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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:06:37 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:06:37 +0000
commit246f239d9f40f633160f0c18f87a20922d4e77bb (patch)
tree5a88572663584b3d4d28e5a20e10abab1be40884 /library/panic_unwind/src/dwarf
parentReleasing progress-linux version 1.64.0+dfsg1-1~progress7.99u1. (diff)
downloadrustc-246f239d9f40f633160f0c18f87a20922d4e77bb.tar.xz
rustc-246f239d9f40f633160f0c18f87a20922d4e77bb.zip
Merging debian version 1.65.0+dfsg1-2.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'library/panic_unwind/src/dwarf')
-rw-r--r--library/panic_unwind/src/dwarf/eh.rs192
-rw-r--r--library/panic_unwind/src/dwarf/mod.rs73
-rw-r--r--library/panic_unwind/src/dwarf/tests.rs19
3 files changed, 0 insertions, 284 deletions
diff --git a/library/panic_unwind/src/dwarf/eh.rs b/library/panic_unwind/src/dwarf/eh.rs
deleted file mode 100644
index 7394feab8..000000000
--- a/library/panic_unwind/src/dwarf/eh.rs
+++ /dev/null
@@ -1,192 +0,0 @@
-//! Parsing of GCC-style Language-Specific Data Area (LSDA)
-//! For details see:
-//! * <https://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-PDA/LSB-PDA/ehframechpt.html>
-//! * <https://itanium-cxx-abi.github.io/cxx-abi/exceptions.pdf>
-//! * <https://www.airs.com/blog/archives/460>
-//! * <https://www.airs.com/blog/archives/464>
-//!
-//! A reference implementation may be found in the GCC source tree
-//! (`<root>/libgcc/unwind-c.c` as of this writing).
-
-#![allow(non_upper_case_globals)]
-#![allow(unused)]
-
-use crate::dwarf::DwarfReader;
-use core::mem;
-
-pub const DW_EH_PE_omit: u8 = 0xFF;
-pub const DW_EH_PE_absptr: u8 = 0x00;
-
-pub const DW_EH_PE_uleb128: u8 = 0x01;
-pub const DW_EH_PE_udata2: u8 = 0x02;
-pub const DW_EH_PE_udata4: u8 = 0x03;
-pub const DW_EH_PE_udata8: u8 = 0x04;
-pub const DW_EH_PE_sleb128: u8 = 0x09;
-pub const DW_EH_PE_sdata2: u8 = 0x0A;
-pub const DW_EH_PE_sdata4: u8 = 0x0B;
-pub const DW_EH_PE_sdata8: u8 = 0x0C;
-
-pub const DW_EH_PE_pcrel: u8 = 0x10;
-pub const DW_EH_PE_textrel: u8 = 0x20;
-pub const DW_EH_PE_datarel: u8 = 0x30;
-pub const DW_EH_PE_funcrel: u8 = 0x40;
-pub const DW_EH_PE_aligned: u8 = 0x50;
-
-pub const DW_EH_PE_indirect: u8 = 0x80;
-
-#[derive(Copy, Clone)]
-pub struct EHContext<'a> {
- pub ip: usize, // Current instruction pointer
- pub func_start: usize, // Address of the current function
- pub get_text_start: &'a dyn Fn() -> usize, // Get address of the code section
- pub get_data_start: &'a dyn Fn() -> usize, // Get address of the data section
-}
-
-pub enum EHAction {
- None,
- Cleanup(usize),
- Catch(usize),
- Terminate,
-}
-
-pub const USING_SJLJ_EXCEPTIONS: bool = cfg!(all(target_os = "ios", target_arch = "arm"));
-
-pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result<EHAction, ()> {
- if lsda.is_null() {
- return Ok(EHAction::None);
- }
-
- let func_start = context.func_start;
- let mut reader = DwarfReader::new(lsda);
-
- let start_encoding = reader.read::<u8>();
- // base address for landing pad offsets
- let lpad_base = if start_encoding != DW_EH_PE_omit {
- read_encoded_pointer(&mut reader, context, start_encoding)?
- } else {
- func_start
- };
-
- let ttype_encoding = reader.read::<u8>();
- if ttype_encoding != DW_EH_PE_omit {
- // Rust doesn't analyze exception types, so we don't care about the type table
- reader.read_uleb128();
- }
-
- let call_site_encoding = reader.read::<u8>();
- let call_site_table_length = reader.read_uleb128();
- let action_table = reader.ptr.offset(call_site_table_length as isize);
- let ip = context.ip;
-
- if !USING_SJLJ_EXCEPTIONS {
- while reader.ptr < action_table {
- let cs_start = read_encoded_pointer(&mut reader, context, call_site_encoding)?;
- let cs_len = read_encoded_pointer(&mut reader, context, call_site_encoding)?;
- let cs_lpad = read_encoded_pointer(&mut reader, context, call_site_encoding)?;
- let cs_action = reader.read_uleb128();
- // Callsite table is sorted by cs_start, so if we've passed the ip, we
- // may stop searching.
- if ip < func_start + cs_start {
- break;
- }
- if ip < func_start + cs_start + cs_len {
- if cs_lpad == 0 {
- return Ok(EHAction::None);
- } else {
- let lpad = lpad_base + cs_lpad;
- return Ok(interpret_cs_action(cs_action, lpad));
- }
- }
- }
- // Ip is not present in the table. This should not happen... but it does: issue #35011.
- // So rather than returning EHAction::Terminate, we do this.
- Ok(EHAction::None)
- } else {
- // SjLj version:
- // The "IP" is an index into the call-site table, with two exceptions:
- // -1 means 'no-action', and 0 means 'terminate'.
- match ip as isize {
- -1 => return Ok(EHAction::None),
- 0 => return Ok(EHAction::Terminate),
- _ => (),
- }
- let mut idx = ip;
- loop {
- let cs_lpad = reader.read_uleb128();
- let cs_action = reader.read_uleb128();
- idx -= 1;
- if idx == 0 {
- // Can never have null landing pad for sjlj -- that would have
- // been indicated by a -1 call site index.
- let lpad = (cs_lpad + 1) as usize;
- return Ok(interpret_cs_action(cs_action, lpad));
- }
- }
- }
-}
-
-fn interpret_cs_action(cs_action: u64, lpad: usize) -> EHAction {
- if cs_action == 0 {
- // If cs_action is 0 then this is a cleanup (Drop::drop). We run these
- // for both Rust panics and foreign exceptions.
- EHAction::Cleanup(lpad)
- } else {
- // Stop unwinding Rust panics at catch_unwind.
- EHAction::Catch(lpad)
- }
-}
-
-#[inline]
-fn round_up(unrounded: usize, align: usize) -> Result<usize, ()> {
- if align.is_power_of_two() { Ok((unrounded + align - 1) & !(align - 1)) } else { Err(()) }
-}
-
-unsafe fn read_encoded_pointer(
- reader: &mut DwarfReader,
- context: &EHContext<'_>,
- encoding: u8,
-) -> Result<usize, ()> {
- if encoding == DW_EH_PE_omit {
- return Err(());
- }
-
- // DW_EH_PE_aligned implies it's an absolute pointer value
- if encoding == DW_EH_PE_aligned {
- reader.ptr = round_up(reader.ptr as usize, mem::size_of::<usize>())? as *const u8;
- return Ok(reader.read::<usize>());
- }
-
- let mut result = match encoding & 0x0F {
- DW_EH_PE_absptr => reader.read::<usize>(),
- DW_EH_PE_uleb128 => reader.read_uleb128() as usize,
- DW_EH_PE_udata2 => reader.read::<u16>() as usize,
- DW_EH_PE_udata4 => reader.read::<u32>() as usize,
- DW_EH_PE_udata8 => reader.read::<u64>() as usize,
- DW_EH_PE_sleb128 => reader.read_sleb128() as usize,
- DW_EH_PE_sdata2 => reader.read::<i16>() as usize,
- DW_EH_PE_sdata4 => reader.read::<i32>() as usize,
- DW_EH_PE_sdata8 => reader.read::<i64>() as usize,
- _ => return Err(()),
- };
-
- result += match encoding & 0x70 {
- DW_EH_PE_absptr => 0,
- // relative to address of the encoded value, despite the name
- DW_EH_PE_pcrel => reader.ptr as usize,
- DW_EH_PE_funcrel => {
- if context.func_start == 0 {
- return Err(());
- }
- context.func_start
- }
- DW_EH_PE_textrel => (*context.get_text_start)(),
- DW_EH_PE_datarel => (*context.get_data_start)(),
- _ => return Err(()),
- };
-
- if encoding & DW_EH_PE_indirect != 0 {
- result = *(result as *const usize);
- }
-
- Ok(result)
-}
diff --git a/library/panic_unwind/src/dwarf/mod.rs b/library/panic_unwind/src/dwarf/mod.rs
deleted file mode 100644
index 652fbe95a..000000000
--- a/library/panic_unwind/src/dwarf/mod.rs
+++ /dev/null
@@ -1,73 +0,0 @@
-//! Utilities for parsing DWARF-encoded data streams.
-//! See <http://www.dwarfstd.org>,
-//! DWARF-4 standard, Section 7 - "Data Representation"
-
-// This module is used only by x86_64-pc-windows-gnu for now, but we
-// are compiling it everywhere to avoid regressions.
-#![allow(unused)]
-
-#[cfg(test)]
-mod tests;
-
-pub mod eh;
-
-use core::mem;
-
-pub struct DwarfReader {
- pub ptr: *const u8,
-}
-
-#[repr(C, packed)]
-struct Unaligned<T>(T);
-
-impl DwarfReader {
- pub fn new(ptr: *const u8) -> DwarfReader {
- DwarfReader { ptr }
- }
-
- // DWARF streams are packed, so e.g., a u32 would not necessarily be aligned
- // on a 4-byte boundary. This may cause problems on platforms with strict
- // alignment requirements. By wrapping data in a "packed" struct, we are
- // telling the backend to generate "misalignment-safe" code.
- pub unsafe fn read<T: Copy>(&mut self) -> T {
- let Unaligned(result) = *(self.ptr as *const Unaligned<T>);
- self.ptr = self.ptr.add(mem::size_of::<T>());
- result
- }
-
- // ULEB128 and SLEB128 encodings are defined in Section 7.6 - "Variable
- // Length Data".
- pub unsafe fn read_uleb128(&mut self) -> u64 {
- let mut shift: usize = 0;
- let mut result: u64 = 0;
- let mut byte: u8;
- loop {
- byte = self.read::<u8>();
- result |= ((byte & 0x7F) as u64) << shift;
- shift += 7;
- if byte & 0x80 == 0 {
- break;
- }
- }
- result
- }
-
- pub unsafe fn read_sleb128(&mut self) -> i64 {
- let mut shift: u32 = 0;
- let mut result: u64 = 0;
- let mut byte: u8;
- loop {
- byte = self.read::<u8>();
- result |= ((byte & 0x7F) as u64) << shift;
- shift += 7;
- if byte & 0x80 == 0 {
- break;
- }
- }
- // sign-extend
- if shift < u64::BITS && (byte & 0x40) != 0 {
- result |= (!0 as u64) << shift;
- }
- result as i64
- }
-}
diff --git a/library/panic_unwind/src/dwarf/tests.rs b/library/panic_unwind/src/dwarf/tests.rs
deleted file mode 100644
index 1644f3708..000000000
--- a/library/panic_unwind/src/dwarf/tests.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-use super::*;
-
-#[test]
-fn dwarf_reader() {
- let encoded: &[u8] = &[1, 2, 3, 4, 5, 6, 7, 0xE5, 0x8E, 0x26, 0x9B, 0xF1, 0x59, 0xFF, 0xFF];
-
- let mut reader = DwarfReader::new(encoded.as_ptr());
-
- unsafe {
- assert!(reader.read::<u8>() == u8::to_be(1u8));
- assert!(reader.read::<u16>() == u16::to_be(0x0203));
- assert!(reader.read::<u32>() == u32::to_be(0x04050607));
-
- assert!(reader.read_uleb128() == 624485);
- assert!(reader.read_sleb128() == -624485);
-
- assert!(reader.read::<i8>() == i8::to_be(-1));
- }
-}