Print source-information when encountering ambiguous method during compilation

Author: timholy

src/codegen.cpp

@@ -1087,7 +1087,8 @@ void *jl_get_llvmf(jl_tupletype_t *tt, bool getwrapper, bool getdeclarations)
     jl_lambda_info_t *linfo = NULL;
     JL_GC_PUSH2(&linfo, &tt);
     if (tt != NULL) {
-        linfo = jl_get_specialization1(tt);
+        int8_t ambig;
+        linfo = jl_get_specialization1(tt, &ambig);
         if (linfo == NULL) {
             linfo = jl_method_lookup_by_type(
                 ((jl_datatype_t*)jl_tparam0(tt))->name->mt, tt, 0, 0);
@@ -2729,7 +2730,11 @@ static jl_cgval_t emit_call(jl_expr_t *ex, jl_codectx_t *ctx)
                   jl_sprint(args[0]),
                   jl_sprint((jl_value_t*)aty));
               }*/
-            jl_lambda_info_t *li = jl_get_specialization1((jl_tupletype_t*)aty);
+            int8_t ambig;
+            jl_lambda_info_t *li = jl_get_specialization1((jl_tupletype_t*)aty, &ambig);
+            if (ambig) {
+                jl_printf(JL_STDERR, "Detected ambiguity while compiling %s\n", ctx->name);
+            }
             if (li != NULL) {
                 assert(li->functionObjectsDecls.functionObject != NULL);
                 theFptr = (Value*)li->functionObjectsDecls.functionObject;
@@ -3506,7 +3511,8 @@ static Function *gen_cfun_wrapper(jl_function_t *ff, jl_value_t *jlrettype, jl_t
         jl_error("va_arg syntax not allowed for cfunction argument list");
 
     const char *name = "cfunction";
-    jl_lambda_info_t *lam = jl_get_specialization1((jl_tupletype_t*)sigt);
+    int8_t ambig;
+    jl_lambda_info_t *lam = jl_get_specialization1((jl_tupletype_t*)sigt, &ambig);
     jl_value_t *astrt = (jl_value_t*)jl_any_type;
     if (lam != NULL) {
         name = jl_symbol_name(lam->def->name);

src/gf.c

@@ -717,6 +717,9 @@ void print_func_loc(JL_STREAM *s, jl_method_t *m)
   To check this, jl_types_equal_generic needs to be more sophisticated
   so (T,T) is not equivalent to (Any,Any). (TODO)
 */
+
+int8_t issued_ambig_warn;
+
 static void issue_ambig_warn(jl_typemap_entry_t *m)
 {
     JL_STREAM *s = JL_STDERR;
@@ -729,6 +732,7 @@ static void issue_ambig_warn(jl_typemap_entry_t *m)
     print_func_loc(s, ambigm->func.method);
     jl_printf(s, "\nSee the documentation for tips on eliminating ambiguities.\n");
     m->ambig = ambigm->ambig = (jl_typemap_entry_t*) jl_nothing;
+    issued_ambig_warn = 1;
 }
 
 struct ambiguous_matches_env {
@@ -990,12 +994,13 @@ jl_lambda_info_t *jl_method_lookup(jl_methtable_t *mt, jl_value_t **args, size_t
 JL_DLLEXPORT jl_value_t *jl_matching_methods(jl_tupletype_t *types, int lim);
 
 // compile-time method lookup
-jl_lambda_info_t *jl_get_specialization1(jl_tupletype_t *types)
+jl_lambda_info_t *jl_get_specialization1(jl_tupletype_t *types, int8_t *ambig)
 {
     assert(jl_nparams(types) > 0);
     if (!jl_is_leaf_type((jl_value_t*)types))
         return NULL;
     assert(jl_is_datatype(jl_tparam0(types)));
+    issued_ambig_warn = 0;
 
     // make sure exactly 1 method matches (issue #7302).
     int i;
@@ -1006,6 +1011,7 @@ jl_lambda_info_t *jl_get_specialization1(jl_tupletype_t *types)
         // to analyze them in detail.
         if (ti == (jl_value_t*)jl_datatype_type || jl_is_tuple_type(ti)) {
             jl_value_t *matches = jl_matching_methods(types, 1);
+            *ambig = issued_ambig_warn;
             if (matches == jl_false)
                 return NULL;
             break;
@@ -1022,6 +1028,7 @@ jl_lambda_info_t *jl_get_specialization1(jl_tupletype_t *types)
     } JL_CATCH {
         goto not_found;
     }
+    *ambig = issued_ambig_warn;
     if (sf == NULL || sf->code == NULL || sf->inInference)
         goto not_found;
     if (sf->functionObjectsDecls.functionObject == NULL) {
@@ -1038,7 +1045,8 @@ jl_lambda_info_t *jl_get_specialization1(jl_tupletype_t *types)
 
 JL_DLLEXPORT void jl_compile_hint(jl_tupletype_t *types)
 {
-    (void)jl_get_specialization1(types);
+    int8_t ambig;
+    (void)jl_get_specialization1(types, &ambig);
 }
 
 // add type of `f` to front of argument tuple type
@@ -1076,6 +1084,7 @@ static int _compile_all_tvar_union(jl_tupletype_t *methsig, jl_svec_t *tvars)
     // and expanding the Union may give a leaf function
     jl_tvar_t **tvs;
     int tvarslen;
+    int8_t ambig;
     if (jl_is_typevar(tvars)) {
         tvs = (jl_tvar_t**)&tvars;
         tvarslen = 1;
@@ -1087,7 +1096,7 @@ static int _compile_all_tvar_union(jl_tupletype_t *methsig, jl_svec_t *tvars)
             if (jl_is_leaf_type((jl_value_t*)methsig)) {
                 // usually can create a specialized version of the function,
                 // if the signature is already a leaftype
-                jl_lambda_info_t *spec = jl_get_specialization1(methsig);
+                jl_lambda_info_t *spec = jl_get_specialization1(methsig, &ambig);
                 if (spec)
                     return 1;
             }
@@ -1120,7 +1129,7 @@ static int _compile_all_tvar_union(jl_tupletype_t *methsig, jl_svec_t *tvars)
             goto getnext; // signature wouldn't be callable / is invalid -- skip it
         }
         if (jl_is_leaf_type(sig)) {
-            if (jl_get_specialization1((jl_tupletype_t*)sig)) {
+            if (jl_get_specialization1((jl_tupletype_t*)sig, &ambig)) {
                 if (!jl_has_typevars((jl_value_t*)sig)) goto getnext; // success
             }
         }

src/julia_internal.h

@@ -281,7 +281,7 @@ int32_t jl_get_llvm_gv(jl_value_t *p);
 void jl_idtable_rehash(jl_array_t **pa, size_t newsz);
 
 JL_DLLEXPORT jl_methtable_t *jl_new_method_table(jl_sym_t *name, jl_module_t *module);
-jl_lambda_info_t *jl_get_specialization1(jl_tupletype_t *types);
+jl_lambda_info_t *jl_get_specialization1(jl_tupletype_t *types, int8_t *ambig);
 jl_function_t *jl_module_get_initializer(jl_module_t *m);
 uint32_t jl_module_next_counter(jl_module_t *m);
 void jl_fptr_to_llvm(jl_fptr_t fptr, jl_lambda_info_t *lam, int specsig);

src/threading.c

@@ -398,7 +398,8 @@ JL_DLLEXPORT jl_value_t *jl_threading_run(jl_svec_t *args)
     int8_t gc_state = jl_gc_unsafe_enter();
     JL_GC_PUSH1(&argtypes);
     argtypes = arg_type_tuple(jl_svec_data(args), jl_svec_len(args));
-    jl_lambda_info_t *li = jl_get_specialization1(argtypes);
+    int8_t ambig;
+    jl_lambda_info_t *li = jl_get_specialization1(argtypes, &ambig);
     jl_generate_fptr(li);
 
     threadwork.command = TI_THREADWORK_RUN;

src/toplevel.c

@@ -81,7 +81,8 @@ static void jl_module_load_time_initialize(jl_module_t *m)
             jl_value_t *tt = jl_is_type(f) ? (jl_value_t*)jl_wrap_Type(f) : jl_typeof(f);
             JL_GC_PUSH1(&tt);
             tt = (jl_value_t*)jl_apply_tuple_type_v(&tt, 1);
-            jl_get_specialization1((jl_tupletype_t*)tt);
+            int8_t ambig;
+            jl_get_specialization1((jl_tupletype_t*)tt, &ambig);
             JL_GC_POP();
         }
     }