From 9f844d7eda5b232a78379c96b61bdc01f8536744 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Sun, 5 Jun 2022 17:56:31 -0700
Subject: txr: fix --free-all crash due to atexit order.

The --free-all feature is broken. It is needed for confirming
lack of memory leaks during development. What breaks it is the
atexit call to run_load_hooks in eval.c, which occurs after
the atexit call to free_all in txr.c which blows everything
away.

* Makefile (tst/tests/019/load-hook.ok): Let's put --free-all
on this test case, because it has to with the load hooks.
Make no mistake though: everything crashes with --free-all,
not this test case specifically.

* txr.c (opt_free_all): New global variable.
(free_all): Free resources only if opt_free_all is true.
Lose the paranoid called flag.
(main): Register free_all with atexit before callilng init.
This ensures that it will be called after any atexit
handlers registered as part of init, like the one in sysif.c
and eval.c.
(txr_main): The --free-all option now just sets opt_free_all.

* txr.h (opt_free_all): Declared.
---
 Makefile |  1 +
 txr.c    | 27 +++++++++++++--------------
 txr.h    |  1 +
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/Makefile b/Makefile
index 698ee5a0..4ca6058f 100644
--- a/Makefile
+++ b/Makefile
@@ -440,6 +440,7 @@ tst/tests/016/%: TXR_DBG_OPTS :=
 tst/tests/017/%: TXR_DBG_OPTS :=
 tst/tests/018/%: TXR_DBG_OPTS :=
 tst/tests/019/%: TXR_DBG_OPTS :=
+tst/tests/019/load-hook.ok: TXR_DBG_OPTS := --free-all
 
 tst/tests/014/dgram-stream.ok: | tst/tests/014/socket-basic.ok
 
diff --git a/txr.c b/txr.c
index dc580f1b..78f7b042 100644
--- a/txr.c
+++ b/txr.c
@@ -80,6 +80,7 @@ int opt_noninteractive = if_full_repl(0, 1);
 int opt_noprofile;
 int opt_compat;
 int opt_dbg_expansion;
+int opt_free_all;
 val stdlib_path;
 
 #if HAVE_FORK_STUFF
@@ -415,6 +416,16 @@ static int license(void)
   return retval;
 }
 
+static void free_all(void)
+{
+  if (opt_free_all) {
+    regex_free_all();
+    gc_free_all();
+    arith_free_all();
+    free(progname);
+  }
+}
+
 int txr_main(int argc, char **argv);
 
 int main(int argc, char **argv)
@@ -423,6 +434,7 @@ int main(int argc, char **argv)
   repress_privilege();
   progname = utf8_dup_from(argv[0] ? argv[0]: "txr");
   progname_u8 = argv[0];
+  atexit(free_all);
   init(&stack_bottom);
   match_init();
   debug_init();
@@ -518,19 +530,6 @@ static int gc_delta(val optval)
   return 1;
 }
 
-static void free_all(void)
-{
-  static int called;
-
-  if (!called) {
-    called = 1;
-    regex_free_all();
-    gc_free_all();
-    arith_free_all();
-    free(progname);
-  }
-}
-
 #ifndef CONFIG_DEBUG_SUPPORT
 static void no_dbg_support(val arg)
 {
@@ -932,7 +931,7 @@ int txr_main(int argc, char **argv)
       } else if (equal(opt, lit("free-all"))) {
         if (org)
           goto noarg;
-        atexit(free_all);
+        opt_free_all = 1;
         continue;
       } else if (equal(opt, lit("noprofile"))) {
         if (org)
diff --git a/txr.h b/txr.h
index f57635bc..6570bf6a 100644
--- a/txr.h
+++ b/txr.h
@@ -41,6 +41,7 @@ extern int opt_debugger;
 extern int opt_dbg_autoload;
 extern int opt_dbg_expansion;
 extern int opt_noprofile;
+extern int opt_free_all;
 extern alloc_bytes_t opt_gc_delta;
 extern const wchli_t *version;
 extern wchar_t *progname;
-- 
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