Commit 91570cc42d
Changed files (3)
lib
std
zig
src
reduce
lib/std/zig/render.zig
@@ -25,7 +25,9 @@ pub const Fixups = struct {
/// These global declarations will be omitted.
omit_nodes: std.AutoHashMapUnmanaged(Ast.Node.Index, void) = .{},
/// These expressions will be replaced with the string value.
- replace_nodes: std.AutoHashMapUnmanaged(Ast.Node.Index, []const u8) = .{},
+ replace_nodes_with_string: std.AutoHashMapUnmanaged(Ast.Node.Index, []const u8) = .{},
+ /// These nodes will be replaced with a different node.
+ replace_nodes_with_node: std.AutoHashMapUnmanaged(Ast.Node.Index, Ast.Node.Index) = .{},
/// Change all identifier names matching the key to be value instead.
rename_identifiers: std.StringArrayHashMapUnmanaged([]const u8) = .{},
@@ -37,7 +39,8 @@ pub const Fixups = struct {
return f.unused_var_decls.count() +
f.gut_functions.count() +
f.omit_nodes.count() +
- f.replace_nodes.count() +
+ f.replace_nodes_with_string.count() +
+ f.replace_nodes_with_node.count() +
f.rename_identifiers.count() +
@intFromBool(f.rebase_imported_paths != null);
}
@@ -46,7 +49,8 @@ pub const Fixups = struct {
f.unused_var_decls.clearRetainingCapacity();
f.gut_functions.clearRetainingCapacity();
f.omit_nodes.clearRetainingCapacity();
- f.replace_nodes.clearRetainingCapacity();
+ f.replace_nodes_with_string.clearRetainingCapacity();
+ f.replace_nodes_with_node.clearRetainingCapacity();
f.rename_identifiers.clearRetainingCapacity();
f.rebase_imported_paths = null;
@@ -56,7 +60,8 @@ pub const Fixups = struct {
f.unused_var_decls.deinit(gpa);
f.gut_functions.deinit(gpa);
f.omit_nodes.deinit(gpa);
- f.replace_nodes.deinit(gpa);
+ f.replace_nodes_with_string.deinit(gpa);
+ f.replace_nodes_with_node.deinit(gpa);
f.rename_identifiers.deinit(gpa);
f.* = undefined;
}
@@ -329,10 +334,12 @@ fn renderExpression(r: *Render, node: Ast.Node.Index, space: Space) Error!void {
const main_tokens = tree.nodes.items(.main_token);
const node_tags = tree.nodes.items(.tag);
const datas = tree.nodes.items(.data);
- if (r.fixups.replace_nodes.get(node)) |replacement| {
+ if (r.fixups.replace_nodes_with_string.get(node)) |replacement| {
try ais.writer().writeAll(replacement);
try renderOnlySpace(r, space);
return;
+ } else if (r.fixups.replace_nodes_with_node.get(node)) |replacement| {
+ return renderExpression(r, replacement, space);
}
switch (node_tags[node]) {
.identifier => {
src/reduce/Walk.zig
@@ -27,6 +27,15 @@ pub const Transformation = union(enum) {
},
/// Replace an expression with `undefined`.
replace_with_undef: Ast.Node.Index,
+ /// Replace an expression with `true`.
+ replace_with_true: Ast.Node.Index,
+ /// Replace an expression with `false`.
+ replace_with_false: Ast.Node.Index,
+ /// Replace a node with another node.
+ replace_node: struct {
+ to_replace: Ast.Node.Index,
+ replacement: Ast.Node.Index,
+ },
/// Replace an `@import` with the imported file contents wrapped in a struct.
inline_imported_file: InlineImportedFile,
@@ -558,7 +567,7 @@ fn walkExpression(w: *Walk, node: Ast.Node.Index) Error!void {
.if_simple,
.@"if",
- => return walkIf(w, ast.fullIf(node).?),
+ => return walkIf(w, node, ast.fullIf(node).?),
.asm_simple,
.@"asm",
@@ -861,8 +870,6 @@ fn walkWhile(w: *Walk, while_node: Ast.full.While) Error!void {
try walkExpression(w, while_node.ast.cont_expr);
}
- try walkExpression(w, while_node.ast.cond_expr); // condition
-
if (while_node.ast.then_expr != 0) {
try walkExpression(w, while_node.ast.then_expr);
}
@@ -881,7 +888,37 @@ fn walkFor(w: *Walk, for_node: Ast.full.For) Error!void {
}
}
-fn walkIf(w: *Walk, if_node: Ast.full.If) Error!void {
+fn walkIf(w: *Walk, node_index: Ast.Node.Index, if_node: Ast.full.If) Error!void {
+ assert(if_node.ast.cond_expr != 0);
+ assert(if_node.ast.then_expr != 0);
+
+ // Perform these transformations in this priority order:
+ // 1. If the `else` expression is missing or an empty block, replace the condition with `if (true)` if it is not already.
+ // 2. If the `then` block is empty, replace the condition with `if (false)` if it is not already.
+ // 3. If the condition is `if (true)`, replace the `if` expression with the contents of the `then` expression.
+ // 4. If the condition is `if (false)`, replace the `if` expression with the contents of the `else` expression.
+ if (!isTrueIdent(w.ast, if_node.ast.cond_expr) and
+ (if_node.ast.else_expr == 0 or isEmptyBlock(w.ast, if_node.ast.else_expr)))
+ {
+ try w.transformations.ensureUnusedCapacity(1);
+ w.transformations.appendAssumeCapacity(.{ .replace_with_true = if_node.ast.cond_expr });
+ } else if (!isFalseIdent(w.ast, if_node.ast.cond_expr) and isEmptyBlock(w.ast, if_node.ast.then_expr)) {
+ try w.transformations.ensureUnusedCapacity(1);
+ w.transformations.appendAssumeCapacity(.{ .replace_with_false = if_node.ast.cond_expr });
+ } else if (isTrueIdent(w.ast, if_node.ast.cond_expr)) {
+ try w.transformations.ensureUnusedCapacity(1);
+ w.transformations.appendAssumeCapacity(.{ .replace_node = .{
+ .to_replace = node_index,
+ .replacement = if_node.ast.then_expr,
+ } });
+ } else if (isFalseIdent(w.ast, if_node.ast.cond_expr)) {
+ try w.transformations.ensureUnusedCapacity(1);
+ w.transformations.appendAssumeCapacity(.{ .replace_node = .{
+ .to_replace = node_index,
+ .replacement = if_node.ast.else_expr,
+ } });
+ }
+
try walkExpression(w, if_node.ast.cond_expr); // condition
if (if_node.ast.then_expr != 0) {
@@ -1002,6 +1039,14 @@ fn isUndefinedIdent(ast: *const Ast, node: Ast.Node.Index) bool {
return isMatchingIdent(ast, node, "undefined");
}
+fn isTrueIdent(ast: *const Ast, node: Ast.Node.Index) bool {
+ return isMatchingIdent(ast, node, "true");
+}
+
+fn isFalseIdent(ast: *const Ast, node: Ast.Node.Index) bool {
+ return isMatchingIdent(ast, node, "false");
+}
+
fn isMatchingIdent(ast: *const Ast, node: Ast.Node.Index, string: []const u8) bool {
const node_tags = ast.nodes.items(.tag);
const main_tokens = ast.nodes.items(.main_token);
@@ -1014,3 +1059,14 @@ fn isMatchingIdent(ast: *const Ast, node: Ast.Node.Index, string: []const u8) bo
else => return false,
}
}
+
+fn isEmptyBlock(ast: *const Ast, node: Ast.Node.Index) bool {
+ const node_tags = ast.nodes.items(.tag);
+ const node_data = ast.nodes.items(.data);
+ switch (node_tags[node]) {
+ .block_two => {
+ return node_data[node].lhs == 0 and node_data[node].rhs == 0;
+ },
+ else => return false,
+ }
+}
src/reduce.zig
@@ -226,7 +226,7 @@ pub fn main(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
}
try std.fs.cwd().writeFile(root_source_file_path, rendered.items);
- //std.debug.print("trying this code:\n{s}\n", .{rendered.items});
+ // std.debug.print("trying this code:\n{s}\n", .{rendered.items});
const interestingness = try runCheck(arena, interestingness_argv.items);
std.debug.print("{d} random transformations: {s}. {d}/{d}\n", .{
@@ -324,11 +324,20 @@ fn transformationsToFixups(
.delete_var_decl => |delete_var_decl| {
try fixups.omit_nodes.put(gpa, delete_var_decl.var_decl_node, {});
for (delete_var_decl.references.items) |ident_node| {
- try fixups.replace_nodes.put(gpa, ident_node, "undefined");
+ try fixups.replace_nodes_with_string.put(gpa, ident_node, "undefined");
}
},
.replace_with_undef => |node| {
- try fixups.replace_nodes.put(gpa, node, "undefined");
+ try fixups.replace_nodes_with_string.put(gpa, node, "undefined");
+ },
+ .replace_with_true => |node| {
+ try fixups.replace_nodes_with_string.put(gpa, node, "true");
+ },
+ .replace_with_false => |node| {
+ try fixups.replace_nodes_with_string.put(gpa, node, "false");
+ },
+ .replace_node => |r| {
+ try fixups.replace_nodes_with_node.put(gpa, r.to_replace, r.replacement);
},
.inline_imported_file => |inline_imported_file| {
const full_imported_path = try std.fs.path.join(gpa, &.{
@@ -371,7 +380,7 @@ fn transformationsToFixups(
try other_file_ast.renderToArrayList(&other_source, inlined_fixups);
try other_source.appendSlice("}");
- try fixups.replace_nodes.put(
+ try fixups.replace_nodes_with_string.put(
gpa,
inline_imported_file.builtin_call_node,
try arena.dupe(u8, other_source.items),