YJIT: Allow --yjit-dump-disasm to dump into a file (#6552)

* YJIT: Allow --yjit-dump-disasm to dump into a file

* YJIT: Move IO implementation to disasm.rs

* YJIT: More consistent naming

yjit/src/backend/ir.rs

@@ -1100,13 +1100,10 @@ impl Assembler
         let gc_offsets = self.compile_with_regs(cb, alloc_regs);
 
         #[cfg(feature = "disasm")]
-        if get_option!(dump_disasm) == DumpDisasm::All || (get_option!(dump_disasm) == DumpDisasm::Inline && cb.inline()) {
+        if let Some(dump_disasm) = get_option_ref!(dump_disasm) {
-            use crate::disasm::disasm_addr_range;
+            use crate::disasm::dump_disasm_addr_range;
-            let last_ptr = cb.get_write_ptr();
+            let end_addr = cb.get_write_ptr().raw_ptr();
-            let disasm = disasm_addr_range(cb, start_addr, last_ptr.raw_ptr() as usize - start_addr as usize);
+            dump_disasm_addr_range(cb, start_addr, end_addr, dump_disasm)
-            if disasm.len() > 0 {
-                println!("{disasm}");
-            }
         }
         gc_offsets
     }

yjit/src/codegen.rs

@@ -612,7 +612,7 @@ pub fn gen_entry_prologue(cb: &mut CodeBlock, iseq: IseqPtr, insn_idx: u32) -> O
     let code_ptr = cb.get_write_ptr();
 
     let mut asm = Assembler::new();
-    if get_option!(dump_disasm).is_enabled() {
+    if get_option_ref!(dump_disasm).is_some() {
         asm.comment(&format!("YJIT entry: {}", iseq_get_location(iseq)));
     } else {
         asm.comment("YJIT entry");
@@ -742,7 +742,7 @@ pub fn gen_single_block(
     let mut asm = Assembler::new();
 
     #[cfg(feature = "disasm")]
-    if get_option!(dump_disasm).is_enabled() {
+    if get_option_ref!(dump_disasm).is_some() {
         asm.comment(&format!("Block: {} (ISEQ offset: {})", iseq_get_location(blockid.iseq), blockid.idx));
     }
 

yjit/src/disasm.rs

@@ -2,6 +2,7 @@ use crate::core::*;
 use crate::cruby::*;
 use crate::yjit::yjit_enabled_p;
 use crate::asm::CodeBlock;
+use crate::options::DumpDisasm;
 
 use std::fmt::Write;
 
@@ -95,7 +96,7 @@ pub fn disasm_iseq_insn_range(iseq: IseqPtr, start_idx: u32, end_idx: u32) -> St
             writeln!(out, "== {:=<60}", block_ident).unwrap();
 
             // Disassemble the instructions
-            out.push_str(&disasm_addr_range(global_cb, start_addr, code_size));
+            out.push_str(&disasm_addr_range(global_cb, start_addr, (start_addr as usize + code_size) as *const u8));
 
             // If this is not the last block
             if block_idx < block_list.len() - 1 {
@@ -115,9 +116,25 @@ pub fn disasm_iseq_insn_range(iseq: IseqPtr, start_idx: u32, end_idx: u32) -> St
     return out;
 }
 
+#[cfg(feature = "disasm")]
+pub fn dump_disasm_addr_range(cb: &CodeBlock, start_addr: *const u8, end_addr: *const u8, dump_disasm: &DumpDisasm) {
+    use std::fs::File;
+    use std::io::Write;
+
+    let disasm = disasm_addr_range(cb, start_addr, end_addr);
+    if disasm.len() > 0 {
+        match dump_disasm {
+            DumpDisasm::Stdout => println!("{disasm}"),
+            DumpDisasm::File(path) => {
+                let mut f = File::options().append(true).create(true).open(path).unwrap();
+                f.write_all(disasm.as_bytes()).unwrap();
+            }
+        };
+    }
+}
 
 #[cfg(feature = "disasm")]
-pub fn disasm_addr_range(cb: &CodeBlock, start_addr: *const u8, code_size: usize) -> String {
+pub fn disasm_addr_range(cb: &CodeBlock, start_addr: *const u8, end_addr: *const u8) -> String {
     let mut out = String::from("");
 
     // Initialize capstone
@@ -141,6 +158,7 @@ pub fn disasm_addr_range(cb: &CodeBlock, start_addr: *const u8, code_size: usize
     cs.set_skipdata(true).unwrap();
 
     // Disassemble the instructions
+    let code_size = end_addr as usize - start_addr as usize;
     let code_slice = unsafe { std::slice::from_raw_parts(start_addr, code_size) };
     let insns = cs.disasm_all(code_slice, start_addr as u64).unwrap();
 

yjit/src/options.rs

@@ -36,7 +36,7 @@ pub struct Options {
     pub dump_insns: bool,
 
     /// Dump all compiled instructions of target cbs.
-    pub dump_disasm: DumpDisasm,
+    pub dump_disasm: Option<DumpDisasm>,
 
     /// Print when specific ISEQ items are compiled or invalidated
     pub dump_iseq_disasm: Option<String>,
@@ -62,26 +62,18 @@ pub static mut OPTIONS: Options = Options {
     gen_stats: false,
     gen_trace_exits: false,
     dump_insns: false,
-    dump_disasm: DumpDisasm::None,
+    dump_disasm: None,
     verify_ctx: false,
     global_constant_state: false,
     dump_iseq_disasm: None,
 };
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub enum DumpDisasm {
-    // Dump only inline cb
+    // Dump to stdout
-    Inline,
+    Stdout,
-    // Dump both inline and outlined cbs
+    // Dump to "yjit_{pid}.log" file under the specified directory
-    All,
+    File(String),
-    // Dont dump anything
-    None,
-}
-
-impl DumpDisasm {
-    pub fn is_enabled(&self) -> bool {
-        *self != DumpDisasm::None
-    }
 }
 
 /// Macro to get an option value by name
@@ -168,9 +160,13 @@ pub fn parse_option(str_ptr: *const std::os::raw::c_char) -> Option<()> {
         },
 
         ("dump-disasm", _) => match opt_val.to_string().as_str() {
-            "all" => unsafe { OPTIONS.dump_disasm = DumpDisasm::All },
+            "" => unsafe { OPTIONS.dump_disasm = Some(DumpDisasm::Stdout) },
-            "" => unsafe { OPTIONS.dump_disasm = DumpDisasm::Inline },
+            directory => {
-            _ => return None,
+                let pid = std::process::id();
+                let path = format!("{directory}/yjit_{pid}.log");
+                println!("YJIT disasm dump: {path}");
+                unsafe { OPTIONS.dump_disasm = Some(DumpDisasm::File(path)) }
+            }
          },
 
         ("dump-iseq-disasm", _) => unsafe {