From 4996c2b6a94b042d86b50eb61c9d8d98e63415af Mon Sep 17 00:00:00 2001 From: Andrew Kelley Date: Wed, 7 Apr 2021 19:38:00 -0700 Subject: stage2: fix incremental compilation Decl deletion logic * `analyzeContainer` now has an `outdated_decls` set as well as `deleted_decls`. Instead of queuing up outdated Decls for re-analysis right away, they are added to this new set. When processing the `deleted_decls` set, we remove deleted Decls from the `outdated_decls` set, to avoid deleted Decl pointers from being in the work_queue. Only after processing the deleted decls do we add analyze_decl work items to the queue. * Module.deletion_set is now an `AutoArrayHashMap` rather than `ArrayList`. `declareDeclDependency` will now remove a Decl from it as appropriate. When processing the `deletion_set` in `Compilation.performAllTheWork`, it now assumes all Decl in the set are to be deleted. * Fix crash when handling parse errors. Currently we unload the `ast.Tree` if any parse errors occur. Previously the code emitted a LazySrcLoc pointing to a token index, but then when we try to resolve the token index to a byte offset to create a compile error message, the ast.Tree` would be unloaded. Now we use `LazySrcLoc.byte_abs` instead of `token_abs` so the error message can be created even with the `ast.Tree` unloaded. Together, these changes solve a crash that happened with incremental compilation when Decls were added and removed in some combinations. --- src/Module.zig | 97 +++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 79 insertions(+), 18 deletions(-) (limited to 'src/Module.zig') diff --git a/src/Module.zig b/src/Module.zig index 9d26738e14..98dad994bd 100644 --- a/src/Module.zig +++ b/src/Module.zig @@ -75,7 +75,7 @@ next_anon_name_index: usize = 0, /// Candidates for deletion. After a semantic analysis update completes, this list /// contains Decls that need to be deleted if they end up having no references to them. -deletion_set: ArrayListUnmanaged(*Decl) = .{}, +deletion_set: std.AutoArrayHashMapUnmanaged(*Decl, void) = .{}, /// Error tags and their values, tag names are duped with mod.gpa. /// Corresponds with `error_name_list`. @@ -192,7 +192,7 @@ pub const Decl = struct { /// to require re-analysis. outdated, }, - /// This flag is set when this Decl is added to a check_for_deletion set, and cleared + /// This flag is set when this Decl is added to `Module.deletion_set`, and cleared /// when removed. deletion_flag: bool, /// Whether the corresponding AST decl has a `pub` keyword. @@ -2393,7 +2393,7 @@ pub fn ensureDeclAnalyzed(mod: *Module, decl: *Decl) InnerError!void { // We don't perform a deletion here, because this Decl or another one // may end up referencing it before the update is complete. dep.deletion_flag = true; - try mod.deletion_set.append(mod.gpa, dep); + try mod.deletion_set.put(mod.gpa, dep, {}); } } decl.dependencies.clearRetainingCapacity(); @@ -3197,6 +3197,11 @@ pub fn declareDeclDependency(mod: *Module, depender: *Decl, dependee: *Decl) !u3 try depender.dependencies.ensureCapacity(mod.gpa, depender.dependencies.count() + 1); try dependee.dependants.ensureCapacity(mod.gpa, dependee.dependants.count() + 1); + if (dependee.deletion_flag) { + dependee.deletion_flag = false; + mod.deletion_set.removeAssertDiscard(dependee); + } + dependee.dependants.putAssumeCapacity(depender, {}); const gop = depender.dependencies.getOrPutAssumeCapacity(dependee); return @intCast(u32, gop.index); @@ -3224,12 +3229,14 @@ pub fn getAstTree(mod: *Module, root_scope: *Scope.File) !*const ast.Tree { var msg = std.ArrayList(u8).init(mod.gpa); defer msg.deinit(); + const token_starts = tree.tokens.items(.start); + try tree.renderError(parse_err, msg.writer()); const err_msg = try mod.gpa.create(ErrorMsg); err_msg.* = .{ .src_loc = .{ .container = .{ .file_scope = root_scope }, - .lazy = .{ .token_abs = parse_err.token }, + .lazy = .{ .byte_abs = token_starts[parse_err.token] }, }, .msg = msg.toOwnedSlice(), }; @@ -3274,6 +3281,14 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { deleted_decls.putAssumeCapacityNoClobber(entry.key, {}); } + // Keep track of decls that are invalidated from the update. Ultimately, + // the goal is to queue up `analyze_decl` tasks in the work queue for + // the outdated decls, but we cannot queue up the tasks until after + // we find out which ones have been deleted, otherwise there would be + // deleted Decl pointers in the work queue. + var outdated_decls = std.AutoArrayHashMap(*Decl, void).init(mod.gpa); + defer outdated_decls.deinit(); + for (decls) |decl_node, decl_i| switch (node_tags[decl_node]) { .fn_decl => { const fn_proto = node_datas[decl_node].lhs; @@ -3284,6 +3299,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3294,6 +3310,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .fn_proto_multi => try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3305,6 +3322,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3315,6 +3333,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .fn_proto => try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3329,6 +3348,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3339,6 +3359,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .fn_proto_multi => try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3350,6 +3371,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3360,6 +3382,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .fn_proto => try mod.semaContainerFn( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3370,6 +3393,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .global_var_decl => try mod.semaContainerVar( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3378,6 +3402,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .local_var_decl => try mod.semaContainerVar( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3386,6 +3411,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .simple_var_decl => try mod.semaContainerVar( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3394,6 +3420,7 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { .aligned_var_decl => try mod.semaContainerVar( container_scope, &deleted_decls, + &outdated_decls, decl_node, decl_i, tree.*, @@ -3446,11 +3473,27 @@ pub fn analyzeContainer(mod: *Module, container_scope: *Scope.Container) !void { }, else => unreachable, }; - // Handle explicitly deleted decls from the source code. Not to be confused - // with when we delete decls because they are no longer referenced. + // Handle explicitly deleted decls from the source code. This is one of two + // places that Decl deletions happen. The other is in `Compilation`, after + // `performAllTheWork`, where we iterate over `Module.deletion_set` and + // delete Decls which are no longer referenced. + // If a Decl is explicitly deleted from source, and also no longer referenced, + // it may be both in this `deleted_decls` set, as well as in the + // `Module.deletion_set`. To avoid deleting it twice, we remove it from the + // deletion set at this time. for (deleted_decls.items()) |entry| { - log.debug("noticed '{s}' deleted from source", .{entry.key.name}); - try mod.deleteDecl(entry.key); + const decl = entry.key; + log.debug("'{s}' deleted from source", .{decl.name}); + if (decl.deletion_flag) { + log.debug("'{s}' redundantly in deletion set; removing", .{decl.name}); + mod.deletion_set.removeAssertDiscard(decl); + } + try mod.deleteDecl(decl, &outdated_decls); + } + // Finally we can queue up re-analysis tasks after we have processed + // the deleted decls. + for (outdated_decls.items()) |entry| { + try mod.markOutdatedDecl(entry.key); } } @@ -3458,6 +3501,7 @@ fn semaContainerFn( mod: *Module, container_scope: *Scope.Container, deleted_decls: *std.AutoArrayHashMap(*Decl, void), + outdated_decls: *std.AutoArrayHashMap(*Decl, void), decl_node: ast.Node.Index, decl_i: usize, tree: ast.Tree, @@ -3489,7 +3533,7 @@ fn semaContainerFn( try mod.failed_decls.putNoClobber(mod.gpa, decl, msg); } else { if (!srcHashEql(decl.contents_hash, contents_hash)) { - try mod.markOutdatedDecl(decl); + try outdated_decls.put(decl, {}); decl.contents_hash = contents_hash; } else switch (mod.comp.bin_file.tag) { .coff => { @@ -3524,6 +3568,7 @@ fn semaContainerVar( mod: *Module, container_scope: *Scope.Container, deleted_decls: *std.AutoArrayHashMap(*Decl, void), + outdated_decls: *std.AutoArrayHashMap(*Decl, void), decl_node: ast.Node.Index, decl_i: usize, tree: ast.Tree, @@ -3549,7 +3594,7 @@ fn semaContainerVar( errdefer err_msg.destroy(mod.gpa); try mod.failed_decls.putNoClobber(mod.gpa, decl, err_msg); } else if (!srcHashEql(decl.contents_hash, contents_hash)) { - try mod.markOutdatedDecl(decl); + try outdated_decls.put(decl, {}); decl.contents_hash = contents_hash; } } else { @@ -3579,17 +3624,27 @@ fn semaContainerField( log.err("TODO: analyze container field", .{}); } -pub fn deleteDecl(mod: *Module, decl: *Decl) !void { +pub fn deleteDecl( + mod: *Module, + decl: *Decl, + outdated_decls: ?*std.AutoArrayHashMap(*Decl, void), +) !void { const tracy = trace(@src()); defer tracy.end(); - try mod.deletion_set.ensureCapacity(mod.gpa, mod.deletion_set.items.len + decl.dependencies.items().len); + log.debug("deleting decl '{s}'", .{decl.name}); + + if (outdated_decls) |map| { + _ = map.swapRemove(decl); + try map.ensureCapacity(map.count() + decl.dependants.count()); + } + try mod.deletion_set.ensureCapacity(mod.gpa, mod.deletion_set.count() + + decl.dependencies.count()); // Remove from the namespace it resides in. In the case of an anonymous Decl it will // not be present in the set, and this does nothing. decl.container.removeDecl(decl); - log.debug("deleting decl '{s}'", .{decl.name}); const name_hash = decl.fullyQualifiedNameHash(); mod.decl_table.removeAssertDiscard(name_hash); // Remove itself from its dependencies, because we are about to destroy the decl pointer. @@ -3600,16 +3655,22 @@ pub fn deleteDecl(mod: *Module, decl: *Decl) !void { // We don't recursively perform a deletion here, because during the update, // another reference to it may turn up. dep.deletion_flag = true; - mod.deletion_set.appendAssumeCapacity(dep); + mod.deletion_set.putAssumeCapacity(dep, {}); } } - // Anything that depends on this deleted decl certainly needs to be re-analyzed. + // Anything that depends on this deleted decl needs to be re-analyzed. for (decl.dependants.items()) |entry| { const dep = entry.key; dep.removeDependency(decl); - if (dep.analysis != .outdated) { - // TODO Move this failure possibility to the top of the function. - try mod.markOutdatedDecl(dep); + if (outdated_decls) |map| { + map.putAssumeCapacity(dep, {}); + } else if (std.debug.runtime_safety) { + // If `outdated_decls` is `null`, it means we're being called from + // `Compilation` after `performAllTheWork` and we cannot queue up any + // more work. `dep` must necessarily be another Decl that is no longer + // being referenced, and will be in the `deletion_set`. Otherwise, + // something has gone wrong. + assert(mod.deletion_set.contains(dep)); } } if (mod.failed_decls.swapRemove(decl)) |entry| { -- cgit v1.2.3