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-rw-r--r--erts/emulator/beam/beam_load.c108
1 files changed, 85 insertions, 23 deletions
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index d9f3e3f4c6..1f9635a6c1 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -507,6 +507,7 @@ static int verify_chunks(LoaderState* stp);
static int load_atom_table(LoaderState* stp);
static int load_import_table(LoaderState* stp);
static int read_export_table(LoaderState* stp);
+static int is_bif(Eterm mod, Eterm func, unsigned arity);
static int read_lambda_table(LoaderState* stp);
static int read_literal_table(LoaderState* stp);
static int read_line_table(LoaderState* stp);
@@ -1313,6 +1314,7 @@ static int
read_export_table(LoaderState* stp)
{
int i;
+ BeamInstr* address;
GetInt(stp, 4, stp->num_exps);
if (stp->num_exps > stp->num_functions) {
@@ -1328,7 +1330,6 @@ read_export_table(LoaderState* stp)
Uint value;
Eterm func;
Uint arity;
- Export* e;
GetInt(stp, 4, n);
GetAtom(stp, n, func);
@@ -1346,21 +1347,34 @@ read_export_table(LoaderState* stp)
if (value == 0) {
LoadError2(stp, "export table entry %d: label %d not resolved", i, n);
}
- stp->export[i].address = stp->code + value;
+ stp->export[i].address = address = stp->code + value;
/*
- * Check that we are not redefining a BIF (except erlang:apply/3).
+ * Find out if there is a BIF with the same name.
*/
- if ((e = erts_find_export_entry(stp->module, func, arity)) != NULL) {
- if (e->code[3] == (BeamInstr) em_apply_bif) {
- if (stp->module != am_erlang ||
- func != am_apply ||
- arity != 3) {
- LoadError2(stp, "exported function %T/%d redefines BIF",
- func, arity);
- }
- }
+
+ if (!is_bif(stp->module, func, arity)) {
+ continue;
}
+
+ /*
+ * This is a stub for a BIF.
+ *
+ * It should not be exported, and the information in its
+ * func_info instruction should be invalidated so that it
+ * can be filtered out by module_info(functions) and by
+ * any other functions that walk through all local functions.
+ */
+
+ if (stp->labels[n].patches) {
+ LoadError3(stp, "there are local calls to the stub for "
+ "the BIF %T:%T/%d",
+ stp->module, func, arity);
+ }
+ stp->export[i].address = NULL;
+ address[-1] = 0;
+ address[-2] = NIL;
+ address[-3] = NIL;
}
return 1;
@@ -1368,6 +1382,27 @@ read_export_table(LoaderState* stp)
return 0;
}
+
+static int
+is_bif(Eterm mod, Eterm func, unsigned arity)
+{
+ Export* e = erts_find_export_entry(mod, func, arity);
+ if (e == NULL) {
+ return 0;
+ }
+ if (e->code[3] != (BeamInstr) em_apply_bif) {
+ return 0;
+ }
+ if (mod == am_erlang && func == am_apply && arity == 3) {
+ /*
+ * erlang:apply/3 is a special case -- it is implemented
+ * as an instruction and it is OK to redefine it.
+ */
+ return 0;
+ }
+ return 1;
+}
+
static int
read_lambda_table(LoaderState* stp)
{
@@ -4255,17 +4290,24 @@ final_touch(LoaderState* stp)
*/
for (i = 0; i < stp->num_exps; i++) {
- Export* ep = erts_export_put(stp->module, stp->export[i].function,
- stp->export[i].arity);
+ Export* ep;
+ BeamInstr* address = stp->export[i].address;
+
+ if (address == NULL) {
+ /* Skip stub for a BIF */
+ continue;
+ }
+ ep = erts_export_put(stp->module, stp->export[i].function,
+ stp->export[i].arity);
if (!on_load) {
- ep->address = stp->export[i].address;
+ ep->address = address;
} else {
/*
* Don't make any of the exported functions
* callable yet.
*/
ep->address = ep->code+3;
- ep->code[4] = (BeamInstr) stp->export[i].address;
+ ep->code[4] = (BeamInstr) address;
}
}
@@ -5037,7 +5079,9 @@ functions_in_module(Process* p, /* Process whose heap to use. */
BeamInstr* code;
int i;
Uint num_functions;
+ Uint need;
Eterm* hp;
+ Eterm* hp_end;
Eterm result = NIL;
if (is_not_atom(mod)) {
@@ -5050,19 +5094,28 @@ functions_in_module(Process* p, /* Process whose heap to use. */
}
code = modp->code;
num_functions = code[MI_NUM_FUNCTIONS];
- hp = HAlloc(p, 5*num_functions);
+ need = 5*num_functions;
+ hp = HAlloc(p, need);
+ hp_end = hp + need;
for (i = num_functions-1; i >= 0 ; i--) {
BeamInstr* func_info = (BeamInstr *) code[MI_FUNCTIONS+i];
Eterm name = (Eterm) func_info[3];
int arity = (int) func_info[4];
Eterm tuple;
- ASSERT(is_atom(name));
- tuple = TUPLE2(hp, name, make_small(arity));
- hp += 3;
- result = CONS(hp, tuple, result);
- hp += 2;
+ /*
+ * If the function name is [], this entry is a stub for
+ * a BIF that should be ignored.
+ */
+ ASSERT(is_atom(name) || is_nil(name));
+ if (is_atom(name)) {
+ tuple = TUPLE2(hp, name, make_small(arity));
+ hp += 3;
+ result = CONS(hp, tuple, result);
+ hp += 2;
+ }
}
+ HRelease(p, hp_end, hp);
return result;
}
@@ -5610,19 +5663,28 @@ stub_final_touch(LoaderState* stp, BeamInstr* fp)
{
int i;
int n = stp->num_exps;
+ Eterm mod = fp[2];
Eterm function = fp[3];
int arity = fp[4];
#ifdef HIPE
Lambda* lp;
#endif
+ if (is_bif(mod, function, arity)) {
+ fp[1] = 0;
+ fp[2] = 0;
+ fp[3] = 0;
+ fp[4] = 0;
+ return;
+ }
+
/*
* Test if the function should be exported.
*/
for (i = 0; i < n; i++) {
if (stp->export[i].function == function && stp->export[i].arity == arity) {
- Export* ep = erts_export_put(fp[2], function, arity);
+ Export* ep = erts_export_put(mod, function, arity);
ep->address = fp+5;
return;
}