T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Parse stack slot decls.

Browse Source 
Add a stack slot array to repr::Function, use repr::StackSlot to reference them.

Parse stack slot declarations in the function preamble, add them to the
function.

Add a new `Context` struct which keeps track of mappings between identifiers
used in the file and real references.
This commit is contained in:
Jakob Stoklund Olesen
2016-04-28 14:35:52 -07:00
parent d1c79e8916
commit ed6677d576
3 changed files with 262 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
cranelift/src/libcretonne/immediates.rs
View File

@@ -74,6 +74,10 @@ impl Imm64 {
pub fn from_bits(x: u64) -> Imm64 {
Imm64(x as i64)
}
pub fn to_bits(&self) -> u64 {
self.0 as u64
}
}
impl Display for Imm64 {

121
cranelift/src/libcretonne/repr.rs
View File

@@ -4,6 +4,7 @@
use types::{Type, FunctionName, Signature};
use immediates::*;
use std::fmt::{self, Display, Formatter, Write};
use std::ops::Index;
use std::u32;
// ====--------------------------------------------------------------------------------------====//
@@ -33,18 +34,29 @@ pub struct Value(u32);
/// A guaranteed invalid value reference.
pub const NO_VALUE: Value = Value(u32::MAX);
/// An opaque reference to a stack slot.
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct StackSlot(u32);
/// A guaranteed invalid stack slot reference.
pub const NO_STACK_SLOT: StackSlot = StackSlot(u32::MAX);
/// A function.
///
/// The `Function` struct owns all of its instructions and extended basic blocks, and it works as a
/// container for those objects by implementing both `Index<Inst>` and `Index<Ebb>`.
///
#[derive(Debug)]
pub struct Function {
/// Name of this function. Mostly used by `.cton` files.
name: FunctionName,
pub name: FunctionName,
/// Signature of this function.
signature: Signature,
/// Stack slots allocated in this function.
stack_slots: Vec<StackSlotData>,
/// Data about all of the instructions in the function. The instructions in this vector is not
/// necessarily in program order. The `Inst` reference indexes into this vector.
instructions: Vec<InstructionData>,
@@ -61,7 +73,15 @@ pub struct Function {
pub return_types: Vec<Type>,
}
/// Contents of a stack slot.
#[derive(Debug)]
pub struct StackSlotData {
/// Size of stack slot in bytes.
pub size: u32,
}
/// Contents of an extended basic block.
#[derive(Debug)]
pub struct EbbData {
/// Arguments for this extended basic block. These values dominate everything in the EBB.
/// All branches to this EBB must provide matching arguments, and the arguments to the entry
@@ -75,6 +95,7 @@ pub struct EbbData {
/// value should have its `ty` field set to `VOID`. The size of `InstructionData` should be kept at
/// 16 bytes on 64-bit architectures. If more space is needed to represent an instruction, use a
/// `Box<AuxData>` to store the additional information out of line.
#[derive(Debug)]
pub enum InstructionData {
Nullary {
opcode: Opcode,
@@ -109,6 +130,7 @@ pub enum InstructionData {
}
/// Payload of a call instruction.
#[derive(Debug)]
pub struct CallData {
// Number of result values.
results: u8,
@@ -119,6 +141,72 @@ pub struct CallData {
}
// ====--------------------------------------------------------------------------------------====//
//
// Stack slot implementation.
//
// ====--------------------------------------------------------------------------------------====//
impl StackSlot {
fn new(index: usize) -> StackSlot {
assert!(index < (u32::MAX as usize));
StackSlot(index as u32)
}
pub fn index(&self) -> usize {
self.0 as usize
}
}
/// Display a `StackSlot` reference as "ss12".
impl Display for StackSlot {
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
write!(fmt, "ss{}", self.0)
}
}
impl StackSlotData {
/// Create a stack slot with the specified byte size.
pub fn new(size: u32) -> StackSlotData {
StackSlotData { size: size }
}
}
impl Display for StackSlotData {
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
write!(fmt, "stack_slot {}", self.size)
}
}
/// Allow immutable access to stack slots via function indexing.
impl Index<StackSlot> for Function {
type Output = StackSlotData;
fn index<'a>(&'a self, ss: StackSlot) -> &'a StackSlotData {
&self.stack_slots[ss.index()]
}
}
/// Stack slot iterator visits all stack slots in a function, returning `StackSlot` references.
pub struct StackSlotIter {
cur: usize,
end: usize,
}
impl Iterator for StackSlotIter {
type Item = StackSlot;
fn next(&mut self) -> Option<Self::Item> {
if self.cur < self.end {
let ss = StackSlot::new(self.cur);
self.cur += 1;
Some(ss)
} else {
None
}
}
}
// ====--------------------------------------------------------------------------------------====//
//
// Extended basic block implementation.
@@ -227,6 +315,7 @@ impl Display for Value {
// Most values are simply the first value produced by an instruction.
// Other values have an entry in the value table.
#[derive(Debug)]
enum ValueData {
// An unused entry in the value table. No instruction should be defining or using this value.
Unused,
@@ -280,6 +369,7 @@ impl Function {
Function {
name: name,
signature: sig,
stack_slots: Vec::new(),
instructions: Vec::new(),
extended_basic_blocks: Vec::new(),
extended_values: Vec::new(),
@@ -292,6 +382,21 @@ impl Function {
Self::with_name_signature(FunctionName::new(), Signature::new())
}
/// Allocate a new stack slot.
pub fn make_stack_slot(&mut self, data: StackSlotData) -> StackSlot {
let ss = StackSlot::new(self.stack_slots.len());
self.stack_slots.push(data);
ss
}
/// Iterate over all stack slots in function.
pub fn stack_slot_iter(&self) -> StackSlotIter {
StackSlotIter {
cur: 0,
end: self.stack_slots.len(),
}
}
/// Resolve an instruction reference.
pub fn inst(&self, i: Inst) -> &InstructionData {
&self.instructions[i.0 as usize]
@@ -351,4 +456,18 @@ mod tests {
assert_eq!(ins.opcode(), Opcode::Iconst);
assert_eq!(ins.first_type(), types::I32);
}
#[test]
fn stack_slot() {
let mut func = Function::new();
let ss0 = func.make_stack_slot(StackSlotData::new(4));
let ss1 = func.make_stack_slot(StackSlotData::new(8));
assert_eq!(format!("{}", ss0), "ss0");
assert_eq!(format!("{}", ss1), "ss1");
assert_eq!(func[ss0].size, 4);
assert_eq!(func[ss1].size, 8);
}
}

141
cranelift/src/libctonfile/parser.rs
View File

@@ -5,11 +5,14 @@
//
// ====--------------------------------------------------------------------------------------====//
use std::collections::HashMap;
use std::result;
use std::fmt::{self, Display, Formatter, Write};
use std::u32;
use lexer::{self, Lexer, Token};
use cretonne::types::{FunctionName, Signature, ArgumentType, ArgumentExtension};
use cretonne::repr::Function;
use cretonne::immediates::Imm64;
use cretonne::repr::{Function, StackSlot, StackSlotData};
pub use lexer::Location;
@@ -40,6 +43,35 @@ pub struct Parser<'a> {
location: Location,
}
// Context for resolving references when parsing a single function.
//
// Many entities like values, stack slots, and function signatures are referenced in the `.cton`
// file by number. We need to map these numbers to real references.
struct Context {
function: Function,
stack_slots: HashMap<u32, StackSlot>,
}
impl Context {
fn new(f: Function) -> Context {
Context {
function: f,
stack_slots: HashMap::new(),
}
}
fn add(&mut self, number: u32, data: StackSlotData, loc: &Location) -> Result<()> {
if self.stack_slots.insert(number, self.function.make_stack_slot(data)).is_some() {
Err(Error {
location: loc.clone(),
message: format!("duplicate stack slot: ss{}", number),
})
} else {
Ok(())
}
}
}
impl<'a> Parser<'a> {
/// Create a new `Parser` which reads `text`. The referenced text must outlive the parser.
pub fn new(text: &'a str) -> Parser {
@@ -111,6 +143,38 @@ impl<'a> Parser<'a> {
}
}
// Match and consume a specific identifier string.
// Used for pseudo-keywords like "stack_slot" that only appear in certain contexts.
fn match_identifier(&mut self, want: &'static str, err_msg: &str) -> Result<Token<'a>> {
if self.token() == Some(Token::Identifier(want)) {
Ok(self.consume())
} else {
Err(self.error(err_msg))
}
}
// Match and consume a stack slot reference.
fn match_ss(&mut self, err_msg: &str) -> Result<u32> {
if let Some(Token::StackSlot(ss)) = self.token() {
self.consume();
Ok(ss)
} else {
Err(self.error(err_msg))
}
}
// Match and consume an Imm64 immediate.
fn match_imm64(&mut self, err_msg: &str) -> Result<Imm64> {
if let Some(Token::Integer(text)) = self.token() {
self.consume();
// Lexer just gives us raw text that looks like an integer.
// Parse it as an Imm64 to check for overflow and other issues.
text.parse().map_err(|e| self.error(e))
} else {
Err(self.error(err_msg))
}
}
/// Parse a list of function definitions.
///
/// This is the top-level parse function matching the whole contents of a file.
@@ -128,14 +192,16 @@ impl<'a> Parser<'a> {
//
fn parse_function(&mut self) -> Result<Function> {
let (name, sig) = try!(self.parse_function_spec());
let mut func = Function::with_name_signature(name, sig);
let mut ctx = Context::new(Function::with_name_signature(name, sig));
// function ::= function-spec * "{" preample function-body "}"
try!(self.match_token(Token::LBrace, "expected '{' before function body"));
// function ::= function-spec "{" * preample function-body "}"
try!(self.parse_preamble(&mut ctx));
// function ::= function-spec "{" preample function-body * "}"
try!(self.match_token(Token::RBrace, "expected '}' after function body"));
Ok(func)
Ok(ctx.function)
}
// Parse a function spec.
@@ -232,6 +298,46 @@ impl<'a> Parser<'a> {
Ok(arg)
}
// Parse the function preamble.
//
// preamble ::= * { preamble-decl }
// preamble-decl ::= * stack-slot-decl
// * function-decl
// * signature-decl
//
// The parsed decls are added to `ctx` rather than returned.
fn parse_preamble(&mut self, ctx: &mut Context) -> Result<()> {
loop {
try!(match self.token() {
Some(Token::StackSlot(..)) => {
self.parse_stack_slot_decl()
.and_then(|(num, dat)| ctx.add(num, dat, &self.location))
}
// More to come..
_ => return Ok(()),
});
}
}
// Parse a stack slot decl, add to `func`.
//
// stack-slot-decl ::= * StackSlot(ss) "=" "stack_slot" Bytes {"," stack-slot-flag}
fn parse_stack_slot_decl(&mut self) -> Result<(u32, StackSlotData)> {
let number = try!(self.match_ss("expected stack slot number: ss«n»"));
try!(self.match_token(Token::Equal, "expected '=' in stack_slot decl"));
try!(self.match_identifier("stack_slot", "expected 'stack_slot'"));
// stack-slot-decl ::= StackSlot(ss) "=" "stack_slot" * Bytes {"," stack-slot-flag}
let bytes = try!(self.match_imm64("expected byte-size in stack_slot decl")).to_bits();
if bytes > u32::MAX as u64 {
return Err(self.error("stack slot too large"));
}
let data = StackSlotData::new(bytes as u32);
// TBD: stack-slot-decl ::= StackSlot(ss) "=" "stack_slot" Bytes * {"," stack-slot-flag}
Ok((number, data))
}
}
#[cfg(test)]
@@ -276,4 +382,33 @@ mod tests {
Parser::new("(i8 -> i8").parse_signature().unwrap_err()),
"1: expected ')' after function arguments");
}
#[test]
fn stack_slot_decl() {
let func = Parser::new("function foo() {
ss3 = stack_slot 13
ss1 = stack_slot 1
}")
.parse_function()
.unwrap();
assert_eq!(func.name, "foo");
let mut iter = func.stack_slot_iter();
let ss0 = iter.next().unwrap();
assert_eq!(format!("{}", ss0), "ss0");
assert_eq!(func[ss0].size, 13);
let ss1 = iter.next().unwrap();
assert_eq!(format!("{}", ss1), "ss1");
assert_eq!(func[ss1].size, 1);
assert_eq!(iter.next(), None);
// Catch suplicate definitions.
assert_eq!(format!("{}",
Parser::new("function bar() {
ss1 = stack_slot 13
ss1 = stack_slot 1
}")
.parse_function()
.unwrap_err()),
"3: duplicate stack slot: ss1");
}
}