Hi Frank,

Frank Ch. Eigler wrote:
Jie Zhang <jie.zh...@analog.com> writes:

To break the recursive loop, one solution is to force emutls to call
the real calloc. [...]

If it were acceptable to change emutls on account of mudflap, this
sort of thing could work.  Other alternatives would include having
emutls define something in addition to HAVE_TLS that activates the
!HAVE_TLS implementation in libmudflap/mf-hooks3.c.

Thanks for your help! How about the attached patch, which follows your advice?


Regards,
Jie


	libmudflap/
	* mf-impl.h (__mf_get_state, __mf_set_state): Don't use
	__thread when TLS support is emulated.
	* mf-hooks3.c (__mf_get_state, __mf_set_state): Likewise.
	* mf-runtime.c (__mf_state_1): Likewise.
	* configure.ac: Use GCC_CHECK_EMUTLS.
	* configure: Regenerate.
	* config.h.in: Regenerate.

	config/
	* tls.m4 (GCC_CHECK_EMUTLS): Define.


Index: libmudflap/mf-impl.h
===================================================================
--- libmudflap/mf-impl.h	(revision 143074)
+++ libmudflap/mf-impl.h	(working copy)
@@ -244,7 +244,7 @@
 #define UNLOCKTH() do {} while (0)
 #endif
 
-#if defined(LIBMUDFLAPTH) && !defined(HAVE_TLS)
+#if defined(LIBMUDFLAPTH) && (!defined(HAVE_TLS) || defined(USE_EMUTLS))
 extern enum __mf_state_enum __mf_get_state (void);
 extern void __mf_set_state (enum __mf_state_enum);
 #else
Index: libmudflap/mf-hooks3.c
===================================================================
--- libmudflap/mf-hooks3.c	(revision 143074)
+++ libmudflap/mf-hooks3.c	(working copy)
@@ -78,7 +78,7 @@
 /* Multithreading support hooks.  */
 
 
-#ifndef HAVE_TLS
+#if !defined(HAVE_TLS) || defined(USE_EMUTLS)
 /* We don't have TLS.  Ordinarily we could use pthread keys, but since we're
    commandeering malloc/free that presents a few problems.  The first is that
    we'll recurse from __mf_get_state to pthread_setspecific to malloc back to
@@ -217,7 +217,7 @@
   if (__mf_opts.heur_std_data)
     __mf_unregister (&errno, sizeof (errno), __MF_TYPE_GUESS);
 
-#ifndef HAVE_TLS
+#if !defined(HAVE_TLS) || defined(USE_EMUTLS)
   struct mf_thread_data *data = __mf_find_threadinfo (0);
   if (data)
     data->used_p = 0;
Index: libmudflap/configure.ac
===================================================================
--- libmudflap/configure.ac	(revision 143074)
+++ libmudflap/configure.ac	(working copy)
@@ -265,6 +265,7 @@
 
 # See if we support thread-local storage.
 GCC_CHECK_TLS
+GCC_CHECK_EMUTLS
 
 AC_CONFIG_FILES([Makefile testsuite/Makefile testsuite/mfconfig.exp])
 AC_OUTPUT
Index: libmudflap/mf-runtime.c
===================================================================
--- libmudflap/mf-runtime.c	(revision 143074)
+++ libmudflap/mf-runtime.c	(working copy)
@@ -178,7 +178,7 @@
 int __mf_starting_p = 1;
 
 #ifdef LIBMUDFLAPTH
-#ifdef HAVE_TLS
+#if defined(HAVE_TLS) && !defined(USE_EMUTLS)
 __thread enum __mf_state_enum __mf_state_1 = reentrant;
 #endif
 #else
Index: config/tls.m4
===================================================================
--- config/tls.m4	(revision 143074)
+++ config/tls.m4	(working copy)
@@ -86,3 +86,20 @@
     AC_DEFINE(HAVE_CC_TLS, 1,
 	      [Define to 1 if the target assembler supports thread-local storage.])
   fi])
+
+dnl Check whether TLS is emulated.
+AC_DEFUN([GCC_CHECK_EMUTLS], [
+  AC_CACHE_CHECK([whether the thread-local storage support is from emutls],
+  		 gcc_cv_use_emutls, [
+    AC_COMPILE_IFELSE([__thread int a; int b; int main() { return a = b; }],
+		      [if grep __emutls_get_address conftest.$ac_objext >/dev/null ; then
+			 gcc_cv_use_emutls=yes
+		       else
+			 gcc_cv_use_emutls=no
+		       fi
+		      ], [gcc_cv_use_emutls=no])]
+    )
+  if test "$gcc_cv_use_emutls" = "yes" ; then
+    AC_DEFINE(USE_EMUTLS, 1,
+      	      [Define to 1 if the target use emutls for thread-local storage.])
+  fi])

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