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| 1 | +//! Synthetic Wasm address space expected by the gdbstub Wasm |
| 2 | +//! extensions. |
| 3 | +
|
| 4 | +use crate::api::{Debuggee, Frame, Memory, Module}; |
| 5 | +use anyhow::Result; |
| 6 | +use gdbstub_arch::wasm::addr::{WasmAddr, WasmAddrType}; |
| 7 | +use std::collections::{HashMap, hash_map::Entry}; |
| 8 | + |
| 9 | +/// Representation of the synthesized Wasm address space. |
| 10 | +pub struct AddrSpace { |
| 11 | + module_ids: HashMap<u64, u32>, |
| 12 | + memory_ids: HashMap<u64, u32>, |
| 13 | + modules: Vec<Module>, |
| 14 | + module_bytecode: Vec<Vec<u8>>, |
| 15 | + memories: Vec<Memory>, |
| 16 | +} |
| 17 | + |
| 18 | +/// The result of a lookup in the address space. |
| 19 | +pub enum AddrSpaceLookup<'a> { |
| 20 | + Module { |
| 21 | + module: &'a Module, |
| 22 | + bytecode: &'a [u8], |
| 23 | + offset: u32, |
| 24 | + }, |
| 25 | + Memory { |
| 26 | + memory: &'a Memory, |
| 27 | + offset: u32, |
| 28 | + }, |
| 29 | + Empty, |
| 30 | +} |
| 31 | + |
| 32 | +impl AddrSpace { |
| 33 | + pub fn new() -> Self { |
| 34 | + AddrSpace { |
| 35 | + module_ids: HashMap::new(), |
| 36 | + modules: vec![], |
| 37 | + module_bytecode: vec![], |
| 38 | + memory_ids: HashMap::new(), |
| 39 | + memories: vec![], |
| 40 | + } |
| 41 | + } |
| 42 | + |
| 43 | + fn module_id(&mut self, m: &Module) -> u32 { |
| 44 | + match self.module_ids.entry(m.unique_id()) { |
| 45 | + Entry::Occupied(o) => *o.get(), |
| 46 | + Entry::Vacant(v) => { |
| 47 | + let id = u32::try_from(self.modules.len()).unwrap(); |
| 48 | + let bytecode = m.bytecode().unwrap_or(vec![]); |
| 49 | + self.module_bytecode.push(bytecode); |
| 50 | + self.modules.push(m.clone()); |
| 51 | + *v.insert(id) |
| 52 | + } |
| 53 | + } |
| 54 | + } |
| 55 | + |
| 56 | + fn memory_id(&mut self, m: &Memory) -> u32 { |
| 57 | + match self.memory_ids.entry(m.unique_id()) { |
| 58 | + Entry::Occupied(o) => *o.get(), |
| 59 | + Entry::Vacant(v) => { |
| 60 | + let id = u32::try_from(self.memories.len()).unwrap(); |
| 61 | + self.memories.push(m.clone()); |
| 62 | + *v.insert(id) |
| 63 | + } |
| 64 | + } |
| 65 | + } |
| 66 | + |
| 67 | + /// Update/create new mappings so that all modules and instances' |
| 68 | + /// memories in the debuggee have mappings. |
| 69 | + pub fn update(&mut self, d: &Debuggee) -> Result<()> { |
| 70 | + for module in d.all_modules() { |
| 71 | + let _ = self.module_id(&module); |
| 72 | + } |
| 73 | + for instance in d.all_instances() { |
| 74 | + let mut idx = 0; |
| 75 | + loop { |
| 76 | + if let Ok(m) = instance.get_memory(d, idx) { |
| 77 | + let _ = self.memory_id(&m); |
| 78 | + idx += 1; |
| 79 | + } else { |
| 80 | + break; |
| 81 | + } |
| 82 | + } |
| 83 | + } |
| 84 | + Ok(()) |
| 85 | + } |
| 86 | + |
| 87 | + /// Iterate over the base `WasmAddr` of every registered module. |
| 88 | + pub fn module_base_addrs(&self) -> impl Iterator<Item = WasmAddr> + '_ { |
| 89 | + (0..self.modules.len()) |
| 90 | + .map(|idx| WasmAddr::new(WasmAddrType::Object, u32::try_from(idx).unwrap(), 0).unwrap()) |
| 91 | + } |
| 92 | + |
| 93 | + /// Build the GDB memory-map XML describing all known regions. |
| 94 | + /// |
| 95 | + /// Module bytecode regions are reported as `rom` (read-only), and |
| 96 | + /// linear memories as `ram` (read-write). |
| 97 | + pub fn memory_map_xml(&self, debuggee: &Debuggee) -> String { |
| 98 | + use std::fmt::Write; |
| 99 | + let mut xml = String::from( |
| 100 | + "<?xml version=\"1.0\"?><!DOCTYPE memory-map SYSTEM \"memory-map.dtd\"><memory-map>", |
| 101 | + ); |
| 102 | + for (idx, bc) in self.module_bytecode.iter().enumerate() { |
| 103 | + let start = |
| 104 | + WasmAddr::new(WasmAddrType::Object, u32::try_from(idx).unwrap(), 0).unwrap(); |
| 105 | + let len = bc.len(); |
| 106 | + if len > 0 { |
| 107 | + write!( |
| 108 | + xml, |
| 109 | + "<memory type=\"rom\" start=\"0x{:x}\" length=\"0x{:x}\"/>", |
| 110 | + start.as_raw(), |
| 111 | + len |
| 112 | + ) |
| 113 | + .unwrap(); |
| 114 | + } |
| 115 | + } |
| 116 | + for (idx, mem) in self.memories.iter().enumerate() { |
| 117 | + let start = |
| 118 | + WasmAddr::new(WasmAddrType::Memory, u32::try_from(idx).unwrap(), 0).unwrap(); |
| 119 | + let len = mem.size_bytes(debuggee); |
| 120 | + if len > 0 { |
| 121 | + write!( |
| 122 | + xml, |
| 123 | + "<memory type=\"ram\" start=\"0x{:x}\" length=\"0x{:x}\"/>", |
| 124 | + start.as_raw(), |
| 125 | + len |
| 126 | + ) |
| 127 | + .unwrap(); |
| 128 | + } |
| 129 | + } |
| 130 | + xml.push_str("</memory-map>"); |
| 131 | + xml |
| 132 | + } |
| 133 | + |
| 134 | + pub fn frame_to_pc(&self, frame: &Frame, debuggee: &Debuggee) -> WasmAddr { |
| 135 | + let module = frame.get_instance(debuggee).unwrap().get_module(debuggee); |
| 136 | + let &module_id = self |
| 137 | + .module_ids |
| 138 | + .get(&module.unique_id()) |
| 139 | + .expect("module not found in addr space"); |
| 140 | + let pc = frame.get_pc(debuggee).unwrap(); |
| 141 | + WasmAddr::new(WasmAddrType::Object, module_id, pc).unwrap() |
| 142 | + } |
| 143 | + |
| 144 | + pub fn frame_to_return_addr(&self, frame: &Frame, debuggee: &Debuggee) -> Option<WasmAddr> { |
| 145 | + let module = frame.get_instance(debuggee).unwrap().get_module(debuggee); |
| 146 | + let &module_id = self |
| 147 | + .module_ids |
| 148 | + .get(&module.unique_id()) |
| 149 | + .expect("module not found in addr space"); |
| 150 | + let ret_pc = frame.get_pc(debuggee).ok()?; |
| 151 | + Some(WasmAddr::new(WasmAddrType::Object, module_id, ret_pc).unwrap()) |
| 152 | + } |
| 153 | + |
| 154 | + pub fn lookup(&self, addr: WasmAddr, d: &Debuggee) -> AddrSpaceLookup<'_> { |
| 155 | + let index = usize::try_from(addr.module_index()).unwrap(); |
| 156 | + match addr.addr_type() { |
| 157 | + WasmAddrType::Object => { |
| 158 | + if index >= self.modules.len() { |
| 159 | + return AddrSpaceLookup::Empty; |
| 160 | + } |
| 161 | + let bytecode = &self.module_bytecode[index]; |
| 162 | + if addr.offset() >= u32::try_from(bytecode.len()).unwrap() { |
| 163 | + return AddrSpaceLookup::Empty; |
| 164 | + } |
| 165 | + AddrSpaceLookup::Module { |
| 166 | + module: &self.modules[index], |
| 167 | + bytecode, |
| 168 | + offset: addr.offset(), |
| 169 | + } |
| 170 | + } |
| 171 | + WasmAddrType::Memory => { |
| 172 | + if index >= self.memories.len() { |
| 173 | + return AddrSpaceLookup::Empty; |
| 174 | + } |
| 175 | + let size = self.memories[index].size_bytes(d); |
| 176 | + if u64::from(addr.offset()) >= size { |
| 177 | + return AddrSpaceLookup::Empty; |
| 178 | + } |
| 179 | + AddrSpaceLookup::Memory { |
| 180 | + memory: &self.memories[index], |
| 181 | + offset: addr.offset(), |
| 182 | + } |
| 183 | + } |
| 184 | + } |
| 185 | + } |
| 186 | +} |
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