Merge branch 'Vexu-build-start'

closes #3810
closes #3793
closes #3798

1 files changed, 21 insertions, 42 deletions

diff --git a/src/codegen.cpp b/src/codegen.cpp
index dc29e8f4b1..324a32485e 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -8229,9 +8229,9 @@ TargetSubsystem detect_subsystem(CodeGen *g) {
     if (g->zig_target->os == OsWindows) {
         if (g->have_dllmain_crt_startup || (g->out_type == OutTypeLib && g->is_dynamic))
             return TargetSubsystemAuto;
-        if (g->have_c_main || g->have_pub_main || g->is_test_build)
+        if (g->have_c_main || g->is_test_build || g->have_winmain_crt_startup)
             return TargetSubsystemConsole;
-        if (g->have_winmain || g->have_winmain_crt_startup)
+        if (g->have_winmain)
             return TargetSubsystemWindows;
     } else if (g->zig_target->os == OsUefi) {
         return TargetSubsystemEfiApplication;
@@ -8375,6 +8375,22 @@ Buf *codegen_generate_builtin_source(CodeGen *g) {
         const char *endian_str = g->is_big_endian ? "Endian.Big" : "Endian.Little";
         buf_appendf(contents, "pub const endian = %s;\n", endian_str);
     }
+    const char *out_type = nullptr;
+    switch (g->out_type) {
+        case OutTypeExe:
+            out_type = "Exe";
+            break;
+        case OutTypeLib:
+            out_type = "Lib";
+            break;
+        case OutTypeObj:
+        case OutTypeUnknown: // This happens when running the `zig builtin` command.
+            out_type = "Obj";
+            break;
+    }
+    buf_appendf(contents, "pub const output_mode = OutputMode.%s;\n", out_type);
+    const char *link_type = g->is_dynamic ? "Dynamic" : "Static"; 
+    buf_appendf(contents, "pub const link_mode = LinkMode.%s;\n", link_type);
     buf_appendf(contents, "pub const is_test = %s;\n", bool_to_str(g->is_test_build));
     buf_appendf(contents, "pub const single_threaded = %s;\n", bool_to_str(g->is_single_threaded));
     buf_appendf(contents, "pub const os = Os.%s;\n", cur_os);
@@ -8441,6 +8457,8 @@ static Error define_builtin_compile_vars(CodeGen *g) {
     cache_buf(&cache_hash, compiler_id);
     cache_int(&cache_hash, g->build_mode);
     cache_bool(&cache_hash, g->strip_debug_symbols);
+    cache_int(&cache_hash, g->out_type);
+    cache_bool(&cache_hash, g->is_dynamic);
     cache_bool(&cache_hash, g->is_test_build);
     cache_bool(&cache_hash, g->is_single_threaded);
     cache_int(&cache_hash, g->zig_target->is_native);
@@ -9148,38 +9166,6 @@ static Buf *get_resolved_root_src_path(CodeGen *g) {
     return resolved_path;
 }
 
-static bool want_startup_code(CodeGen *g) {
-    // Test builds get handled separately.
-    if (g->is_test_build)
-        return false;
-
-    // WASM freestanding can still have an entry point but other freestanding targets do not.
-    if (g->zig_target->os == OsFreestanding && !target_is_wasm(g->zig_target))
-        return false;
-
-    // Declaring certain export functions means skipping the start code
-    if (g->have_c_main || g->have_winmain || g->have_winmain_crt_startup)
-        return false;
-
-    // If there is a pub main in the root source file, that means we need start code.
-    if (g->have_pub_main) {
-        return true;
-    } else {
-        if (g->zig_target->os == OsUefi)
-            return false;
-    }
-
-    if (g->out_type == OutTypeExe) {
-        // For build-exe, we might add start code even though there is no pub main, so that the
-        // programmer gets the "no pub main" compile error. However if linking libc and there is
-        // a C source file, that might have main().
-        return g->c_source_files.length == 0 || g->libc_link_lib == nullptr;
-    }
-
-    // For objects and libraries, and we don't have pub main, no start code.
-    return false;
-}
-
 static void gen_root_source(CodeGen *g) {
     Buf *resolved_path = get_resolved_root_src_path(g);
     if (resolved_path == nullptr)
@@ -9241,21 +9227,14 @@ static void gen_root_source(CodeGen *g) {
         assert(g->panic_fn != nullptr);
     }
 
-
     if (!g->error_during_imports) {
         semantic_analyze(g);
     }
     report_errors_and_maybe_exit(g);
 
-    if (want_startup_code(g)) {
+    if (!g->is_test_build) {
         g->start_import = add_special_code(g, create_start_pkg(g, g->root_package), "start.zig");
     }
-    if (g->zig_target->os == OsWindows && !g->have_dllmain_crt_startup &&
-            g->out_type == OutTypeLib && g->is_dynamic)
-    {
-        g->start_import = add_special_code(g, create_start_pkg(g, g->root_package), "start_lib.zig");
-    }
-
     if (!g->error_during_imports) {
         semantic_analyze(g);
     }