Commit `fff3c1fff4`

Andrew Kelley <andrew@ziglang.org>

2019-12-13 00:27:17

un-special-case startup code in the std lib

Previously, the compiler had special logic to determine whether to include the startup code, which was in `std/special/start.zig`. Now, the file is moved to `std/start.zig`, and there is no special logic in the compiler. Instead, the standard library unconditionally imports the `start.zig` file, which then has a `comptime` block that does the logic of determining what, if any, start symbols to export. Instead of `start.zig` being in its own special package, it is just another normal file that is part of the standard library. `std.builtin.TestFn` is now part of the standard library rather than specially generated by the compiler.

master

1 parent b37acc4

Changed files (13)

lib

std

special

start_windows_tls.zig

src

@@ -1,9 +1,9 @@
 const std = @import("std");
 const io = std.io;
 const builtin = @import("builtin");
-const test_fn_list = builtin.test_functions;
 
 pub fn main() anyerror!void {
+    const test_fn_list = builtin.test_functions;
     var ok_count: usize = 0;
     var skip_count: usize = 0;
     var progress = std.Progress{};
@@ -16,7 +16,9 @@ pub fn main() anyerror!void {
         var test_node = root_node.start(test_fn.name, null);
         test_node.activate();
         progress.refresh();
-        if (progress.terminal == null) std.debug.warn("{}/{} {}...", .{ i + 1, test_fn_list.len, test_fn.name });
+        if (progress.terminal == null) {
+            std.debug.warn("{}/{} {}...", .{ i + 1, test_fn_list.len, test_fn.name });
+        }
         if (test_fn.func()) |_| {
             ok_count += 1;
             test_node.end();

@@ -412,6 +412,13 @@ pub const CallOptions = struct {
     };
 };
 
+/// This function type is used by the Zig language code generation and
+/// therefore must be kept in sync with the compiler implementation.
+pub const TestFn = struct {
+    name: []const u8,
+    func: fn()anyerror!void,
+};
+
 /// This function type is used by the Zig language code generation and
 /// therefore must be kept in sync with the compiler implementation.
 pub const PanicFn = fn ([]const u8, ?*StackTrace) noreturn;

@@ -1,1 +0,0 @@
-pub const start = @import("special/start.zig");

@@ -1,8 +1,8 @@
 // This file is included in the compilation unit when exporting an executable.
 
 const root = @import("root");
-const std = @import("std");
-const builtin = @import("builtin");
+const std = @import("std.zig");
+const builtin = std.builtin;
 const assert = std.debug.assert;
 const uefi = std.os.uefi;

@@ -1,5 +1,5 @@
 const std = @import("std");
-const builtin = @import("builtin");
+const builtin = std.builtin;
 
 export var _tls_index: u32 = std.os.windows.TLS_OUT_OF_INDEXES;
 export var _tls_start: u8 linksection(".tls") = 0;

@@ -65,7 +65,13 @@ pub const time = @import("time.zig");
 pub const unicode = @import("unicode.zig");
 pub const valgrind = @import("valgrind.zig");
 pub const zig = @import("zig.zig");
-pub const special = @import("special.zig");
+pub const start = @import("start.zig");
+
+// This forces the start.zig file to be imported, and the comptime logic inside that
+// file decides whether to export any appropriate start symbols.
+comptime {
+    _ = start;
+}
 
 test "" {
     meta.refAllDecls(@This());

@@ -2003,10 +2003,11 @@ struct CodeGen {
     ZigPackage *std_package;
     ZigPackage *test_runner_package;
     ZigPackage *compile_var_package;
+    ZigPackage *root_pkg; // @import("root")
+    ZigPackage *main_pkg; // usually same as root_pkg, except for `zig test`
     ZigType *compile_var_import;
     ZigType *root_import;
     ZigType *start_import;
-    ZigType *test_runner_import;
 
     struct {
         ZigType *entry_bool;
@@ -2179,7 +2180,6 @@ struct CodeGen {
     Buf *root_out_name;
     Buf *test_filter;
     Buf *test_name_prefix;
-    ZigPackage *root_package;
     Buf *zig_lib_dir;
     Buf *zig_std_dir;
     Buf *dynamic_linker_path;

@@ -3536,7 +3536,7 @@ static void preview_test_decl(CodeGen *g, AstNode *node, ScopeDecls *decls_scope
         return;
 
     ZigType *import = get_scope_import(&decls_scope->base);
-    if (import->data.structure.root_struct->package != g->root_package)
+    if (import->data.structure.root_struct->package != g->main_pkg)
         return;
 
     Buf *decl_name_buf = node->data.test_decl.name;
@@ -3577,7 +3577,7 @@ void update_compile_var(CodeGen *g, Buf *name, ZigValue *value) {
     resolve_top_level_decl(g, tld, tld->source_node, false);
     assert(tld->id == TldIdVar);
     TldVar *tld_var = (TldVar *)tld;
-    tld_var->var->const_value = value;
+    copy_const_val(tld_var->var->const_value, value);
     tld_var->var->var_type = value->type;
     tld_var->var->align_bytes = get_abi_alignment(g, value->type);
 }
@@ -9178,3 +9178,42 @@ bool is_anon_container(ZigType *ty) {
         ty->data.structure.special == StructSpecialInferredTuple ||
         ty->data.structure.special == StructSpecialInferredStruct);
 }
+
+bool is_opt_err_set(ZigType *ty) {
+    return ty->id == ZigTypeIdErrorSet ||
+        (ty->id == ZigTypeIdOptional && ty->data.maybe.child_type->id == ZigTypeIdErrorSet);
+}
+
+// Returns whether the x_optional field of ZigValue is active.
+bool type_has_optional_repr(ZigType *ty) {
+    if (ty->id != ZigTypeIdOptional) {
+        return false;
+    } else if (get_codegen_ptr_type(ty) != nullptr) {
+        return false;
+    } else if (is_opt_err_set(ty)) {
+        return false;
+    } else {
+        return true;
+    }
+}
+
+void copy_const_val(ZigValue *dest, ZigValue *src) {
+    memcpy(dest, src, sizeof(ZigValue));
+    if (src->special != ConstValSpecialStatic)
+        return;
+    dest->parent.id = ConstParentIdNone;
+    if (dest->type->id == ZigTypeIdStruct) {
+        dest->data.x_struct.fields = alloc_const_vals_ptrs(dest->type->data.structure.src_field_count);
+        for (size_t i = 0; i < dest->type->data.structure.src_field_count; i += 1) {
+            copy_const_val(dest->data.x_struct.fields[i], src->data.x_struct.fields[i]);
+            dest->data.x_struct.fields[i]->parent.id = ConstParentIdStruct;
+            dest->data.x_struct.fields[i]->parent.data.p_struct.struct_val = dest;
+            dest->data.x_struct.fields[i]->parent.data.p_struct.field_index = i;
+        }
+    } else if (type_has_optional_repr(dest->type) && dest->data.x_optional != nullptr) {
+        dest->data.x_optional = create_const_vals(1);
+        copy_const_val(dest->data.x_optional, src->data.x_optional);
+        dest->data.x_optional->parent.id = ConstParentIdOptionalPayload;
+        dest->data.x_optional->parent.data.p_optional_payload.optional_val = dest;
+    }
+}

@@ -276,4 +276,7 @@ Error analyze_import(CodeGen *codegen, ZigType *source_import, Buf *import_targe
         ZigType **out_import, Buf **out_import_target_path, Buf *out_full_path);
 ZigValue *get_the_one_possible_value(CodeGen *g, ZigType *type_entry);
 bool is_anon_container(ZigType *ty);
+void copy_const_val(ZigValue *dest, ZigValue *src);
+bool type_has_optional_repr(ZigType *ty);
+bool is_opt_err_set(ZigType *ty);
 #endif

@@ -8440,11 +8440,7 @@ Buf *codegen_generate_builtin_source(CodeGen *g) {
 
     if (g->is_test_build) {
         buf_appendf(contents,
-            "const TestFn = struct {\n"
-                "name: []const u8,\n"
-                "func: fn()anyerror!void,\n"
-            "};\n"
-            "pub const test_functions = {}; // overwritten later\n"
+            "pub var test_functions: []TestFn = undefined; // overwritten later\n"
         );
     }
 
@@ -8535,23 +8531,23 @@ static Error define_builtin_compile_vars(CodeGen *g) {
         }
     }
 
-    assert(g->root_package);
+    assert(g->main_pkg);
     assert(g->std_package);
     g->compile_var_package = new_package(buf_ptr(this_dir), builtin_zig_basename, "builtin");
-    g->compile_var_package->package_table.put(buf_create_from_str("std"), g->std_package);
-    g->root_package->package_table.put(buf_create_from_str("builtin"), g->compile_var_package);
-    g->std_package->package_table.put(buf_create_from_str("builtin"), g->compile_var_package);
-    g->std_package->package_table.put(buf_create_from_str("std"), g->std_package);
-    ZigPackage *root_pkg;
     if (g->is_test_build) {
         if (g->test_runner_package == nullptr) {
             g->test_runner_package = create_test_runner_pkg(g);
         }
-        root_pkg = g->test_runner_package;
+        g->root_pkg = g->test_runner_package;
     } else {
-        root_pkg = g->root_package;
+        g->root_pkg = g->main_pkg;
     }
-    g->std_package->package_table.put(buf_create_from_str("root"), root_pkg);
+    g->compile_var_package->package_table.put(buf_create_from_str("std"), g->std_package);
+    g->main_pkg->package_table.put(buf_create_from_str("builtin"), g->compile_var_package);
+    g->main_pkg->package_table.put(buf_create_from_str("root"), g->root_pkg);
+    g->std_package->package_table.put(buf_create_from_str("builtin"), g->compile_var_package);
+    g->std_package->package_table.put(buf_create_from_str("std"), g->std_package);
+    g->std_package->package_table.put(buf_create_from_str("root"), g->root_pkg);
     g->compile_var_import = add_source_file(g, g->compile_var_package, builtin_zig_path, contents,
             SourceKindPkgMain);
 
@@ -8670,7 +8666,7 @@ static void init(CodeGen *g) {
     // no longer reference DW_AT_comp_dir, for the purpose of being able to support the
     // common practice of stripping all but the line number sections from an executable.
     const char *compile_unit_dir = target_os_is_darwin(g->zig_target->os) ? "." :
-        buf_ptr(&g->root_package->root_src_dir);
+        buf_ptr(&g->main_pkg->root_src_dir);
 
     ZigLLVMDIFile *compile_unit_file = ZigLLVMCreateFile(g->dbuilder, buf_ptr(g->root_out_name),
             compile_unit_dir);
@@ -9083,30 +9079,7 @@ void codegen_translate_c(CodeGen *g, Buf *full_path, FILE *out_file, bool use_us
     }
 }
 
-static ZigType *add_special_code(CodeGen *g, ZigPackage *package, const char *basename) {
-    Buf *code_basename = buf_create_from_str(basename);
-    Buf path_to_code_src = BUF_INIT;
-    os_path_join(g->zig_std_special_dir, code_basename, &path_to_code_src);
-
-    Buf *resolve_paths[] = {&path_to_code_src};
-    Buf *resolved_path = buf_alloc();
-    *resolved_path = os_path_resolve(resolve_paths, 1);
-    Buf *import_code = buf_alloc();
-    Error err;
-    if ((err = file_fetch(g, resolved_path, import_code))) {
-        zig_panic("unable to open '%s': %s\n", buf_ptr(&path_to_code_src), err_str(err));
-    }
-
-    return add_source_file(g, package, resolved_path, import_code, SourceKindPkgMain);
-}
-
-static ZigPackage *create_start_pkg(CodeGen *g, ZigPackage *pkg_with_main) {
-    ZigPackage *package = codegen_create_package(g, buf_ptr(g->zig_std_special_dir), "start.zig", "std.special");
-    package->package_table.put(buf_create_from_str("root"), pkg_with_main);
-    return package;
-}
-
-static void create_test_compile_var_and_add_test_runner(CodeGen *g) {
+static void update_test_functions_builtin_decl(CodeGen *g) {
     Error err;
 
     assert(g->is_test_build);
@@ -9166,16 +9139,15 @@ static void create_test_compile_var_and_add_test_runner(CodeGen *g) {
 
     update_compile_var(g, buf_create_from_str("test_functions"), test_fn_slice);
     assert(g->test_runner_package != nullptr);
-    g->test_runner_import = add_special_code(g, g->test_runner_package, "test_runner.zig");
 }
 
 static Buf *get_resolved_root_src_path(CodeGen *g) {
     // TODO memoize
-    if (buf_len(&g->root_package->root_src_path) == 0)
+    if (buf_len(&g->main_pkg->root_src_path) == 0)
         return nullptr;
 
     Buf rel_full_path = BUF_INIT;
-    os_path_join(&g->root_package->root_src_dir, &g->root_package->root_src_path, &rel_full_path);
+    os_path_join(&g->main_pkg->root_src_dir, &g->main_pkg->root_src_path, &rel_full_path);
 
     Buf *resolved_path = buf_alloc();
     Buf *resolve_paths[] = {&rel_full_path};
@@ -9198,7 +9170,7 @@ static void gen_root_source(CodeGen *g) {
         exit(1);
     }
 
-    ZigType *root_import_alias = add_source_file(g, g->root_package, resolved_path, source_code, SourceKindRoot);
+    ZigType *root_import_alias = add_source_file(g, g->main_pkg, resolved_path, source_code, SourceKindRoot);
     assert(root_import_alias == g->root_import);
 
     assert(g->root_out_name);
@@ -9250,16 +9222,8 @@ static void gen_root_source(CodeGen *g) {
     }
     report_errors_and_maybe_exit(g);
 
-    if (!g->is_test_build) {
-        g->start_import = add_special_code(g, create_start_pkg(g, g->root_package), "start.zig");
-    }
-    if (!g->error_during_imports) {
-        semantic_analyze(g);
-    }
     if (g->is_test_build) {
-        create_test_compile_var_and_add_test_runner(g);
-        g->start_import = add_special_code(g, create_start_pkg(g, g->test_runner_package), "start.zig");
-
+        update_test_functions_builtin_decl(g);
         if (!g->error_during_imports) {
             semantic_analyze(g);
         }
@@ -10058,7 +10022,7 @@ static Error check_cache(CodeGen *g, Buf *manifest_dir, Buf *digest) {
     CacheHash *ch = &g->cache_hash;
     cache_init(ch, manifest_dir);
 
-    add_cache_pkg(g, ch, g->root_package);
+    add_cache_pkg(g, ch, g->main_pkg);
     if (g->linker_script != nullptr) {
         cache_file(ch, buf_create_from_str(g->linker_script));
     }
@@ -10141,7 +10105,7 @@ static Error check_cache(CodeGen *g, Buf *manifest_dir, Buf *digest) {
 }
 
 static bool need_llvm_module(CodeGen *g) {
-    return buf_len(&g->root_package->root_src_path) != 0;
+    return buf_len(&g->main_pkg->root_src_path) != 0;
 }
 
 static void resolve_out_paths(CodeGen *g) {
@@ -10388,8 +10352,7 @@ ZigPackage *codegen_create_package(CodeGen *g, const char *root_src_dir, const c
         assert(g->compile_var_package != nullptr);
         pkg->package_table.put(buf_create_from_str("std"), g->std_package);
 
-        ZigPackage *main_pkg = g->is_test_build ? g->test_runner_package : g->root_package;
-        pkg->package_table.put(buf_create_from_str("root"), main_pkg);
+        pkg->package_table.put(buf_create_from_str("root"), g->root_pkg);
 
         pkg->package_table.put(buf_create_from_str("builtin"), g->compile_var_package);
     }
@@ -10516,15 +10479,13 @@ CodeGen *codegen_create(Buf *main_pkg_path, Buf *root_src_path, const ZigTarget
                     buf_len(&resolved_root_src_path) - buf_len(&resolved_main_pkg_path) - 1);
         }
 
-        g->root_package = new_package(buf_ptr(root_pkg_path), buf_ptr(rel_root_src_path), "");
+        g->main_pkg = new_package(buf_ptr(root_pkg_path), buf_ptr(rel_root_src_path), "");
         g->std_package = new_package(buf_ptr(g->zig_std_dir), "std.zig", "std");
-        g->root_package->package_table.put(buf_create_from_str("std"), g->std_package);
+        g->main_pkg->package_table.put(buf_create_from_str("std"), g->std_package);
     } else {
-        g->root_package = new_package(".", "", "");
+        g->main_pkg = new_package(".", "", "");
     }
 
-    g->root_package->package_table.put(buf_create_from_str("root"), g->root_package);
-
     g->zig_std_special_dir = buf_alloc();
     os_path_join(g->zig_std_dir, buf_sprintf("special"), g->zig_std_special_dir);

@@ -1216,7 +1216,7 @@ void zig_print_analysis_dump(CodeGen *g, FILE *f, const char *one_indent, const
     jw_end_object(jw);
 
     jw_object_field(jw, "rootPkg");
-    anal_dump_pkg_ref(&ctx, g->root_package);
+    anal_dump_pkg_ref(&ctx, g->main_pkg);
 
     // Poke the functions
     for (size_t i = 0; i < g->fn_defs.length; i += 1) {

@@ -232,7 +232,6 @@ static Error ir_read_const_ptr(IrAnalyze *ira, CodeGen *codegen, AstNode *source
 static IrInstruction *ir_analyze_ptr_cast(IrAnalyze *ira, IrInstruction *source_instr, IrInstruction *ptr,
         ZigType *dest_type, IrInstruction *dest_type_src, bool safety_check_on);
 static ZigValue *ir_resolve_const(IrAnalyze *ira, IrInstruction *value, UndefAllowed undef_allowed);
-static void copy_const_val(ZigValue *dest, ZigValue *src);
 static Error resolve_ptr_align(IrAnalyze *ira, ZigType *ty, uint32_t *result_align);
 static IrInstruction *ir_analyze_int_to_ptr(IrAnalyze *ira, IrInstruction *source_instr, IrInstruction *target,
         ZigType *ptr_type);
@@ -718,11 +717,6 @@ static ZigValue *const_ptr_pointee_unchecked(CodeGen *g, ZigValue *const_val) {
     return result;
 }
 
-static bool is_opt_err_set(ZigType *ty) {
-    return ty->id == ZigTypeIdErrorSet ||
-        (ty->id == ZigTypeIdOptional && ty->data.maybe.child_type->id == ZigTypeIdErrorSet);
-}
-
 static bool is_tuple(ZigType *type) {
     return type->id == ZigTypeIdStruct && type->data.structure.special == StructSpecialInferredTuple;
 }
@@ -11451,40 +11445,6 @@ static ZigType *ir_resolve_peer_types(IrAnalyze *ira, AstNode *source_node, ZigT
     }
 }
 
-// Returns whether the x_optional field of ZigValue is active.
-static bool type_has_optional_repr(ZigType *ty) {
-    if (ty->id != ZigTypeIdOptional) {
-        return false;
-    } else if (get_codegen_ptr_type(ty) != nullptr) {
-        return false;
-    } else if (is_opt_err_set(ty)) {
-        return false;
-    } else {
-        return true;
-    }
-}
-
-static void copy_const_val(ZigValue *dest, ZigValue *src) {
-    memcpy(dest, src, sizeof(ZigValue));
-    if (src->special != ConstValSpecialStatic)
-        return;
-    dest->parent.id = ConstParentIdNone;
-    if (dest->type->id == ZigTypeIdStruct) {
-        dest->data.x_struct.fields = alloc_const_vals_ptrs(dest->type->data.structure.src_field_count);
-        for (size_t i = 0; i < dest->type->data.structure.src_field_count; i += 1) {
-            copy_const_val(dest->data.x_struct.fields[i], src->data.x_struct.fields[i]);
-            dest->data.x_struct.fields[i]->parent.id = ConstParentIdStruct;
-            dest->data.x_struct.fields[i]->parent.data.p_struct.struct_val = dest;
-            dest->data.x_struct.fields[i]->parent.data.p_struct.field_index = i;
-        }
-    } else if (type_has_optional_repr(dest->type) && dest->data.x_optional != nullptr) {
-        dest->data.x_optional = create_const_vals(1);
-        copy_const_val(dest->data.x_optional, src->data.x_optional);
-        dest->data.x_optional->parent.id = ConstParentIdOptionalPayload;
-        dest->data.x_optional->parent.data.p_optional_payload.optional_val = dest;
-    }
-}
-
 static bool eval_const_expr_implicit_cast(IrAnalyze *ira, IrInstruction *source_instr,
         CastOp cast_op,
         ZigValue *other_val, ZigType *other_type,

@@ -623,7 +623,7 @@ int main(int argc, char **argv) {
 
         ZigPackage *build_pkg = codegen_create_package(g, buf_ptr(&build_file_dirname),
                 buf_ptr(&build_file_basename), "std.special");
-        g->root_package->package_table.put(buf_create_from_str("@build"), build_pkg);
+        g->main_pkg->package_table.put(buf_create_from_str("@build"), build_pkg);
         g->enable_cache = get_cache_opt(enable_cache, true);
         codegen_build_and_link(g);
         if (root_progress_node != nullptr) {
@@ -1269,7 +1269,7 @@ int main(int argc, char **argv) {
                 codegen_set_test_name_prefix(g, buf_create_from_str(test_name_prefix));
             }
 
-            add_package(g, cur_pkg, g->root_package);
+            add_package(g, cur_pkg, g->main_pkg);
 
             if (cmd == CmdBuild || cmd == CmdRun || cmd == CmdTest) {
                 g->c_source_files = c_source_files;

Commit fff3c1fff4

Commit `fff3c1fff4`