Add comments to `builtin.odin`, documenting ODIN_* constants. (#5218)

And document constants not previously listed.

4 files changed, 101 insertions, 81 deletions

diff --git a/src/build_settings.cpp b/src/build_settings.cpp
index 00594c1b4..9d1685cd7 100644
--- a/src/build_settings.cpp
+++ b/src/build_settings.cpp
@@ -31,6 +31,24 @@ enum TargetOsKind : u16 {
 	TargetOs_COUNT,
 };
 
+gb_global String target_os_names[TargetOs_COUNT] = {
+	str_lit(""),
+	str_lit("windows"),
+	str_lit("darwin"),
+	str_lit("linux"),
+	str_lit("essence"),
+	str_lit("freebsd"),
+	str_lit("openbsd"),
+	str_lit("netbsd"),
+	str_lit("haiku"),
+
+	str_lit("wasi"),
+	str_lit("js"),
+	str_lit("orca"),
+
+	str_lit("freestanding"),
+};
+
 enum TargetArchKind : u16 {
 	TargetArch_Invalid,
 
@@ -45,6 +63,17 @@ enum TargetArchKind : u16 {
 	TargetArch_COUNT,
 };
 
+gb_global String target_arch_names[TargetArch_COUNT] = {
+	str_lit(""),
+	str_lit("amd64"),
+	str_lit("i386"),
+	str_lit("arm32"),
+	str_lit("arm64"),
+	str_lit("wasm32"),
+	str_lit("wasm64p32"),
+	str_lit("riscv64"),
+};
+
 enum TargetEndianKind : u8 {
 	TargetEndian_Little,
 	TargetEndian_Big,
@@ -52,6 +81,11 @@ enum TargetEndianKind : u8 {
 	TargetEndian_COUNT,
 };
 
+gb_global String target_endian_names[TargetEndian_COUNT] = {
+	str_lit("little"),
+	str_lit("big"),
+};
+
 enum TargetABIKind : u16 {
 	TargetABI_Default,
 
@@ -61,7 +95,14 @@ enum TargetABIKind : u16 {
 	TargetABI_COUNT,
 };
 
+gb_global String target_abi_names[TargetABI_COUNT] = {
+	str_lit(""),
+	str_lit("win64"),
+	str_lit("sysv"),
+};
+
 enum Windows_Subsystem : u8 {
+	Windows_Subsystem_UNKNOWN,
  	Windows_Subsystem_BOOT_APPLICATION,
 	Windows_Subsystem_CONSOLE,                 // Default,
 	Windows_Subsystem_EFI_APPLICATION,
@@ -75,38 +116,23 @@ enum Windows_Subsystem : u8 {
 	Windows_Subsystem_COUNT,
 };
 
-struct MicroarchFeatureList {
-	String microarch;
-	String features;
-};
-
-gb_global String target_os_names[TargetOs_COUNT] = {
+gb_global String windows_subsystem_names[Windows_Subsystem_COUNT] = {
 	str_lit(""),
-	str_lit("windows"),
-	str_lit("darwin"),
-	str_lit("linux"),
-	str_lit("essence"),
-	str_lit("freebsd"),
-	str_lit("openbsd"),
-	str_lit("netbsd"),
-	str_lit("haiku"),
-	
-	str_lit("wasi"),
-	str_lit("js"),
-	str_lit("orca"),
-
-	str_lit("freestanding"),
+	str_lit("BOOT_APPLICATION"),
+	str_lit("CONSOLE"), // Default
+	str_lit("EFI_APPLICATION"),
+	str_lit("EFI_BOOT_SERVICE_DRIVER"),
+	str_lit("EFI_ROM"),
+	str_lit("EFI_RUNTIME_DRIVER"),
+	str_lit("NATIVE"),
+	str_lit("POSIX"),
+	str_lit("WINDOWS"),
+	str_lit("WINDOWSCE"),
 };
 
-gb_global String target_arch_names[TargetArch_COUNT] = {
-	str_lit(""),
-	str_lit("amd64"),
-	str_lit("i386"),
-	str_lit("arm32"),
-	str_lit("arm64"),
-	str_lit("wasm32"),
-	str_lit("wasm64p32"),
-	str_lit("riscv64"),
+struct MicroarchFeatureList {
+	String microarch;
+	String features;
 };
 
 #if defined(GB_SYSTEM_WINDOWS)
@@ -114,20 +140,8 @@ gb_global String target_arch_names[TargetArch_COUNT] = {
 #else
 	#include <llvm/Config/llvm-config.h>
 #endif
-
 #include "build_settings_microarch.cpp"
 
-gb_global String target_endian_names[TargetEndian_COUNT] = {
-	str_lit("little"),
-	str_lit("big"),
-};
-
-gb_global String target_abi_names[TargetABI_COUNT] = {
-	str_lit(""),
-	str_lit("win64"),
-	str_lit("sysv"),
-};
-
 gb_global TargetEndianKind target_endians[TargetArch_COUNT] = {
 	TargetEndian_Little,
 	TargetEndian_Little,
@@ -138,19 +152,6 @@ gb_global TargetEndianKind target_endians[TargetArch_COUNT] = {
 	TargetEndian_Little,
 };
 
-gb_global String windows_subsystem_names[Windows_Subsystem_COUNT] = {
-	str_lit("BOOT_APPLICATION"),
-	str_lit("CONSOLE"),                 // Default
-	str_lit("EFI_APPLICATION"),
-	str_lit("EFI_BOOT_SERVICE_DRIVER"),
-	str_lit("EFI_ROM"),
-	str_lit("EFI_RUNTIME_DRIVER"),
-	str_lit("NATIVE"),
-	str_lit("POSIX"),
-	str_lit("WINDOWS"),
-	str_lit("WINDOWSCE"),
-};
-
 #ifndef ODIN_VERSION_RAW
 #define ODIN_VERSION_RAW "dev-unknown-unknown"
 #endif
@@ -393,17 +394,17 @@ String linker_choices[Linker_COUNT] = {
 // This stores the information for the specify architecture of this build
 struct BuildContext {
 	// Constants
-	String ODIN_OS;                       // Target operating system
-	String ODIN_ARCH;                     // Target architecture
-	String ODIN_VENDOR;                   // Compiler vendor
-	String ODIN_VERSION;                  // Compiler version
-	String ODIN_ROOT;                     // Odin ROOT
-	String ODIN_BUILD_PROJECT_NAME;       // Odin main/initial package's directory name
-	String ODIN_WINDOWS_SUBSYSTEM;        // Empty string for non-Windows targets
-	bool   ODIN_DEBUG;                    // Odin in debug mode
-	bool   ODIN_DISABLE_ASSERT;           // Whether the default 'assert' et al is disabled in code or not
-	bool   ODIN_DEFAULT_TO_NIL_ALLOCATOR; // Whether the default allocator is a "nil" allocator or not (i.e. it does nothing)
-	bool   ODIN_DEFAULT_TO_PANIC_ALLOCATOR; // Whether the default allocator is a "panic" allocator or not (i.e. panics on any call to it)
+	String ODIN_OS;                           // Target operating system
+	String ODIN_ARCH;                         // Target architecture
+	String ODIN_VENDOR;                       // Compiler vendor
+	String ODIN_VERSION;                      // Compiler version
+	String ODIN_ROOT;                         // Odin ROOT
+	String ODIN_BUILD_PROJECT_NAME;           // Odin main/initial package's directory name
+	Windows_Subsystem ODIN_WINDOWS_SUBSYSTEM; // .Console, .Windows
+	bool   ODIN_DEBUG;                        // Odin in debug mode
+	bool   ODIN_DISABLE_ASSERT;               // Whether the default 'assert' et al is disabled in code or not
+	bool   ODIN_DEFAULT_TO_NIL_ALLOCATOR;     // Whether the default allocator is a "nil" allocator or not (i.e. it does nothing)
+	bool   ODIN_DEFAULT_TO_PANIC_ALLOCATOR;   // Whether the default allocator is a "panic" allocator or not (i.e. panics on any call to it)
 	bool   ODIN_FOREIGN_ERROR_PROCEDURES;
 	bool   ODIN_VALGRIND_SUPPORT;
 
@@ -1788,8 +1789,8 @@ gb_internal void init_build_context(TargetMetrics *cross_target, Subtarget subta
 	}
 
 	// Default to subsystem:CONSOLE on Windows targets
-	if (bc->ODIN_WINDOWS_SUBSYSTEM == "" && bc->metrics.os == TargetOs_windows) {
-		bc->ODIN_WINDOWS_SUBSYSTEM = windows_subsystem_names[Windows_Subsystem_CONSOLE];
+	if (bc->ODIN_WINDOWS_SUBSYSTEM == Windows_Subsystem_UNKNOWN && bc->metrics.os == TargetOs_windows) {
+		bc->ODIN_WINDOWS_SUBSYSTEM = Windows_Subsystem_CONSOLE;
 	}
 
 	if (subtarget == Subtarget_Android) {
diff --git a/src/checker.cpp b/src/checker.cpp
index aaa815365..9bc02cd87 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -1078,11 +1078,30 @@ gb_internal void init_universal(void) {
 	add_global_bool_constant("true",  true);
 	add_global_bool_constant("false", false);
 
-	add_global_string_constant("ODIN_VENDOR",             bc->ODIN_VENDOR);
-	add_global_string_constant("ODIN_VERSION",            bc->ODIN_VERSION);
-	add_global_string_constant("ODIN_ROOT",               bc->ODIN_ROOT);
-	add_global_string_constant("ODIN_BUILD_PROJECT_NAME", bc->ODIN_BUILD_PROJECT_NAME);
-	add_global_string_constant("ODIN_WINDOWS_SUBSYSTEM",  bc->ODIN_WINDOWS_SUBSYSTEM);
+	add_global_string_constant("ODIN_VENDOR",                   bc->ODIN_VENDOR);
+	add_global_string_constant("ODIN_VERSION",                  bc->ODIN_VERSION);
+	add_global_string_constant("ODIN_ROOT",                     bc->ODIN_ROOT);
+	add_global_string_constant("ODIN_BUILD_PROJECT_NAME",       bc->ODIN_BUILD_PROJECT_NAME);
+
+	{
+		GlobalEnumValue values[Windows_Subsystem_COUNT] = {
+			{"Unknown",                 Windows_Subsystem_UNKNOWN},
+		 	{"Boot_Application",        Windows_Subsystem_BOOT_APPLICATION},
+			{"Console",                 Windows_Subsystem_CONSOLE},
+			{"EFI_Application",         Windows_Subsystem_EFI_APPLICATION},
+			{"EFI_Boot_Service_Driver", Windows_Subsystem_EFI_BOOT_SERVICE_DRIVER},
+			{"EFI_Rom",                 Windows_Subsystem_EFI_ROM},
+			{"EFI_Runtime_Driver",      Windows_Subsystem_EFI_RUNTIME_DRIVER},
+			{"Native",                  Windows_Subsystem_NATIVE},
+			{"Posix",                   Windows_Subsystem_POSIX},
+			{"Windows",                 Windows_Subsystem_WINDOWS},
+			{"Windows_CE",              Windows_Subsystem_WINDOWSCE},
+		};
+
+		auto fields = add_global_enum_type(str_lit("Odin_Windows_Subsystem_Type"), values, gb_count_of(values));
+		add_global_enum_constant(fields, "ODIN_WINDOWS_SUBSYSTEM",  bc->ODIN_WINDOWS_SUBSYSTEM);
+		add_global_string_constant("ODIN_WINDOWS_SUBSYSTEM_STRING", windows_subsystem_names[bc->ODIN_WINDOWS_SUBSYSTEM]);
+	}
 
 	{
 		GlobalEnumValue values[TargetOs_COUNT] = {
@@ -1102,7 +1121,7 @@ gb_internal void init_universal(void) {
 		};
 
 		auto fields = add_global_enum_type(str_lit("Odin_OS_Type"), values, gb_count_of(values));
-		add_global_enum_constant(fields, "ODIN_OS", bc->metrics.os);
+		add_global_enum_constant(fields, "ODIN_OS",  bc->metrics.os);
 		add_global_string_constant("ODIN_OS_STRING", target_os_names[bc->metrics.os]);
 	}
 
diff --git a/src/linker.cpp b/src/linker.cpp
index 447d66d0a..71aee3a3b 100644
--- a/src/linker.cpp
+++ b/src/linker.cpp
@@ -321,7 +321,7 @@ try_cross_linking:;
 					"",
 					LIT(build_context.ODIN_ROOT), object_files, LIT(output_filename),
 					link_settings,
-					LIT(build_context.ODIN_WINDOWS_SUBSYSTEM),
+					LIT(windows_subsystem_names[build_context.ODIN_WINDOWS_SUBSYSTEM]),
 					LIT(build_context.link_flags),
 					LIT(build_context.extra_linker_flags),
 					lib_str
@@ -341,7 +341,7 @@ try_cross_linking:;
 					"",
 					LIT(build_context.ODIN_ROOT), object_files, LIT(output_filename),
 					link_settings,
-					LIT(build_context.ODIN_WINDOWS_SUBSYSTEM),
+					LIT(windows_subsystem_names[build_context.ODIN_WINDOWS_SUBSYSTEM]),
 					LIT(build_context.link_flags),
 					LIT(build_context.extra_linker_flags),
 					lib_str
@@ -404,7 +404,7 @@ try_cross_linking:;
 					"",
 					LIT(vs_exe_path), LIT(linker_name), object_files, LIT(res_path), LIT(output_filename),
 					link_settings,
-					LIT(build_context.ODIN_WINDOWS_SUBSYSTEM),
+					LIT(windows_subsystem_names[build_context.ODIN_WINDOWS_SUBSYSTEM]),
 					LIT(build_context.link_flags),
 					LIT(build_context.extra_linker_flags),
 					lib_str
diff --git a/src/main.cpp b/src/main.cpp
index 1ffdd0dba..dfc2f3213 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1627,9 +1627,9 @@ gb_internal bool parse_build_flags(Array<String> args) {
 							GB_ASSERT(value.kind == ExactValue_String);
 							String subsystem = value.value_string;
 							bool subsystem_found = false;
-							for (int i = 0; i < Windows_Subsystem_COUNT; i++) {
+							for (int i = 1; i < Windows_Subsystem_COUNT; i++) {
 								if (str_eq_ignore_case(subsystem, windows_subsystem_names[i])) {
-									build_context.ODIN_WINDOWS_SUBSYSTEM = windows_subsystem_names[i];
+									build_context.ODIN_WINDOWS_SUBSYSTEM = Windows_Subsystem(i);
 									subsystem_found = true;
 									break;
 								}
@@ -1638,7 +1638,7 @@ gb_internal bool parse_build_flags(Array<String> args) {
 							// WINDOW is a hidden alias for WINDOWS. Check it.
 							String subsystem_windows_alias = str_lit("WINDOW");
 							if (!subsystem_found && str_eq_ignore_case(subsystem, subsystem_windows_alias)) {
-								build_context.ODIN_WINDOWS_SUBSYSTEM = windows_subsystem_names[Windows_Subsystem_WINDOWS];
+								build_context.ODIN_WINDOWS_SUBSYSTEM = Windows_Subsystem_WINDOWS;
 								subsystem_found = true;
 								break;
 							}
@@ -1646,8 +1646,8 @@ gb_internal bool parse_build_flags(Array<String> args) {
 							if (!subsystem_found) {
 								gb_printf_err("Invalid -subsystem string, got %.*s. Expected one of:\n", LIT(subsystem));
 								gb_printf_err("\t");
-								for (int i = 0; i < Windows_Subsystem_COUNT; i++) {
-									if (i > 0) {
+								for (int i = 1; i < Windows_Subsystem_COUNT; i++) {
+									if (i > 1) {
 										gb_printf_err(", ");
 									}
 									gb_printf_err("%.*s", LIT(windows_subsystem_names[i]));