1 files changed, 213 insertions, 0 deletions
diff --git a/pkgs/os-specific/darwin/print-reexports/main.c b/pkgs/os-specific/darwin/print-reexports/main.c
new file mode 100644
index 00000000000..e6ff527da96
--- /dev/null
+++ b/pkgs/os-specific/darwin/print-reexports/main.c
@@ -0,0 +1,213 @@
+/**
+ * Display the list of re-exported libraries from a TAPI v2 .tbd file, one per
+ * line on stdout.
+ *
+ * TAPI files are the equivalent of library files for the purposes of linking.
+ * Like dylib files, they may re-export other libraries. In upstream usage
+ * these refer to the absolute paths of dylibs, and are resolved to .tbd files
+ * in combination with the syslibroot option. In nixpkgs, the .tbd files refer
+ * directly to other .tbd files without a syslibroot. Note that each .tbd file
+ * contains an install name, so the re-exported path does not affect the final
+ * result.
+ *
+ * In nixpkgs each framework is a distinct store path and some frameworks
+ * re-export other frameworks. The re-exported names are rewritten to refer to
+ * the store paths of dependencies via textual substitution. This utility is
+ * used to emit every file that is listed as a re-exported library, which
+ * allows the framework builder to verify their existence.
+ */
+
+#include <stdio.h>
+#include <sys/errno.h>
+#include <yaml.h>
+
+#define LOG(str, ...) fprintf(stderr, "%s", str)
+
+#define LOGF(...) fprintf(stderr, __VA_ARGS__)
+
+static yaml_node_t *get_mapping_entry(yaml_document_t *document, yaml_node_t *mapping, const char *name) {
+  if (!mapping) {
+    fprintf(stderr, "get_mapping_entry: mapping is null\n");
+    return NULL;
+  }
+
+  for (
+      yaml_node_pair_t *pair = mapping->data.mapping.pairs.start;
+      pair < mapping->data.mapping.pairs.top;
+      ++pair
+  ) {
+    yaml_node_t *key = yaml_document_get_node(document, pair->key);
+
+    if (!key) {
+      LOGF("key (%d) is null\n", pair->key);
+      return NULL;
+    }
+
+    if (key->type != YAML_SCALAR_NODE) {
+      LOG("get_mapping_entry: key is not a scalar\n");
+      return NULL;
+    }
+
+    if (strncmp((const char *)key->data.scalar.value, name, key->data.scalar.length) != 0) {
+      continue;
+    }
+
+    return yaml_document_get_node(document, pair->value);
+  }
+
+  return NULL;
+}
+
+static int emit_reexports_v2(yaml_document_t *document) {
+  yaml_node_t *root = yaml_document_get_root_node(document);
+
+  yaml_node_t *exports = get_mapping_entry(document, root, "exports");
+
+  if (!exports) {
+    return 1;
+  }
+
+  if (exports->type != YAML_SEQUENCE_NODE) {
+    LOG("value is not a sequence\n");
+    return 0;
+  }
+
+  for (
+      yaml_node_item_t *export = exports->data.sequence.items.start;
+      export < exports->data.sequence.items.top;
+      ++export
+  ) {
+    yaml_node_t *export_node = yaml_document_get_node(document, *export);
+
+    yaml_node_t *reexports = get_mapping_entry(document, export_node, "re-exports");
+
+    if (!reexports) {
+      continue;
+    }
+
+    if (reexports->type != YAML_SEQUENCE_NODE) {
+      LOG("re-exports is not a sequence\n");
+      return 0;
+    }
+
+    for (
+        yaml_node_item_t *reexport = reexports->data.sequence.items.start;
+        reexport < reexports->data.sequence.items.top;
+        ++reexport
+    ) {
+      yaml_node_t *val = yaml_document_get_node(document, *reexport);
+
+      if (val->type != YAML_SCALAR_NODE) {
+        LOG("item is not a scalar\n");
+        return 0;
+      }
+
+      fwrite(val->data.scalar.value, val->data.scalar.length, 1, stdout);
+      putchar('\n');
+    }
+  }
+
+  return 1;
+}
+
+static int emit_reexports_v4(yaml_document_t *document) {
+  yaml_node_t *root = yaml_document_get_root_node(document);
+  yaml_node_t *reexports = get_mapping_entry(document, root, "reexported-libraries");
+
+  if (!reexports) {
+    return 1;
+  }
+
+  if (reexports->type != YAML_SEQUENCE_NODE) {
+    LOG("value is not a sequence\n");
+    return 0;
+  }
+
+  for (
+      yaml_node_item_t *entry = reexports->data.sequence.items.start;
+      entry < reexports->data.sequence.items.top;
+      ++entry
+  ) {
+    yaml_node_t *entry_node = yaml_document_get_node(document, *entry);
+
+    yaml_node_t *libs = get_mapping_entry(document, entry_node, "libraries");
+
+    if (!libs) {
+      continue;
+    }
+
+    if (libs->type != YAML_SEQUENCE_NODE) {
+      LOG("libraries is not a sequence\n");
+      return 0;
+    }
+
+    for (
+        yaml_node_item_t *lib = libs->data.sequence.items.start;
+        lib < libs->data.sequence.items.top;
+        ++lib
+    ) {
+      yaml_node_t *val = yaml_document_get_node(document, *lib);
+
+      if (val->type != YAML_SCALAR_NODE) {
+        LOG("item is not a scalar\n");
+        return 0;
+      }
+
+      fwrite(val->data.scalar.value, val->data.scalar.length, 1, stdout);
+      putchar('\n');
+    }
+  }
+
+  return 1;
+}
+
+int main(int argc, char **argv) {
+  int result = 0;
+
+  if (argc != 2) {
+    fprintf(stderr, "Invalid usage\n");
+    result = 2;
+    goto done;
+  }
+
+  FILE *f = fopen(argv[1], "r");
+  if (!f) {
+    perror("opening input file");
+    result = errno;
+    goto done;
+  }
+
+  yaml_parser_t yaml_parser;
+  if (!yaml_parser_initialize(&yaml_parser)) {
+    fprintf(stderr, "Failed to initialize yaml parser\n");
+    result = 1;
+    goto err_file;
+  }
+
+  yaml_parser_set_input_file(&yaml_parser, f);
+
+  yaml_document_t yaml_document;
+
+  if(!yaml_parser_load(&yaml_parser, &yaml_document)) {
+    fprintf(stderr, "Failed to load yaml file\n");
+    result = 1;
+    goto err_yaml;
+  }
+
+  // Try both, only fail if one reports an error.  A lack of re-exports is not
+  // considered an error.
+  int ok = 1;
+  ok = ok && emit_reexports_v2(&yaml_document);
+  ok = ok && emit_reexports_v4(&yaml_document);
+
+  result = !ok;
+
+err_yaml:
+  yaml_parser_delete(&yaml_parser);
+
+err_file:
+  fclose(f);
+
+done:
+  return result;
+}