From cb132d17302199a502af00be238f689e5e786c93 Mon Sep 17 00:00:00 2001
From: Luke Gorrie <luke@snabb.co>
Date: Sun, 21 May 2017 18:32:52 +0000
Subject: [PATCH] Add lj_auditlog (very preliminary)

---
 src/Makefile      |  2 +-
 src/lj_auditlog.c | 40 ++++++++++++++++++++++++++++++++++++++++
 src/lj_auditlog.h | 16 ++++++++++++++++
 src/lj_trace.c    |  3 +++
 4 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 src/lj_auditlog.c
 create mode 100644 src/lj_auditlog.h

diff --git a/src/Makefile b/src/Makefile
index 896947fb98..0227e719eb 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -469,7 +469,7 @@ LJCORE_O= lj_gc.o lj_err.o lj_char.o lj_bc.o lj_obj.o lj_buf.o \
 	  lj_ir.o lj_opt_mem.o lj_opt_fold.o lj_opt_narrow.o \
 	  lj_opt_dce.o lj_opt_loop.o lj_opt_split.o lj_opt_sink.o \
 	  lj_mcode.o lj_snap.o lj_record.o lj_crecord.o lj_ffrecord.o \
-	  lj_asm.o lj_trace.o lj_gdbjit.o \
+	  lj_asm.o lj_trace.o lj_gdbjit.o lj_auditlog.o \
 	  lj_ctype.o lj_cdata.o lj_cconv.o lj_ccall.o lj_ccallback.o \
 	  lj_carith.o lj_clib.o lj_cparse.o \
 	  lj_lib.o lj_alloc.o lib_aux.o \
diff --git a/src/lj_auditlog.c b/src/lj_auditlog.c
new file mode 100644
index 0000000000..fa1c7fd553
--- /dev/null
+++ b/src/lj_auditlog.c
@@ -0,0 +1,40 @@
+/*
+** Audit log. Records JIT/runtime events for offline analysis.
+*/
+
+#define lj_auditlog_c
+
+#include <stdio.h>
+
+#include "lj_auditlog.h"
+
+FILE *fp;
+
+/* Ensure that the log file is open. */
+static void ensure_log_open()
+{
+  if (!fp) {
+    fp = fopen("audit.log", "w");
+    lua_assert(fp != NULL);
+  }
+}
+
+/* Log a snapshot of an object in memory. */
+static void log(const char *type, void *ptr, unsigned int size)
+{
+  ensure_log_open();
+  fprintf(fp, "type=%s address=%p size=%d data:\n", type, ptr, size);
+  fwrite(ptr, size, 1, fp);
+}
+
+/* Log a trace that has just been compiled. */
+void lj_auditlog_trace_stop(jit_State *J, GCtrace *T)
+{
+  /* Log the memory containing the GCtrace object and other important
+     memory that it references. */
+  log("GCtrace", T, sizeof(*T));
+  log("MCode[]", T->mcode, T->szmcode);
+  log("SnapShot[]", T->snap, T->nsnap * sizeof(*T->snap));
+  log("SnapEntry[]", T->snapmap, T->nsnapmap * sizeof(*T->snapmap));
+}
+
diff --git a/src/lj_auditlog.h b/src/lj_auditlog.h
new file mode 100644
index 0000000000..63ac71e7b2
--- /dev/null
+++ b/src/lj_auditlog.h
@@ -0,0 +1,16 @@
+/*
+** Audit log. Records JIT/runtime events for offline analysis.
+*/
+
+#ifndef _LJ_AUDITLOG_H
+#define _LJ_AUDITLOG_H
+
+#include "lj_jit.h"
+
+void lj_auditlog_trace_flush(jit_State *J);
+void lj_auditlog_trace_start(jit_State *J);
+void lj_auditlog_trace_stop(jit_State *J, GCtrace *T);
+void lj_auditlog_trace_abort(jit_State *J);
+void lj_auditlog_trace_record_bytecode(jit_State *J);
+
+#endif
diff --git a/src/lj_trace.c b/src/lj_trace.c
index 0b674ec276..21c1e6dafe 100644
--- a/src/lj_trace.c
+++ b/src/lj_trace.c
@@ -9,6 +9,7 @@
 #include "lj_obj.h"
 
 
+#include "lj_auditlog.h"
 #include "lj_gc.h"
 #include "lj_err.h"
 #include "lj_debug.h"
@@ -28,6 +29,7 @@
 #include "lj_dispatch.h"
 #include "lj_vm.h"
 #include "lj_target.h"
+#include "lj_auditlog.h"
 
 /* -- Error handling ------------------------------------------------------ */
 
@@ -122,6 +124,7 @@ static void trace_save(jit_State *J, GCtrace *T)
   setgcrefp(J->trace[T->traceno], T);
   lj_gc_barriertrace(J2G(J), T->traceno);
   lj_gdbjit_addtrace(J, T);
+  lj_auditlog_trace_stop(J, T);
 }
 
 void lj_trace_free(global_State *g, GCtrace *T)