Changes to src/linker.c. All files

src/linker.c

@@ -23,11 +23,15 @@ struct lib_entry {   char *name;   block def;-  int loading;+};+struct loading_lib {+  const char *name;+  struct loading_lib *next; }; struct lib_loading_state {   struct lib_entry *entries;   uint64_t ct;+  struct loading_lib *loading; }; static int load_library(jq_state *jq, jv lib_path,                         int is_data, int raw, int optional,@@ -312,16 +316,6 @@ static int process_dependencies(jq_state *jq, jv jq_origin, jv lib_origin, block       }        if (state_idx < lib_state->ct) { // Found-        if (lib_state->entries[state_idx].loading) {-          jq_report_error(jq, jv_string_fmt("jq: error: circular import of %s\n",-                                            jv_string_value(resolved)));-          jv_free(resolved);-          jv_free(as);-          jv_free(deps);-          jv_free(jq_origin);-          jv_free(lib_origin);-          return 1;-        }         jv_free(resolved);         // Bind the library to the program         bk = block_bind_library(lib_state->entries[state_idx].def, bk, OP_IS_CALL_PSEUDO, as_str);@@ -351,11 +345,20 @@ static int load_library(jq_state *jq, jv lib_path, int is_data, int raw, int opt   struct locfile* src = NULL;   block program;   jv data;+  for (struct loading_lib *l = lib_state->loading; l; l = l->next) {+    if (strcmp(l->name, jv_string_value(lib_path)) == 0) {+      jq_report_error(jq, jv_string_fmt("jq: error: circular import of %s\n",+                                        jv_string_value(lib_path)));+      *out_block = gen_noop();+      jv_free(lib_path);+      return 1;+    }+  }   if (is_data && !raw)     data = jv_load_file(jv_string_value(lib_path), 0);   else     data = jv_load_file(jv_string_value(lib_path), 1);-  int state_idx;+  uint64_t state_idx;   if (!jv_is_valid(data)) {     program = gen_noop();     if (!optional) {@@ -373,29 +376,33 @@ static int load_library(jq_state *jq, jv lib_path, int is_data, int raw, int opt     lib_state->entries = jv_mem_realloc(lib_state->entries, lib_state->ct * sizeof(struct lib_entry));     lib_state->entries[state_idx].name = strdup(jv_string_value(lib_path));     lib_state->entries[state_idx].def = program;-    lib_state->entries[state_idx].loading = 0;   } else {     // import "foo" as bar;     src = locfile_init(jq, jv_string_value(lib_path), jv_string_value(data), jv_string_length_bytes(jv_copy(data)));     nerrors += jq_parse_library(src, &program);     locfile_free(src);     if (nerrors == 0) {-      // Register the library before processing its dependencies so that-      // circular imports can be detected.-      state_idx = lib_state->ct++;-      lib_state->entries = jv_mem_realloc(lib_state->entries, lib_state->ct * sizeof(struct lib_entry));-      lib_state->entries[state_idx].name = strdup(jv_string_value(lib_path));-      lib_state->entries[state_idx].def = gen_noop();-      lib_state->entries[state_idx].loading = 1;-+      // Mark the library as being loaded while its dependencies are processed,+      // so that a recursive reference to it is reported as a circular import.+      // The node lives on this frame and is popped before lib_path is freed,+      // so it can borrow the path string.+      struct loading_lib loading = { jv_string_value(lib_path), lib_state->loading };+      lib_state->loading = &loading;       char *lib_origin = strdup(jv_string_value(lib_path));       nerrors += process_dependencies(jq, jq_get_jq_origin(jq),                                       jv_string(dirname(lib_origin)),                                       &program, lib_state);       free(lib_origin);+      lib_state->loading = loading.next;       program = block_bind_self(program, OP_IS_CALL_PSEUDO);+      // Register the library only once its dependencies have been processed,+      // to keep lib_state->entries in dependency order.  Register it even when+      // its dependencies failed, so that other importers reuse this entry+      // rather than loading and diagnosing the same library again.+      state_idx = lib_state->ct++;+      lib_state->entries = jv_mem_realloc(lib_state->entries, lib_state->ct * sizeof(struct lib_entry));+      lib_state->entries[state_idx].name = strdup(jv_string_value(lib_path));       lib_state->entries[state_idx].def = program;-      lib_state->entries[state_idx].loading = 0;     }   }   *out_block = program;@@ -435,7 +442,7 @@ jv load_module_meta(jq_state *jq, jv mod_relpath) { int load_program(jq_state *jq, struct locfile* src, block *out_block) {   int nerrors = 0;   block program;-  struct lib_loading_state lib_state = {0,0};+  struct lib_loading_state lib_state = {0,0,0};   nerrors = jq_parse(src, &program);   if (nerrors)     return nerrors;