Improve reader error handling

1 files changed, 40 insertions, 31 deletions

diff --git a/src/n3.c b/src/n3.c
index 844204fb..570ba91d 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -495,14 +495,17 @@ read_PN_CHARS(SerdReader* reader, SerdNode* dest)
 static SerdStatus
 read_PERCENT(SerdReader* reader, SerdNode* dest)
 {
-  push_byte(reader, dest, eat_byte_safe(reader, '%'));
+  SerdStatus st = push_byte(reader, dest, eat_byte_safe(reader, '%'));
+  if (st) {
+    return st;
+  }
+
   const uint8_t h1 = read_HEX(reader);
   const uint8_t h2 = read_HEX(reader);
   if (h1 && h2) {
     push_byte(reader, dest, h1);
     return push_byte(reader, dest, h2);
   }
-
   return SERD_ERR_BAD_SYNTAX;
 }
 
@@ -694,7 +697,7 @@ read_IRIREF_scheme(SerdReader* reader, SerdNode* dest)
     }
   }
 
-  return r_err(reader, SERD_ERR_BAD_SYNTAX, "unexpected end of file\n");
+  return SERD_FAILURE;
 }
 
 static SerdStatus
@@ -704,7 +707,9 @@ read_IRIREF(SerdReader* reader, SerdNode** dest)
     return SERD_ERR_BAD_SYNTAX;
   }
 
-  *dest = push_node(reader, SERD_URI, "", 0);
+  if (!(*dest = push_node(reader, SERD_URI, "", 0))) {
+    return SERD_ERR_OVERFLOW;
+  }
 
   if (!fancy_syntax(reader) && read_IRIREF_scheme(reader, *dest)) {
     return r_err(reader, SERD_ERR_BAD_SYNTAX, "expected IRI scheme\n");
@@ -784,11 +789,12 @@ read_PrefixedName(SerdReader* reader,
     return SERD_FAILURE;
   }
 
-  push_byte(reader, dest, eat_byte_safe(reader, ':'));
-
-  st = read_PN_LOCAL(reader, dest, ate_dot);
+  if ((st = push_byte(reader, dest, eat_byte_safe(reader, ':'))) ||
+      (st = read_PN_LOCAL(reader, dest, ate_dot)) > SERD_FAILURE) {
+    return st;
+  }
 
-  return (st > SERD_FAILURE) ? st : SERD_SUCCESS;
+  return SERD_SUCCESS;
 }
 
 static SerdStatus
@@ -882,21 +888,21 @@ read_iri(SerdReader* reader, SerdNode** dest, bool* ate_dot)
   case '<':
     return read_IRIREF(reader, dest);
   default:
-    if (!(*dest = push_node(reader, SERD_CURIE, "", 0))) {
-      return SERD_ERR_OVERFLOW;
-    }
-    return read_PrefixedName(reader, *dest, true, ate_dot);
+    *dest = push_node(reader, SERD_CURIE, "", 0);
+    return *dest ? read_PrefixedName(reader, *dest, true, ate_dot)
+                 : SERD_ERR_OVERFLOW;
   }
 }
 
 static SerdStatus
 read_literal(SerdReader* reader, SerdNode** dest, bool* ate_dot)
 {
-  *dest = push_node(reader, SERD_LITERAL, "", 0);
+  if (!(*dest = push_node(reader, SERD_LITERAL, "", 0))) {
+    return SERD_ERR_OVERFLOW;
+  }
 
   SerdStatus st = read_String(reader, *dest);
   if (st) {
-    *dest = NULL;
     return st;
   }
 
@@ -905,17 +911,13 @@ read_literal(SerdReader* reader, SerdNode** dest, bool* ate_dot)
   case '@':
     eat_byte_safe(reader, '@');
     (*dest)->flags |= SERD_HAS_LANGUAGE;
-    if ((st = read_LANGTAG(reader))) {
-      return r_err(reader, st, "bad literal\n");
-    }
+    TRY(st, read_LANGTAG(reader));
     break;
   case '^':
     eat_byte_safe(reader, '^');
     eat_byte_check(reader, '^');
     (*dest)->flags |= SERD_HAS_DATATYPE;
-    if ((st = read_iri(reader, &datatype, ate_dot))) {
-      return r_err(reader, st, "bad literal\n");
-    }
+    TRY(st, read_iri(reader, &datatype, ate_dot));
     break;
   }
   return SERD_SUCCESS;
@@ -943,8 +945,9 @@ read_verb(SerdReader* reader, SerdNode** dest)
   if (!st && node->n_bytes == 1 && serd_node_string(node)[0] == 'a' &&
       next != ':' && !is_PN_CHARS_BASE((uint32_t)next)) {
     serd_stack_pop_to(&reader->stack, orig_stack_size);
-    *dest = push_node(reader, SERD_URI, NS_RDF "type", 47);
-    return SERD_SUCCESS;
+    return ((*dest = push_node(reader, SERD_URI, NS_RDF "type", 47))
+              ? SERD_SUCCESS
+              : SERD_ERR_OVERFLOW);
   }
 
   if (st > SERD_FAILURE || read_PrefixedName(reader, *dest, false, &ate_dot) ||
@@ -961,13 +964,15 @@ read_BLANK_NODE_LABEL(SerdReader* reader, SerdNode** dest, bool* ate_dot)
 {
   eat_byte_safe(reader, '_');
   eat_byte_check(reader, ':');
+  if (!(*dest = push_node(reader,
+                          SERD_BLANK,
+                          reader->bprefix ? reader->bprefix : "",
+                          reader->bprefix_len))) {
+    return SERD_ERR_OVERFLOW;
+  }
 
-  SerdNode* n = *dest = push_node(reader,
-                                  SERD_BLANK,
-                                  reader->bprefix ? reader->bprefix : "",
-                                  reader->bprefix_len);
-
-  int c = peek_byte(reader); // First: (PN_CHARS | '_' | [0-9])
+  SerdNode* n = *dest;
+  int       c = peek_byte(reader); // First: (PN_CHARS | '_' | [0-9])
   if (is_digit(c) || c == '_') {
     push_byte(reader, n, eat_byte_safe(reader, c));
   } else if (read_PN_CHARS(reader, n)) {
@@ -1092,6 +1097,7 @@ read_object(SerdReader* reader, ReadContext* ctx, bool emit, bool* ate_dot)
       return r_err(reader, SERD_ERR_BAD_SYNTAX, "expected: ':', '<', or '_'\n");
     }
   }
+
   switch (c) {
   case EOF:
   case ')':
@@ -1144,8 +1150,11 @@ read_object(SerdReader* reader, ReadContext* ctx, bool emit, bool* ate_dot)
         (o->n_bytes == 5 && !memcmp(serd_node_string(o), "false", 5))) {
       o->flags |= SERD_HAS_DATATYPE;
       o->type = SERD_LITERAL;
-      push_node(reader, SERD_URI, XSD_BOOLEAN, XSD_BOOLEAN_LEN);
-      ret = SERD_SUCCESS;
+      if (!(push_node(reader, SERD_URI, XSD_BOOLEAN, XSD_BOOLEAN_LEN))) {
+        ret = SERD_ERR_OVERFLOW;
+      } else {
+        ret = SERD_SUCCESS;
+      }
     } else if (read_PN_PREFIX_tail(reader, o) > SERD_FAILURE) {
       ret = SERD_ERR_BAD_SYNTAX;
     } else {
@@ -1342,7 +1351,7 @@ read_labelOrSubject(SerdReader* reader, SerdNode** dest)
       return SERD_ERR_BAD_SYNTAX;
     }
     *dest = blank_id(reader);
-    return SERD_SUCCESS;
+    return *dest ? SERD_SUCCESS : SERD_ERR_OVERFLOW;
   case '_':
     return read_BLANK_NODE_LABEL(reader, dest, &ate_dot);
   default: