From d16cc79d7b7091f67328a0080634ce6cd4880dbd Mon Sep 17 00:00:00 2001 From: iximeow Date: Fri, 21 Jun 2024 02:05:24 -0700 Subject: things compile again, add a few more caution signs around InstructionTextBuffer --- src/display.rs | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) (limited to 'src/display.rs') diff --git a/src/display.rs b/src/display.rs index e495aee..9b72cb3 100644 --- a/src/display.rs +++ b/src/display.rs @@ -211,6 +211,11 @@ impl<'buf> fmt::Write for InstructionTextSink<'buf> { 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. // @@ -640,6 +645,12 @@ impl DisplaySink for alloc::string::String { 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 buf = unsafe { self.buf.as_mut_vec() }; let new_bytes = s.as_bytes(); @@ -671,6 +682,12 @@ 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"); + } + } + // SAFETY: todo let buf = unsafe { self.buf.as_mut_vec() }; let new_bytes = s.as_bytes(); @@ -745,6 +762,12 @@ 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"); + } + } + // SAFETY: todo let buf = unsafe { self.buf.as_mut_vec() }; let new_bytes = s.as_bytes(); @@ -810,6 +833,12 @@ 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"); + } + } + // SAFETY: todo let buf = unsafe { self.buf.as_mut_vec() }; let new_bytes = s.as_bytes(); @@ -881,6 +910,12 @@ 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"); + } + } + let buf = unsafe { self.buf.as_mut_vec() }; let new_len = buf.len() + printed_size; @@ -914,10 +949,17 @@ 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"); + } + } + let buf = unsafe { self.buf.as_mut_vec() }; let new_len = buf.len() + printed_size; @@ -951,10 +993,17 @@ 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"); + } + } + let buf = unsafe { self.buf.as_mut_vec() }; let new_len = buf.len() + printed_size; @@ -988,10 +1037,17 @@ 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"); + } + } + let buf = unsafe { self.buf.as_mut_vec() }; let new_len = buf.len() + printed_size; -- cgit v1.1