compiler: JIT zig reduce

See #19063

build.zig

@@ -34,7 +34,6 @@ pub fn build(b: *std.Build) !void {
     const skip_install_langref = b.option(bool, "no-langref", "skip copying of langref to the installation prefix") orelse skip_install_lib_files;
     const skip_install_autodocs = b.option(bool, "no-autodocs", "skip copying of standard library autodocs to the installation prefix") orelse skip_install_lib_files;
     const no_bin = b.option(bool, "no-bin", "skip emitting compiler binary") orelse false;
-    const only_reduce = b.option(bool, "only-reduce", "only build zig reduce") orelse false;
 
     const docgen_exe = b.addExecutable(.{
         .name = "docgen",
@@ -245,7 +244,6 @@ pub fn build(b: *std.Build) !void {
     exe_options.addOption(bool, "force_gpa", force_gpa);
     exe_options.addOption(bool, "only_c", only_c);
     exe_options.addOption(bool, "only_core_functionality", only_c);
-    exe_options.addOption(bool, "only_reduce", only_reduce);
 
     if (link_libc) {
         exe.linkLibC();
@@ -407,7 +405,6 @@ pub fn build(b: *std.Build) !void {
     test_cases_options.addOption(bool, "force_gpa", force_gpa);
     test_cases_options.addOption(bool, "only_c", only_c);
     test_cases_options.addOption(bool, "only_core_functionality", true);
-    test_cases_options.addOption(bool, "only_reduce", false);
     test_cases_options.addOption(bool, "enable_qemu", b.enable_qemu);
     test_cases_options.addOption(bool, "enable_wine", b.enable_wine);
     test_cases_options.addOption(bool, "enable_wasmtime", b.enable_wasmtime);
@@ -599,7 +596,6 @@ fn addWasiUpdateStep(b: *std.Build, version: [:0]const u8) !void {
     exe_options.addOption(bool, "enable_tracy_allocation", false);
     exe_options.addOption(bool, "value_tracing", false);
     exe_options.addOption(bool, "only_core_functionality", true);
-    exe_options.addOption(bool, "only_reduce", false);
 
     const run_opt = b.addSystemCommand(&.{
         "wasm-opt",

lib/std/zig/reduce.zig

@@ -2,7 +2,6 @@ const std = @import("std");
 const mem = std.mem;
 const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
-const fatal = @import("./main.zig").fatal;
 const Ast = std.zig.Ast;
 const Walk = @import("reduce/Walk.zig");
 const AstGen = std.zig.AstGen;
@@ -47,7 +46,16 @@ const Interestingness = enum { interesting, unknown, boring };
 // - reduce flags sent to the compiler
 // - integrate with the build system?
 
-pub fn main(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
+pub fn main() !void {
+    var arena_instance = std.heap.ArenaAllocator.init(std.heap.page_allocator);
+    defer arena_instance.deinit();
+    const arena = arena_instance.allocator();
+
+    var general_purpose_allocator: std.heap.GeneralPurposeAllocator(.{}) = .{};
+    const gpa = general_purpose_allocator.allocator();
+
+    const args = try std.process.argsAlloc(arena);
+
     var opt_checker_path: ?[]const u8 = null;
     var opt_root_source_file_path: ?[]const u8 = null;
     var argv: []const []const u8 = &.{};
@@ -55,7 +63,7 @@ pub fn main(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
     var skip_smoke_test = false;
 
     {
-        var i: usize = 2; // skip over "zig" and "reduce"
+        var i: usize = 1;
         while (i < args.len) : (i += 1) {
             const arg = args[i];
             if (mem.startsWith(u8, arg, "-")) {
@@ -411,3 +419,8 @@ fn parse(gpa: Allocator, file_path: []const u8) !Ast {
 
     return tree;
 }
+
+fn fatal(comptime format: []const u8, args: anytype) noreturn {
+    std.log.err(format, args);
+    std.process.exit(1);
+}

src/main.zig

@@ -203,14 +203,6 @@ pub fn main() anyerror!void {
         }
     }
 
-    if (build_options.only_reduce) {
-        if (mem.eql(u8, args[1], "reduce")) {
-            return @import("reduce.zig").main(gpa, arena, args);
-        } else {
-            @panic("only reduce is supported in a -Donly-reduce build");
-        }
-    }
-
     return mainArgs(gpa, arena, args);
 }
 
@@ -302,7 +294,7 @@ fn mainArgs(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
     } else if (mem.eql(u8, cmd, "rc")) {
         return cmdRc(gpa, arena, args[1..]);
     } else if (mem.eql(u8, cmd, "fmt")) {
-        return cmdFmt(gpa, arena, cmd_args);
+        return jitCmd(gpa, arena, cmd_args, "fmt", "fmt.zig");
     } else if (mem.eql(u8, cmd, "objcopy")) {
         return @import("objcopy.zig").cmdObjCopy(gpa, arena, cmd_args);
     } else if (mem.eql(u8, cmd, "fetch")) {
@@ -325,7 +317,7 @@ fn mainArgs(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
         verifyLibcxxCorrectlyLinked();
         return @import("print_env.zig").cmdEnv(arena, cmd_args, io.getStdOut().writer());
     } else if (mem.eql(u8, cmd, "reduce")) {
-        return @import("reduce.zig").main(gpa, arena, args);
+        return jitCmd(gpa, arena, cmd_args, "reduce", "reduce.zig");
     } else if (mem.eql(u8, cmd, "zen")) {
         return io.getStdOut().writeAll(info_zen);
     } else if (mem.eql(u8, cmd, "help") or mem.eql(u8, cmd, "-h") or mem.eql(u8, cmd, "--help")) {
@@ -5710,7 +5702,13 @@ fn cmdBuild(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
     }
 }
 
-fn cmdFmt(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
+fn jitCmd(
+    gpa: Allocator,
+    arena: Allocator,
+    args: []const []const u8,
+    cmd_name: []const u8,
+    root_src_path: []const u8,
+) !void {
     const color: Color = .auto;
 
     const target_query: std.Target.Query = .{};
@@ -5721,7 +5719,7 @@ fn cmdFmt(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
     };
 
     const exe_basename = try std.zig.binNameAlloc(arena, .{
-        .root_name = "fmt",
+        .root_name = cmd_name,
         .target = resolved_target.result,
         .output_mode = .Exe,
     });
@@ -5771,7 +5769,7 @@ fn cmdFmt(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
                 .root_dir = zig_lib_directory,
                 .sub_path = "std/zig",
             },
-            .root_src_path = "fmt.zig",
+            .root_src_path = root_src_path,
         };
 
         const config = try Compilation.Config.resolve(.{
@@ -5801,7 +5799,7 @@ fn cmdFmt(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
             .zig_lib_directory = zig_lib_directory,
             .local_cache_directory = global_cache_directory,
             .global_cache_directory = global_cache_directory,
-            .root_name = "fmt",
+            .root_name = cmd_name,
             .config = config,
             .root_mod = root_mod,
             .main_mod = root_mod,
@@ -5820,8 +5818,8 @@ fn cmdFmt(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
             else => |e| return e,
         };
 
-        const fmt_exe = try global_cache_directory.join(arena, &.{comp.cache_use.whole.bin_sub_path.?});
+        const exe_path = try global_cache_directory.join(arena, &.{comp.cache_use.whole.bin_sub_path.?});
-        child_argv.appendAssumeCapacity(fmt_exe);
+        child_argv.appendAssumeCapacity(exe_path);
     }
 
     child_argv.appendSliceAssumeCapacity(args);

stage1/config.zig.in

@@ -13,4 +13,3 @@ pub const skip_non_native = false;
 pub const only_c = false;
 pub const force_gpa = false;
 pub const only_core_functionality = true;
-pub const only_reduce = false;