1 files changed, 197 insertions, 33 deletions

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 59a9ea1417..66bccedd94 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -1047,9 +1047,11 @@ static BeamInstr* handle_error(Process* c_p, BeamInstr* pc,
 			       Eterm* reg, BifFunction bf) NOINLINE;
 static BeamInstr* call_error_handler(Process* p, BeamInstr* ip,
 				     Eterm* reg, Eterm func) NOINLINE;
-static BeamInstr* fixed_apply(Process* p, Eterm* reg, Uint arity) NOINLINE;
+static BeamInstr* fixed_apply(Process* p, Eterm* reg, Uint arity,
+			      BeamInstr *I, Uint offs) NOINLINE;
 static BeamInstr* apply(Process* p, Eterm module, Eterm function,
-			Eterm args, Eterm* reg) NOINLINE;
+			Eterm args, Eterm* reg,
+			BeamInstr *I, Uint offs) NOINLINE;
 static BeamInstr* call_fun(Process* p, int arity,
 			   Eterm* reg, Eterm args) NOINLINE;
 static BeamInstr* apply_fun(Process* p, Eterm fun,
@@ -3194,7 +3196,7 @@ do {						\
  OpCase(i_apply): {
      BeamInstr *next;
      HEAVY_SWAPOUT;
-     next = apply(c_p, r(0), x(1), x(2), reg);
+     next = apply(c_p, r(0), x(1), x(2), reg, NULL, 0);
      HEAVY_SWAPIN;
      if (next != NULL) {
 	 SET_CP(c_p, I+1);
@@ -3208,7 +3210,7 @@ do {						\
  OpCase(i_apply_last_P): {
      BeamInstr *next;
      HEAVY_SWAPOUT;
-     next = apply(c_p, r(0), x(1), x(2), reg);
+     next = apply(c_p, r(0), x(1), x(2), reg, I, Arg(0));
      HEAVY_SWAPIN;
      if (next != NULL) {
 	 SET_CP(c_p, (BeamInstr *) E[0]);
@@ -3223,7 +3225,7 @@ do {						\
  OpCase(i_apply_only): {
      BeamInstr *next;
      HEAVY_SWAPOUT;
-     next = apply(c_p, r(0), x(1), x(2), reg);
+     next = apply(c_p, r(0), x(1), x(2), reg, I, 0);
      HEAVY_SWAPIN;
      if (next != NULL) {
 	 SET_I(next);
@@ -3237,7 +3239,7 @@ do {						\
      BeamInstr *next;
 
      HEAVY_SWAPOUT;
-     next = fixed_apply(c_p, reg, Arg(0));
+     next = fixed_apply(c_p, reg, Arg(0), NULL, 0);
      HEAVY_SWAPIN;
      if (next != NULL) {
 	 SET_CP(c_p, I+2);
@@ -3252,7 +3254,7 @@ do {						\
      BeamInstr *next;
 
      HEAVY_SWAPOUT;
-     next = fixed_apply(c_p, reg, Arg(0));
+     next = fixed_apply(c_p, reg, Arg(0), I, Arg(1));
      HEAVY_SWAPIN;
      if (next != NULL) {
 	 SET_CP(c_p, (BeamInstr *) E[0]);
@@ -5844,12 +5846,13 @@ save_stacktrace(Process* c_p, BeamInstr* pc, Eterm* reg, BifFunction bf,
     s->depth = 0;
 
     /*
-     * If the failure was in a BIF other than 'error', 'exit' or
-     * 'throw', find the bif-table index and save the argument
-     * registers by consing up an arglist.
+     * If the failure was in a BIF other than 'error/1', 'error/2',
+     * 'exit/1' or 'throw/1', find the bif-table index and save the
+     * argument registers by consing up an arglist.
      */
-    if (bf != NULL && bf != error_1 && bf != error_2 &&
-	bf != exit_1 && bf != throw_1) {
+    if (bf != NULL && bf != error_1 && bf != error_2 && bf != exit_1
+	&& bf != throw_1 && bf != wrap_error_1 && bf != wrap_error_2
+	&& bf != wrap_exit_1 && bf != wrap_throw_1) {
         int i;
 	int a = 0;
 	for (i = 0; i < BIF_SIZE; i++) {
@@ -5945,12 +5948,30 @@ erts_save_stacktrace(Process* p, struct StackTrace* s, int depth)
 	    p->cp) {
 	    /* Cannot follow cp here - code may be unloaded */
 	    BeamInstr *cpp = p->cp;
+	    int trace_cp;
 	    if (cpp == beam_exception_trace || cpp == beam_return_trace) {
 		/* Skip return_trace parameters */
 		ptr += 2;
+		trace_cp = 1;
 	    } else if (cpp == beam_return_to_trace) {
 		/* Skip return_to_trace parameters */
 		ptr += 1;
+		trace_cp = 1;
+	    }
+	    else {
+		trace_cp = 0;
+	    }
+	    if (trace_cp && s->pc == cpp) {
+		/*
+		 * If process 'cp' points to a return/exception trace
+		 * instruction and 'cp' has been saved as 'pc' in
+		 * stacktrace, we need to update 'pc' in stacktrace
+		 * with the actual 'cp' located on the top of the
+		 * stack; otherwise, we will lose the top stackframe
+		 * when building the stack trace.
+		 */
+		ASSERT(is_CP(p->stop[0]));
+		s->pc = cp_val(p->stop[0]);
 	    }
 	}
 	while (ptr < STACK_START(p) && depth > 0) {
@@ -6070,12 +6091,15 @@ build_stacktrace(Process* c_p, Eterm exc) {
 	erts_set_current_function(&fi, s->current);
     }
 
+    depth = s->depth;
     /*
-     * If fi.current is still NULL, default to the initial function
+     * If fi.current is still NULL, and we have no
+     * stack at all, default to the initial function
      * (e.g. spawn_link(erlang, abs, [1])).
      */
     if (fi.current == NULL) {
-	erts_set_current_function(&fi, c_p->u.initial);
+	if (depth <= 0)
+	    erts_set_current_function(&fi, c_p->u.initial);
 	args = am_true; /* Just in case */
     } else {
 	args = get_args_from_exc(exc);
@@ -6085,10 +6109,9 @@ build_stacktrace(Process* c_p, Eterm exc) {
      * Look up all saved continuation pointers and calculate
      * needed heap space.
      */
-    depth = s->depth;
     stk = stkp = (FunctionInfo *) erts_alloc(ERTS_ALC_T_TMP,
 				      depth*sizeof(FunctionInfo));
-    heap_size = fi.needed + 2;
+    heap_size = fi.current ? fi.needed + 2 : 0;
     for (i = 0; i < depth; i++) {
 	erts_lookup_function_info(stkp, s->trace[i], 1);
 	if (stkp->current) {
@@ -6107,8 +6130,10 @@ build_stacktrace(Process* c_p, Eterm exc) {
 	res = CONS(hp, mfa, res);
 	hp += 2;
     }
-    hp = erts_build_mfa_item(&fi, hp, args, &mfa);
-    res = CONS(hp, mfa, res);
+    if (fi.current) {
+	hp = erts_build_mfa_item(&fi, hp, args, &mfa);
+	res = CONS(hp, mfa, res);
+    }
 
     erts_free(ERTS_ALC_T_TMP, (void *) stk);
     return res;
@@ -6205,8 +6230,107 @@ apply_setup_error_handler(Process* p, Eterm module, Eterm function, Uint arity,
     return ep;
 }
 
+static ERTS_INLINE void
+apply_bif_error_adjustment(Process *p, Export *ep,
+			   Eterm *reg, Uint arity,
+			   BeamInstr *I, Uint stack_offset)
+{
+    /*
+     * I is only set when the apply is a tail call, i.e.,
+     * from the instructions i_apply_only, i_apply_last_P,
+     * and apply_last_IP.
+     */
+    if (I
+	&& ep->code[3] == (BeamInstr) em_apply_bif
+	&& (ep == bif_export[BIF_error_1]
+	    || ep == bif_export[BIF_error_2]
+	    || ep == bif_export[BIF_exit_1]
+	    || ep == bif_export[BIF_throw_1])) {
+	/*
+	 * We are about to tail apply one of the BIFs
+	 * erlang:error/1, erlang:error/2, erlang:exit/1,
+	 * or erlang:throw/1. Error handling of these BIFs is
+	 * special!
+	 *
+	 * We need 'p->cp' to point into the calling
+	 * function when handling the error after the BIF has
+	 * been applied. This in order to get the topmost
+	 * stackframe correct. Without the following adjustment,
+	 * 'p->cp' will point into the function that called
+	 * current function when handling the error. We add a
+	 * dummy stackframe in order to achive this.
+	 *
+	 * Note that these BIFs unconditionally will cause
+	 * an exception to be raised. That is, our modifications
+	 * of 'p->cp' as well as the stack will be corrected by
+	 * the error handling code.
+	 *
+	 * If we find an exception/return-to trace continuation
+	 * pointer as the topmost continuation pointer, we do not
+	 * need to do anything since the information already will
+	 * be available for generation of the stacktrace.
+	 */
+	int apply_only = stack_offset == 0;
+	BeamInstr *cpp;
+
+	if (apply_only) {
+	    ASSERT(p->cp != NULL);
+	    cpp = p->cp;
+	}
+	else {
+	    ASSERT(is_CP(p->stop[0]));
+	    cpp = cp_val(p->stop[0]);
+	}
+
+	if (cpp != beam_exception_trace
+	    && cpp != beam_return_trace
+	    && cpp != beam_return_to_trace) {
+	    Uint need = stack_offset /* bytes */ / sizeof(Eterm);
+	    if (need == 0)
+		need = 1; /* i_apply_only */
+	    if (p->stop - p->htop < need)
+		erts_garbage_collect(p, (int) need, reg, arity+1);
+	    p->stop -= need;
+
+	    if (apply_only) {
+		/*
+		 * Called from the i_apply_only instruction.
+		 *
+		 * 'p->cp' contains continuation pointer pointing
+		 * into the function that called current function.
+		 * We push that continuation pointer onto the stack,
+		 * and set 'p->cp' to point into current function.
+		 */
+
+		p->stop[0] = make_cp(p->cp);
+		p->cp = I;
+	    }
+	    else {
+		/*
+		 * Called from an i_apply_last_p, or apply_last_IP,
+		 * instruction.
+		 *
+		 * Calling instruction will after we return read
+		 * a continuation pointer from the stack and write
+		 * it to 'p->cp', and then remove the topmost
+		 * stackframe of size 'stack_offset'.
+		 *
+		 * We have sized the dummy-stackframe so that it
+		 * will be removed by the instruction we currently
+		 * are executing, and leave the stackframe that
+		 * normally would have been removed intact.
+		 *
+		 */
+		p->stop[0] = make_cp(I);
+	    }
+	}
+    }
+}
+
 static BeamInstr*
-apply(Process* p, Eterm module, Eterm function, Eterm args, Eterm* reg)
+apply(
+Process* p, Eterm module, Eterm function, Eterm args, Eterm* reg,
+BeamInstr *I, Uint stack_offset)
 {
     int arity;
     Export* ep;
@@ -6231,21 +6355,54 @@ apply(Process* p, Eterm module, Eterm function, Eterm args, Eterm* reg)
 	return 0;
     }
 
-    /* The module argument may be either an atom or an abstract module
-     * (currently implemented using tuples, but this might change).
-     */
-    this = THE_NON_VALUE;
-    if (is_not_atom(module)) {
-	Eterm* tp;
+    while (1) {
+	Eterm m, f, a;
+	/* The module argument may be either an atom or an abstract module
+	 * (currently implemented using tuples, but this might change).
+	 */
+	this = THE_NON_VALUE;
+	if (is_not_atom(module)) {
+	    Eterm* tp;
+
+	    if (is_not_tuple(module)) goto error;
+	    tp = tuple_val(module);
+	    if (arityval(tp[0]) < 1) goto error;
+	    this = module;
+	    module = tp[1];
+	    if (is_not_atom(module)) goto error;
+	}
 
-        if (is_not_tuple(module)) goto error;
-        tp = tuple_val(module);
-        if (arityval(tp[0]) < 1) goto error;
-        this = module;
-        module = tp[1];
-        if (is_not_atom(module)) goto error;
+	if (module != am_erlang || function != am_apply)
+	    break;
+
+	/* Adjust for multiple apply of apply/3... */
+
+	a = args;
+	if (is_list(a)) {
+	    Eterm *consp = list_val(a);
+	    m = CAR(consp);
+	    a = CDR(consp);
+	    if (is_list(a)) {
+		consp = list_val(a);
+		f = CAR(consp);
+		a = CDR(consp);
+		if (is_list(a)) {
+		    consp = list_val(a);
+		    a = CAR(consp);
+		    if (is_nil(CDR(consp))) {
+			/* erlang:apply/3 */
+			module = m;
+			function = f;
+			args = a;
+			if (is_not_atom(f))
+			    goto error;
+			continue;
+		    }
+		}
+	    }
+	}
+	break; /* != erlang:apply/3 */
     }
-    
     /*
      * Walk down the 3rd parameter of apply (the argument list) and copy
      * the parameters to the x registers (reg[]). If the module argument
@@ -6283,12 +6440,14 @@ apply(Process* p, Eterm module, Eterm function, Eterm args, Eterm* reg)
     } else if (ERTS_PROC_GET_SAVED_CALLS_BUF(p)) {
 	save_calls(p, ep);
     }
+    apply_bif_error_adjustment(p, ep, reg, arity, I, stack_offset);
     DTRACE_GLOBAL_CALL_FROM_EXPORT(p, ep);
     return ep->addressv[erts_active_code_ix()];
 }
 
 static BeamInstr*
-fixed_apply(Process* p, Eterm* reg, Uint arity)
+fixed_apply(Process* p, Eterm* reg, Uint arity,
+	    BeamInstr *I, Uint stack_offset)
 {
     Export* ep;
     Eterm module;
@@ -6318,6 +6477,10 @@ fixed_apply(Process* p, Eterm* reg, Uint arity)
         if (is_not_atom(module)) goto error;
         ++arity;
     }
+
+    /* Handle apply of apply/3... */
+    if (module == am_erlang && function == am_apply && arity == 3)
+	return apply(p, reg[0], reg[1], reg[2], reg, I, stack_offset);
     
     /*
      * Get the index into the export table, or failing that the export
@@ -6332,6 +6495,7 @@ fixed_apply(Process* p, Eterm* reg, Uint arity)
     } else if (ERTS_PROC_GET_SAVED_CALLS_BUF(p)) {
 	save_calls(p, ep);
     }
+    apply_bif_error_adjustment(p, ep, reg, arity, I, stack_offset);
     DTRACE_GLOBAL_CALL_FROM_EXPORT(p, ep);
     return ep->addressv[erts_active_code_ix()];
 }