROR avoid using named labels
diff --git a/tests/ui/asm/named-asm-labels.stderr b/tests/ui/asm/named-asm-labels.stderr
index c8380629e12ea..89c058499675c 100644
--- a/tests/ui/asm/named-asm-labels.stderr
+++ b/tests/ui/asm/named-asm-labels.stderr
@@ -245,7 +245,88 @@ LL | ab: nop // ab: does foo
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:124:14
+ --> $DIR/named-asm-labels.rs:132:19
+ |
+LL | asm!("test_{}: nop", in(reg) 10);
+ | ^^^^^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:134:15
+ |
+LL | asm!("test_{}: nop", const 10);
+ | ^^^^^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:135:15
+ |
+LL | asm!("test_{}: nop", sym main);
+ | ^^^^^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:136:15
+ |
+LL | asm!("{}_test: nop", const 10);
+ | ^^^^^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:137:15
+ |
+LL | asm!("test_{}_test: nop", const 10);
+ | ^^^^^^^^^^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:138:15
+ |
+LL | asm!("{}: nop", const 10);
+ | ^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:140:15
+ |
+LL | asm!("{uwu}: nop", uwu = const 10);
+ | ^^^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:141:15
+ |
+LL | asm!("{0}: nop", const 10);
+ | ^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:142:15
+ |
+LL | asm!("{1}: nop", "/* {0} */", const 10, const 20);
+ | ^^^
+ |
+ = help: only local labels of the form `<number>:` should be used in inline asm
+ = note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+
+error: avoid using named labels in inline assembly
+ --> $DIR/named-asm-labels.rs:145:14
|
LL | asm!(include_str!("named-asm-labels.s"));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -254,7 +335,7 @@ LL | asm!(include_str!("named-asm-labels.s"));
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
warning: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:134:19
+ --> $DIR/named-asm-labels.rs:155:19
|
LL | asm!("warned: nop");
| ^^^^^^
@@ -262,13 +343,13 @@ LL | asm!("warned: nop");
= help: only local labels of the form `<number>:` should be used in inline asm
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
note: the lint level is defined here
- --> $DIR/named-asm-labels.rs:132:16
+ --> $DIR/named-asm-labels.rs:153:16
|
LL | #[warn(named_asm_labels)]
| ^^^^^^^^^^^^^^^^
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:143:20
+ --> $DIR/named-asm-labels.rs:164:20
|
LL | unsafe { asm!(".Lfoo: mov rax, {}; ret;", "nop", const 1, options(noreturn)) }
| ^^^^^
@@ -277,7 +358,7 @@ LL | unsafe { asm!(".Lfoo: mov rax, {}; ret;", "nop", const 1, options(noret
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:149:20
+ --> $DIR/named-asm-labels.rs:170:20
|
LL | unsafe { asm!(".Lbar: mov rax, {}; ret;", "nop", const 1, options(noreturn)) }
| ^^^^^
@@ -286,7 +367,7 @@ LL | unsafe { asm!(".Lbar: mov rax, {}; ret;", "nop", const 1, options(noret
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:157:20
+ --> $DIR/named-asm-labels.rs:178:20
|
LL | unsafe { asm!(".Laaa: nop; ret;", options(noreturn)) }
| ^^^^^
@@ -295,7 +376,7 @@ LL | unsafe { asm!(".Laaa: nop; ret;", options(noreturn)) }
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:167:24
+ --> $DIR/named-asm-labels.rs:188:24
|
LL | unsafe { asm!(".Lbbb: nop; ret;", options(noreturn)) }
| ^^^^^
@@ -304,7 +385,7 @@ LL | unsafe { asm!(".Lbbb: nop; ret;", options(noreturn)) }
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:176:15
+ --> $DIR/named-asm-labels.rs:197:15
|
LL | asm!("closure1: nop");
| ^^^^^^^^
@@ -313,7 +394,7 @@ LL | asm!("closure1: nop");
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:180:15
+ --> $DIR/named-asm-labels.rs:201:15
|
LL | asm!("closure2: nop");
| ^^^^^^^^
@@ -322,7 +403,7 @@ LL | asm!("closure2: nop");
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
error: avoid using named labels in inline assembly
- --> $DIR/named-asm-labels.rs:190:19
+ --> $DIR/named-asm-labels.rs:211:19
|
LL | asm!("closure3: nop");
| ^^^^^^^^
@@ -330,5 +411,5 @@ LL | asm!("closure3: nop");
= help: only local labels of the form `<number>:` should be used in inline asm
= note: see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
-error: aborting due to 35 previous errors; 1 warning emitted
+error: aborting due to 44 previous errors; 1 warning emitted