Merge pull request #1624 from bjorng/bjorn/add-beam-internal-doc

Add internal documentation for the beam_makeops script

OTP-14626

5 files changed, 32 insertions, 22 deletions

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 60d0008d8f..bc95ccec52 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -400,12 +400,13 @@ static BeamInstr* apply_fun(Process* p, Eterm fun,
 			    Eterm args, Eterm* reg) NOINLINE;
 static Eterm new_fun(Process* p, Eterm* reg,
 		     ErlFunEntry* fe, int num_free) NOINLINE;
-static Eterm new_map(Process* p, Eterm* reg, Uint live, Uint n, BeamInstr* ptr) NOINLINE;
-static Eterm new_small_map_lit(Process* p, Eterm* reg, Eterm keys_literal,
+static Eterm erts_gc_new_map(Process* p, Eterm* reg, Uint live,
+                             Uint n, BeamInstr* ptr) NOINLINE;
+static Eterm erts_gc_new_small_map_lit(Process* p, Eterm* reg, Eterm keys_literal,
                                Uint live, BeamInstr* ptr) NOINLINE;
-static Eterm update_map_assoc(Process* p, Eterm* reg, Uint live,
+static Eterm erts_gc_update_map_assoc(Process* p, Eterm* reg, Uint live,
                               Uint n, BeamInstr* new_p) NOINLINE;
-static Eterm update_map_exact(Process* p, Eterm* reg, Uint live,
+static Eterm erts_gc_update_map_exact(Process* p, Eterm* reg, Uint live,
                               Uint n, Eterm* new_p) NOINLINE;
 static Eterm get_map_element(Eterm map, Eterm key);
 static Eterm get_map_element_hash(Eterm map, Eterm key, Uint32 hx);
@@ -2755,7 +2756,7 @@ do {						\
 
 
 static Eterm
-new_map(Process* p, Eterm* reg, Uint live, Uint n, BeamInstr* ptr)
+erts_gc_new_map(Process* p, Eterm* reg, Uint live, Uint n, BeamInstr* ptr)
 {
     Uint i;
     Uint need = n + 1 /* hdr */ + 1 /*size*/ + 1 /* ptr */ + 1 /* arity */;
@@ -2812,7 +2813,8 @@ new_map(Process* p, Eterm* reg, Uint live, Uint n, BeamInstr* ptr)
 }
 
 static Eterm
-new_small_map_lit(Process* p, Eterm* reg, Eterm keys_literal, Uint live, BeamInstr* ptr)
+erts_gc_new_small_map_lit(Process* p, Eterm* reg, Eterm keys_literal,
+                          Uint live, BeamInstr* ptr)
 {
     Eterm* keys = tuple_val(keys_literal);
     Uint n = arityval(*keys);
@@ -2846,7 +2848,8 @@ new_small_map_lit(Process* p, Eterm* reg, Eterm keys_literal, Uint live, BeamIns
 }
 
 static Eterm
-update_map_assoc(Process* p, Eterm* reg, Uint live, Uint n, BeamInstr* new_p)
+erts_gc_update_map_assoc(Process* p, Eterm* reg, Uint live,
+                         Uint n, BeamInstr* new_p)
 {
     Uint num_old;
     Uint num_updates;
@@ -2892,7 +2895,7 @@ update_map_assoc(Process* p, Eterm* reg, Uint live, Uint n, BeamInstr* new_p)
      */
 
     if (num_old == 0) {
-	return new_map(p, reg, live, n, new_p);
+	return erts_gc_new_map(p, reg, live, n, new_p);
     }
 
     /*
@@ -3048,7 +3051,7 @@ update_map_assoc(Process* p, Eterm* reg, Uint live, Uint n, BeamInstr* new_p)
  */
 
 static Eterm
-update_map_exact(Process* p, Eterm* reg, Uint live, Uint n, Eterm* new_p)
+erts_gc_update_map_exact(Process* p, Eterm* reg, Uint live, Uint n, Eterm* new_p)
 {
     Uint i;
     Uint num_old;
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 7331c331a6..4fcfea527c 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -2384,8 +2384,18 @@ load_code(LoaderState* stp)
 		    code[ci++] = NIL;
 		    break;
 		case TAG_q:
-		    new_literal_patch(stp, ci);
-		    code[ci++] = tmp_op->a[arg].val;
+                    {
+                        BeamInstr val = tmp_op->a[arg].val;
+                        Eterm term = stp->literals[val].term;
+                        new_literal_patch(stp, ci);
+                        code[ci++] = val;
+                        switch (loader_tag(term)) {
+                        case LOADER_X_REG:
+                        case LOADER_Y_REG:
+                            LoadError1(stp, "the term '%T' would be confused "
+                                       "with a register", term);
+                        }
+                    }
 		    break;
 		default:
 		    LoadError1(stp, "bad tag %d for general source",
diff --git a/erts/emulator/beam/macros.tab b/erts/emulator/beam/macros.tab
index e0b5f56b53..494fe8961e 100644
--- a/erts/emulator/beam/macros.tab
+++ b/erts/emulator/beam/macros.tab
@@ -20,13 +20,12 @@
 //
 
 //
-// Use if there is a garbage collection before storing to a
-// general destination (either X or Y register).
+// Define a regular expression that will match instructions that
+// perform GC.  That will allow beam_makeops to check for instructions
+// that don't use $REFRESH_GEN_DEST() when they should.
 //
 
-REFRESH_GEN_DEST() {
-    dst_ptr = REG_TARGET_PTR(dst);
-}
+GC_REGEXP=erts_garbage_collect|erts_gc|GcBifFunction;
 
 // $Offset is relative to the start of the instruction (not to the
 // location of the failure label reference). Since combined
diff --git a/erts/emulator/beam/map_instrs.tab b/erts/emulator/beam/map_instrs.tab
index bbb2f49b66..c594a87298 100644
--- a/erts/emulator/beam/map_instrs.tab
+++ b/erts/emulator/beam/map_instrs.tab
@@ -31,7 +31,7 @@ new_map(Dst, Live, N) {
     Eterm res;
 
     HEAVY_SWAPOUT;
-    res = new_map(c_p, reg, $Live, $N, $NEXT_INSTRUCTION);
+    res = erts_gc_new_map(c_p, reg, $Live, $N, $NEXT_INSTRUCTION);
     HEAVY_SWAPIN;
     $REFRESH_GEN_DEST();
     $Dst = res;
@@ -44,7 +44,7 @@ i_new_small_map_lit(Dst, Live, Keys) {
     Eterm keys = $Keys;
 
     HEAVY_SWAPOUT;
-    res = new_small_map_lit(c_p, reg, keys, $Live, $NEXT_INSTRUCTION);
+    res = erts_gc_new_small_map_lit(c_p, reg, keys, $Live, $NEXT_INSTRUCTION);
     HEAVY_SWAPIN;
     $REFRESH_GEN_DEST();
     $Dst = res;
@@ -133,7 +133,7 @@ update_map_assoc(Src, Dst, Live, N) {
 
     reg[live] = $Src;
     HEAVY_SWAPOUT;
-    res = update_map_assoc(c_p, reg, live, $N, $NEXT_INSTRUCTION);
+    res = erts_gc_update_map_assoc(c_p, reg, live, $N, $NEXT_INSTRUCTION);
     HEAVY_SWAPIN;
     ASSERT(is_value(res));
     $REFRESH_GEN_DEST();
@@ -147,7 +147,7 @@ update_map_exact(Fail, Src, Dst, Live, N) {
 
     reg[live] = $Src;
     HEAVY_SWAPOUT;
-    res = update_map_exact(c_p, reg, live, $N, $NEXT_INSTRUCTION);
+    res = erts_gc_update_map_exact(c_p, reg, live, $N, $NEXT_INSTRUCTION);
     HEAVY_SWAPIN;
     if (is_value(res)) {
         $REFRESH_GEN_DEST();
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 7a2c39b3a8..a560bde920 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -511,8 +511,6 @@ put_list y x x
 put_list y y x
 put_list x y x
 
-put_list y x x
-
 # put_list SrcReg Constant Dst
 
 put_list x c x