zig/lib/fuzzer/web/main.zig

456 lines
17 KiB
Zig

const std = @import("std");
const assert = std.debug.assert;
const abi = std.Build.Fuzz.abi;
const gpa = std.heap.wasm_allocator;
const log = std.log;
const Coverage = std.debug.Coverage;
const Allocator = std.mem.Allocator;
const Walk = @import("Walk");
const Decl = Walk.Decl;
const html_render = @import("html_render");
/// Nanoseconds.
var server_base_timestamp: i64 = 0;
/// Milliseconds.
var client_base_timestamp: i64 = 0;
/// Relative to `server_base_timestamp`.
var start_fuzzing_timestamp: i64 = undefined;
const js = struct {
extern "js" fn log(ptr: [*]const u8, len: usize) void;
extern "js" fn panic(ptr: [*]const u8, len: usize) noreturn;
extern "js" fn timestamp() i64;
extern "js" fn emitSourceIndexChange() void;
extern "js" fn emitCoverageUpdate() void;
extern "js" fn emitEntryPointsUpdate() void;
};
pub const std_options: std.Options = .{
.logFn = logFn,
};
pub fn panic(msg: []const u8, st: ?*std.builtin.StackTrace, addr: ?usize) noreturn {
_ = st;
_ = addr;
log.err("panic: {s}", .{msg});
@trap();
}
fn logFn(
comptime message_level: log.Level,
comptime scope: @TypeOf(.enum_literal),
comptime format: []const u8,
args: anytype,
) void {
const level_txt = comptime message_level.asText();
const prefix2 = if (scope == .default) ": " else "(" ++ @tagName(scope) ++ "): ";
var buf: [500]u8 = undefined;
const line = std.fmt.bufPrint(&buf, level_txt ++ prefix2 ++ format, args) catch l: {
buf[buf.len - 3 ..][0..3].* = "...".*;
break :l &buf;
};
js.log(line.ptr, line.len);
}
export fn alloc(n: usize) [*]u8 {
const slice = gpa.alloc(u8, n) catch @panic("OOM");
return slice.ptr;
}
var message_buffer: std.ArrayListAlignedUnmanaged(u8, @alignOf(u64)) = .empty;
/// Resizes the message buffer to be the correct length; returns the pointer to
/// the query string.
export fn message_begin(len: usize) [*]u8 {
message_buffer.resize(gpa, len) catch @panic("OOM");
return message_buffer.items.ptr;
}
export fn message_end() void {
const msg_bytes = message_buffer.items;
const tag: abi.ToClientTag = @enumFromInt(msg_bytes[0]);
switch (tag) {
.current_time => return currentTimeMessage(msg_bytes),
.source_index => return sourceIndexMessage(msg_bytes) catch @panic("OOM"),
.coverage_update => return coverageUpdateMessage(msg_bytes) catch @panic("OOM"),
.entry_points => return entryPointsMessage(msg_bytes) catch @panic("OOM"),
_ => unreachable,
}
}
export fn unpack(tar_ptr: [*]u8, tar_len: usize) void {
const tar_bytes = tar_ptr[0..tar_len];
log.debug("received {d} bytes of tar file", .{tar_bytes.len});
unpackInner(tar_bytes) catch |err| {
fatal("unable to unpack tar: {s}", .{@errorName(err)});
};
}
/// Set by `set_input_string`.
var input_string: std.ArrayListUnmanaged(u8) = .empty;
var string_result: std.ArrayListUnmanaged(u8) = .empty;
export fn set_input_string(len: usize) [*]u8 {
input_string.resize(gpa, len) catch @panic("OOM");
return input_string.items.ptr;
}
/// Looks up the root struct decl corresponding to a file by path.
/// Uses `input_string`.
export fn find_file_root() Decl.Index {
const file: Walk.File.Index = @enumFromInt(Walk.files.getIndex(input_string.items) orelse return .none);
return file.findRootDecl();
}
export fn decl_source_html(decl_index: Decl.Index) String {
const decl = decl_index.get();
string_result.clearRetainingCapacity();
html_render.fileSourceHtml(decl.file, &string_result, decl.ast_node, .{}) catch |err| {
fatal("unable to render source: {s}", .{@errorName(err)});
};
return String.init(string_result.items);
}
export fn totalSourceLocations() usize {
return coverage_source_locations.items.len;
}
export fn coveredSourceLocations() usize {
const covered_bits = recent_coverage_update.items[@sizeOf(abi.CoverageUpdateHeader)..];
var count: usize = 0;
for (covered_bits) |byte| count += @popCount(byte);
return count;
}
fn getCoverageUpdateHeader() *abi.CoverageUpdateHeader {
return @alignCast(@ptrCast(recent_coverage_update.items[0..@sizeOf(abi.CoverageUpdateHeader)]));
}
export fn totalRuns() u64 {
const header = getCoverageUpdateHeader();
return header.n_runs;
}
export fn uniqueRuns() u64 {
const header = getCoverageUpdateHeader();
return header.unique_runs;
}
export fn totalRunsPerSecond() f64 {
@setFloatMode(.optimized);
const header = getCoverageUpdateHeader();
const ns_elapsed: f64 = @floatFromInt(nsSince(start_fuzzing_timestamp));
const n_runs: f64 = @floatFromInt(header.n_runs);
return n_runs / (ns_elapsed / std.time.ns_per_s);
}
const String = Slice(u8);
fn Slice(T: type) type {
return packed struct(u64) {
ptr: u32,
len: u32,
fn init(s: []const T) @This() {
return .{
.ptr = @intFromPtr(s.ptr),
.len = s.len,
};
}
};
}
fn unpackInner(tar_bytes: []u8) !void {
var fbs = std.io.fixedBufferStream(tar_bytes);
var file_name_buffer: [1024]u8 = undefined;
var link_name_buffer: [1024]u8 = undefined;
var it = std.tar.iterator(fbs.reader(), .{
.file_name_buffer = &file_name_buffer,
.link_name_buffer = &link_name_buffer,
});
while (try it.next()) |tar_file| {
switch (tar_file.kind) {
.file => {
if (tar_file.size == 0 and tar_file.name.len == 0) break;
if (std.mem.endsWith(u8, tar_file.name, ".zig")) {
log.debug("found file: '{s}'", .{tar_file.name});
const file_name = try gpa.dupe(u8, tar_file.name);
if (std.mem.indexOfScalar(u8, file_name, '/')) |pkg_name_end| {
const pkg_name = file_name[0..pkg_name_end];
const gop = try Walk.modules.getOrPut(gpa, pkg_name);
const file: Walk.File.Index = @enumFromInt(Walk.files.entries.len);
if (!gop.found_existing or
std.mem.eql(u8, file_name[pkg_name_end..], "/root.zig") or
std.mem.eql(u8, file_name[pkg_name_end + 1 .. file_name.len - ".zig".len], pkg_name))
{
gop.value_ptr.* = file;
}
const file_bytes = tar_bytes[fbs.pos..][0..@intCast(tar_file.size)];
assert(file == try Walk.add_file(file_name, file_bytes));
}
} else {
log.warn("skipping: '{s}' - the tar creation should have done that", .{tar_file.name});
}
},
else => continue,
}
}
}
fn fatal(comptime format: []const u8, args: anytype) noreturn {
var buf: [500]u8 = undefined;
const line = std.fmt.bufPrint(&buf, format, args) catch l: {
buf[buf.len - 3 ..][0..3].* = "...".*;
break :l &buf;
};
js.panic(line.ptr, line.len);
}
fn currentTimeMessage(msg_bytes: []u8) void {
client_base_timestamp = js.timestamp();
server_base_timestamp = @bitCast(msg_bytes[1..][0..8].*);
}
/// Nanoseconds passed since a server timestamp.
fn nsSince(server_timestamp: i64) i64 {
const ms_passed = js.timestamp() - client_base_timestamp;
const ns_passed = server_base_timestamp - server_timestamp;
return ns_passed + ms_passed * std.time.ns_per_ms;
}
fn sourceIndexMessage(msg_bytes: []u8) error{OutOfMemory}!void {
const Header = abi.SourceIndexHeader;
const header: Header = @bitCast(msg_bytes[0..@sizeOf(Header)].*);
const directories_start = @sizeOf(Header);
const directories_end = directories_start + header.directories_len * @sizeOf(Coverage.String);
const files_start = directories_end;
const files_end = files_start + header.files_len * @sizeOf(Coverage.File);
const source_locations_start = files_end;
const source_locations_end = source_locations_start + header.source_locations_len * @sizeOf(Coverage.SourceLocation);
const string_bytes = msg_bytes[source_locations_end..][0..header.string_bytes_len];
const directories: []const Coverage.String = @alignCast(std.mem.bytesAsSlice(Coverage.String, msg_bytes[directories_start..directories_end]));
const files: []const Coverage.File = @alignCast(std.mem.bytesAsSlice(Coverage.File, msg_bytes[files_start..files_end]));
const source_locations: []const Coverage.SourceLocation = @alignCast(std.mem.bytesAsSlice(Coverage.SourceLocation, msg_bytes[source_locations_start..source_locations_end]));
start_fuzzing_timestamp = header.start_timestamp;
try updateCoverage(directories, files, source_locations, string_bytes);
js.emitSourceIndexChange();
}
fn coverageUpdateMessage(msg_bytes: []u8) error{OutOfMemory}!void {
recent_coverage_update.clearRetainingCapacity();
recent_coverage_update.appendSlice(gpa, msg_bytes) catch @panic("OOM");
js.emitCoverageUpdate();
}
var entry_points: std.ArrayListUnmanaged(u32) = .empty;
fn entryPointsMessage(msg_bytes: []u8) error{OutOfMemory}!void {
const header: abi.EntryPointHeader = @bitCast(msg_bytes[0..@sizeOf(abi.EntryPointHeader)].*);
entry_points.resize(gpa, header.flags.locs_len) catch @panic("OOM");
@memcpy(entry_points.items, std.mem.bytesAsSlice(u32, msg_bytes[@sizeOf(abi.EntryPointHeader)..]));
js.emitEntryPointsUpdate();
}
export fn entryPoints() Slice(u32) {
return Slice(u32).init(entry_points.items);
}
/// Index into `coverage_source_locations`.
const SourceLocationIndex = enum(u32) {
_,
fn haveCoverage(sli: SourceLocationIndex) bool {
return @intFromEnum(sli) < coverage_source_locations.items.len;
}
fn ptr(sli: SourceLocationIndex) *Coverage.SourceLocation {
return &coverage_source_locations.items[@intFromEnum(sli)];
}
fn sourceLocationLinkHtml(
sli: SourceLocationIndex,
out: *std.ArrayListUnmanaged(u8),
) Allocator.Error!void {
const sl = sli.ptr();
try out.writer(gpa).print("<a href=\"#l{d}\">", .{@intFromEnum(sli)});
try sli.appendPath(out);
try out.writer(gpa).print(":{d}:{d}</a>", .{ sl.line, sl.column });
}
fn appendPath(sli: SourceLocationIndex, out: *std.ArrayListUnmanaged(u8)) Allocator.Error!void {
const sl = sli.ptr();
const file = coverage.fileAt(sl.file);
const file_name = coverage.stringAt(file.basename);
const dir_name = coverage.stringAt(coverage.directories.keys()[file.directory_index]);
try html_render.appendEscaped(out, dir_name);
try out.appendSlice(gpa, "/");
try html_render.appendEscaped(out, file_name);
}
fn toWalkFile(sli: SourceLocationIndex) ?Walk.File.Index {
var buf: std.ArrayListUnmanaged(u8) = .empty;
defer buf.deinit(gpa);
sli.appendPath(&buf) catch @panic("OOM");
return @enumFromInt(Walk.files.getIndex(buf.items) orelse return null);
}
fn fileHtml(
sli: SourceLocationIndex,
out: *std.ArrayListUnmanaged(u8),
) error{ OutOfMemory, SourceUnavailable }!void {
const walk_file_index = sli.toWalkFile() orelse return error.SourceUnavailable;
const root_node = walk_file_index.findRootDecl().get().ast_node;
var annotations: std.ArrayListUnmanaged(html_render.Annotation) = .empty;
defer annotations.deinit(gpa);
try computeSourceAnnotations(sli.ptr().file, walk_file_index, &annotations, coverage_source_locations.items);
html_render.fileSourceHtml(walk_file_index, out, root_node, .{
.source_location_annotations = annotations.items,
}) catch |err| {
fatal("unable to render source: {s}", .{@errorName(err)});
};
}
};
fn computeSourceAnnotations(
cov_file_index: Coverage.File.Index,
walk_file_index: Walk.File.Index,
annotations: *std.ArrayListUnmanaged(html_render.Annotation),
source_locations: []const Coverage.SourceLocation,
) !void {
// Collect all the source locations from only this file into this array
// first, then sort by line, col, so that we can collect annotations with
// O(N) time complexity.
var locs: std.ArrayListUnmanaged(SourceLocationIndex) = .empty;
defer locs.deinit(gpa);
for (source_locations, 0..) |sl, sli_usize| {
if (sl.file != cov_file_index) continue;
const sli: SourceLocationIndex = @enumFromInt(sli_usize);
try locs.append(gpa, sli);
}
std.mem.sortUnstable(SourceLocationIndex, locs.items, {}, struct {
pub fn lessThan(context: void, lhs: SourceLocationIndex, rhs: SourceLocationIndex) bool {
_ = context;
const lhs_ptr = lhs.ptr();
const rhs_ptr = rhs.ptr();
if (lhs_ptr.line < rhs_ptr.line) return true;
if (lhs_ptr.line > rhs_ptr.line) return false;
return lhs_ptr.column < rhs_ptr.column;
}
}.lessThan);
const source = walk_file_index.get_ast().source;
var line: usize = 1;
var column: usize = 1;
var next_loc_index: usize = 0;
for (source, 0..) |byte, offset| {
if (byte == '\n') {
line += 1;
column = 1;
} else {
column += 1;
}
while (true) {
if (next_loc_index >= locs.items.len) return;
const next_sli = locs.items[next_loc_index];
const next_sl = next_sli.ptr();
if (next_sl.line > line or (next_sl.line == line and next_sl.column >= column)) break;
try annotations.append(gpa, .{
.file_byte_offset = offset,
.dom_id = @intFromEnum(next_sli),
});
next_loc_index += 1;
}
}
}
var coverage = Coverage.init;
/// Index of type `SourceLocationIndex`.
var coverage_source_locations: std.ArrayListUnmanaged(Coverage.SourceLocation) = .empty;
/// Contains the most recent coverage update message, unmodified.
var recent_coverage_update: std.ArrayListAlignedUnmanaged(u8, @alignOf(u64)) = .empty;
fn updateCoverage(
directories: []const Coverage.String,
files: []const Coverage.File,
source_locations: []const Coverage.SourceLocation,
string_bytes: []const u8,
) !void {
coverage.directories.clearRetainingCapacity();
coverage.files.clearRetainingCapacity();
coverage.string_bytes.clearRetainingCapacity();
coverage_source_locations.clearRetainingCapacity();
try coverage_source_locations.appendSlice(gpa, source_locations);
try coverage.string_bytes.appendSlice(gpa, string_bytes);
try coverage.files.entries.resize(gpa, files.len);
@memcpy(coverage.files.entries.items(.key), files);
try coverage.files.reIndexContext(gpa, .{ .string_bytes = coverage.string_bytes.items });
try coverage.directories.entries.resize(gpa, directories.len);
@memcpy(coverage.directories.entries.items(.key), directories);
try coverage.directories.reIndexContext(gpa, .{ .string_bytes = coverage.string_bytes.items });
}
export fn sourceLocationLinkHtml(index: SourceLocationIndex) String {
string_result.clearRetainingCapacity();
index.sourceLocationLinkHtml(&string_result) catch @panic("OOM");
return String.init(string_result.items);
}
/// Returns empty string if coverage metadata is not available for this source location.
export fn sourceLocationPath(sli: SourceLocationIndex) String {
string_result.clearRetainingCapacity();
if (sli.haveCoverage()) sli.appendPath(&string_result) catch @panic("OOM");
return String.init(string_result.items);
}
export fn sourceLocationFileHtml(sli: SourceLocationIndex) String {
string_result.clearRetainingCapacity();
sli.fileHtml(&string_result) catch |err| switch (err) {
error.OutOfMemory => @panic("OOM"),
error.SourceUnavailable => {},
};
return String.init(string_result.items);
}
export fn sourceLocationFileCoveredList(sli_file: SourceLocationIndex) Slice(SourceLocationIndex) {
const global = struct {
var result: std.ArrayListUnmanaged(SourceLocationIndex) = .empty;
fn add(i: u32, want_file: Coverage.File.Index) void {
const src_loc_index: SourceLocationIndex = @enumFromInt(i);
if (src_loc_index.ptr().file == want_file) result.appendAssumeCapacity(src_loc_index);
}
};
const want_file = sli_file.ptr().file;
global.result.clearRetainingCapacity();
// This code assumes 64-bit elements, which is incorrect if the executable
// being fuzzed is not a 64-bit CPU. It also assumes little-endian which
// can also be incorrect.
comptime assert(abi.CoverageUpdateHeader.trailing[0] == .pc_bits_usize);
const n_bitset_elems = (coverage_source_locations.items.len + @bitSizeOf(u64) - 1) / @bitSizeOf(u64);
const covered_bits = std.mem.bytesAsSlice(
u64,
recent_coverage_update.items[@sizeOf(abi.CoverageUpdateHeader)..][0 .. n_bitset_elems * @sizeOf(u64)],
);
var sli: u32 = 0;
for (covered_bits) |elem| {
global.result.ensureUnusedCapacity(gpa, 64) catch @panic("OOM");
for (0..@bitSizeOf(u64)) |i| {
if ((elem & (@as(u64, 1) << @intCast(i))) != 0) global.add(sli, want_file);
sli += 1;
}
}
return Slice(SourceLocationIndex).init(global.result.items);
}