Implement --mjit-dump-disasm

1 files changed, 43 insertions, 0 deletions

diff --git a/mjit_c.c b/mjit_c.c
index 9ba023e84b..0af2e4b239 100644
--- a/mjit_c.c
+++ b/mjit_c.c
@@ -38,6 +38,49 @@
 #define SIZEOF(type) RB_SIZE2NUM(sizeof(type))
 #define SIGNED_TYPE_P(type) RBOOL((type)(-1) < (type)(1))
 
+// macOS: brew install capstone
+// Ubuntu/Debian: apt-get install libcapstone-dev
+// Fedora: dnf -y install capstone-devel
+//#ifdef HAVE_LIBCAPSTONE
+#if 1
+#include <capstone/capstone.h>
+
+#define CODE "\x55\x48\x8b\x05\xb8\x13\x00\x00"
+
+// Return an array of [address, mnemonic, op_str]
+static VALUE
+dump_disasm(rb_execution_context_t *ec, VALUE self, VALUE from, VALUE to)
+{
+    // Prepare for calling cs_disasm
+    static csh handle;
+    if (cs_open(CS_ARCH_X86, CS_MODE_64, &handle) != CS_ERR_OK) {
+        rb_raise(rb_eRuntimeError, "failed to make Capstone handle");
+    }
+    size_t from_addr = NUM2SIZET(from);
+    size_t to_addr = NUM2SIZET(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);
+    VALUE result = rb_ary_new_capa(count);
+    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);
+    }
+
+    // Free memory used by capstone
+    cs_free(insns, count);
+    cs_close(&handle);
+    return result;
+}
+#else
+static VALUE
+mjit_disasm(VALUE self, VALUE from, VALUE to)
+{
+    return rb_ary_new();
+}
+#endif
+
 #include "mjit_c.rbinc"
 
 #endif // USE_MJIT