fix(extract): receiver-qualify Go method QNs

internal/cbm/doclink_go.c

@@ -43,10 +43,10 @@
  *                           drops these lines and so carries no line number
  *                           at all.
  *   G  path                 go.mod: the module path
- * w says who keeps the node. A Go method node has a FLAT qualified name
- * (<dir>.<Method>), so a function, the methods of every receiver, a type and
- * a value of one name all claim the node <dir>.<name>, and within a file the
- * declaration on the LAST line keeps it (cbm_gbuf_upsert_node). w is 1 for
+ * w says who keeps the node <dir>.<name>. A function, a type and a value of
+ * one name all claim it, and within a file the declaration on the LAST line
+ * keeps it (cbm_gbuf_upsert_node). A method claims nothing: its node is
+ * receiver-qualified (<dir>.<Recv>.<Method>, #1913), and its w is `-`. w is 1 for
  * that declaration, 0 for the others of that name, x when two of them start
  * on that last line, and - for a value the extractor gives no node at all
  * (it gives one to the first name of a constant spec and of a parenthesis-
@@ -1511,9 +1511,11 @@ static void go_scan_method(go_scan_t *s, TSNode m) {
         recv = "?";
         recv_len = SKIP_ONE;
     }
-    go_push_claim(s,
-                  cbm_arena_sprintf(s->tmp, "M\t%.*s\t%.*s", (int)recv_len, recv, (int)len, name),
-                  name, len, m);
+    /* #1913: a Go method node is receiver-qualified (<dir>.<Recv>.<Method>),
+     * so a method claims no flat name: w is `-`, and the method is found
+     * through its receiver (the member table), never through <dir>.<name>. */
+    (void)go_push_rec(
+        s, cbm_arena_sprintf(s->tmp, "M\t%.*s\t%.*s\t-", (int)recv_len, recv, (int)len, name));
 }
 
 /* The implied name of an embedded field: the type's own name, without

internal/cbm/extract_calls.c

@@ -4493,6 +4493,24 @@ CBMInvocationDescriptor handle_calls(CBMExtractCtx *ctx, TSNode node, const CBML
                     }
                 }
             }
+            // Go receiver-aware guard (same direction as the TS/JS flag above).
+            // Flag a selector call x.foo(). The Go AST cannot separate a method
+            // call on a value from a package-qualified call — but every selector
+            // call the Go LSP or the import/qualified registry strategies CAN
+            // place never reaches the weak short-name guards, so the flag only
+            // bites on unresolvable receivers (`f.Close()` on an os.File,
+            // `sha256.New()` behind an unindexed import), where a project-wide
+            // short-name match fabricates an edge to an unrelated project
+            // symbol sharing the name. Bare calls (helper()) keep
+            // is_method=false and resolve same-module/import paths as before.
+            if (ctx->language == CBM_LANG_GO &&
+                strcmp(ts_node_type(node), "call_expression") == 0) {
+                TSNode gofn = ts_node_child_by_field_name(node, TS_FIELD("function"));
+                if (!ts_node_is_null(gofn) &&
+                    strcmp(ts_node_type(gofn), "selector_expression") == 0) {
+                    call.is_method = true;
+                }
+            }
 
             TSNode args = ts_node_child_by_field_name(node, TS_FIELD("arguments"));
             /* tree-sitter-elixir attaches NO field name to a call's arguments

internal/cbm/extract_defs.c

@@ -5453,7 +5453,7 @@ static void set_def_complexity(CBMDefinition *def, TSNode body, const CBMLangSpe
  * Walks to the parameter_declaration's `type` field, unwrapping pointer_type
  * and generic_type, and returns the type_identifier text (e.g. "OrderService").
  * Returns NULL if no type_identifier is found. */
-static char *go_receiver_type_name(CBMArena *a, TSNode recv, const char *source) {
+char *cbm_go_receiver_type_name(CBMArena *a, TSNode recv, const char *source) {
     uint32_t nc = ts_node_child_count(recv);
     for (uint32_t i = 0; i < nc; i++) {
         TSNode child = ts_node_child(recv, i);
@@ -6687,12 +6687,27 @@ static void extract_func_def(CBMExtractCtx *ctx, TSNode node, const CBMLangSpec
          * (and downstream Go IMPLEMENTS/OVERRIDE) link the method to its owning
          * struct/type node.  The parent QN must match the type's node QN, which
          * is computed the same way (cbm_fqn_compute on the type name). */
-        char *recv_type = go_receiver_type_name(a, recv, ctx->source);
+        char *recv_type = cbm_go_receiver_type_name(a, recv, ctx->source);
         if (recv_type && recv_type[0]) {
             /* Must match the Go type node QN (directory-based module) so the
              * DEFINES_METHOD edge links the method to its owning type. */
             def.parent_class = cbm_fqn_compute_source_lang(a, ctx->project, ctx->rel_path,
                                                            recv_type, ctx->language);
+            /* Receiver-qualify the method QN (proj.pkg.Recv.method) — same
+             * shape as the C++ out-of-line path below and Go interface
+             * members. With the flat proj.pkg.method QN every same-name
+             * method in a package collided in the graph upsert: one body
+             * survived and the twins' call edges accreted onto it. The
+             * call-scope side (compute_func_qn in extract_unified.c) mirrors
+             * this formula, and go_lsp consumers read the def QN and
+             * parent_class (receiver_type) verbatim, so resolution joins
+             * stay exact. Go only: templ's Go-derived grammar reaches this
+             * branch too, but its call-scope QN (compute_func_qn) stays flat,
+             * and a def QN the calls do not share would orphan every call
+             * inside a templ method. */
+            if (ctx->language == CBM_LANG_GO && def.parent_class) {
+                def.qualified_name = cbm_arena_sprintf(a, "%s.%s", def.parent_class, name);
+            }
         }
     }
 

internal/cbm/extract_unified.c

@@ -1110,6 +1110,29 @@ static const char *compute_func_qn(CBMExtractCtx *ctx, TSNode node, const CBMLan
         }
     }
 
+    /* Go method `func (s *Storage) Close() {...}`: the def extractor records
+     * this as Method "proj.pkg.Storage.Close" (receiver-qualified, mirroring
+     * the C++ out-of-line rule above). The call-scope QN must match — a bare
+     * "proj.pkg.Close" names a node that no longer exists, so every call
+     * inside the method body would fall back to File-node attribution
+     * (calls_find_source). Same ONE-formula contract as the def side:
+     * cbm_go_receiver_type_name + cbm_fqn_compute_source_lang. */
+    if (ctx->language == CBM_LANG_GO && strcmp(ts_node_type(node), "method_declaration") == 0) {
+        TSNode recv = ts_node_child_by_field_name(node, TS_FIELD("receiver"));
+        if (!ts_node_is_null(recv)) {
+            char *recv_type = cbm_go_receiver_type_name(ctx->arena, recv, ctx->source);
+            if (recv_type && recv_type[0]) {
+                const char *type_qn = cbm_fqn_compute_source_lang(
+                    ctx->arena, ctx->project, ctx->rel_path, recv_type, ctx->language);
+                /* NULL only on allocation failure: fall through to the flat
+                 * QN, as the def side does (extract_defs.c). */
+                if (type_qn) {
+                    return cbm_arena_sprintf(ctx->arena, "%s.%s", type_qn, name);
+                }
+            }
+        }
+    }
+
     /* Nix: a binding's own attrpath contributes scope (`a.b.fn = …`), and the def
      * extractor bakes it into the def QN. Compose it identically here — otherwise
      * an in-body call sources to a QN one or more segments short of the def, and

internal/cbm/helpers.h

@@ -173,6 +173,12 @@ TSNode cbm_resolve_func_name(TSNode node, CBMLanguage lang);
 // def extractor — drift dropped the class qualifier from in-body calls (#554/#621).
 char *cbm_cpp_out_of_line_parent_class(CBMArena *a, TSNode node, const char *source);
 
+/* Go: resolve a method_declaration's receiver parameter_list down to the bare
+ * receiver type_identifier (unwrapping pointer_type / generic_type). Shared by
+ * def extraction (extract_defs.c) and call-scope attribution
+ * (extract_unified.c) so the receiver-qualified method QN has ONE formula. */
+char *cbm_go_receiver_type_name(CBMArena *a, TSNode recv, const char *source);
+
 // Find a child node by kind string.
 TSNode cbm_find_child_by_kind(TSNode parent, const char *kind);
 

internal/cbm/lsp/go_lsp.c

@@ -1987,15 +1987,24 @@ static void process_function(GoLSPContext *ctx, TSNode func_node) {
     if (!func_name || !func_name[0])
         return;
 
-    // Enclosing-function QN must be the BARE package.Func form (no receiver
-    // type segment). The textual call events (extract_unified.c) source calls
-    // as package_qn.func_name — methods included — and the defs pass creates
-    // the graph Method node under the same QN, so any other form breaks the
-    // caller-QN join in cbm_pipeline_find_lsp_resolution and the LSP-resolved
-    // call silently falls back to the registry short-name resolver. The
-    // receiver type still reaches the registry via the def's parent_class /
-    // method->receiver_type; it just does not appear in the caller QN.
+    // Enclosing-function QN must be EXACTLY the QN the textual call events
+    // (extract_unified.c compute_func_qn) and the defs pass produce, or the
+    // caller-QN join in cbm_pipeline_find_lsp_resolution breaks and the
+    // LSP-resolved call silently falls back to the registry short-name
+    // resolver. Since #1909 receiver-qualified Go method QNs, that shared
+    // form is package_qn.ReceiverType.method for methods (the ONE-formula
+    // contract: cbm_go_receiver_type_name) and package_qn.func for functions.
     ctx->enclosing_func_qn = cbm_arena_sprintf(ctx->arena, "%s.%s", ctx->package_qn, func_name);
+    if (strcmp(ts_node_type(func_node), "method_declaration") == 0) {
+        TSNode recv = ts_node_child_by_field_name(func_node, "receiver", 8);
+        if (!ts_node_is_null(recv)) {
+            char *recv_type = cbm_go_receiver_type_name(ctx->arena, recv, ctx->source);
+            if (recv_type && recv_type[0]) {
+                ctx->enclosing_func_qn = cbm_arena_sprintf(ctx->arena, "%s.%s.%s", ctx->package_qn,
+                                                           recv_type, func_name);
+            }
+        }
+    }
 
     // Push function scope
     CBMScope *saved_scope = ctx->current_scope;

src/pipeline/doc_links_go.c

@@ -32,10 +32,11 @@
  * fields of its own struct declaration and the methods of its own interface
  * declaration: nothing promoted through embedding.
  *
- * Binding. The graph keeps one node per qualified name, Go method nodes have
- * a FLAT name (<dir>.<Method>), and <dir> is the directory, not the package
- * clause: functions, methods of every receiver, types and values of one name,
- * in every file of the directory, share one node, and the node is ONE of those
+ * Binding. The graph keeps one node per qualified name, and <dir> is the
+ * directory, not the package clause. Go method nodes are receiver-qualified
+ * (<dir>.<Recv>.<Method>, #1913) and are found through their receiver only.
+ * Functions, types and values of one name, in every file of the directory,
+ * share one node <dir>.<name>, and the node is ONE of those
  * declarations (cbm_gbuf_upsert_node keeps the smallest file path, then the
  * last line). So a reference binds only when the node IS the entity it names:
  * the node's file is a file of the named package, the declaration that keeps
@@ -59,7 +60,7 @@
  * not), missing (a repository package that does not declare the name; an
  * import path inside a module without a package there), graph_gap (declared,
  * but the node is another declaration's or absent: block variables, later
- * names of a declaration, embedded fields, methods that lost the flat name;
+ * names of a declaration, embedded fields;
  * also an undeclared name in a package with a parse error), test_only_target
  * (product code naming a declaration that only test files have), ambiguous
  * (several modules or packages fit; a name declared as two kinds; a name two
@@ -1063,7 +1064,7 @@ static void go_record_decl(go_index_t *ix, go_file_t *file, char **f, int nf) {
         FIELD_FIELDS = 4,
         IM_FIELDS = 3
     };
-    enum { F_OWNER = 2, T_ALIAS = 3, T_OWNER = 4, V_OWNER = 2, M_OWNER = 3, FIELD_NODE = 3 };
+    enum { F_OWNER = 2, T_ALIAS = 3, T_OWNER = 4, V_OWNER = 2, FIELD_NODE = 3 };
     char kind = f[0][0];
     if (nf < IM_FIELDS || !go_name_ok(f[SKIP_ONE])) {
         return;
@@ -1078,10 +1079,12 @@ static void go_record_decl(go_index_t *ix, go_file_t *file, char **f, int nf) {
         go_add_sym(ix, file, GO_KIND_VALUE, f[SKIP_ONE], NULL);
         go_add_claim(ix, file, GO_KIND_VALUE, f[SKIP_ONE], NULL, f[V_OWNER]);
     } else if (kind == 'M' && nf == M_FIELDS && go_name_ok(f[PAIR_LEN])) {
+        /* #1913: a method is found through its receiver only; it claims no
+         * flat <dir>.<name> (its record says w `-`), so a type, function or
+         * value of the same name keeps that node. */
         if (strcmp(f[SKIP_ONE], "?") != 0) {
             go_add_member(ix, file, GO_MEM_METHOD, f[SKIP_ONE], f[PAIR_LEN], true);
         }
-        go_add_claim(ix, file, GO_KIND_METHOD, f[PAIR_LEN], f[SKIP_ONE], f[M_OWNER]);
     } else if (kind == 'f' && nf == FIELD_FIELDS && go_name_ok(f[PAIR_LEN])) {
         go_add_member(ix, file, GO_MEM_FIELD, f[SKIP_ONE], f[PAIR_LEN], f[FIELD_NODE][0] == '1');
     } else if (kind == 'm' && nf == IM_FIELDS && go_name_ok(f[PAIR_LEN])) {
@@ -1342,9 +1345,9 @@ static const cbm_gbuf_node_t *go_member_node(const go_ctx_t *c, const go_pkg_t *
     return (fm && (fm->node_kinds & kind)) ? n : NULL;
 }
 
-/* The node of the method `recv.name`: its receiver-qualified node, else the
- * flat node <dir>.<name> when the method is the one that kept it (the last
- * declaration of that name in the node's file). */
+/* The node of the method `recv.name`: its receiver-qualified node. The flat
+ * fallback below (the method that kept <dir>.<name>) is unreachable since
+ * #1913: no method record claims a flat name any more. */
 static const cbm_gbuf_node_t *go_method_node(const go_ctx_t *c, const go_pkg_t *pkg, go_str_t recv,
                                              go_str_t name) {
     const cbm_gbuf_node_t *qualified = go_member_node(c, pkg, GO_MEM_METHOD, recv, name);

src/pipeline/doc_links_pdf.c

@@ -328,9 +328,10 @@ static void qn_candidate(const pdfr_index_t *x, const cbm_gbuf_node_t *n, const
     const char *rel = rel_qn(x, n->qualified_name);
     char alt[PDFR_KEY_CAP];
     bool owned = owner_name(x, n, alt, sizeof(alt));
-    /* A member whose QN leaves its owner out (a Go method's has no receiver)
-     * is named through the owner: `time.Now` is package time's function,
-     * never the method Now of a type that package time declares. */
+    /* A member whose QN leaves its owner out (a templ method's keeps the flat
+     * package QN; a Go method's did before index format 4) is named through
+     * the owner: `time.Now` is package time's function, never the method Now
+     * of a type that package time declares. */
     bool ownerless_qn = owned && !comp_suffix(rel, alt);
     bool via_rel = !ownerless_qn && comp_suffix(rel, s);
     bool via_alt = !via_rel && owned && strcmp(alt, rel) != 0 && comp_suffix(alt, s);

src/pipeline/pass_calls.c

@@ -1103,7 +1103,13 @@ static int resolve_single_call(cbm_pipeline_ctx_t *ctx, CBMCall *call, const CBM
      * language gated on only one resolver produces an edge on the sequential
      * path and not the parallel one (or vice versa), breaking MT determinism.
      * ArkTS belongs to the JS/TS family here (#1842); dropping it would
-     * reintroduce the #592/#606 false-edge class for .ets files. */
+     * reintroduce the #592/#606 false-edge class for .ets files.
+     *
+     * Go (#1906) rides the same deferred-drop plumbing through its OWN
+     * predicate: its drop-list differs (field_type_hint is receiver-aware for
+     * Go, and unique_name drops only when import-unreachability-penalized), so
+     * it composes via cbm_go_suppress_weak_method_match instead of widening
+     * the shared gate. Same lockstep rule: mirror pass_parallel.c. */
     bool suppress_weak_member = lang == CBM_LANG_PYTHON || lang == CBM_LANG_JAVASCRIPT ||
                                 lang == CBM_LANG_TYPESCRIPT || lang == CBM_LANG_TSX ||
                                 lang == CBM_LANG_ARKTS ||
@@ -1131,6 +1137,8 @@ static int resolve_single_call(cbm_pipeline_ctx_t *ctx, CBMCall *call, const CBM
                                              res.strategy)) ||
         cbm_suppress_weak_local_binding_call(suppress_weak_local_binding,
                                              call->callee_is_locally_bound, res.strategy) ||
+        cbm_go_suppress_weak_method_match(lang == CBM_LANG_GO, call->is_method, res.strategy,
+                                          res.confidence) ||
         /* Import-binding suppression (#2127): an external `from m import f`
          * binds `f` for the whole module, so a weak short-name match onto a
          * project `X.f` outside m is fabricated. Python-only (the import

src/pipeline/pass_parallel.c

@@ -3364,7 +3364,15 @@ static void resolve_file_calls(resolve_ctx_t *rc, resolve_worker_state_t *ws, CB
         }
 
         _rc_t0 = extract_now_ns();
-        try_field_type_hint(rc, &res, call->callee_name, source_node->id);
+        /* Not for Go (F-G9): the hint matches the capitalized receiver
+         * VARIABLE name as a substring of a candidate QN (`t.Run` -> any
+         * `...T...Run`), with no type evidence. The sequential resolver has no
+         * such step, so for Go it produced parallel-only edges (par/seq CALLS
+         * diverged), and the Go selector guard could not see them as the weak
+         * pick they are. SCIP precision of Go field_type_hint: 0.016. */
+        if (lang != CBM_LANG_GO) {
+            try_field_type_hint(rc, &res, call->callee_name, source_node->id);
+        }
         /* Cross-language veto — the same predicate as pass_calls.c, applied
          * AFTER the field-type hint so the hint may still re-pick a compatible
          * candidate first, and BEFORE the empty-resolution fallbacks below so a
@@ -3401,7 +3409,9 @@ static void resolve_file_calls(resolve_ctx_t *rc, resolve_worker_state_t *ws, CB
          * #606 direction.
          *
          * This language set MUST match the one in pass_calls.c exactly — see the
-         * note there. ArkTS belongs to the JS/TS family (#1842). */
+         * note there. ArkTS belongs to the JS/TS family (#1842). Go (#1906)
+         * composes via its own predicate (different drop-list — see
+         * cbm_go_suppress_weak_method_match), mirrored in pass_calls.c. */
         bool suppress_weak_member = lang == CBM_LANG_PYTHON || lang == CBM_LANG_JAVASCRIPT ||
                                     lang == CBM_LANG_TYPESCRIPT || lang == CBM_LANG_TSX ||
                                     lang == CBM_LANG_ARKTS ||
@@ -3419,6 +3429,8 @@ static void resolve_file_calls(resolve_ctx_t *rc, resolve_worker_state_t *ws, CB
                                                  call->callee_name, res.strategy)) ||
             cbm_suppress_weak_local_binding_call(suppress_weak_local_binding,
                                                  call->callee_is_locally_bound, res.strategy) ||
+            cbm_go_suppress_weak_method_match(lang == CBM_LANG_GO, call->is_method, res.strategy,
+                                              res.confidence) ||
             /* Import-binding suppression (#2127) — see pass_calls.c; this gate
              * MUST stay identical to the one there. */
             (lang == CBM_LANG_PYTHON &&