RJIT: Simplify how Capstone is used in tests

lib/ruby_vm/rjit/code_block.rb

@@ -58,8 +58,8 @@ module RubyVM::RJIT
       (@mem_block...(@mem_block + @mem_size)).include?(addr)
     end
 
-    def dump_disasm(from, to, io: STDOUT, color: true)
+    def dump_disasm(from, to, io: STDOUT, color: true, test: false)
-      C.dump_disasm(from, to).each do |address, mnemonic, op_str|
+      C.dump_disasm(from, to, test:).each do |address, mnemonic, op_str|
         @comments.fetch(address, []).each do |comment|
           io.puts colorize("  # #{comment}", bold: true, color:)
         end

rjit_c.c

@@ -420,7 +420,7 @@ static size_t rjit_insn_exits[VM_INSTRUCTION_SIZE] = { 0 };
 
 // Return an array of [address, mnemonic, op_str]
 static VALUE
-dump_disasm(rb_execution_context_t *ec, VALUE self, VALUE from, VALUE to)
+dump_disasm(rb_execution_context_t *ec, VALUE self, VALUE from, VALUE to, VALUE test)
 {
     VALUE result = rb_ary_new();
 #ifdef HAVE_LIBCAPSTONE
@@ -434,7 +434,8 @@ dump_disasm(rb_execution_context_t *ec, VALUE self, VALUE from, VALUE to)
 
     // Call cs_disasm and convert results to a Ruby array
     cs_insn *insns;
-    size_t count = cs_disasm(handle, (const uint8_t *)from_addr, to_addr - from_addr, from_addr, 0, &insns);
+    size_t base_addr = RTEST(test) ? 0 : from_addr; // On tests, start from 0 for output stability.
+    size_t count = cs_disasm(handle, (const uint8_t *)from_addr, to_addr - from_addr, base_addr, 0, &insns);
     for (size_t i = 0; i < count; i++) {
         VALUE vals = rb_ary_new_from_args(3, LONG2NUM(insns[i].address), rb_str_new2(insns[i].mnemonic), rb_str_new2(insns[i].op_str));
         rb_ary_push(result, vals);

rjit_c.rb

@@ -48,8 +48,8 @@ module RubyVM::RJIT # :nodoc: all
 
     # @param from [Integer] - From address
     # @param to [Integer]   - To address
-    def dump_disasm(from, to)
+    def dump_disasm(from, to, test: false)
-      Primitive.dump_disasm(from, to)
+      Primitive.dump_disasm(from, to, test)
     end
 
     # Convert a Ruby object to a VALUE in Integer

test/ruby/rjit/test_assembler.rb

@@ -166,7 +166,7 @@ module RubyVM::RJIT
       asm.jmp([:rax, 8])   # JMP r/m64 (Mod 01: [reg]+disp8)
       asm.jmp(:rax)        # JMP r/m64 (Mod 11: reg)
       assert_compile(asm, <<~EOS)
-        0x0: jmp 0x2
+        0x0: jmp 2
         0x2: jmp 0xff
         0x7: jmp qword ptr [rax + 8]
         0xa: jmp rax
@@ -338,23 +338,12 @@ module RubyVM::RJIT
       end_addr = @cb.write_addr
 
       io = StringIO.new
-      @cb.dump_disasm(start_addr, end_addr, io:, color: false)
+      @cb.dump_disasm(start_addr, end_addr, io:, color: false, test: true)
       io.seek(0)
       disasm = io.read
 
       disasm.gsub!(/^  /, '')
       disasm.sub!(/\n\z/, '')
-      disasm.gsub!(/0x(\h{12})/) do
-        offset = $1.to_i(16) - start_addr
-        if offset.negative?
-          "-0x#{offset.to_s(16)}"
-        else
-          "0x#{offset.to_s(16)}"
-        end
-      end
-      (start_addr...end_addr).each do |addr|
-        disasm.gsub!("0x#{addr.to_s(16)}", "0x#{(addr - start_addr).to_s(16)}")
-      end
       disasm
     end
   end