Fix crash in Dict test

Now, that bottom is a leaftype, we need to be careful not to assume that
all leaf types are datatypes. Fix the specific instance that caused the
crash in array.c and audit other uses, inserting appropriate assertions.

Author: Keno

src/array.c

@@ -24,8 +24,9 @@ extern "C" {
 
 static inline int store_unboxed(jl_value_t *el_type) // jl_isbits
 {
-    return jl_is_leaf_type(el_type) && jl_is_immutable(el_type) &&
-        ((jl_datatype_t*)el_type)->layout && ((jl_datatype_t*)el_type)->layout->pointerfree;
+    return jl_is_leaf_type(el_type) && el_type != jl_bottom_type &&
+        jl_is_immutable(el_type) && ((jl_datatype_t*)el_type)->layout &&
+        ((jl_datatype_t*)el_type)->layout->pointerfree;
 }
 
 int jl_array_store_unboxed(jl_value_t *el_type)

src/cgutils.cpp

@@ -212,6 +212,7 @@ static DIType julia_type_to_di(jl_value_t *jt, DIBuilder *dbuilder, bool isboxed
         return ct;
     }
     else {
+        assert(jl_is_datatype(jt));
         jdt->ditype = dbuilder->createTypedef(jl_pvalue_dillvmt,
             jl_symbol_name(jdt->name->name), NULL, 0, NULL);
         return (llvm::DIType*)jdt->ditype;

src/codegen.cpp

@@ -2750,6 +2750,7 @@ static bool emit_builtin_call(jl_cgval_t *ret, jl_value_t *f, jl_value_t **args,
                 sz = emit_datatype_nfields(boxed(arg1, ctx));
             }
             else {
+                assert(jl_is_datatype(aty));
                 sz = ConstantInt::get(T_size, jl_datatype_nfields(aty));
             }
             *ret = mark_julia_type(sz, false, jl_long_type, ctx);
@@ -2832,6 +2833,7 @@ static bool emit_builtin_call(jl_cgval_t *ret, jl_value_t *f, jl_value_t **args,
             JL_GC_POP();
             return false;
         }
+        assert(jl_is_datatype(stt));
 
         ssize_t fieldidx = -1;
         if (jl_is_quotenode(args[2]) && jl_is_symbol(jl_fieldref(args[2], 0))) {

src/jltypes.c

@@ -881,13 +881,18 @@ static jl_value_t *inst_datatype(jl_datatype_t *dt, jl_svec_t *p, jl_value_t **i
         size_t i;
         for(i=0; i < ntp; i++) {
             jl_value_t *pi = iparams[i];
-            if (!jl_is_leaf_type(pi) || ((jl_datatype_t*)pi)->abstract) {
-                // normalize types equal to wrappers
-                jl_value_t *tw = extract_wrapper(pi);
-                if (tw && tw != pi && jl_types_equal(pi, tw)) {
-                    iparams[i] = tw;
-                    if (p) jl_gc_wb(p, tw);
-                }
+            if (pi == jl_bottom_type)
+                continue;
+            if (jl_is_leaf_type(pi)) {
+                assert(jl_is_datatype(pi));
+                if (!((jl_datatype_t*)pi)->abstract)
+                    continue;
+            }
+            // normalize types equal to wrappers
+            jl_value_t *tw = extract_wrapper(pi);
+            if (tw && tw != pi && jl_types_equal(pi, tw)) {
+                iparams[i] = tw;
+                if (p) jl_gc_wb(p, tw);
             }
         }
         jl_value_t *lkup = (jl_value_t*)lookup_type(tn, iparams, ntp);

src/subtype.c

@@ -191,9 +191,9 @@ static int obviously_unequal(jl_value_t *a, jl_value_t *b)
 {
     if (a == b)
         return 0;
-    if (jl_is_leaf_type(a) && !((jl_datatype_t*)a)->abstract)
+    if (a != jl_bottom_type && jl_is_leaf_type(a) && !((jl_datatype_t*)a)->abstract)
         return 1;
-    if (jl_is_leaf_type(b) && !((jl_datatype_t*)b)->abstract)
+    if (b != jl_bottom_type && jl_is_leaf_type(b) && !((jl_datatype_t*)b)->abstract)
         return 1;
     if (jl_is_unionall(a)) a = jl_unwrap_unionall(a);
     if (jl_is_unionall(b)) b = jl_unwrap_unionall(b);