Fix potentially undefined behaviour in the linker when parsing input statements.

	* ldlang.h (LANG_FOR_EACH_INPUT_STATEMENT): Check for an empty
	file chain before examining the first input statement.

diff --git a/ld/ChangeLog b/ld/ChangeLog
index e4e3f7405849e75815c18949e19db95bf73839ab..5a3b2ddd1cac063d5f784cb385809cd2955dbeb6 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2019-11-21  Nick Clifton  <nickc@redhat.com>
+
+       * ldlang.h (LANG_FOR_EACH_INPUT_STATEMENT): Check for an empty
+       file chain before examining the first input statement.
+
 2019-11-21  Alan Modra  <amodra@gmail.com>
 
        PR 46

diff --git a/ld/ldlang.h b/ld/ldlang.h
index 8cc5cf7f900670de68e76a784bc8011a8027bce2..3e3e6a028940b4f8b6d937773bfa217b0e98787b 100644 (file)
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -574,7 +574,7 @@ extern asection *section_for_dot
 
 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                       \
   lang_input_statement_type *statement;                                        \
-  for (statement = &file_chain.head->input_statement;                  \
+  for (statement = file_chain.head == NULL ? NULL : &file_chain.head->input_statement; \
        statement != NULL;                                              \
        statement = statement->next)