From 975bc18481879b69603674266a5239ecb579f928 Mon Sep 17 00:00:00 2001 From: Cameron Steffen Date: Thu, 5 Aug 2021 11:58:52 -0500 Subject: [PATCH 1/6] Make Arguments constructors unsafe --- compiler/rustc_builtin_macros/src/format.rs | 30 +++++++--- library/core/src/fmt/mod.rs | 31 ++++++++++ library/core/src/lib.rs | 1 + library/core/src/macros/mod.rs | 1 + library/core/src/panicking.rs | 10 +++- src/test/pretty/dollar-crate.pp | 10 ++-- src/test/pretty/issue-4264.pp | 56 +++++++++++-------- .../ui/attributes/key-value-expansion.stderr | 16 ++++-- 8 files changed, 114 insertions(+), 41 deletions(-) diff --git a/compiler/rustc_builtin_macros/src/format.rs b/compiler/rustc_builtin_macros/src/format.rs index 00f2f37146db6..1dbf772842163 100644 --- a/compiler/rustc_builtin_macros/src/format.rs +++ b/compiler/rustc_builtin_macros/src/format.rs @@ -3,8 +3,8 @@ use Position::*; use rustc_ast as ast; use rustc_ast::ptr::P; -use rustc_ast::token; use rustc_ast::tokenstream::TokenStream; +use rustc_ast::{token, BlockCheckMode, UnsafeSource}; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::{pluralize, Applicability, DiagnosticBuilder}; use rustc_expand::base::{self, *}; @@ -838,12 +838,15 @@ impl<'a, 'b> Context<'a, 'b> { // // But the nested match expression is proved to perform not as well // as series of let's; the first approach does. - let pat = self.ecx.pat_tuple(self.macsp, pats); - let arm = self.ecx.arm(self.macsp, pat, args_array); - let head = self.ecx.expr(self.macsp, ast::ExprKind::Tup(heads)); - let result = self.ecx.expr_match(self.macsp, head, vec![arm]); + let args_match = { + let pat = self.ecx.pat_tuple(self.macsp, pats); + let arm = self.ecx.arm(self.macsp, pat, args_array); + let head = self.ecx.expr(self.macsp, ast::ExprKind::Tup(heads)); + self.ecx.expr_match(self.macsp, head, vec![arm]) + }; - let args_slice = self.ecx.expr_addr_of(self.macsp, result); + let ident = Ident::from_str_and_span("args", self.macsp); + let args_slice = self.ecx.expr_ident(self.macsp, ident); // Now create the fmt::Arguments struct with all our locals we created. let (fn_name, fn_args) = if self.all_pieces_simple { @@ -857,7 +860,20 @@ impl<'a, 'b> Context<'a, 'b> { }; let path = self.ecx.std_path(&[sym::fmt, sym::Arguments, Symbol::intern(fn_name)]); - self.ecx.expr_call_global(self.macsp, path, fn_args) + let arguments = self.ecx.expr_call_global(self.macsp, path, fn_args); + let body = self.ecx.expr_block(P(ast::Block { + stmts: vec![self.ecx.stmt_expr(arguments)], + id: ast::DUMMY_NODE_ID, + rules: BlockCheckMode::Unsafe(UnsafeSource::CompilerGenerated), + span: self.macsp, + tokens: None, + })); + + let ident = Ident::from_str_and_span("args", self.macsp); + let binding_mode = ast::BindingMode::ByRef(ast::Mutability::Not); + let pat = self.ecx.pat_ident_binding_mode(self.macsp, ident, binding_mode); + let arm = self.ecx.arm(self.macsp, pat, body); + self.ecx.expr_match(self.macsp, args_match, vec![arm]) } fn format_arg( diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs index 6ad10990840c2..b32b1f8633697 100644 --- a/library/core/src/fmt/mod.rs +++ b/library/core/src/fmt/mod.rs @@ -334,11 +334,29 @@ enum FlagV1 { impl<'a> Arguments<'a> { /// When using the format_args!() macro, this function is used to generate the /// Arguments structure. + #[cfg(not(bootstrap))] + #[doc(hidden)] + #[inline] + #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")] + #[rustc_const_unstable(feature = "const_fmt_arguments_new", issue = "none")] + pub const unsafe fn new_v1( + pieces: &'a [&'static str], + args: &'a [ArgumentV1<'a>], + ) -> Arguments<'a> { + if pieces.len() < args.len() || pieces.len() > args.len() + 1 { + panic!("invalid args"); + } + Arguments { pieces, fmt: None, args } + } + #[cfg(bootstrap)] #[doc(hidden)] #[inline] #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")] #[rustc_const_unstable(feature = "const_fmt_arguments_new", issue = "none")] pub const fn new_v1(pieces: &'a [&'static str], args: &'a [ArgumentV1<'a>]) -> Arguments<'a> { + if pieces.len() < args.len() || pieces.len() > args.len() + 1 { + panic!("invalid args"); + } Arguments { pieces, fmt: None, args } } @@ -348,6 +366,19 @@ impl<'a> Arguments<'a> { /// `CountIsParam` or `CountIsNextParam` has to point to an argument /// created with `argumentusize`. However, failing to do so doesn't cause /// unsafety, but will ignore invalid . + #[cfg(not(bootstrap))] + #[doc(hidden)] + #[inline] + #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")] + #[rustc_const_unstable(feature = "const_fmt_arguments_new", issue = "none")] + pub const unsafe fn new_v1_formatted( + pieces: &'a [&'static str], + args: &'a [ArgumentV1<'a>], + fmt: &'a [rt::v1::Argument], + ) -> Arguments<'a> { + Arguments { pieces, fmt: Some(fmt), args } + } + #[cfg(bootstrap)] #[doc(hidden)] #[inline] #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")] diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index 37c3f8d4c16ab..229b05ee50574 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -110,6 +110,7 @@ // // Language features: #![feature(abi_unadjusted)] +#![feature(allow_internal_unsafe)] #![feature(allow_internal_unstable)] #![feature(asm)] #![feature(associated_type_bounds)] diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs index 476f37699ee73..a3a074ac131af 100644 --- a/library/core/src/macros/mod.rs +++ b/library/core/src/macros/mod.rs @@ -828,6 +828,7 @@ pub(crate) mod builtin { /// assert_eq!(s, format!("hello {}", "world")); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[allow_internal_unsafe] #[allow_internal_unstable(fmt_internals)] #[rustc_builtin_macro] #[macro_export] diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs index 2ec6b4d15ffd1..85728551f53ac 100644 --- a/library/core/src/panicking.rs +++ b/library/core/src/panicking.rs @@ -47,7 +47,15 @@ pub fn panic(expr: &'static str) -> ! { // truncation and padding (even though none is used here). Using // Arguments::new_v1 may allow the compiler to omit Formatter::pad from the // output binary, saving up to a few kilobytes. - panic_fmt(fmt::Arguments::new_v1(&[expr], &[])); + panic_fmt( + #[cfg(bootstrap)] + fmt::Arguments::new_v1(&[expr], &[]), + #[cfg(not(bootstrap))] + // SAFETY: Arguments::new_v1 is safe with exactly one str and zero args + unsafe { + fmt::Arguments::new_v1(&[expr], &[]) + }, + ); } #[inline] diff --git a/src/test/pretty/dollar-crate.pp b/src/test/pretty/dollar-crate.pp index f4be3c1c63a84..4eccba06b134f 100644 --- a/src/test/pretty/dollar-crate.pp +++ b/src/test/pretty/dollar-crate.pp @@ -10,9 +10,11 @@ fn main() { { - ::std::io::_print(::core::fmt::Arguments::new_v1(&["rust\n"], - &match () { - () => [], - })); + ::std::io::_print(match match () { () => [], } { + ref args => unsafe { + ::core::fmt::Arguments::new_v1(&["rust\n"], + args) + } + }); }; } diff --git a/src/test/pretty/issue-4264.pp b/src/test/pretty/issue-4264.pp index 199aee05622be..a21ea520121e3 100644 --- a/src/test/pretty/issue-4264.pp +++ b/src/test/pretty/issue-4264.pp @@ -32,29 +32,39 @@ ({ let res = ((::alloc::fmt::format as - for<'r> fn(Arguments<'r>) -> String {format})(((::core::fmt::Arguments::new_v1 - as - fn(&[&'static str], &[ArgumentV1]) -> Arguments {Arguments::new_v1})((&([("test" - as - &str)] - as - [&str; 1]) - as - &[&str; 1]), - (&(match (() - as - ()) - { - () - => - ([] - as - [ArgumentV1; 0]), - } - as - [ArgumentV1; 0]) - as - &[ArgumentV1; 0])) + for<'r> fn(Arguments<'r>) -> String {format})((match (match (() + as + ()) + { + () + => + ([] + as + [ArgumentV1; 0]), + } + as + [ArgumentV1; 0]) + { + ref args + => + unsafe + { + ((::core::fmt::Arguments::new_v1 + as + unsafe fn(&[&'static str], &[ArgumentV1]) -> Arguments {Arguments::new_v1})((&([("test" + as + &str)] + as + [&str; 1]) + as + &[&str; 1]), + (args + as + &[ArgumentV1; 0])) + as + Arguments) + } + } as Arguments)) as String); diff --git a/src/test/ui/attributes/key-value-expansion.stderr b/src/test/ui/attributes/key-value-expansion.stderr index 31e93ef54f260..03ca515265cb0 100644 --- a/src/test/ui/attributes/key-value-expansion.stderr +++ b/src/test/ui/attributes/key-value-expansion.stderr @@ -17,12 +17,16 @@ LL | bug!(); error: unexpected token: `{ let res = - ::alloc::fmt::format(::core::fmt::Arguments::new_v1(&[""], - &match (&"u8",) { - (arg0,) => - [::core::fmt::ArgumentV1::new(arg0, - ::core::fmt::Display::fmt)], - })); + ::alloc::fmt::format(match match (&"u8",) { + (arg0,) => + [::core::fmt::ArgumentV1::new(arg0, + ::core::fmt::Display::fmt)], + } { + ref args => unsafe { + ::core::fmt::Arguments::new_v1(&[""], + args) + } + }); res }.as_str()` --> $DIR/key-value-expansion.rs:48:23 From f4ef07c2a9adf6df5717c6d664fad0b8fea7a1bd Mon Sep 17 00:00:00 2001 From: Cameron Steffen Date: Thu, 5 Aug 2021 12:02:41 -0500 Subject: [PATCH 2/6] Get piece unchecked in write --- library/core/src/fmt/mod.rs | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs index b32b1f8633697..1d75ac3d254bd 100644 --- a/library/core/src/fmt/mod.rs +++ b/library/core/src/fmt/mod.rs @@ -4,7 +4,6 @@ use crate::cell::{Cell, Ref, RefCell, RefMut, UnsafeCell}; use crate::char::EscapeDebugExtArgs; -use crate::iter; use crate::marker::PhantomData; use crate::mem; use crate::num::fmt as numfmt; @@ -1141,7 +1140,10 @@ pub fn write(output: &mut dyn Write, args: Arguments<'_>) -> Result { match args.fmt { None => { // We can use default formatting parameters for all arguments. - for (arg, piece) in iter::zip(args.args, args.pieces) { + for (i, arg) in args.args.iter().enumerate() { + // SAFETY: args.args and args.pieces come from the same Arguments, + // which guarantees the indexes are always within bounds. + let piece = unsafe { args.pieces.get_unchecked(i) }; if !piece.is_empty() { formatter.buf.write_str(*piece)?; } @@ -1152,7 +1154,10 @@ pub fn write(output: &mut dyn Write, args: Arguments<'_>) -> Result { Some(fmt) => { // Every spec has a corresponding argument that is preceded by // a string piece. - for (arg, piece) in iter::zip(fmt, args.pieces) { + for (i, arg) in fmt.iter().enumerate() { + // SAFETY: fmt and args.pieces come from the same Arguments, + // which guarantees the indexes are always within bounds. + let piece = unsafe { args.pieces.get_unchecked(i) }; if !piece.is_empty() { formatter.buf.write_str(*piece)?; } From 46377c48a400bc39110fb9a930c2c200ceac7cd2 Mon Sep 17 00:00:00 2001 From: Cameron Steffen Date: Mon, 7 Jun 2021 17:43:35 -0500 Subject: [PATCH 3/6] Add unnecessary unsafe test --- .../unsafe-around-compiler-generated-unsafe.mir.stderr | 8 +++++++- .../ui/unsafe/unsafe-around-compiler-generated-unsafe.rs | 3 +++ .../unsafe-around-compiler-generated-unsafe.thir.stderr | 8 +++++++- 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.mir.stderr b/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.mir.stderr index 29bd84cd0db53..62199e5a2ec0b 100644 --- a/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.mir.stderr +++ b/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.mir.stderr @@ -10,5 +10,11 @@ note: the lint level is defined here LL | #![deny(unused_unsafe)] | ^^^^^^^^^^^^^ -error: aborting due to previous error +error: unnecessary `unsafe` block + --> $DIR/unsafe-around-compiler-generated-unsafe.rs:13:5 + | +LL | unsafe { println!("foo"); } + | ^^^^^^ unnecessary `unsafe` block + +error: aborting due to 2 previous errors diff --git a/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.rs b/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.rs index e9c7efb9e8b80..c1a3276403985 100644 --- a/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.rs +++ b/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.rs @@ -8,4 +8,7 @@ fn main() { let _ = async { unsafe { async {}.await; } //~ ERROR unnecessary `unsafe` }; + + // `format_args!` expands with a compiler-generated unsafe block + unsafe { println!("foo"); } //~ ERROR unnecessary `unsafe` } diff --git a/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.thir.stderr b/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.thir.stderr index 29bd84cd0db53..62199e5a2ec0b 100644 --- a/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.thir.stderr +++ b/src/test/ui/unsafe/unsafe-around-compiler-generated-unsafe.thir.stderr @@ -10,5 +10,11 @@ note: the lint level is defined here LL | #![deny(unused_unsafe)] | ^^^^^^^^^^^^^ -error: aborting due to previous error +error: unnecessary `unsafe` block + --> $DIR/unsafe-around-compiler-generated-unsafe.rs:13:5 + | +LL | unsafe { println!("foo"); } + | ^^^^^^ unnecessary `unsafe` block + +error: aborting due to 2 previous errors From 51979ac1c710f334d3a13379b0279599b2f14fdc Mon Sep 17 00:00:00 2001 From: Cameron Steffen Date: Sat, 3 Jul 2021 13:06:51 -0500 Subject: [PATCH 4/6] Fix a debuginfo test --- src/test/debuginfo/rc_arc.rs | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/test/debuginfo/rc_arc.rs b/src/test/debuginfo/rc_arc.rs index 55cddf7c6c6b4..144a746062daa 100644 --- a/src/test/debuginfo/rc_arc.rs +++ b/src/test/debuginfo/rc_arc.rs @@ -75,5 +75,7 @@ fn main() { let a1 = Arc::clone(&a); let w2 = Arc::downgrade(&a); - print!(""); // #break + zzz(); // #break } + +fn zzz() { () } From d3097fc496d2fb87f988618a24f133026229120c Mon Sep 17 00:00:00 2001 From: Cameron Steffen Date: Fri, 16 Jul 2021 08:54:08 -0500 Subject: [PATCH 5/6] clippy: Fix format_args expansion parsing --- src/tools/clippy/clippy_utils/src/higher.rs | 35 ++++++++++++--------- 1 file changed, 20 insertions(+), 15 deletions(-) diff --git a/src/tools/clippy/clippy_utils/src/higher.rs b/src/tools/clippy/clippy_utils/src/higher.rs index 29b698e56e3c0..6437363bad74c 100644 --- a/src/tools/clippy/clippy_utils/src/higher.rs +++ b/src/tools/clippy/clippy_utils/src/higher.rs @@ -485,12 +485,28 @@ impl FormatArgsExpn<'tcx> { if let ExpnKind::Macro(_, name) = expr.span.ctxt().outer_expn_data().kind; let name = name.as_str(); if name.ends_with("format_args") || name.ends_with("format_args_nl"); - if let ExprKind::Call(_, args) = expr.kind; - if let Some((strs_ref, args, fmt_expr)) = match args { + + if let ExprKind::Match(inner_match, [arm], _) = expr.kind; + + // `match match`, if you will + if let ExprKind::Match(args, [inner_arm], _) = inner_match.kind; + if let ExprKind::Tup(value_args) = args.kind; + if let Some(value_args) = value_args + .iter() + .map(|e| match e.kind { + ExprKind::AddrOf(_, _, e) => Some(e), + _ => None, + }) + .collect(); + if let ExprKind::Array(args) = inner_arm.body.kind; + + if let ExprKind::Block(Block { stmts: [], expr: Some(expr), .. }, _) = arm.body.kind; + if let ExprKind::Call(_, call_args) = expr.kind; + if let Some((strs_ref, fmt_expr)) = match call_args { // Arguments::new_v1 - [strs_ref, args] => Some((strs_ref, args, None)), + [strs_ref, _] => Some((strs_ref, None)), // Arguments::new_v1_formatted - [strs_ref, args, fmt_expr] => Some((strs_ref, args, Some(fmt_expr))), + [strs_ref, _, fmt_expr] => Some((strs_ref, Some(fmt_expr))), _ => None, }; if let ExprKind::AddrOf(BorrowKind::Ref, _, strs_arr) = strs_ref.kind; @@ -506,17 +522,6 @@ impl FormatArgsExpn<'tcx> { None }) .collect(); - if let ExprKind::AddrOf(BorrowKind::Ref, _, args) = args.kind; - if let ExprKind::Match(args, [arm], _) = args.kind; - if let ExprKind::Tup(value_args) = args.kind; - if let Some(value_args) = value_args - .iter() - .map(|e| match e.kind { - ExprKind::AddrOf(_, _, e) => Some(e), - _ => None, - }) - .collect(); - if let ExprKind::Array(args) = arm.body.kind; then { Some(FormatArgsExpn { format_string_span: strs_ref.span, From b1e07b82dcef6d31556a92cb75d825bce6032519 Mon Sep 17 00:00:00 2001 From: Cameron Steffen Date: Sun, 15 Aug 2021 19:18:18 -0500 Subject: [PATCH 6/6] Fix a coverage-reports test --- .../coverage-reports/expected_show_coverage.issue-84561.txt | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.issue-84561.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.issue-84561.txt index f24f7c6940473..b35f3f54de904 100644 --- a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.issue-84561.txt +++ b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.issue-84561.txt @@ -31,15 +31,15 @@ 24| 1| println!("{:?}", Foo(1)); 25| 1| 26| 1| assert_ne!(Foo(0), Foo(5), "{}", if is_true { "true message" } else { "false message" }); - ^0 ^0 ^0 + ^0 ^0 ^0 ^0 27| 1| assert_ne!( 28| | Foo(0) 29| | , 30| | Foo(5) 31| | , 32| 0| "{}" - 33| 0| , - 34| 0| if + 33| | , + 34| | if 35| 0| is_true 36| | { 37| 0| "true message"