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-rw-r--r--src/display/display_sink.rs896
1 files changed, 455 insertions, 441 deletions
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 {
generated by cgit v1.1 at 2024-11-22 07:40:37 +0000