ZJIT: Handle ZJIT options properly (ruby#13197)

Author: k0kubun

ruby.c

@@ -307,7 +307,9 @@ usage(const char *name, int help, int highlight, int columns)
 #define M(shortopt, longopt, desc) RUBY_OPT_MESSAGE(shortopt, longopt, desc)
 
 #if USE_YJIT
-# define PLATFORM_JIT_OPTION "--yjit"
+# define DEFAULT_JIT_OPTION "--yjit"
+#elif USE_ZJIT
+# define DEFAULT_JIT_OPTION "--zjit"
 #endif
 
     /* This message really ought to be max 23 lines.
@@ -338,13 +340,15 @@ usage(const char *name, int help, int highlight, int columns)
         M("-W[level=2|:category]", "",             "Set warning flag ($-W):\n"
             "0 for silent; 1 for moderate; 2 for verbose."),
         M("-x[dirpath]",   "",			   "Execute Ruby code starting from a #!ruby line."),
-#if USE_YJIT
-        M("--jit",         "",                     "Enable JIT for the platform; same as " PLATFORM_JIT_OPTION "."),
+#if USE_YJIT || USE_ZJIT
+        M("--jit",         "",                     "Enable the default JIT for the build; same as " DEFAULT_JIT_OPTION "."),
 #endif
 #if USE_YJIT
         M("--yjit",        "",                     "Enable in-process JIT compiler."),
 #endif
-        M("--zjit",        "",                     "Enable in-process JIT compiler."),
+#if USE_ZJIT
+        M("--zjit",        "",                     "Enable method-based JIT compiler."),
+#endif
         M("-h",		   "",			   "Print this help message; use --help for longer message."),
     };
     STATIC_ASSERT(usage_msg_size, numberof(usage_msg) < 26);
@@ -381,6 +385,9 @@ usage(const char *name, int help, int highlight, int columns)
         M("frozen-string-literal", "", "Freeze all string literals (default: disabled)."),
 #if USE_YJIT
         M("yjit",                  "", "In-process JIT compiler (default: disabled)."),
+#endif
+#if USE_ZJIT
+        M("zjit",                  "", "Method-based JIT compiler (default: disabled)."),
 #endif
     };
     static const struct ruby_opt_message warn_categories[] = {
@@ -419,6 +426,11 @@ usage(const char *name, int help, int highlight, int columns)
     printf("%s""YJIT options:%s\n", sb, se);
     rb_yjit_show_usage(help, highlight, w, columns);
 #endif
+#if USE_ZJIT
+    printf("%s""ZJIT options:%s\n", sb, se);
+    extern void rb_zjit_show_usage(int help, int highlight, unsigned int width, int columns);
+    rb_zjit_show_usage(help, highlight, w, columns);
+#endif
 }
 
 #define rubylib_path_new rb_str_new
@@ -1993,7 +2005,7 @@ copy_str(VALUE str, rb_encoding *enc, bool intern)
     return rb_enc_interned_str(RSTRING_PTR(str), RSTRING_LEN(str), enc);
 }
 
-#if USE_YJIT
+#if USE_YJIT || USE_ZJIT
 // Check that an environment variable is set to a truthy value
 static bool
 env_var_truthy(const char *name)
@@ -2345,6 +2357,10 @@ process_options(int argc, char **argv, ruby_cmdline_options_t *opt)
         if (!FEATURE_USED_P(opt->features, yjit) && env_var_truthy("RUBY_YJIT_ENABLE")) {
             FEATURE_SET(opt->features, FEATURE_BIT(yjit));
         }
+#elif USE_ZJIT
+        if (!FEATURE_USED_P(opt->features, zjit) && env_var_truthy("RUBY_ZJIT_ENABLE")) {
+            FEATURE_SET(opt->features, FEATURE_BIT(zjit));
+        }
 #endif
     }
     if (MULTI_BITS_P(FEATURE_SET_BITS(opt->features) & feature_jit_mask)) {

zjit/src/options.rs

@@ -1,4 +1,5 @@
-use std::{ffi::CStr, os::raw::c_char};
+use std::{ffi::{CStr, CString}, ptr::null};
+use std::os::raw::{c_char, c_int, c_uint};
 
 /// Number of calls to start profiling YARV instructions.
 /// They are profiled `rb_zjit_call_threshold - rb_zjit_profile_threshold` times,
@@ -34,6 +35,25 @@ pub struct Options {
     pub dump_disasm: bool,
 }
 
+/// Return an Options with default values
+pub fn init_options() -> Options {
+    Options {
+        num_profiles: 1,
+        debug: false,
+        dump_hir_init: None,
+        dump_hir_opt: None,
+        dump_lir: false,
+        dump_disasm: false,
+    }
+}
+
+/// `ruby --help` descriptions for user-facing options. Do not add options for ZJIT developers.
+/// Note that --help allows only 80 chars per line, including indentation.    80-char limit --> |
+pub const ZJIT_OPTIONS: &'static [(&str, &str)] = &[
+    ("--zjit-call-threshold=num", "Number of calls to trigger JIT (default: 2)."),
+    ("--zjit-num-profiles=num",   "Number of profiled calls before JIT (default: 1)."),
+];
+
 #[derive(Clone, Copy, Debug)]
 pub enum DumpHIR {
     // Dump High-level IR without Snapshot
@@ -66,18 +86,6 @@ pub extern "C" fn rb_zjit_init_options() -> *const u8 {
     Box::into_raw(Box::new(options)) as *const u8
 }
 
-/// Return an Options with default values
-pub fn init_options() -> Options {
-    Options {
-        num_profiles: 1,
-        debug: false,
-        dump_hir_init: None,
-        dump_hir_opt: None,
-        dump_lir: false,
-        dump_disasm: false,
-    }
-}
-
 /// Parse a --zjit* command-line flag
 #[unsafe(no_mangle)]
 pub extern "C" fn rb_zjit_parse_option(options: *const u8, str_ptr: *const c_char) -> bool {
@@ -155,6 +163,21 @@ fn update_profile_threshold(options: &Options) {
     }
 }
 
+/// Print YJIT options for `ruby --help`. `width` is width of option parts, and
+/// `columns` is indent width of descriptions.
+#[unsafe(no_mangle)]
+pub extern "C" fn rb_zjit_show_usage(help: c_int, highlight: c_int, width: c_uint, columns: c_int) {
+    for &(name, description) in ZJIT_OPTIONS.iter() {
+        unsafe extern "C" {
+            fn ruby_show_usage_line(name: *const c_char, secondary: *const c_char, description: *const c_char,
+                                    help: c_int, highlight: c_int, width: c_uint, columns: c_int);
+        }
+        let name = CString::new(name).unwrap();
+        let description = CString::new(description).unwrap();
+        unsafe { ruby_show_usage_line(name.as_ptr(), null(), description.as_ptr(), help, highlight, width, columns) }
+    }
+}
+
 /// Macro to print a message only when --zjit-debug is given
 macro_rules! debug {
     ($($msg:tt)*) => {