diff options
| -rw-r--r-- | goodfile | 1 | ||||
| -rw-r--r-- | src/display.rs | 5 | ||||
| -rw-r--r-- | src/display/display_sink.rs | 896 | ||||
| -rw-r--r-- | src/lib.rs | 1 | ||||
| -rw-r--r-- | tests/display.rs | 17 |
5 files changed, 477 insertions, 443 deletions
@@ -5,6 +5,7 @@ Step.push("build") Build.run({"cargo", "build"}) Step.advance("test") +-- TODO: set `-D warnings` here and below... Build.run({"cargo", "test"}, {name="test default features"}) -- `cargo test` ends up running doc tests. great! but yaxpeax-arch's docs reference items in std only. diff --git a/src/display.rs b/src/display.rs index 77f6ba9..3965bdc 100644 --- a/src/display.rs +++ b/src/display.rs @@ -10,12 +10,15 @@ use core::ops::Neg; mod display_sink; -pub use display_sink::{DisplaySink, FmtSink, InstructionTextSink}; +pub use display_sink::{DisplaySink, FmtSink}; +#[cfg(feature = "alloc")] +pub use display_sink::InstructionTextSink; /// translate a byte in range `[0, 15]` to a lowercase base-16 digit. /// /// if `c` is in range, the output is always valid as the sole byte in a utf-8 string. if `c` is out /// of range, the returned character might not be a valid single-byte utf-8 codepoint. +#[cfg(feature = "alloc")] // this function is of course not directly related to alloc, but it's only needed by impls that themselves are only present with alloc. fn u8_to_hex(c: u8) -> u8 { // this conditional branch is faster than a lookup for... most architectures (especially x86 // with cmov) diff --git a/src/display/display_sink.rs b/src/display/display_sink.rs index 418b6aa..1fb8837 100644 --- a/src/display/display_sink.rs +++ b/src/display/display_sink.rs @@ -1,9 +1,5 @@ use core::fmt; -use crate::display::u8_to_hex; - -use crate::safer_unchecked::unreachable_kinda_unchecked; - /// `DisplaySink` allows client code to collect output and minimal markup. this is currently used /// in formatting instructions for two reasons: /// * `DisplaySink` implementations have the opportunity to collect starts and ends of tokens at @@ -372,469 +368,518 @@ impl<'a, T: fmt::Write> fmt::Write for FmtSink<'a, T> { } } -/// this is an implementation detail of yaxpeax-arch and related crates. if you are a user of the -/// disassemblers, do not use this struct. do not depend on this struct existing. this struct is -/// not stable. this struct is not safe for general use. if you use this struct you and your -/// program will be eaten by gremlins. -/// -/// if you are implementing an instruction formatter for the yaxpeax family of crates: this struct -/// is guaranteed to contain a string that is long enough to hold a fully-formatted instruction. -/// because the buffer is guaranteed to be long enough, writes through `InstructionTextSink` are -/// not bounds-checked, and the buffer is never grown. -/// -/// this is wildly dangerous in general use. the public constructor of `InstructionTextSink` is -/// unsafe as a result. as used in `InstructionFormatter`, the buffer is guaranteed to be -/// `clear()`ed before use, `InstructionFormatter` ensures the buffer is large enough, *and* -/// `InstructionFormatter` never allows `InstructionTextSink` to exist in a context where it would -/// be written to without being rewound first. -/// -/// because this opens a very large hole through which `fmt::Write` can become unsafe, incorrect -/// uses of this struct will be hard to debug in general. `InstructionFormatter` is probably at the -/// limit of easily-reasoned-about lifecycle of the buffer, which "only" leaves the problem of -/// ensuring that instruction formatting impls this buffer is passed to are appropriately sized. -/// -/// this is intended to be hidden in docs. if you see this in docs, it's a bug. -#[doc(hidden)] -pub struct InstructionTextSink<'buf> { - buf: &'buf mut alloc::string::String -} +#[cfg(feature = "alloc")] +mod instruction_text_sink { + use core::fmt; -impl<'buf> InstructionTextSink<'buf> { - // TODO: safety - pub unsafe fn new(buf: &'buf mut alloc::string::String) -> Self { - Self { buf } - } -} + use super::{DisplaySink, u8_to_hex}; + use crate::safer_unchecked::unreachable_kinda_unchecked; -impl<'buf> fmt::Write for InstructionTextSink<'buf> { - fn write_str(&mut self, s: &str) -> Result<(), core::fmt::Error> { - self.buf.write_str(s) - } - fn write_char(&mut self, c: char) -> Result<(), core::fmt::Error> { - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + 1 { - panic!("InstructionTextSink::write_char would overflow output"); - } - } - // SAFETY: `buf` is assumed to be long enough to hold all input, `buf` at `underlying.len()` - // is valid for writing, but may be uninitialized. - // - // this function is essentially equivalent to `Vec::push` specialized for the case that - // `len < buf.capacity()`: - // https://github.com/rust-lang/rust/blob/be9e27e/library/alloc/src/vec/mod.rs#L1993-L2006 - unsafe { - let underlying = self.buf.as_mut_vec(); - // `InstructionTextSink::write_char` is only used by yaxpeax-x86, and is only used to - // write single ASCII characters. this is wrong in the general case, but `write_char` - // here is not going to be used in the general case. - if cfg!(debug_asertions) { - panic!("InstructionTextSink::write_char would truncate output"); - } - let to_push = c as u8; - // `ptr::write` here because `underlying.add(underlying.len())` may not point to an - // initialized value, which would mean that turning that pointer into a `&mut u8` to - // store through would be UB. `ptr::write` avoids taking the mut ref. - underlying.as_mut_ptr().offset(underlying.len() as isize).write(to_push); - // we have initialized all (one) bytes that `set_len` is increasing the length to - // include. - underlying.set_len(underlying.len() + 1); - } - Ok(()) + /// this is an implementation detail of yaxpeax-arch and related crates. if you are a user of the + /// disassemblers, do not use this struct. do not depend on this struct existing. this struct is + /// not stable. this struct is not safe for general use. if you use this struct you and your + /// program will be eaten by gremlins. + /// + /// if you are implementing an instruction formatter for the yaxpeax family of crates: this struct + /// is guaranteed to contain a string that is long enough to hold a fully-formatted instruction. + /// because the buffer is guaranteed to be long enough, writes through `InstructionTextSink` are + /// not bounds-checked, and the buffer is never grown. + /// + /// this is wildly dangerous in general use. the public constructor of `InstructionTextSink` is + /// unsafe as a result. as used in `InstructionFormatter`, the buffer is guaranteed to be + /// `clear()`ed before use, `InstructionFormatter` ensures the buffer is large enough, *and* + /// `InstructionFormatter` never allows `InstructionTextSink` to exist in a context where it would + /// be written to without being rewound first. + /// + /// because this opens a very large hole through which `fmt::Write` can become unsafe, incorrect + /// uses of this struct will be hard to debug in general. `InstructionFormatter` is probably at the + /// limit of easily-reasoned-about lifecycle of the buffer, which "only" leaves the problem of + /// ensuring that instruction formatting impls this buffer is passed to are appropriately sized. + /// + /// this is intended to be hidden in docs. if you see this in docs, it's a bug. +#[doc(hidden)] + pub struct InstructionTextSink<'buf> { + buf: &'buf mut alloc::string::String } -} -/// this [`DisplaySink`] impl exists to support somewhat more performant buffering of the kinds of -/// strings `yaxpeax-x86` uses in formatting instructions. -/// -/// span information is discarded at zero cost. -impl DisplaySink for alloc::string::String { - #[inline(always)] - fn write_fixed_size(&mut self, s: &str) -> Result<(), core::fmt::Error> { - self.reserve(s.len()); - let buf = unsafe { self.as_mut_vec() }; - let new_bytes = s.as_bytes(); - - if new_bytes.len() == 0 { - unsafe { unreachable_kinda_unchecked() } + impl<'buf> InstructionTextSink<'buf> { + // TODO: safety + pub unsafe fn new(buf: &'buf mut alloc::string::String) -> Self { + Self { buf } } + } - if new_bytes.len() >= 16 { - unsafe { unreachable_kinda_unchecked() } + impl<'buf> fmt::Write for InstructionTextSink<'buf> { + fn write_str(&mut self, s: &str) -> Result<(), core::fmt::Error> { + self.buf.write_str(s) } - - unsafe { - let dest = buf.as_mut_ptr().offset(buf.len() as isize); - - // this used to be enough to bamboozle llvm away from - // https://github.com/rust-lang/rust/issues/92993#issuecomment-2028915232 - // if `s` is not fixed size. somewhere between Rust 1.68 and Rust 1.74 this stopped - // being sufficient, so `write_fixed_size` truly should only be used for fixed size `s` - // (otherwise this is a libc memcpy call in disguise). for fixed-size strings this - // unrolls into some kind of appropriate series of `mov`. - dest.offset(0 as isize).write(new_bytes[0]); - for i in 1..new_bytes.len() { - dest.offset(i as isize).write(new_bytes[i]); + fn write_char(&mut self, c: char) -> Result<(), core::fmt::Error> { + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + 1 { + panic!("InstructionTextSink::write_char would overflow output"); + } } - - buf.set_len(buf.len() + new_bytes.len()); + // SAFETY: `buf` is assumed to be long enough to hold all input, `buf` at `underlying.len()` + // is valid for writing, but may be uninitialized. + // + // this function is essentially equivalent to `Vec::push` specialized for the case that + // `len < buf.capacity()`: + // https://github.com/rust-lang/rust/blob/be9e27e/library/alloc/src/vec/mod.rs#L1993-L2006 + unsafe { + let underlying = self.buf.as_mut_vec(); + // `InstructionTextSink::write_char` is only used by yaxpeax-x86, and is only used to + // write single ASCII characters. this is wrong in the general case, but `write_char` + // here is not going to be used in the general case. + if cfg!(debug_asertions) { + panic!("InstructionTextSink::write_char would truncate output"); + } + let to_push = c as u8; + // `ptr::write` here because `underlying.add(underlying.len())` may not point to an + // initialized value, which would mean that turning that pointer into a `&mut u8` to + // store through would be UB. `ptr::write` avoids taking the mut ref. + underlying.as_mut_ptr().offset(underlying.len() as isize).write(to_push); + // we have initialized all (one) bytes that `set_len` is increasing the length to + // include. + underlying.set_len(underlying.len() + 1); + } + Ok(()) } - - Ok(()) } - unsafe fn write_lt_32(&mut self, s: &str) -> Result<(), fmt::Error> { - self.reserve(s.len()); - // SAFETY: todo - let buf = unsafe { self.as_mut_vec() }; - let new_bytes = s.as_bytes(); - - // should get DCE - if new_bytes.len() >= 32 { - unsafe { core::hint::unreachable_unchecked() } - } - - unsafe { - let dest = buf.as_mut_ptr().offset(buf.len() as isize); - let src = new_bytes.as_ptr(); + impl<'buf> DisplaySink for InstructionTextSink<'buf> { + #[inline(always)] + fn write_fixed_size(&mut self, s: &str) -> Result<(), core::fmt::Error> { + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + s.len() { + panic!("InstructionTextSink::write_fixed_size would overflow output"); + } + } - let rem = new_bytes.len() as isize; + let buf = unsafe { self.buf.as_mut_vec() }; + let new_bytes = s.as_bytes(); - // set_len early because there is no way to avoid the following asm!() writing that - // same number of bytes into buf - buf.set_len(buf.len() + new_bytes.len()); - - core::arch::asm!( - "6:", - "cmp {rem:e}, 16", - "jb 7f", - "mov {buf:r}, qword ptr [{src} + {rem} - 16]", - "mov qword ptr [{dest} + {rem} - 16], {buf:r}", - "mov {buf:r}, qword ptr [{src} + {rem} - 8]", - "mov qword ptr [{dest} + {rem} - 8], {buf:r}", - "sub {rem:e}, 16", - "jz 11f", - "7:", - "cmp {rem:e}, 8", - "jb 8f", - "mov {buf:r}, qword ptr [{src} + {rem} - 8]", - "mov qword ptr [{dest} + {rem} - 8], {buf:r}", - "sub {rem:e}, 8", - "jz 11f", - "8:", - "cmp {rem:e}, 4", - "jb 9f", - "mov {buf:e}, dword ptr [{src} + {rem} - 4]", - "mov dword ptr [{dest} + {rem} - 4], {buf:e}", - "sub {rem:e}, 4", - "jz 11f", - "9:", - "cmp {rem:e}, 2", - "jb 10f", - "mov {buf:x}, word ptr [{src} + {rem} - 2]", - "mov word ptr [{dest} + {rem} - 2], {buf:x}", - "sub {rem:e}, 2", - "jz 11f", - "10:", - "cmp {rem:e}, 1", - "jb 11f", - "mov {buf:l}, byte ptr [{src} + {rem} - 1]", - "mov byte ptr [{dest} + {rem} - 1], {buf:l}", - "11:", - src = in(reg) src, - dest = in(reg) dest, - rem = inout(reg) rem => _, - buf = out(reg) _, - options(nostack), - ); - } + if new_bytes.len() == 0 { + return Ok(()); + } - Ok(()) - } - unsafe fn write_lt_16(&mut self, s: &str) -> Result<(), fmt::Error> { - self.reserve(s.len()); + if new_bytes.len() >= 16 { + unsafe { unreachable_kinda_unchecked() } + } - // SAFETY: todo - let buf = unsafe { self.as_mut_vec() }; - let new_bytes = s.as_bytes(); + unsafe { + let dest = buf.as_mut_ptr().offset(buf.len() as isize); + + // this used to be enough to bamboozle llvm away from + // https://github.com/rust-lang/rust/issues/92993#issuecomment-2028915232https://github.com/rust-lang/rust/issues/92993#issuecomment-2028915232 + // if `s` is not fixed size. somewhere between Rust 1.68 and Rust 1.74 this stopped + // being sufficient, so `write_fixed_size` truly should only be used for fixed size `s` + // (otherwise this is a libc memcpy call in disguise). for fixed-size strings this + // unrolls into some kind of appropriate series of `mov`. + dest.offset(0 as isize).write(new_bytes[0]); + for i in 1..new_bytes.len() { + dest.offset(i as isize).write(new_bytes[i]); + } + + buf.set_len(buf.len() + new_bytes.len()); + } - // should get DCE - if new_bytes.len() >= 16 { - unsafe { core::hint::unreachable_unchecked() } + Ok(()) } + unsafe fn write_lt_32(&mut self, s: &str) -> Result<(), fmt::Error> { + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + s.len() { + panic!("InstructionTextSink::write_lt_32 would overflow output"); + } + } - unsafe { - let dest = buf.as_mut_ptr().offset(buf.len() as isize); - let src = new_bytes.as_ptr(); - - let rem = new_bytes.len() as isize; - - // set_len early because there is no way to avoid the following asm!() writing that - // same number of bytes into buf - buf.set_len(buf.len() + new_bytes.len()); - - core::arch::asm!( - "7:", - "cmp {rem:e}, 8", - "jb 8f", - "mov {buf:r}, qword ptr [{src} + {rem} - 8]", - "mov qword ptr [{dest} + {rem} - 8], {buf:r}", - "sub {rem:e}, 8", - "jz 11f", - "8:", - "cmp {rem:e}, 4", - "jb 9f", - "mov {buf:e}, dword ptr [{src} + {rem} - 4]", - "mov dword ptr [{dest} + {rem} - 4], {buf:e}", - "sub {rem:e}, 4", - "jz 11f", - "9:", - "cmp {rem:e}, 2", - "jb 10f", - "mov {buf:x}, word ptr [{src} + {rem} - 2]", - "mov word ptr [{dest} + {rem} - 2], {buf:x}", - "sub {rem:e}, 2", - "jz 11f", - "10:", - "cmp {rem:e}, 1", - "jb 11f", - "mov {buf:l}, byte ptr [{src} + {rem} - 1]", - "mov byte ptr [{dest} + {rem} - 1], {buf:l}", - "11:", - src = in(reg) src, - dest = in(reg) dest, - rem = inout(reg) rem => _, - buf = out(reg) _, - options(nostack), - ); - } + // SAFETY: todo + let buf = unsafe { self.buf.as_mut_vec() }; + let new_bytes = s.as_bytes(); - Ok(()) - } - unsafe fn write_lt_8(&mut self, s: &str) -> Result<(), fmt::Error> { - self.reserve(s.len()); + // should get DCE + if new_bytes.len() >= 32 { + unsafe { core::hint::unreachable_unchecked() } + } - // SAFETY: todo - let buf = unsafe { self.as_mut_vec() }; - let new_bytes = s.as_bytes(); + unsafe { + let dest = buf.as_mut_ptr().offset(buf.len() as isize); + let src = new_bytes.as_ptr(); + + let rem = new_bytes.len() as isize; + + // set_len early because there is no way to avoid the following asm!() writing that + // same number of bytes into buf + buf.set_len(buf.len() + new_bytes.len()); + + core::arch::asm!( + "6:", + "cmp {rem:e}, 16", + "jb 7f", + "mov {buf:r}, qword ptr [{src} + {rem} - 16]", + "mov qword ptr [{dest} + {rem} - 16], {buf:r}", + "mov {buf:r}, qword ptr [{src} + {rem} - 8]", + "mov qword ptr [{dest} + {rem} - 8], {buf:r}", + "sub {rem:e}, 16", + "jz 11f", + "7:", + "cmp {rem:e}, 8", + "jb 8f", + "mov {buf:r}, qword ptr [{src} + {rem} - 8]", + "mov qword ptr [{dest} + {rem} - 8], {buf:r}", + "sub {rem:e}, 8", + "jz 11f", + "8:", + "cmp {rem:e}, 4", + "jb 9f", + "mov {buf:e}, dword ptr [{src} + {rem} - 4]", + "mov dword ptr [{dest} + {rem} - 4], {buf:e}", + "sub {rem:e}, 4", + "jz 11f", + "9:", + "cmp {rem:e}, 2", + "jb 10f", + "mov {buf:x}, word ptr [{src} + {rem} - 2]", + "mov word ptr [{dest} + {rem} - 2], {buf:x}", + "sub {rem:e}, 2", + "jz 11f", + "10:", + "cmp {rem:e}, 1", + "jb 11f", + "mov {buf:l}, byte ptr [{src} + {rem} - 1]", + "mov byte ptr [{dest} + {rem} - 1], {buf:l}", + "11:", + src = in(reg) src, + dest = in(reg) dest, + rem = inout(reg) rem => _, + buf = out(reg) _, + options(nostack), + ); + } - // should get DCE - if new_bytes.len() >= 8 { - unsafe { core::hint::unreachable_unchecked() } + Ok(()) } + unsafe fn write_lt_16(&mut self, s: &str) -> Result<(), fmt::Error> { + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + s.len() { + panic!("InstructionTextSink::write_lt_16 would overflow output"); + } + } - unsafe { - let dest = buf.as_mut_ptr().offset(buf.len() as isize); - let src = new_bytes.as_ptr(); + // SAFETY: todo + let buf = unsafe { self.buf.as_mut_vec() }; + let new_bytes = s.as_bytes(); - let rem = new_bytes.len() as isize; + // should get DCE + if new_bytes.len() >= 16 { + unsafe { core::hint::unreachable_unchecked() } + } - // set_len early because there is no way to avoid the following asm!() writing that - // same number of bytes into buf - buf.set_len(buf.len() + new_bytes.len()); + unsafe { + let dest = buf.as_mut_ptr().offset(buf.len() as isize); + let src = new_bytes.as_ptr(); + + let rem = new_bytes.len() as isize; + + // set_len early because there is no way to avoid the following asm!() writing that + // same number of bytes into buf + buf.set_len(buf.len() + new_bytes.len()); + + core::arch::asm!( + "7:", + "cmp {rem:e}, 8", + "jb 8f", + "mov {buf:r}, qword ptr [{src} + {rem} - 8]", + "mov qword ptr [{dest} + {rem} - 8], {buf:r}", + "sub {rem:e}, 8", + "jz 11f", + "8:", + "cmp {rem:e}, 4", + "jb 9f", + "mov {buf:e}, dword ptr [{src} + {rem} - 4]", + "mov dword ptr [{dest} + {rem} - 4], {buf:e}", + "sub {rem:e}, 4", + "jz 11f", + "9:", + "cmp {rem:e}, 2", + "jb 10f", + "mov {buf:x}, word ptr [{src} + {rem} - 2]", + "mov word ptr [{dest} + {rem} - 2], {buf:x}", + "sub {rem:e}, 2", + "jz 11f", + "10:", + "cmp {rem:e}, 1", + "jb 11f", + "mov {buf:l}, byte ptr [{src} + {rem} - 1]", + "mov byte ptr [{dest} + {rem} - 1], {buf:l}", + "11:", + src = in(reg) src, + dest = in(reg) dest, + rem = inout(reg) rem => _, + buf = out(reg) _, + options(nostack), + ); + } - core::arch::asm!( - "8:", - "cmp {rem:e}, 4", - "jb 9f", - "mov {buf:e}, dword ptr [{src} + {rem} - 4]", - "mov dword ptr [{dest} + {rem} - 4], {buf:e}", - "sub {rem:e}, 4", - "jz 11f", - "9:", - "cmp {rem:e}, 2", - "jb 10f", - "mov {buf:x}, word ptr [{src} + {rem} - 2]", - "mov word ptr [{dest} + {rem} - 2], {buf:x}", - "sub {rem:e}, 2", - "jz 11f", - "10:", - "cmp {rem:e}, 1", - "jb 11f", - "mov {buf:l}, byte ptr [{src} + {rem} - 1]", - "mov byte ptr [{dest} + {rem} - 1], {buf:l}", - "11:", - src = in(reg) src, - dest = in(reg) dest, - rem = inout(reg) rem => _, - buf = out(reg) _, - options(nostack), - ); + Ok(()) } + unsafe fn write_lt_8(&mut self, s: &str) -> Result<(), fmt::Error> { + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + s.len() { + panic!("InstructionTextSink::write_lt_8 would overflow output"); + } + } - Ok(()) - } - /// write a u8 to the output as a base-16 integer. - /// - /// this is provided for optimization opportunities when the formatted integer can be written - /// directly to the sink (rather than formatted to an intermediate buffer and output as a - /// followup step) - #[inline(always)] - fn write_u8(&mut self, mut v: u8) -> Result<(), core::fmt::Error> { - if v == 0 { - return self.write_fixed_size("0"); - } - // we can fairly easily predict the size of a formatted string here with lzcnt, which also - // means we can write directly into the correct offsets of the output string. - let printed_size = ((8 - v.leading_zeros() + 3) >> 2) as usize; + // SAFETY: todo + let buf = unsafe { self.buf.as_mut_vec() }; + let new_bytes = s.as_bytes(); - self.reserve(printed_size); + // should get DCE + if new_bytes.len() >= 8 { + unsafe { core::hint::unreachable_unchecked() } + } - let buf = unsafe { self.as_mut_vec() }; - let new_len = buf.len() + printed_size; + unsafe { + let dest = buf.as_mut_ptr().offset(buf.len() as isize); + let src = new_bytes.as_ptr(); + + let rem = new_bytes.len() as isize; + + // set_len early because there is no way to avoid the following asm!() writing that + // same number of bytes into buf + buf.set_len(buf.len() + new_bytes.len()); + + core::arch::asm!( + "8:", + "cmp {rem:e}, 4", + "jb 9f", + "mov {buf:e}, dword ptr [{src} + {rem} - 4]", + "mov dword ptr [{dest} + {rem} - 4], {buf:e}", + "sub {rem:e}, 4", + "jz 11f", + "9:", + "cmp {rem:e}, 2", + "jb 10f", + "mov {buf:x}, word ptr [{src} + {rem} - 2]", + "mov word ptr [{dest} + {rem} - 2], {buf:x}", + "sub {rem:e}, 2", + "jz 11f", + "10:", + "cmp {rem:e}, 1", + "jb 11f", + "mov {buf:l}, byte ptr [{src} + {rem} - 1]", + "mov byte ptr [{dest} + {rem} - 1], {buf:l}", + "11:", + src = in(reg) src, + dest = in(reg) dest, + rem = inout(reg) rem => _, + buf = out(reg) _, + options(nostack), + ); + } - unsafe { - buf.set_len(new_len); + Ok(()) } - let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + /// write a u8 to the output as a base-16 integer. + /// + /// this is provided for optimization opportunities when the formatted integer can be written + /// directly to the sink (rather than formatted to an intermediate buffer and output as a + /// followup step) + #[inline(always)] + fn write_u8(&mut self, mut v: u8) -> Result<(), core::fmt::Error> { + if v == 0 { + return self.write_fixed_size("0"); + } + // we can fairly easily predict the size of a formatted string here with lzcnt, which also + // means we can write directly into the correct offsets of the output string. + let printed_size = ((8 - v.leading_zeros() + 3) >> 2) as usize; + + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + printed_size { + panic!("InstructionTextSink::write_u8 would overflow output"); + } + } + + let buf = unsafe { self.buf.as_mut_vec() }; + let new_len = buf.len() + printed_size; - loop { - let digit = v % 16; - let c = u8_to_hex(digit as u8); unsafe { - p = p.offset(-1); - p.write(c); + buf.set_len(new_len); } - v = v / 16; - if v == 0 { - break; + let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + + loop { + let digit = v % 16; + let c = u8_to_hex(digit as u8); + unsafe { + p = p.offset(-1); + p.write(c); + } + v = v / 16; + if v == 0 { + break; + } } - } - Ok(()) - } - /// write a u16 to the output as a base-16 integer. - /// - /// this is provided for optimization opportunities when the formatted integer can be written - /// directly to the sink (rather than formatted to an intermediate buffer and output as a - /// followup step) - #[inline(always)] - fn write_u16(&mut self, mut v: u16) -> Result<(), core::fmt::Error> { - if v == 0 { - return self.write_fixed_size("0"); + Ok(()) } - // we can fairly easily predict the size of a formatted string here with lzcnt, which also - // means we can write directly into the correct offsets of the output string. - let printed_size = ((16 - v.leading_zeros() + 3) >> 2) as usize; + /// write a u16 to the output as a base-16 integer. + /// + /// this is provided for optimization opportunities when the formatted integer can be written + /// directly to the sink (rather than formatted to an intermediate buffer and output as a + /// followup step) + #[inline(always)] + fn write_u16(&mut self, mut v: u16) -> Result<(), core::fmt::Error> { + if v == 0 { + return self.write_fixed_size("0"); + } - self.reserve(printed_size); + // we can fairly easily predict the size of a formatted string here with lzcnt, which also + // means we can write directly into the correct offsets of the output string. + let printed_size = ((16 - v.leading_zeros() + 3) >> 2) as usize; - let buf = unsafe { self.as_mut_vec() }; - let new_len = buf.len() + printed_size; + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + printed_size { + panic!("InstructionTextSink::write_u16 would overflow output"); + } + } - unsafe { - buf.set_len(new_len); - } - let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + let buf = unsafe { self.buf.as_mut_vec() }; + let new_len = buf.len() + printed_size; - loop { - let digit = v % 16; - let c = u8_to_hex(digit as u8); unsafe { - p = p.offset(-1); - p.write(c); + buf.set_len(new_len); } - v = v / 16; - if v == 0 { - break; + let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + + loop { + let digit = v % 16; + let c = u8_to_hex(digit as u8); + unsafe { + p = p.offset(-1); + p.write(c); + } + v = v / 16; + if v == 0 { + break; + } } - } - Ok(()) - } - /// write a u32 to the output as a base-16 integer. - /// - /// this is provided for optimization opportunities when the formatted integer can be written - /// directly to the sink (rather than formatted to an intermediate buffer and output as a - /// followup step) - #[inline(always)] - fn write_u32(&mut self, mut v: u32) -> Result<(), core::fmt::Error> { - if v == 0 { - return self.write_fixed_size("0"); + Ok(()) } - // we can fairly easily predict the size of a formatted string here with lzcnt, which also - // means we can write directly into the correct offsets of the output string. - let printed_size = ((32 - v.leading_zeros() + 3) >> 2) as usize; + /// write a u32 to the output as a base-16 integer. + /// + /// this is provided for optimization opportunities when the formatted integer can be written + /// directly to the sink (rather than formatted to an intermediate buffer and output as a + /// followup step) + #[inline(always)] + fn write_u32(&mut self, mut v: u32) -> Result<(), core::fmt::Error> { + if v == 0 { + return self.write_fixed_size("0"); + } - self.reserve(printed_size); + // we can fairly easily predict the size of a formatted string here with lzcnt, which also + // means we can write directly into the correct offsets of the output string. + let printed_size = ((32 - v.leading_zeros() + 3) >> 2) as usize; - let buf = unsafe { self.as_mut_vec() }; - let new_len = buf.len() + printed_size; + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + printed_size { + panic!("InstructionTextSink::write_u32 would overflow output"); + } + } - unsafe { - buf.set_len(new_len); - } - let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + let buf = unsafe { self.buf.as_mut_vec() }; + let new_len = buf.len() + printed_size; - loop { - let digit = v % 16; - let c = u8_to_hex(digit as u8); unsafe { - p = p.offset(-1); - p.write(c); + buf.set_len(new_len); } - v = v / 16; - if v == 0 { - break; + let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + + loop { + let digit = v % 16; + let c = u8_to_hex(digit as u8); + unsafe { + p = p.offset(-1); + p.write(c); + } + v = v / 16; + if v == 0 { + break; + } } - } - Ok(()) - } - /// write a u64 to the output as a base-16 integer. - /// - /// this is provided for optimization opportunities when the formatted integer can be written - /// directly to the sink (rather than formatted to an intermediate buffer and output as a - /// followup step) - #[inline(always)] - fn write_u64(&mut self, mut v: u64) -> Result<(), core::fmt::Error> { - if v == 0 { - return self.write_fixed_size("0"); + Ok(()) } - // we can fairly easily predict the size of a formatted string here with lzcnt, which also - // means we can write directly into the correct offsets of the output string. - let printed_size = ((64 - v.leading_zeros() + 3) >> 2) as usize; + /// write a u64 to the output as a base-16 integer. + /// + /// this is provided for optimization opportunities when the formatted integer can be written + /// directly to the sink (rather than formatted to an intermediate buffer and output as a + /// followup step) + #[inline(always)] + fn write_u64(&mut self, mut v: u64) -> Result<(), core::fmt::Error> { + if v == 0 { + return self.write_fixed_size("0"); + } - self.reserve(printed_size); + // we can fairly easily predict the size of a formatted string here with lzcnt, which also + // means we can write directly into the correct offsets of the output string. + let printed_size = ((64 - v.leading_zeros() + 3) >> 2) as usize; - let buf = unsafe { self.as_mut_vec() }; - let new_len = buf.len() + printed_size; + if cfg!(debug_assertions) { + if self.buf.capacity() < self.buf.len() + printed_size { + panic!("InstructionTextSink::write_u64 would overflow output"); + } + } - unsafe { - buf.set_len(new_len); - } - let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + let buf = unsafe { self.buf.as_mut_vec() }; + let new_len = buf.len() + printed_size; - loop { - let digit = v % 16; - let c = u8_to_hex(digit as u8); unsafe { - p = p.offset(-1); - p.write(c); + buf.set_len(new_len); } - v = v / 16; - if v == 0 { - break; + let mut p = unsafe { buf.as_mut_ptr().offset(new_len as isize) }; + + loop { + let digit = v % 16; + let c = u8_to_hex(digit as u8); + unsafe { + p = p.offset(-1); + p.write(c); + } + v = v / 16; + if v == 0 { + break; + } } - } - Ok(()) + Ok(()) + } } } +#[cfg(feature = "alloc")] +pub use instruction_text_sink::InstructionTextSink; + + +#[cfg(feature = "alloc")] +use crate::display::u8_to_hex; + +#[cfg(feature = "alloc")] +use crate::safer_unchecked::unreachable_kinda_unchecked; -impl<'buf> DisplaySink for InstructionTextSink<'buf> { +/// this [`DisplaySink`] impl exists to support somewhat more performant buffering of the kinds of +/// strings `yaxpeax-x86` uses in formatting instructions. +/// +/// span information is discarded at zero cost. +#[cfg(feature = "alloc")] +impl DisplaySink for alloc::string::String { #[inline(always)] fn write_fixed_size(&mut self, s: &str) -> Result<(), core::fmt::Error> { - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + s.len() { - panic!("InstructionTextSink::write_fixed_size would overflow output"); - } - } - - let buf = unsafe { self.buf.as_mut_vec() }; + self.reserve(s.len()); + let buf = unsafe { self.as_mut_vec() }; let new_bytes = s.as_bytes(); if new_bytes.len() == 0 { - return Ok(()); + unsafe { unreachable_kinda_unchecked() } } if new_bytes.len() >= 16 { @@ -845,7 +890,7 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { let dest = buf.as_mut_ptr().offset(buf.len() as isize); // this used to be enough to bamboozle llvm away from - // https://github.com/rust-lang/rust/issues/92993#issuecomment-2028915232https://github.com/rust-lang/rust/issues/92993#issuecomment-2028915232 + // https://github.com/rust-lang/rust/issues/92993#issuecomment-2028915232 // if `s` is not fixed size. somewhere between Rust 1.68 and Rust 1.74 this stopped // being sufficient, so `write_fixed_size` truly should only be used for fixed size `s` // (otherwise this is a libc memcpy call in disguise). for fixed-size strings this @@ -861,14 +906,10 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { Ok(()) } unsafe fn write_lt_32(&mut self, s: &str) -> Result<(), fmt::Error> { - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + s.len() { - panic!("InstructionTextSink::write_lt_32 would overflow output"); - } - } + self.reserve(s.len()); // SAFETY: todo - let buf = unsafe { self.buf.as_mut_vec() }; + let buf = unsafe { self.as_mut_vec() }; let new_bytes = s.as_bytes(); // should get DCE @@ -934,14 +975,10 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { Ok(()) } unsafe fn write_lt_16(&mut self, s: &str) -> Result<(), fmt::Error> { - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + s.len() { - panic!("InstructionTextSink::write_lt_16 would overflow output"); - } - } + self.reserve(s.len()); // SAFETY: todo - let buf = unsafe { self.buf.as_mut_vec() }; + let buf = unsafe { self.as_mut_vec() }; let new_bytes = s.as_bytes(); // should get DCE @@ -998,14 +1035,10 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { Ok(()) } unsafe fn write_lt_8(&mut self, s: &str) -> Result<(), fmt::Error> { - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + s.len() { - panic!("InstructionTextSink::write_lt_8 would overflow output"); - } - } + self.reserve(s.len()); // SAFETY: todo - let buf = unsafe { self.buf.as_mut_vec() }; + let buf = unsafe { self.as_mut_vec() }; let new_bytes = s.as_bytes(); // should get DCE @@ -1068,13 +1101,9 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { // means we can write directly into the correct offsets of the output string. let printed_size = ((8 - v.leading_zeros() + 3) >> 2) as usize; - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + printed_size { - panic!("InstructionTextSink::write_u8 would overflow output"); - } - } + self.reserve(printed_size); - let buf = unsafe { self.buf.as_mut_vec() }; + let buf = unsafe { self.as_mut_vec() }; let new_len = buf.len() + printed_size; unsafe { @@ -1107,18 +1136,13 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { if v == 0 { return self.write_fixed_size("0"); } - // we can fairly easily predict the size of a formatted string here with lzcnt, which also // means we can write directly into the correct offsets of the output string. let printed_size = ((16 - v.leading_zeros() + 3) >> 2) as usize; - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + printed_size { - panic!("InstructionTextSink::write_u16 would overflow output"); - } - } + self.reserve(printed_size); - let buf = unsafe { self.buf.as_mut_vec() }; + let buf = unsafe { self.as_mut_vec() }; let new_len = buf.len() + printed_size; unsafe { @@ -1151,18 +1175,13 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { if v == 0 { return self.write_fixed_size("0"); } - // we can fairly easily predict the size of a formatted string here with lzcnt, which also // means we can write directly into the correct offsets of the output string. let printed_size = ((32 - v.leading_zeros() + 3) >> 2) as usize; - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + printed_size { - panic!("InstructionTextSink::write_u32 would overflow output"); - } - } + self.reserve(printed_size); - let buf = unsafe { self.buf.as_mut_vec() }; + let buf = unsafe { self.as_mut_vec() }; let new_len = buf.len() + printed_size; unsafe { @@ -1195,18 +1214,13 @@ impl<'buf> DisplaySink for InstructionTextSink<'buf> { if v == 0 { return self.write_fixed_size("0"); } - // we can fairly easily predict the size of a formatted string here with lzcnt, which also // means we can write directly into the correct offsets of the output string. let printed_size = ((64 - v.leading_zeros() + 3) >> 2) as usize; - if cfg!(debug_assertions) { - if self.buf.capacity() < self.buf.len() + printed_size { - panic!("InstructionTextSink::write_u64 would overflow output"); - } - } + self.reserve(printed_size); - let buf = unsafe { self.buf.as_mut_vec() }; + let buf = unsafe { self.as_mut_vec() }; let new_len = buf.len() + printed_size; unsafe { @@ -27,7 +27,6 @@ pub use color::ColorSettings; #[cfg(feature = "alloc")] extern crate alloc; -#[cfg(feature = "alloc")] pub mod display; pub mod testkit; diff --git a/tests/display.rs b/tests/display.rs index 9a8ef2e..887db53 100644 --- a/tests/display.rs +++ b/tests/display.rs @@ -22,6 +22,23 @@ fn sinks_are_equivalent() { } */ +#[test] +#[allow(deprecated)] +fn formatters_are_not_feature_gated() { + use yaxpeax_arch::display::{ + u8_hex, u16_hex, u32_hex, u64_hex, + signed_i8_hex, signed_i16_hex, signed_i32_hex, signed_i64_hex + }; + let _ = u8_hex(10); + let _ = u16_hex(10); + let _ = u32_hex(10); + let _ = u64_hex(10); + let _ = signed_i8_hex(10); + let _ = signed_i16_hex(10); + let _ = signed_i32_hex(10); + let _ = signed_i64_hex(10); +} + #[cfg(feature="alloc")] #[test] fn display_sink_write_hex_helpers() { |