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// -*- coding: utf-8 -*-
// ------------------------------------------------------------------------------------------------
// Copyright © 2021, stack-graphs authors.
// Licensed under either of Apache License, Version 2.0, or MIT license, at your option.
// Please see the LICENSE-APACHE or LICENSE-MIT files in this distribution for license details.
// ------------------------------------------------------------------------------------------------
//! Defines a C API for working with stack graphs in other languages.
#![allow(non_camel_case_types)]
use std::convert::TryInto;
use std::sync::atomic::AtomicUsize;
use libc::c_char;
use crate::arena::Arena;
use crate::arena::Handle;
use crate::graph::File;
use crate::graph::InternedString;
use crate::graph::Node;
use crate::graph::NodeID;
use crate::graph::StackGraph;
use crate::graph::Symbol;
use crate::partial::PartialPath;
use crate::partial::PartialPathEdge;
use crate::partial::PartialPathEdgeList;
use crate::partial::PartialPaths;
use crate::partial::PartialScopeStack;
use crate::partial::PartialScopedSymbol;
use crate::partial::PartialSymbolStack;
use crate::stitching::Database;
use crate::stitching::ForwardPartialPathStitcher;
use crate::CancellationError;
use crate::CancellationFlag;
/// Contains all of the nodes and edges that make up a stack graph.
pub struct sg_stack_graph {
pub inner: StackGraph,
}
/// Creates a new, initially empty stack graph.
#[no_mangle]
pub extern "C" fn sg_stack_graph_new() -> *mut sg_stack_graph {
Box::into_raw(Box::new(sg_stack_graph {
inner: StackGraph::new(),
}))
}
/// Frees a stack graph, and all of its contents.
#[no_mangle]
pub extern "C" fn sg_stack_graph_free(graph: *mut sg_stack_graph) {
drop(unsafe { Box::from_raw(graph) })
}
/// Manages the state of a collection of partial paths to be used in the path-stitching algorithm.
pub struct sg_partial_path_arena {
pub inner: PartialPaths,
}
/// Creates a new, initially empty partial path arena.
#[no_mangle]
pub extern "C" fn sg_partial_path_arena_new() -> *mut sg_partial_path_arena {
Box::into_raw(Box::new(sg_partial_path_arena {
inner: PartialPaths::new(),
}))
}
/// Frees a path arena, and all of its contents.
#[no_mangle]
pub extern "C" fn sg_partial_path_arena_free(partials: *mut sg_partial_path_arena) {
drop(unsafe { Box::from_raw(partials) })
}
/// Contains a "database" of partial paths.
///
/// This type is meant to be a lazily loaded "view" into a proper storage layer. During the
/// path-stitching algorithm, we repeatedly try to extend a currently incomplete path with any
/// partial paths that are compatible with it. For large codebases, or projects with a large
/// number of dependencies, it can be prohibitive to load in _all_ of the partial paths up-front.
/// We've written the path-stitching algorithm so that you have a chance to only load in the
/// partial paths that are actually needed, placing them into a sg_partial_path_database instance
/// as they're needed.
pub struct sg_partial_path_database {
pub inner: Database,
}
/// Creates a new, initially empty partial path database.
#[no_mangle]
pub extern "C" fn sg_partial_path_database_new() -> *mut sg_partial_path_database {
Box::into_raw(Box::new(sg_partial_path_database {
inner: Database::new(),
}))
}
/// Frees a partial path database, and all of its contents.
#[no_mangle]
pub extern "C" fn sg_partial_path_database_free(db: *mut sg_partial_path_database) {
drop(unsafe { Box::from_raw(db) })
}
/// The null value for all of our handles.
pub const SG_NULL_HANDLE: u32 = 0;
/// The handle of an empty list.
pub const SG_LIST_EMPTY_HANDLE: u32 = 0xffffffff;
/// Describes in which direction the content of a deque is stored in memory.
#[repr(C)]
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum sg_deque_direction {
SG_DEQUE_FORWARDS,
SG_DEQUE_BACKWARDS,
}
impl Default for sg_deque_direction {
fn default() -> sg_deque_direction {
sg_deque_direction::SG_DEQUE_FORWARDS
}
}
/// Ensures all partial paths in the database are availabe in both forwards and backwards orientation.
#[no_mangle]
pub extern "C" fn sg_partial_path_database_ensure_both_directions(
db: *mut sg_partial_path_database,
partials: *mut sg_partial_path_arena,
) {
let db = unsafe { &mut (*db).inner };
let partials = unsafe { &mut (*partials).inner };
db.ensure_both_directions(partials);
}
/// Ensures all partial paths in the database are in forwards orientation.
#[no_mangle]
pub extern "C" fn sg_partial_path_database_ensure_forwards(
db: *mut sg_partial_path_database,
partials: *mut sg_partial_path_arena,
) {
let db = unsafe { &mut (*db).inner };
let partials = unsafe { &mut (*partials).inner };
db.ensure_forwards(partials);
}
//-------------------------------------------------------------------------------------------------
// Symbols
/// A name that we are trying to resolve using stack graphs.
///
/// This typically represents a portion of an identifier as it appears in the source language. It
/// can also represent some other "operation" that can occur in source code, and which needs to be
/// modeled in a stack graph — for instance, many languages will use a "fake" symbol named `.` to
/// represent member access.
#[repr(C)]
pub struct sg_symbol {
pub symbol: *const c_char,
pub symbol_len: usize,
}
/// A handle to a symbol in a stack graph. A zero handle represents a missing symbol.
///
/// We deduplicate symbols in a stack graph — that is, we ensure that there are never multiple
/// `struct sg_symbol` instances with the same content. That means that you can compare symbol
/// handles using simple equality, without having to dereference them.
pub type sg_symbol_handle = u32;
/// An array of all of the symbols in a stack graph. Symbol handles are indices into this array.
/// There will never be a valid symbol at index 0; a handle with the value 0 represents a missing
/// symbol.
#[repr(C)]
pub struct sg_symbols {
pub symbols: *const sg_symbol,
pub count: usize,
}
/// Returns a reference to the array of symbol data in this stack graph. The resulting array
/// pointer is only valid until the next call to any function that mutates the stack graph.
#[no_mangle]
pub extern "C" fn sg_stack_graph_symbols(graph: *const sg_stack_graph) -> sg_symbols {
let graph = unsafe { &(*graph).inner };
sg_symbols {
symbols: graph.symbols.as_ptr() as *const sg_symbol,
count: graph.symbols.len(),
}
}
/// Adds new symbols to the stack graph. You provide all of the symbol content concatenated
/// together into a single string, and an array of the lengths of each symbol. You also provide an
/// output array, which must have the same size as `lengths`. We will place each symbol's handle
/// in the output array.
///
/// We ensure that there is only ever one copy of a particular symbol stored in the graph — we
/// guarantee that identical symbols will have the same handles, meaning that you can compare the
/// handles using simple integer equality.
///
/// We copy the symbol data into the stack graph. The symbol content you pass in does not need to
/// outlive the call to this function.
///
/// Each symbol must be a valid UTF-8 string. If any symbol isn't valid UTF-8, it won't be added
/// to the stack graph, and the corresponding entry in the output array will be the null handle.
#[no_mangle]
pub extern "C" fn sg_stack_graph_add_symbols(
graph: *mut sg_stack_graph,
count: usize,
symbols: *const c_char,
lengths: *const usize,
handles_out: *mut sg_symbol_handle,
) {
let graph = unsafe { &mut (*graph).inner };
let mut symbols = symbols as *const u8;
let lengths = unsafe { std::slice::from_raw_parts(lengths, count) };
let handles_out = unsafe {
std::slice::from_raw_parts_mut(handles_out as *mut Option<Handle<Symbol>>, count)
};
for i in 0..count {
let symbol = unsafe { std::slice::from_raw_parts(symbols, lengths[i]) };
handles_out[i] = match std::str::from_utf8(symbol) {
Ok(symbol) => Some(graph.add_symbol(symbol)),
Err(_) => None,
};
unsafe { symbols = symbols.add(lengths[i]) };
}
}
//-------------------------------------------------------------------------------------------------
// Interned strings
/// Arbitrary string content associated with some part of a stack graph.
#[repr(C)]
pub struct sg_string {
pub content: *const c_char,
pub length: usize,
}
/// A handle to an interned string in a stack graph. A zero handle represents a missing string.
///
/// We deduplicate strings in a stack graph — that is, we ensure that there are never multiple
/// `struct sg_string` instances with the same content. That means that you can compare string
/// handles using simple equality, without having to dereference them.
pub type sg_string_handle = u32;
/// An array of all of the interned strings in a stack graph. String handles are indices into this
/// array. There will never be a valid string at index 0; a handle with the value 0 represents a
/// missing string.
#[repr(C)]
pub struct sg_strings {
pub strings: *const sg_string,
pub count: usize,
}
/// Returns a reference to the array of string data in this stack graph. The resulting array
/// pointer is only valid until the next call to any function that mutates the stack graph.
#[no_mangle]
pub extern "C" fn sg_stack_graph_strings(graph: *const sg_stack_graph) -> sg_strings {
let graph = unsafe { &(*graph).inner };
sg_strings {
strings: graph.strings.as_ptr() as *const sg_string,
count: graph.strings.len(),
}
}
/// Adds new strings to the stack graph. You provide all of the string content concatenated
/// together into a single string, and an array of the lengths of each string. You also provide an
/// output array, which must have the same size as `lengths`. We will place each string's handle
/// in the output array.
///
/// We ensure that there is only ever one copy of a particular string stored in the graph — we
/// guarantee that identical strings will have the same handles, meaning that you can compare the
/// handles using simple integer equality.
///
/// We copy the string data into the stack graph. The string content you pass in does not need to
/// outlive the call to this function.
///
/// Each string must be a valid UTF-8 string. If any string isn't valid UTF-8, it won't be added
/// to the stack graph, and the corresponding entry in the output array will be the null handle.
#[no_mangle]
pub extern "C" fn sg_stack_graph_add_strings(
graph: *mut sg_stack_graph,
count: usize,
strings: *const c_char,
lengths: *const usize,
handles_out: *mut sg_string_handle,
) {
let graph = unsafe { &mut (*graph).inner };
let mut strings = strings as *const u8;
let lengths = unsafe { std::slice::from_raw_parts(lengths, count) };
let handles_out = unsafe {
std::slice::from_raw_parts_mut(handles_out as *mut Option<Handle<InternedString>>, count)
};
for i in 0..count {
let string = unsafe { std::slice::from_raw_parts(strings, lengths[i]) };
handles_out[i] = match std::str::from_utf8(string) {
Ok(string) => Some(graph.add_string(string)),
Err(_) => None,
};
unsafe { strings = strings.add(lengths[i]) };
}
}
//-------------------------------------------------------------------------------------------------
// Files
/// A source file that we have extracted stack graph data from.
///
/// It's up to you to choose what names to use for your files, but they must be unique within a
/// stack graph. If you are analyzing files from the local filesystem, the file's path is a good
/// choice. If your files belong to packages or repositories, they should include the package or
/// repository IDs to make sure that files in different packages or repositories don't clash with
/// each other.
#[repr(C)]
pub struct sg_file {
pub name: *const c_char,
pub name_len: usize,
}
/// A handle to a file in a stack graph. A zero handle represents a missing file.
///
/// We deduplicate files in a stack graph — that is, we ensure that there are never multiple
/// `struct sg_file` instances with the same filename. That means that you can compare file
/// handles using simple equality, without having to dereference them.
pub type sg_file_handle = u32;
impl Into<Handle<File>> for sg_file_handle {
fn into(self) -> Handle<File> {
unsafe { std::mem::transmute(self) }
}
}
/// An array of all of the files in a stack graph. File handles are indices into this array.
/// There will never be a valid file at index 0; a handle with the value 0 represents a missing
/// file.
#[repr(C)]
pub struct sg_files {
pub files: *const sg_file,
pub count: usize,
}
/// Returns a reference to the array of file data in this stack graph. The resulting array pointer
/// is only valid until the next call to any function that mutates the stack graph.
#[no_mangle]
pub extern "C" fn sg_stack_graph_files(graph: *const sg_stack_graph) -> sg_files {
let graph = unsafe { &(*graph).inner };
sg_files {
files: graph.files.as_ptr() as *const sg_file,
count: graph.files.len(),
}
}
/// Adds new files to the stack graph. You provide all of the file content concatenated together
/// into a single string, and an array of the lengths of each file. You also provide an output
/// array, which must have the same size as `lengths`. We will place each file's handle in the
/// output array.
///
/// There can only ever be one file with a particular name in the graph. If you try to add a file
/// with a name that already exists, you'll get the same handle as a result.
///
/// We copy the filenames into the stack graph. The filenames you pass in do not need to outlive
/// the call to this function.
///
/// Each filename must be a valid UTF-8 string. If any filename isn't valid UTF-8, it won't be
/// added to the stack graph, and the corresponding entry in the output array will be the null
/// handle.
#[no_mangle]
pub extern "C" fn sg_stack_graph_add_files(
graph: *mut sg_stack_graph,
count: usize,
files: *const c_char,
lengths: *const usize,
handles_out: *mut sg_file_handle,
) {
let graph = unsafe { &mut (*graph).inner };
let mut files = files as *const u8;
let lengths = unsafe { std::slice::from_raw_parts(lengths, count) };
let handles_out =
unsafe { std::slice::from_raw_parts_mut(handles_out as *mut Option<Handle<File>>, count) };
for i in 0..count {
let file = unsafe { std::slice::from_raw_parts(files, lengths[i]) };
handles_out[i] = match std::str::from_utf8(file) {
Ok(file) => Some(graph.get_or_create_file(file)),
Err(_) => None,
};
unsafe { files = files.add(lengths[i]) };
}
}
//-------------------------------------------------------------------------------------------------
// Nodes
/// Uniquely identifies a node in a stack graph.
///
/// Each node (except for the _root node_ and _jump to scope_ node) lives in a file, and has a
/// _local ID_ that must be unique within its file.
#[repr(C)]
#[derive(Clone, Copy, Default, Eq, PartialEq)]
pub struct sg_node_id {
pub file: sg_file_handle,
pub local_id: u32,
}
impl sg_node_id {
fn is_empty(self) -> bool {
self.file == 0 && self.local_id == 0
}
}
impl Into<NodeID> for sg_node_id {
fn into(self) -> NodeID {
unsafe { std::mem::transmute(self) }
}
}
/// The local_id of the singleton root node.
pub const SG_ROOT_NODE_ID: u32 = 1;
/// The local_id of the singleton "jump to scope" node.
pub const SG_JUMP_TO_NODE_ID: u32 = 2;
/// A node in a stack graph.
#[repr(C)]
#[derive(Clone)]
pub struct sg_node {
pub kind: sg_node_kind,
pub id: sg_node_id,
/// The symbol associated with this node. For push nodes, this is the symbol that will be
/// pushed onto the symbol stack. For pop nodes, this is the symbol that we expect to pop off
/// the symbol stack. For all other node types, this will be null.
pub symbol: sg_symbol_handle,
/// The scope associated with this node. For push scope nodes, this is the scope that will be
/// attached to the symbol before it's pushed onto the symbol stack. For all other node types,
/// this will be null.
pub scope: sg_node_id,
/// Whether this node is an endpoint. For push nodes, this indicates that the node represents
/// a reference in the source. For pop nodes, this indicates that the node represents a
/// definition in the source. For scopes, this indicates that the scope is exported. For all
/// other node types, this field will be unused.
pub is_endpoint: bool,
}
impl Into<Node> for sg_node {
fn into(self) -> Node {
unsafe { std::mem::transmute(self) }
}
}
/// The different kinds of node that can appear in a stack graph.
#[repr(C)]
#[derive(Clone, Copy)]
pub enum sg_node_kind {
/// Removes everything from the current scope stack.
SG_NODE_KIND_DROP_SCOPES,
/// The singleton "jump to" node, which allows a name binding path to jump back to another part
/// of the graph.
SG_NODE_KIND_JUMP_TO,
/// Pops a scoped symbol from the symbol stack. If the top of the symbol stack doesn't match
/// the requested symbol, or if the top of the symbol stack doesn't have an attached scope
/// list, then the path is not allowed to enter this node.
SG_NODE_KIND_POP_SCOPED_SYMBOL,
/// Pops a symbol from the symbol stack. If the top of the symbol stack doesn't match the
/// requested symbol, then the path is not allowed to enter this node.
SG_NODE_KIND_POP_SYMBOL,
/// Pushes a scoped symbol onto the symbol stack.
SG_NODE_KIND_PUSH_SCOPED_SYMBOL,
/// Pushes a symbol onto the symbol stack.
SG_NODE_KIND_PUSH_SYMBOL,
/// The singleton root node, which allows a name binding path to cross between files.
SG_NODE_KIND_ROOT,
/// A node that adds structure to the graph. If the node is exported, it can be
/// referred to on the scope stack, which allows "jump to" nodes in any other
/// part of the graph can jump back here.
SG_NODE_KIND_SCOPE,
}
/// A handle to a node in a stack graph. A zero handle represents a missing node.
pub type sg_node_handle = u32;
impl Into<Handle<Node>> for sg_node_handle {
fn into(self) -> Handle<Node> {
unsafe { std::mem::transmute(self) }
}
}
/// The handle of the singleton root node.
pub const SG_ROOT_NODE_HANDLE: sg_node_handle = 1;
/// The handle of the singleton "jump to scope" node.
pub const SG_JUMP_TO_NODE_HANDLE: sg_node_handle = 2;
/// An array of all of the nodes in a stack graph. Node handles are indices into this array.
/// There will never be a valid node at index 0; a handle with the value 0 represents a missing
/// node.
#[repr(C)]
pub struct sg_nodes {
pub nodes: *const sg_node,
pub count: usize,
}
/// Returns a reference to the array of nodes in this stack graph. The resulting array pointer is
/// only valid until the next call to any function that mutates the stack graph.
#[no_mangle]
pub extern "C" fn sg_stack_graph_nodes(graph: *const sg_stack_graph) -> sg_nodes {
let graph = unsafe { &(*graph).inner };
sg_nodes {
nodes: graph.nodes.as_ptr() as *const sg_node,
count: graph.nodes.len(),
}
}
/// Adds new nodes to the stack graph. You provide an array of `struct sg_node` instances. You
/// also provide an output array, which must have the same length as `nodes`, in which we will
/// place each node's handle in the stack graph.
///
/// We copy the node content into the stack graph. The array you pass in does not need to outlive
/// the call to this function.
///
/// You cannot add new instances of the root node or "jump to scope" node, since those are
/// singletons and already exist in the stack graph.
///
/// If you try to add a new node that has the same ID as an existing node in the stack graph, the
/// new node will be ignored, and the corresponding entry in the `handles_out` array will contain
/// the handle of the _existing_ node with that ID.
///
/// If any node that you pass in is invalid, it will not be added to the graph, and the
/// corresponding entry in the `handles_out` array will be null.
#[no_mangle]
pub extern "C" fn sg_stack_graph_get_or_create_nodes(
graph: *mut sg_stack_graph,
count: usize,
nodes: *const sg_node,
handles_out: *mut sg_node_handle,
) {
let graph = unsafe { &mut (*graph).inner };
let nodes = unsafe { std::slice::from_raw_parts(nodes, count) };
let handles_out =
unsafe { std::slice::from_raw_parts_mut(handles_out as *mut Option<Handle<Node>>, count) };
for i in 0..count {
let node_id = nodes[i].id;
handles_out[i] = validate_node(graph, &nodes[i])
.map(|node| graph.get_or_create_node(node_id.into(), node));
}
}
fn validate_node_id(graph: &StackGraph, node_id: sg_node_id) -> Option<()> {
if node_id.file == 0 || node_id.file >= (graph.files.len() as u32) {
return None;
}
Some(())
}
fn validate_node(graph: &StackGraph, node: &sg_node) -> Option<Node> {
if matches!(
&node.kind,
sg_node_kind::SG_NODE_KIND_JUMP_TO | sg_node_kind::SG_NODE_KIND_ROOT
) {
// You can never add a singleton node, since there already is one!
return None;
}
// Every node must have a valid ID, which refers to an existing file.
validate_node_id(graph, node.id)?;
// Push and pop nodes must have a non-null symbol, and all other nodes must have a null symbol.
if (node.symbol != 0)
!= matches!(
&node.kind,
sg_node_kind::SG_NODE_KIND_POP_SCOPED_SYMBOL
| sg_node_kind::SG_NODE_KIND_POP_SYMBOL
| sg_node_kind::SG_NODE_KIND_PUSH_SCOPED_SYMBOL
| sg_node_kind::SG_NODE_KIND_PUSH_SYMBOL
)
{
return None;
}
// Push scoped symbol nodes must have a non-null scope, and all other nodes must have a null
// scope.
if (node.scope.is_empty())
== matches!(&node.kind, sg_node_kind::SG_NODE_KIND_PUSH_SCOPED_SYMBOL)
{
return None;
}
Some(node.clone().into())
}
//-------------------------------------------------------------------------------------------------
// Edges
/// Connects two nodes in a stack graph.
///
/// These edges provide the basic graph connectivity that allow us to search for name binding paths
/// in a stack graph. (Though not all sequence of edges is a well-formed name binding: the nodes
/// that you encounter along the path must also satisfy all of the rules for maintaining correct
/// symbol and scope stacks.)
#[repr(C)]
pub struct sg_edge {
pub source: sg_node_handle,
pub sink: sg_node_handle,
pub precedence: i32,
}
/// Adds new edges to the stack graph. You provide an array of `struct sg_edges` instances. A
/// stack graph can contain at most one edge between any two nodes. It is not an error if you try
/// to add an edge that already exists, but it won't have any effect on the graph.
#[no_mangle]
pub extern "C" fn sg_stack_graph_add_edges(
graph: *mut sg_stack_graph,
count: usize,
edges: *const sg_edge,
) {
let graph = unsafe { &mut (*graph).inner };
let edges = unsafe { std::slice::from_raw_parts(edges, count) };
for i in 0..count {
let source = unsafe { std::mem::transmute(edges[i].source) };
let sink = unsafe { std::mem::transmute(edges[i].sink) };
graph.add_edge(source, sink, edges[i].precedence);
}
}
//-------------------------------------------------------------------------------------------------
// Source info
/// Contains information about a range of code in a source code file.
#[repr(C)]
#[derive(Clone, Copy, Default)]
pub struct sg_source_info {
/// The location in its containing file of the source code that this node represents.
pub span: sg_span,
/// The kind of syntax entity this node represents (e.g. `function`, `class`, `method`, etc.).
pub syntax_type: sg_string_handle,
/// The full content of the line containing this node in its source file.
pub containing_line: sg_string_handle,
/// The location in its containing file of the source code that this node's definiens represents.
/// This is used for things like the bodies of functions, rather than the RHSes of equations.
/// If you need one of these to make the type checker happy, but you don't have one, just use
/// sg_span::default(), as this will correspond to the all-0s spans which mean "no definiens".
pub definiens_span: sg_span,
}
/// All of the position information that we have about a range of content in a source file
#[repr(C)]
#[derive(Clone, Copy, Default)]
pub struct sg_span {
pub start: sg_position,
pub end: sg_position,
}
/// All of the position information that we have about a character in a source file
#[repr(C)]
#[derive(Clone, Copy, Default)]
pub struct sg_position {
/// The 0-indexed line number containing the character
pub line: usize,
/// The offset of the character within its containing line, expressed as both a UTF-8 byte
/// index and a UTF-16 code point index
pub column: sg_offset,
/// The UTF-8 byte indexes (within the file) of the start and end of the line containing the
/// character
pub containing_line: sg_utf8_bounds,
/// The UTF-8 byte indexes (within the file) of the start and end of the line containing the
/// character, with any leading and trailing whitespace removed
pub trimmed_line: sg_utf8_bounds,
}
/// The offset of a character within a string (typically a line of source code), using several
/// different units
///
/// All offsets are 0-indexed.
#[repr(C)]
#[derive(Clone, Copy, Default)]
pub struct sg_offset {
/// The number of UTF-8-encoded bytes appearing before this character in the string
pub utf8_offset: usize,
/// The number of UTF-16 code units appearing before this character in the string
pub utf16_offset: usize,
/// The number of graphemes appearing before this character in the string
pub grapheme_offset: usize,
}
/// A half-open range identifying a range of characters in a string.
#[repr(C)]
#[derive(Clone, Copy, Default)]
pub struct sg_utf8_bounds {
/// The UTF-8 byte index of the first character in the range.
pub start: usize,
/// The UTF-8 byte index of the first character _after_ the range.
pub end: usize,
}
/// An array of all of the source information in a stack graph. Source information is associated
/// with nodes, so node handles are indices into this array. It is _not_ guaranteed that there
/// will an entry in this array for every node handle; if you have a node handle whose value is
/// larger than `count`, then use a 0-valued `sg_source_info` if you need source information for
/// that node.
///
/// There will never be a valid entry at index 0; a handle with the value 0 represents a missing
/// node.
#[repr(C)]
pub struct sg_source_infos {
pub infos: *const sg_source_info,
pub count: usize,
}
/// Returns a reference to the array of source information in this stack graph. The resulting
/// array pointer is only valid until the next call to any function that mutates the stack graph.
#[no_mangle]
pub extern "C" fn sg_stack_graph_source_infos(graph: *const sg_stack_graph) -> sg_source_infos {
let graph = unsafe { &(*graph).inner };
sg_source_infos {
infos: graph.source_info.as_ptr() as *const sg_source_info,
count: graph.source_info.len(),
}
}
/// A tuple of a node handle and source information for that node. Used with the
/// `sg_add_source_info` function to add source information to a stack graph.
#[repr(C)]
#[derive(Clone, Copy)]
pub struct sg_node_source_info {
pub node: sg_node_handle,
pub source_info: sg_source_info,
}
/// Adds new source information to the stack graph. You provide an array of `sg_node_source_info`
/// instances. Any existing source information for any node mentioned in the array is overwritten.
#[no_mangle]
pub extern "C" fn sg_stack_graph_add_source_infos(
graph: *mut sg_stack_graph,
count: usize,
infos: *const sg_node_source_info,
) {
let graph = unsafe { &mut (*graph).inner };
let infos = unsafe { std::slice::from_raw_parts(infos, count) };
for i in 0..count {
let node = unsafe { std::mem::transmute(infos[i].node) };
let info = graph.source_info_mut(node);
*info = unsafe { std::mem::transmute(infos[i].source_info) };
}
}
//-------------------------------------------------------------------------------------------------
// Partial symbol stacks
/// Represents an unknown list of scoped symbols.
pub type sg_symbol_stack_variable = u32;
/// A symbol with an unknown, but possibly empty, list of exported scopes attached to it.
#[repr(C)]
#[derive(Clone, Copy, Eq, PartialEq)]
pub struct sg_partial_scoped_symbol {
pub symbol: sg_symbol_handle,
pub scopes: sg_partial_scope_stack,
}
impl Into<PartialScopedSymbol> for sg_partial_scoped_symbol {
fn into(self) -> PartialScopedSymbol {
unsafe { std::mem::transmute(self) }
}
}
/// A pattern that might match against a symbol stack. Consists of a (possibly empty) list of
/// partial scoped symbols.
///
/// (Note that unlike partial scope stacks, we don't store any "symbol stack variable" here. We
/// could! But with our current path-finding rules, every partial path will always have exactly
/// one symbol stack variable, which will appear at the end of its precondition and postcondition.
/// So for simplicity we just leave it out. At some point in the future we might add it in so that
/// the symbol and scope stack formalisms and implementations are more obviously symmetric.)
#[repr(C)]
#[derive(Clone, Copy, Default, Eq, PartialEq)]
pub struct sg_partial_symbol_stack {
/// The handle of the first element in the partial symbol stack, or SG_LIST_EMPTY_HANDLE if the
/// list is empty, or 0 if the list is null.
pub cells: sg_partial_symbol_stack_cell_handle,
pub length: u32,
/// The symbol stack variable representing the unknown content of a partial symbol stack, or 0
/// if the variable is missing. (If so, this partial symbol stack can only match a symbol
/// stack with exactly the list of symbols in `cells`, instead of any symbol stack with those
/// symbols as a prefix.)
pub variable: sg_symbol_stack_variable,
}
impl From<PartialSymbolStack> for sg_partial_symbol_stack {
fn from(stack: PartialSymbolStack) -> sg_partial_symbol_stack {
unsafe { std::mem::transmute(stack) }
}
}
/// A handle to an element of a partial symbol stack. A zero handle represents a missing partial
/// symbol stack. A UINT32_MAX handle represents an empty partial symbol stack.
pub type sg_partial_symbol_stack_cell_handle = u32;
/// An element of a partial symbol stack.
#[repr(C)]
pub struct sg_partial_symbol_stack_cell {
/// The partial scoped symbol at this position in the partial symbol stack.
pub head: sg_partial_scoped_symbol,
/// The handle of the next element in the partial symbol stack, or SG_LIST_EMPTY_HANDLE if this
/// is the last element.
pub tail: sg_partial_symbol_stack_cell_handle,
/// The handle of the reversal of this partial scope stack.
pub reversed: sg_partial_symbol_stack_cell_handle,
}
/// The array of all of the partial symbol stack content in a partial path arena.
#[repr(C)]
pub struct sg_partial_symbol_stack_cells {
pub cells: *const sg_partial_symbol_stack_cell,
pub count: usize,
}
/// Returns a reference to the array of partial symbol stack content in a partial path arena. The
/// resulting array pointer is only valid until the next call to any function that mutates the path
/// arena.
#[no_mangle]
pub extern "C" fn sg_partial_path_arena_partial_symbol_stack_cells(
partials: *const sg_partial_path_arena,
) -> sg_partial_symbol_stack_cells {
let partials = unsafe { &(*partials).inner };
sg_partial_symbol_stack_cells {
cells: partials.partial_symbol_stacks.as_ptr() as *const sg_partial_symbol_stack_cell,
count: partials.partial_symbol_stacks.len(),
}
}
/// Adds new partial symbol stacks to the partial path arena. `count` is the number of partial
/// symbol stacks you want to create. The content of each partial symbol stack comes from two
/// arrays. The `lengths` array must have `count` elements, and provides the number of symbols in
/// each partial symbol stack. The `symbols` array contains the contents of each of these partial
/// symbol stacks in one contiguous array. Its length must be the sum of all of the counts in the
/// `lengths` array. The `variables` array must have `count` elements, and provides the optional
/// symbol stack variable for each partial symbol stack.
///
/// You must also provide an `out` array, which must also have room for `count` elements. We will
/// fill this array in with the `sg_partial_symbol_stack` instances for each partial symbol stack
/// that is created.
#[no_mangle]
pub extern "C" fn sg_partial_path_arena_add_partial_symbol_stacks(
partials: *mut sg_partial_path_arena,
count: usize,
mut symbols: *const sg_partial_scoped_symbol,
lengths: *const usize,
variables: *const sg_symbol_stack_variable,
out: *mut sg_partial_symbol_stack,
) {
let partials = unsafe { &mut (*partials).inner };
let lengths = unsafe { std::slice::from_raw_parts(lengths, count) };
let variables = unsafe { std::slice::from_raw_parts(variables, count) };
let out = unsafe { std::slice::from_raw_parts_mut(out, count) };
for i in 0..count {
let length = lengths[i];
let symbols_slice = unsafe { std::slice::from_raw_parts(symbols, length) };
let mut stack = if variables[i] == 0 {
PartialSymbolStack::empty()
} else {
PartialSymbolStack::from_variable(variables[i].try_into().unwrap())
};
for j in (0..length).rev() {
let symbol = symbols_slice[j].into();
stack.push_front(partials, symbol);
}
// We ensure that the list will also be available in reverse order.
stack.ensure_both_directions(partials);
out[i] = stack.into();
unsafe { symbols = symbols.add(length) };
}
}
//-------------------------------------------------------------------------------------------------
// Partial scope stacks
/// Represents an unknown list of exported scopes.
pub type sg_scope_stack_variable = u32;
/// A pattern that might match against a scope stack. Consists of a (possibly empty) list of
/// exported scopes, along with an optional scope stack variable.
#[repr(C)]
#[derive(Clone, Copy, Default, Eq, PartialEq)]
pub struct sg_partial_scope_stack {
/// The handle of the first element in the partial scope stack, or SG_LIST_EMPTY_HANDLE if the
/// list is empty, or 0 if the list is null.
pub cells: sg_partial_scope_stack_cell_handle,
pub length: u32,
/// The scope stack variable representing the unknown content of a partial scope stack, or 0 if
/// the variable is missing. (If so, this partial scope stack can only match a scope stack
/// with exactly the list of scopes in `cells`, instead of any scope stack with those scopes as
/// a prefix.)
pub variable: sg_scope_stack_variable,
}
impl From<PartialScopeStack> for sg_partial_scope_stack {
fn from(stack: PartialScopeStack) -> sg_partial_scope_stack {
unsafe { std::mem::transmute(stack) }
}
}
/// A handle to an element of a partial scope stack. A zero handle represents a missing partial
/// scope stack. A UINT32_MAX handle represents an empty partial scope stack.
pub type sg_partial_scope_stack_cell_handle = u32;
/// An element of a partial scope stack.
#[repr(C)]
pub struct sg_partial_scope_stack_cell {
/// The exported scope at this position in the partial scope stack.
pub head: sg_node_handle,
/// The handle of the next element in the partial scope stack, or SG_LIST_EMPTY_HANDLE if this
/// is the last element.
pub tail: sg_partial_scope_stack_cell_handle,
/// The handle of the reversal of this partial scope stack.
pub reversed: sg_partial_scope_stack_cell_handle,
}
/// The array of all of the partial scope stack content in a partial path arena.
#[repr(C)]
pub struct sg_partial_scope_stack_cells {
pub cells: *const sg_partial_scope_stack_cell,
pub count: usize,
}
/// Returns a reference to the array of partial scope stack content in a partial path arena. The
/// resulting array pointer is only valid until the next call to any function that mutates the
/// partial path arena.
#[no_mangle]
pub extern "C" fn sg_partial_path_arena_partial_scope_stack_cells(
partials: *const sg_partial_path_arena,
) -> sg_partial_scope_stack_cells {
let partials = unsafe { &(*partials).inner };
sg_partial_scope_stack_cells {
cells: partials.partial_scope_stacks.as_ptr() as *const sg_partial_scope_stack_cell,
count: partials.partial_scope_stacks.len(),
}
}
/// Adds new partial scope stacks to the partial path arena. `count` is the number of partial
/// scope stacks you want to create. The content of each partial scope stack comes from three
/// arrays. The `lengths` array must have `count` elements, and provides the number of scopes in
/// each scope stack. The `scopes` array contains the contents of each of these scope stacks in
/// one contiguous array. Its length must be the sum of all of the counts in the `lengths` array.
/// The `variables` array must have `count` elements, and provides the optional scope stack
/// variable for each partial scope stack.
///
/// You must also provide an `out` array, which must also have room for `count` elements. We will
/// fill this array in with the `sg_partial_scope_stack` instances for each partial scope stack
/// that is created.
#[no_mangle]
pub extern "C" fn sg_partial_path_arena_add_partial_scope_stacks(
partials: *mut sg_partial_path_arena,
count: usize,
mut scopes: *const sg_node_handle,
lengths: *const usize,
variables: *const sg_scope_stack_variable,
out: *mut sg_partial_scope_stack,
) {
let partials = unsafe { &mut (*partials).inner };
let lengths = unsafe { std::slice::from_raw_parts(lengths, count) };
let variables = unsafe { std::slice::from_raw_parts(variables, count) };
let out = unsafe { std::slice::from_raw_parts_mut(out, count) };
for i in 0..count {
let length = lengths[i];
let scopes_slice = unsafe { std::slice::from_raw_parts(scopes, length) };
let mut stack = if variables[i] == 0 {
PartialScopeStack::empty()
} else {
PartialScopeStack::from_variable(variables[i].try_into().unwrap())
};
for j in (0..length).rev() {
let node = scopes_slice[j].into();
stack.push_front(partials, node);
}
// We ensure that the list will also be available in reverse order.
stack.ensure_both_directions(partials);
out[i] = stack.into();
unsafe { scopes = scopes.add(length) };
}
}
//-------------------------------------------------------------------------------------------------
// Partial edge lists
/// Details about one of the edges in a partial path
#[repr(C)]
#[derive(Clone, Copy, Eq, PartialEq)]
pub struct sg_partial_path_edge {
pub source_node_id: sg_node_id,
pub precedence: i32,
}
impl Into<PartialPathEdge> for sg_partial_path_edge {
fn into(self) -> PartialPathEdge {
unsafe { std::mem::transmute(self) }
}
}
/// The edges in a path keep track of precedence information so that we can correctly handle
/// shadowed definitions.
#[repr(C)]
#[derive(Clone, Copy, Default, Eq, PartialEq)]
pub struct sg_partial_path_edge_list {
/// The handle of the first element in the edge list, or SG_LIST_EMPTY_HANDLE if the list is
/// empty, or 0 if the list is null.
pub cells: sg_partial_path_edge_list_cell_handle,