Add symbolizer (for mcode).

Display a backtrace in case of failed check or assert failure.

3 files changed, 136 insertions, 25 deletions

diff --git a/src/grt/config/grt_itf.h b/src/grt/config/grt_itf.h
new file mode 100644
index 000000000..1b17c3a8b
--- /dev/null
+++ b/src/grt/config/grt_itf.h
@@ -0,0 +1,40 @@
+/*  Declarations to interface with Ada code.
+    Copyright (C) 2015 Tristan Gingold.
+
+    GHDL is free software; you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation; either version 2, or (at your option) any later
+    version.
+
+    GHDL is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with GCC; see the file COPYING.  If not, write to the Free
+    Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+    02111-1307, USA.
+
+    As a special exception, if other files instantiate generics from this
+    unit, or you link this unit with other files to produce an executable,
+    this unit does not by itself cause the resulting executable to be
+    covered by the GNU General Public License. This exception does not
+    however invalidate any other reasons why the executable file might be
+    covered by the GNU Public License.
+*/
+
+struct backtrace_addrs
+{
+  int size;
+  int skip;
+  void *addrs[32];
+};
+
+void grt_save_backtrace (struct backtrace_addrs *bt, int skip);
+
+extern void grt_overflow_error (struct backtrace_addrs *bt);
+extern void grt_null_access_error (struct backtrace_addrs *bt);
+
+void __ghdl_maybe_return_via_longjump (int val);
+int __ghdl_run_through_longjump (int (*func)(void));
diff --git a/src/grt/config/jumps.c b/src/grt/config/jumps.c
index a544f8372..00e17d37d 100644
--- a/src/grt/config/jumps.c
+++ b/src/grt/config/jumps.c
@@ -29,11 +29,17 @@
 #include <signal.h>
 #include <fcntl.h>
 
-#if defined (__linux__) && defined (__i386__)
-/* On i386/Linux, the context must be inspected.  */
+#if defined (__linux__) || defined (__APPLE__)
+#define HAVE_BACKTRACE 1
 #include <sys/ucontext.h>
 #endif
 
+#ifdef HAVE_BACKTRACE
+#include <execinfo.h>
+#endif
+
+#include "grt_itf.h"
+
 /* There is a simple setjmp/longjmp mechanism used to report failures.
    We have the choice between 3 mechanisms:
    * USE_BUITLIN_SJLJ: gcc builtin setjmp/longjmp, very fast but gcc specific.
@@ -70,49 +76,89 @@ typedef jmp_buf JMP_BUF;
 static int run_env_en;
 static JMP_BUF run_env;
 
-extern void grt_overflow_error (void);
-extern void grt_null_access_error (void);
-
 #ifdef __APPLE__
 #define NEED_SIGFPE_HANDLER
+#define NEED_SIGBUS_HANDLER
 #endif
 
 static struct sigaction prev_sigfpe_act;
 
+#ifdef NEED_SIGFPE_HANDLER
+static struct sigaction prev_sigsegv_act;
+#endif
+#ifdef NEED_SIGBUS_HANDLER
+static struct sigaction prev_sigbus_act;
+#endif
+
+static void
+get_bt_from_ucontext (void *uctxt, struct backtrace_addrs *bt)
+{
+  void *pc = NULL;
+  int i;
+
+#ifdef HAVE_BACKTRACE
+  bt->size = backtrace (bt->addrs, sizeof (bt->addrs) / sizeof (void *));
+  bt->skip = 0;
+#else
+  bt->size = 0;
+  return;
+#endif
+
+#if defined (__linux__) && defined (__x86_64__)
+  ucontext *u = (ucontext *)uctxt;
+  pc = (void *)u->uc_mcontext.gregs[REG_RIP];
+#endif
+#if defined (__APPLE__) && defined (__i386__)
+  ucontext_t *u = (ucontext_t *)uctxt;
+  pc = (void *)u->uc_mcontext->__ss.__eip;
+  bt->skip = 3;  /* This frame + sighandler + trampoline + marker - pc.  */
+  bt->addrs[3] = pc;
+#endif
+}
+
 /* Handler for SIGFPE signal.
    It is also raised in case of overflow (i386 linux).  */
-static void grt_overflow_handler (int signo, siginfo_t *info, void *ptr)
+static void
+grt_overflow_handler (int signo, siginfo_t *info, void *ptr)
 {
-  grt_overflow_error ();
-}
+  struct backtrace_addrs bt;
 
-static struct sigaction prev_sigsegv_act;
+  get_bt_from_ucontext (ptr, &bt);
+  grt_overflow_error (&bt);
+}
 
 /* Posix handler for overflow.  This is used only by mcode.  */
-static void grt_sigsegv_handler (int signo, siginfo_t *info, void *ptr)
+static void
+grt_sigsegv_handler (int signo, siginfo_t *info, void *ptr)
 {
-#if defined (__linux__) && defined (__i386__)
-  ucontext_t *uctxt = (ucontext_t *)ptr;
+  struct backtrace_addrs bt;
 
-  /* Linux generates a SIGSEGV (!) for an overflow exception.  */
-  if (uctxt->uc_mcontext.gregs[REG_TRAPNO] == 4)
+  get_bt_from_ucontext (ptr, &bt);
+
+#if defined (__linux__) && defined (__i386__)
+  if (signo == SIGSEGV)
     {
-      grt_overflow_error ();
+      ucontext_t *uctxt = (ucontext_t *)ptr;
+
+      /* Linux generates a SIGSEGV (!) for an overflow exception.  */
+      if (uctxt->uc_mcontext.gregs[REG_TRAPNO] == 4)
+	grt_overflow_error (&bt);
     }
 #endif
 
   /* We loose.  */
-  grt_null_access_error ();
+  grt_null_access_error (&bt);
 }
 
-static void grt_signal_setup (void)
+static void
+grt_signal_setup (void)
 {
   {
     struct sigaction sigsegv_act;
 
     sigsegv_act.sa_sigaction = &grt_sigsegv_handler;
     sigemptyset (&sigsegv_act.sa_mask);
-    sigsegv_act.sa_flags = SA_ONSTACK | SA_SIGINFO;
+    sigsegv_act.sa_flags = SA_SIGINFO;
 #ifdef SA_ONESHOT
     sigsegv_act.sa_flags |= SA_ONESHOT;
 #elif defined (SA_RESETHAND)
@@ -122,6 +168,10 @@ static void grt_signal_setup (void)
     /* We don't care about the return status.
        If the handler is not installed, then some feature are lost.  */
     sigaction (SIGSEGV, &sigsegv_act, &prev_sigsegv_act);
+
+#ifdef NEED_SIGBUS_HANDLER
+    sigaction (SIGBUS, &sigsegv_act, &prev_sigbus_act);
+#endif
   }
 
 #ifdef NEED_SIGFPE_HANDLER
@@ -137,10 +187,15 @@ static void grt_signal_setup (void)
 #endif
 }
 
-static void grt_signal_restore (void)
+static void
+grt_signal_restore (void)
 {
   sigaction (SIGSEGV, &prev_sigsegv_act, NULL);
 
+#ifdef NEED_SIGBUS_HANDLER
+  sigaction (SIGBUS, &prev_sigbus_act, NULL);
+#endif
+
 #ifdef NEED_SIGFPE_HANDLER
   sigaction (SIGFPE, &prev_sigfpe_act, NULL);
 #endif
@@ -167,3 +222,14 @@ __ghdl_run_through_longjump (int (*func)(void))
   run_env_en = 0;
   return res;
 }
+
+void
+grt_save_backtrace (struct backtrace_addrs *bt, int skip)
+{
+#ifdef HAVE_BACKTRACE
+  bt->size = backtrace (bt->addrs, sizeof (bt->addrs) / sizeof (void *));
+  bt->skip = skip + 1;
+#else
+  bt->size = 0;
+#endif
+}
diff --git a/src/grt/config/win32.c b/src/grt/config/win32.c
index 869c7ca61..63d11a23e 100644
--- a/src/grt/config/win32.c
+++ b/src/grt/config/win32.c
@@ -30,13 +30,11 @@
 #include <assert.h>
 #include <excpt.h>
 
+#include "grt_itf.h"
+
 static int run_env_en;
 static jmp_buf run_env;
 
-extern void grt_overflow_error (void);
-extern void grt_null_access_error (void);
-void __ghdl_maybe_return_via_longjump (int val);
-
 static EXCEPTION_DISPOSITION
 ghdl_SEH_handler (struct _EXCEPTION_RECORD* ExceptionRecord,
 		  void *EstablisherFrame,
@@ -60,7 +58,8 @@ ghdl_SEH_handler (struct _EXCEPTION_RECORD* ExceptionRecord,
   switch (ExceptionRecord->ExceptionCode)
     {
     case EXCEPTION_ACCESS_VIOLATION:
-      grt_null_access_error ();
+      /* Pc is ExceptionRecord->ExceptionAddress.  */
+      grt_null_access_error (NULL);
       break;
 
     case EXCEPTION_FLT_DENORMAL_OPERAND:
@@ -77,7 +76,7 @@ ghdl_SEH_handler (struct _EXCEPTION_RECORD* ExceptionRecord,
       break;
 
     case EXCEPTION_INT_OVERFLOW:
-      grt_overflow_error ();
+      grt_overflow_error (NULL);
       break;
 
     case EXCEPTION_STACK_OVERFLOW:
@@ -132,6 +131,12 @@ __ghdl_run_through_longjump (int (*func)(void))
   return res;
 }
 
+void
+grt_save_backtrace (struct backtrace_addrs *bt, int skip)
+{
+  bt->size = 0;
+}
+
 #include <math.h>
 
 double acosh (double x)