stage2: eliminate the "compiler id" concept

Instead, append a "dirty suffix" to the version string when there are
dirty git changes and use the version string as the compiler id.

This avoids a dependency on the cache hash system, and saves time on
first invocation of the compiler since it does not have to compute its
compiler id. It also saves time by not having to check the cache for a
saved compiler id.

1 files changed, 86 insertions, 63 deletions

diff --git a/build.zig b/build.zig
index d3846fbdf8..1666d92274 100644
--- a/build.zig
+++ b/build.zig
@@ -56,69 +56,6 @@ pub fn build(b: *Builder) !void {
     const enable_llvm = b.option(bool, "enable-llvm", "Build self-hosted compiler with LLVM backend enabled") orelse false;
     const config_h_path_option = b.option([]const u8, "config_h", "Path to the generated config.h");
 
-    if (!only_install_lib_files) {
-        var exe = b.addExecutable("zig", "src-self-hosted/main.zig");
-        exe.install();
-        exe.setBuildMode(mode);
-        exe.setTarget(target);
-        test_step.dependOn(&exe.step);
-        b.default_step.dependOn(&exe.step);
-
-        exe.addBuildOption(bool, "have_llvm", enable_llvm);
-        if (enable_llvm) {
-            const config_h_text = if (config_h_path_option) |config_h_path|
-                try std.fs.cwd().readFileAlloc(b.allocator, toNativePathSep(b, config_h_path), max_config_h_bytes)
-            else
-                try findAndReadConfigH(b);
-
-            var ctx = parseConfigH(b, config_h_text);
-            ctx.llvm = try findLLVM(b, ctx.llvm_config_exe);
-
-            try configureStage2(b, exe, ctx);
-        }
-        const tracy = b.option([]const u8, "tracy", "Enable Tracy integration. Supply path to Tracy source");
-        const link_libc = b.option(bool, "force-link-libc", "Force self-hosted compiler to link libc") orelse enable_llvm;
-        if (link_libc) {
-            exe.linkLibC();
-            test_stage2.linkLibC();
-        }
-
-        const log_scopes = b.option([]const []const u8, "log", "Which log scopes to enable") orelse &[0][]const u8{};
-        const zir_dumps = b.option([]const []const u8, "dump-zir", "Which functions to dump ZIR for before codegen") orelse &[0][]const u8{};
-
-        const opt_version_string = b.option([]const u8, "version-string", "Override Zig version string. Default is to find out with git.");
-        const version = if (opt_version_string) |version| version else v: {
-            var code: u8 = undefined;
-            const version_untrimmed = b.execAllowFail(&[_][]const u8{
-                "git",    "-C",          b.build_root,     "name-rev", "HEAD",
-                "--tags", "--name-only", "--no-undefined", "--always",
-            }, &code, .Ignore) catch |err| {
-                std.debug.print(
-                    \\Unable to determine zig version string: {}
-                    \\Provide the zig version string explicitly using the `version-string` build option.
-                , .{err});
-                std.process.exit(1);
-            };
-            const trimmed = mem.trim(u8, version_untrimmed, " \n\r");
-            break :v b.fmt("{}.{}.{}+{}", .{ zig_version.major, zig_version.minor, zig_version.patch, trimmed });
-        };
-        exe.addBuildOption([]const u8, "version", version);
-
-        exe.addBuildOption([]const []const u8, "log_scopes", log_scopes);
-        exe.addBuildOption([]const []const u8, "zir_dumps", zir_dumps);
-        exe.addBuildOption(bool, "enable_tracy", tracy != null);
-        if (tracy) |tracy_path| {
-            const client_cpp = fs.path.join(
-                b.allocator,
-                &[_][]const u8{ tracy_path, "TracyClient.cpp" },
-            ) catch unreachable;
-            exe.addIncludeDir(tracy_path);
-            exe.addCSourceFile(client_cpp, &[_][]const u8{ "-DTRACY_ENABLE=1", "-fno-sanitize=undefined" });
-            exe.linkSystemLibraryName("c++");
-            exe.linkLibC();
-        }
-    }
-
     b.installDirectory(InstallDirectoryOptions{
         .source_dir = "lib",
         .install_dir = .Lib,
@@ -132,6 +69,91 @@ pub fn build(b: *Builder) !void {
         },
     });
 
+    if (only_install_lib_files)
+        return;
+
+    var exe = b.addExecutable("zig", "src-self-hosted/main.zig");
+    exe.install();
+    exe.setBuildMode(mode);
+    exe.setTarget(target);
+    test_step.dependOn(&exe.step);
+    b.default_step.dependOn(&exe.step);
+
+    exe.addBuildOption(bool, "have_llvm", enable_llvm);
+    if (enable_llvm) {
+        const config_h_text = if (config_h_path_option) |config_h_path|
+            try std.fs.cwd().readFileAlloc(b.allocator, toNativePathSep(b, config_h_path), max_config_h_bytes)
+        else
+            try findAndReadConfigH(b);
+
+        var ctx = parseConfigH(b, config_h_text);
+        ctx.llvm = try findLLVM(b, ctx.llvm_config_exe);
+
+        try configureStage2(b, exe, ctx);
+    }
+    const tracy = b.option([]const u8, "tracy", "Enable Tracy integration. Supply path to Tracy source");
+    const link_libc = b.option(bool, "force-link-libc", "Force self-hosted compiler to link libc") orelse enable_llvm;
+    if (link_libc) {
+        exe.linkLibC();
+        test_stage2.linkLibC();
+    }
+
+    const log_scopes = b.option([]const []const u8, "log", "Which log scopes to enable") orelse &[0][]const u8{};
+    const zir_dumps = b.option([]const []const u8, "dump-zir", "Which functions to dump ZIR for before codegen") orelse &[0][]const u8{};
+
+    const opt_version_string = b.option([]const u8, "version-string", "Override Zig version string. Default is to find out with git.");
+    const version = if (opt_version_string) |version| version else v: {
+        const version_string = b.fmt("{}.{}.{}", .{ zig_version.major, zig_version.minor, zig_version.patch });
+
+        var code: u8 = undefined;
+        const git_sha_untrimmed = b.execAllowFail(&[_][]const u8{
+            "git",    "-C",          b.build_root,     "name-rev", "HEAD",
+            "--tags", "--name-only", "--no-undefined", "--always",
+        }, &code, .Ignore) catch {
+            break :v version_string;
+        };
+        const git_sha_trimmed = mem.trim(u8, git_sha_untrimmed, " \n\r");
+        // Detect dirty changes.
+        const diff_untrimmed = b.execAllowFail(&[_][]const u8{
+            "git", "-C", b.build_root, "diff", "HEAD",
+        }, &code, .Ignore) catch |err| {
+            std.debug.print("Error executing git diff: {}", .{err});
+            std.process.exit(1);
+        };
+        const trimmed_diff = mem.trim(u8, diff_untrimmed, " \n\r");
+        const dirty_suffix = if (trimmed_diff.len == 0) "" else s: {
+            const dirty_hash = std.hash.Wyhash.hash(0, trimmed_diff);
+            break :s b.fmt("dirty{x}", .{@truncate(u32, dirty_hash)});
+        };
+
+        // This will look like e.g. "0.6.0^0" for a tag commit.
+        if (mem.endsWith(u8, git_sha_trimmed, "^0")) {
+            const git_ver_string = git_sha_trimmed[0 .. git_sha_trimmed.len - 2];
+            if (!mem.eql(u8, git_ver_string, version_string)) {
+                std.debug.print("Expected git tag '{}', found '{}'", .{ version_string, git_ver_string });
+                std.process.exit(1);
+            }
+            break :v b.fmt("{}{}", .{ version_string, dirty_suffix });
+        } else {
+            break :v b.fmt("{}+{}{}", .{ version_string, git_sha_trimmed, dirty_suffix });
+        }
+    };
+    exe.addBuildOption([]const u8, "version", version);
+
+    exe.addBuildOption([]const []const u8, "log_scopes", log_scopes);
+    exe.addBuildOption([]const []const u8, "zir_dumps", zir_dumps);
+    exe.addBuildOption(bool, "enable_tracy", tracy != null);
+    if (tracy) |tracy_path| {
+        const client_cpp = fs.path.join(
+            b.allocator,
+            &[_][]const u8{ tracy_path, "TracyClient.cpp" },
+        ) catch unreachable;
+        exe.addIncludeDir(tracy_path);
+        exe.addCSourceFile(client_cpp, &[_][]const u8{ "-DTRACY_ENABLE=1", "-fno-sanitize=undefined" });
+        exe.linkSystemLibraryName("c++");
+        exe.linkLibC();
+    }
+
     const test_filter = b.option([]const u8, "test-filter", "Skip tests that do not match filter");
 
     const is_wine_enabled = b.option(bool, "enable-wine", "Use Wine to run cross compiled Windows tests") orelse false;
@@ -144,6 +166,7 @@ pub fn build(b: *Builder) !void {
     test_stage2.addBuildOption(bool, "enable_wine", is_wine_enabled);
     test_stage2.addBuildOption(bool, "enable_wasmtime", is_wasmtime_enabled);
     test_stage2.addBuildOption(?[]const u8, "glibc_multi_install_dir", glibc_multi_dir);
+    test_stage2.addBuildOption([]const u8, "version", version);
 
     const test_stage2_step = b.step("test-stage2", "Run the stage2 compiler tests");
     test_stage2_step.dependOn(&test_stage2.step);