diff options
Diffstat (limited to 'tvix/eval/src/vm.rs')
| -rw-r--r-- | tvix/eval/src/vm.rs | 551 |
1 files changed, 283 insertions, 268 deletions
diff --git a/tvix/eval/src/vm.rs b/tvix/eval/src/vm.rs index daee8c886c..ebf3de297b 100644 --- a/tvix/eval/src/vm.rs +++ b/tvix/eval/src/vm.rs @@ -362,342 +362,357 @@ impl<'o> VM<'o> { self.observer .observe_execute_op(self.frame().ip, &op, &self.stack); - match op { - OpCode::OpConstant(idx) => { - let c = self.chunk()[idx].clone(); - self.push(c); - } - - OpCode::OpPop => { - self.pop(); - } + let res = self.run_op(op); - OpCode::OpAdd => { - let b = self.pop(); - let a = self.pop(); - - let result = match (&a, &b) { - (Value::String(s1), Value::String(s2)) => Value::String(s1.concat(s2)), - (Value::Path(p), v) => { - let mut path = p.to_string_lossy().into_owned(); - path.push_str( - &v.coerce_to_string(CoercionKind::Weak, self) - .map_err(|ek| self.error(ek))?, - ); - PathBuf::from(path).clean().into() - } - _ => fallible!(self, arithmetic_op!(&a, &b, +)), - }; - - self.push(result) - } + if self.frame().ip.0 == self.chunk().code.len() { + self.frames.pop(); + return res; + } else { + res?; + } + } + } - OpCode::OpSub => arithmetic_op!(self, -), - OpCode::OpMul => arithmetic_op!(self, *), - OpCode::OpDiv => arithmetic_op!(self, /), + fn run_op(&mut self, op: OpCode) -> EvalResult<()> { + match op { + OpCode::OpConstant(idx) => { + let c = self.chunk()[idx].clone(); + self.push(c); + } - OpCode::OpInvert => { - let v = fallible!(self, self.pop().as_bool()); - self.push(Value::Bool(!v)); - } + OpCode::OpPop => { + self.pop(); + } - OpCode::OpNegate => match self.pop() { - Value::Integer(i) => self.push(Value::Integer(-i)), - Value::Float(f) => self.push(Value::Float(-f)), - v => { - return Err(self.error(ErrorKind::TypeError { - expected: "number (either int or float)", - actual: v.type_of(), - })); + OpCode::OpAdd => { + let b = self.pop(); + let a = self.pop(); + + let result = match (&a, &b) { + (Value::String(s1), Value::String(s2)) => Value::String(s1.concat(s2)), + (Value::Path(p), v) => { + let mut path = p.to_string_lossy().into_owned(); + path.push_str( + &v.coerce_to_string(CoercionKind::Weak, self) + .map_err(|ek| self.error(ek))?, + ); + PathBuf::from(path).clean().into() } - }, + _ => fallible!(self, arithmetic_op!(&a, &b, +)), + }; + + self.push(result) + } - OpCode::OpEqual => { - let v2 = self.pop(); - let v1 = self.pop(); - let res = fallible!(self, v1.nix_eq(&v2, self)); + OpCode::OpSub => arithmetic_op!(self, -), + OpCode::OpMul => arithmetic_op!(self, *), + OpCode::OpDiv => arithmetic_op!(self, /), - self.push(Value::Bool(res)) + OpCode::OpInvert => { + let v = fallible!(self, self.pop().as_bool()); + self.push(Value::Bool(!v)); + } + + OpCode::OpNegate => match self.pop() { + Value::Integer(i) => self.push(Value::Integer(-i)), + Value::Float(f) => self.push(Value::Float(-f)), + v => { + return Err(self.error(ErrorKind::TypeError { + expected: "number (either int or float)", + actual: v.type_of(), + })); } + }, - OpCode::OpLess => cmp_op!(self, <), - OpCode::OpLessOrEq => cmp_op!(self, <=), - OpCode::OpMore => cmp_op!(self, >), - OpCode::OpMoreOrEq => cmp_op!(self, >=), + OpCode::OpEqual => { + let v2 = self.pop(); + let v1 = self.pop(); + let res = fallible!(self, v1.nix_eq(&v2, self)); - OpCode::OpNull => self.push(Value::Null), - OpCode::OpTrue => self.push(Value::Bool(true)), - OpCode::OpFalse => self.push(Value::Bool(false)), + self.push(Value::Bool(res)) + } - OpCode::OpAttrs(Count(count)) => self.run_attrset(count)?, + OpCode::OpLess => cmp_op!(self, <), + OpCode::OpLessOrEq => cmp_op!(self, <=), + OpCode::OpMore => cmp_op!(self, >), + OpCode::OpMoreOrEq => cmp_op!(self, >=), - OpCode::OpAttrsUpdate => { - let rhs = unwrap_or_clone_rc(fallible!(self, self.pop().to_attrs())); - let lhs = unwrap_or_clone_rc(fallible!(self, self.pop().to_attrs())); + OpCode::OpNull => self.push(Value::Null), + OpCode::OpTrue => self.push(Value::Bool(true)), + OpCode::OpFalse => self.push(Value::Bool(false)), - self.push(Value::attrs(lhs.update(rhs))) - } + OpCode::OpAttrs(Count(count)) => self.run_attrset(count)?, - OpCode::OpAttrsSelect => { - let key = fallible!(self, self.pop().to_str()); - let attrs = fallible!(self, self.pop().to_attrs()); + OpCode::OpAttrsUpdate => { + let rhs = unwrap_or_clone_rc(fallible!(self, self.pop().to_attrs())); + let lhs = unwrap_or_clone_rc(fallible!(self, self.pop().to_attrs())); - match attrs.select(key.as_str()) { - Some(value) => self.push(value.clone()), + self.push(Value::attrs(lhs.update(rhs))) + } + + OpCode::OpAttrsSelect => { + let key = fallible!(self, self.pop().to_str()); + let attrs = fallible!(self, self.pop().to_attrs()); + + match attrs.select(key.as_str()) { + Some(value) => self.push(value.clone()), - None => { - return Err(self.error(ErrorKind::AttributeNotFound { - name: key.as_str().to_string(), - })) - } + None => { + return Err(self.error(ErrorKind::AttributeNotFound { + name: key.as_str().to_string(), + })) } } + } - OpCode::OpAttrsTrySelect => { - let key = fallible!(self, self.pop().to_str()); - let value = match self.pop() { - Value::Attrs(attrs) => match attrs.select(key.as_str()) { - Some(value) => value.clone(), - None => Value::AttrNotFound, - }, + OpCode::OpAttrsTrySelect => { + let key = fallible!(self, self.pop().to_str()); + let value = match self.pop() { + Value::Attrs(attrs) => match attrs.select(key.as_str()) { + Some(value) => value.clone(), + None => Value::AttrNotFound, + }, - _ => Value::AttrNotFound, - }; + _ => Value::AttrNotFound, + }; - self.push(value); - } + self.push(value); + } - OpCode::OpHasAttr => { - let key = fallible!(self, self.pop().to_str()); - let result = match self.pop() { - Value::Attrs(attrs) => attrs.contains(key.as_str()), + OpCode::OpHasAttr => { + let key = fallible!(self, self.pop().to_str()); + let result = match self.pop() { + Value::Attrs(attrs) => attrs.contains(key.as_str()), - // Nix allows use of `?` on non-set types, but - // always returns false in those cases. - _ => false, - }; + // Nix allows use of `?` on non-set types, but + // always returns false in those cases. + _ => false, + }; - self.push(Value::Bool(result)); - } + self.push(Value::Bool(result)); + } - OpCode::OpList(Count(count)) => { - let list = - NixList::construct(count, self.stack.split_off(self.stack.len() - count)); - self.push(Value::List(list)); - } + OpCode::OpList(Count(count)) => { + let list = + NixList::construct(count, self.stack.split_off(self.stack.len() - count)); + self.push(Value::List(list)); + } - OpCode::OpConcat => { - let rhs = fallible!(self, self.pop().to_list()); - let lhs = fallible!(self, self.pop().to_list()); - self.push(Value::List(lhs.concat(&rhs))) - } + OpCode::OpConcat => { + let rhs = fallible!(self, self.pop().to_list()); + let lhs = fallible!(self, self.pop().to_list()); + self.push(Value::List(lhs.concat(&rhs))) + } - OpCode::OpInterpolate(Count(count)) => self.run_interpolate(count)?, + OpCode::OpInterpolate(Count(count)) => self.run_interpolate(count)?, - OpCode::OpCoerceToString => { - // TODO: handle string context, copying to store - let string = fallible!( - self, - // note that coerce_to_string also forces - self.pop().coerce_to_string(CoercionKind::Weak, self) - ); - self.push(Value::String(string)); - } + OpCode::OpCoerceToString => { + // TODO: handle string context, copying to store + let string = fallible!( + self, + // note that coerce_to_string also forces + self.pop().coerce_to_string(CoercionKind::Weak, self) + ); + self.push(Value::String(string)); + } - OpCode::OpFindFile => { - let path = self.pop().to_str().map_err(|e| self.error(e))?; - let resolved = self.nix_path.resolve(path).map_err(|e| self.error(e))?; - self.push(resolved.into()); - } + OpCode::OpFindFile => { + let path = self.pop().to_str().map_err(|e| self.error(e))?; + let resolved = self.nix_path.resolve(path).map_err(|e| self.error(e))?; + self.push(resolved.into()); + } - OpCode::OpJump(JumpOffset(offset)) => { - debug_assert!(offset != 0); + OpCode::OpJump(JumpOffset(offset)) => { + debug_assert!(offset != 0); + self.frame_mut().ip += offset; + } + + OpCode::OpJumpIfTrue(JumpOffset(offset)) => { + debug_assert!(offset != 0); + if fallible!(self, self.peek(0).as_bool()) { self.frame_mut().ip += offset; } + } - OpCode::OpJumpIfTrue(JumpOffset(offset)) => { - debug_assert!(offset != 0); - if fallible!(self, self.peek(0).as_bool()) { - self.frame_mut().ip += offset; - } + OpCode::OpJumpIfFalse(JumpOffset(offset)) => { + debug_assert!(offset != 0); + if !fallible!(self, self.peek(0).as_bool()) { + self.frame_mut().ip += offset; } + } - OpCode::OpJumpIfFalse(JumpOffset(offset)) => { - debug_assert!(offset != 0); - if !fallible!(self, self.peek(0).as_bool()) { - self.frame_mut().ip += offset; - } + OpCode::OpJumpIfNotFound(JumpOffset(offset)) => { + debug_assert!(offset != 0); + if matches!(self.peek(0), Value::AttrNotFound) { + self.pop(); + self.frame_mut().ip += offset; } + } - OpCode::OpJumpIfNotFound(JumpOffset(offset)) => { - debug_assert!(offset != 0); - if matches!(self.peek(0), Value::AttrNotFound) { - self.pop(); - self.frame_mut().ip += offset; - } + // These assertion operations error out if the stack + // top is not of the expected type. This is necessary + // to implement some specific behaviours of Nix + // exactly. + OpCode::OpAssertBool => { + let val = self.peek(0); + if !val.is_bool() { + return Err(self.error(ErrorKind::TypeError { + expected: "bool", + actual: val.type_of(), + })); } + } - // These assertion operations error out if the stack - // top is not of the expected type. This is necessary - // to implement some specific behaviours of Nix - // exactly. - OpCode::OpAssertBool => { - let val = self.peek(0); - if !val.is_bool() { - return Err(self.error(ErrorKind::TypeError { - expected: "bool", - actual: val.type_of(), - })); - } - } + // Remove the given number of elements from the stack, + // but retain the top value. + OpCode::OpCloseScope(Count(count)) => { + // Immediately move the top value into the right + // position. + let target_idx = self.stack.len() - 1 - count; + self.stack[target_idx] = self.pop(); - // Remove the given number of elements from the stack, - // but retain the top value. - OpCode::OpCloseScope(Count(count)) => { - // Immediately move the top value into the right - // position. - let target_idx = self.stack.len() - 1 - count; - self.stack[target_idx] = self.pop(); - - // Then drop the remaining values. - for _ in 0..(count - 1) { - self.pop(); - } + // Then drop the remaining values. + for _ in 0..(count - 1) { + self.pop(); } + } - OpCode::OpGetLocal(StackIdx(local_idx)) => { - let idx = self.frame().stack_offset + local_idx; - self.push(self.stack[idx].clone()); - } + OpCode::OpGetLocal(StackIdx(local_idx)) => { + let idx = self.frame().stack_offset + local_idx; + self.push(self.stack[idx].clone()); + } - OpCode::OpPushWith(StackIdx(idx)) => { - self.with_stack.push(self.frame().stack_offset + idx) - } + OpCode::OpPushWith(StackIdx(idx)) => { + self.with_stack.push(self.frame().stack_offset + idx) + } - OpCode::OpPopWith => { - self.with_stack.pop(); - } + OpCode::OpPopWith => { + self.with_stack.pop(); + } - OpCode::OpResolveWith => { - let ident = fallible!(self, self.pop().to_str()); - let value = self.resolve_with(ident.as_str())?; - self.push(value) - } + OpCode::OpResolveWith => { + let ident = fallible!(self, self.pop().to_str()); + let value = self.resolve_with(ident.as_str())?; + self.push(value) + } - OpCode::OpResolveWithOrUpvalue(idx) => { - let ident = fallible!(self, self.pop().to_str()); - match self.resolve_with(ident.as_str()) { - // Variable found in local `with`-stack. - Ok(value) => self.push(value), - - // Variable not found => check upvalues. - Err(Error { - kind: ErrorKind::UnknownDynamicVariable(_), - .. - }) => { - let value = self.frame().upvalue(idx).clone(); - self.push(value); - } - - Err(err) => return Err(err), + OpCode::OpResolveWithOrUpvalue(idx) => { + let ident = fallible!(self, self.pop().to_str()); + match self.resolve_with(ident.as_str()) { + // Variable found in local `with`-stack. + Ok(value) => self.push(value), + + // Variable not found => check upvalues. + Err(Error { + kind: ErrorKind::UnknownDynamicVariable(_), + .. + }) => { + let value = self.frame().upvalue(idx).clone(); + self.push(value); } - } - OpCode::OpAssertFail => { - return Err(self.error(ErrorKind::AssertionFailed)); + Err(err) => return Err(err), } + } - OpCode::OpCall => { - let callable = self.pop(); - self.call_value(&callable)?; - } + OpCode::OpAssertFail => { + return Err(self.error(ErrorKind::AssertionFailed)); + } - OpCode::OpTailCall => { - let callable = self.pop(); - self.tail_call_value(callable)?; - } + OpCode::OpCall => { + let callable = self.pop(); + self.call_value(&callable)?; + } - OpCode::OpGetUpvalue(upv_idx) => { - let value = self.frame().upvalue(upv_idx).clone(); - self.push(value); - } + OpCode::OpTailCall => { + let callable = self.pop(); + self.tail_call_value(callable)?; + } - OpCode::OpClosure(idx) => { - let blueprint = match &self.chunk()[idx] { - Value::Blueprint(lambda) => lambda.clone(), - _ => panic!("compiler bug: non-blueprint in blueprint slot"), - }; - - let upvalue_count = blueprint.upvalue_count; - debug_assert!( - upvalue_count > 0, - "OpClosure should not be called for plain lambdas" - ); - - let closure = Closure::new(blueprint); - let upvalues = closure.upvalues_mut(); - self.push(Value::Closure(closure.clone())); - - // From this point on we internally mutate the - // closure object's upvalues. The closure is - // already in its stack slot, which means that it - // can capture itself as an upvalue for - // self-recursion. - self.populate_upvalues(upvalue_count, upvalues)?; - } + OpCode::OpGetUpvalue(upv_idx) => { + let value = self.frame().upvalue(upv_idx).clone(); + self.push(value); + } - OpCode::OpThunk(idx) => { - let blueprint = match &self.chunk()[idx] { - Value::Blueprint(lambda) => lambda.clone(), - _ => panic!("compiler bug: non-blueprint in blueprint slot"), - }; + OpCode::OpClosure(idx) => { + let blueprint = match &self.chunk()[idx] { + Value::Blueprint(lambda) => lambda.clone(), + _ => panic!("compiler bug: non-blueprint in blueprint slot"), + }; + + let upvalue_count = blueprint.upvalue_count; + debug_assert!( + upvalue_count > 0, + "OpClosure should not be called for plain lambdas" + ); + + let closure = Closure::new(blueprint); + let upvalues = closure.upvalues_mut(); + self.push(Value::Closure(closure.clone())); + + // From this point on we internally mutate the + // closure object's upvalues. The closure is + // already in its stack slot, which means that it + // can capture itself as an upvalue for + // self-recursion. + self.populate_upvalues(upvalue_count, upvalues)?; + } - let upvalue_count = blueprint.upvalue_count; - let thunk = Thunk::new(blueprint, self.current_span()); - let upvalues = thunk.upvalues_mut(); + OpCode::OpThunk(idx) => { + let blueprint = match &self.chunk()[idx] { + Value::Blueprint(lambda) => lambda.clone(), + _ => panic!("compiler bug: non-blueprint in blueprint slot"), + }; - self.push(Value::Thunk(thunk.clone())); - self.populate_upvalues(upvalue_count, upvalues)?; - } + let upvalue_count = blueprint.upvalue_count; + let thunk = Thunk::new(blueprint, self.current_span()); + let upvalues = thunk.upvalues_mut(); - OpCode::OpForce => { - let mut value = self.pop(); + self.push(Value::Thunk(thunk.clone())); + self.populate_upvalues(upvalue_count, upvalues)?; + } - if let Value::Thunk(thunk) = value { - fallible!(self, thunk.force(self)); - value = thunk.value().clone(); - } + OpCode::OpForce => { + let mut value = self.pop(); - self.push(value); + if let Value::Thunk(thunk) = value { + fallible!(self, thunk.force(self)); + value = thunk.value().clone(); } - OpCode::OpFinalise(StackIdx(idx)) => { - match &self.stack[self.frame().stack_offset + idx] { - Value::Closure(closure) => closure - .resolve_deferred_upvalues(&self.stack[self.frame().stack_offset..]), + self.push(value); + } - Value::Thunk(thunk) => thunk - .resolve_deferred_upvalues(&self.stack[self.frame().stack_offset..]), + OpCode::OpFinalise(StackIdx(idx)) => { + match &self.stack[self.frame().stack_offset + idx] { + Value::Closure(closure) => { + closure.resolve_deferred_upvalues(&self.stack[self.frame().stack_offset..]) + } - // In functions with "formals" attributes, it is - // possible for `OpFinalise` to be called on a - // non-capturing value, in which case it is a no-op. - // - // TODO: detect this in some phase and skip the finalise; fail here - _ => { /* TODO: panic here again to catch bugs */ } + Value::Thunk(thunk) => { + thunk.resolve_deferred_upvalues(&self.stack[self.frame().stack_offset..]) } - } - // Data-carrying operands should never be executed, - // that is a critical error in the VM. - OpCode::DataLocalIdx(_) - | OpCode::DataDeferredLocal(_) - | OpCode::DataUpvalueIdx(_) - | OpCode::DataCaptureWith => { - panic!("VM bug: attempted to execute data-carrying operand") + // In functions with "formals" attributes, it is + // possible for `OpFinalise` to be called on a + // non-capturing value, in which case it is a no-op. + // + // TODO: detect this in some phase and skip the finalise; fail here + _ => { /* TODO: panic here again to catch bugs */ } } } + + // Data-carrying operands should never be executed, + // that is a critical error in the VM. + OpCode::DataLocalIdx(_) + | OpCode::DataDeferredLocal(_) + | OpCode::DataUpvalueIdx(_) + | OpCode::DataCaptureWith => { + panic!("VM bug: attempted to execute data-carrying operand") + } } + + Ok(()) } fn run_attrset(&mut self, count: usize) -> EvalResult<()> { |