[binutils-gdb] .gdb_index writer: close the file before unlinking it

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=16b7a7199881fa26fc863279bbf08741e5674b5d

commit 16b7a7199881fa26fc863279bbf08741e5674b5d
Author: Pedro Alves <palves@redhat.com>
Date:   Mon Jun 19 12:46:47 2017 +0100

    .gdb_index writer: close the file before unlinking it
    
    We should close the file before unlinking because on MS-Windows one
    cannot delete a file that is still open.
    
    I considered making 'gdb::unlinker::unlinker(const char *)'
    'noexcept(true)' and then adding
      static_assert (noexcept (gdb::unlinker (filename.c_str ())), "");
    
    but that doesn't really work because gdb::unlinker has a gdb_assert,
    which can throw a QUIT if/when the assertion fails.  'noexcept(true)'
    would cause GDB to abruptly terminate if/when the assertion fails.
    
    gdb/ChangeLog:
    2017-06-19  Pedro Alves  <palves@redhat.com>
    
    	* dwarf2read.c (write_psymtabs_to_index): Construct file_closer
    	after gdb::unlinker.

Diff:
---
 gdb/ChangeLog    | 5 +++++
 gdb/dwarf2read.c | 6 +++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index aaf4b89..c7cf410 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-06-19  Pedro Alves  <palves@redhat.com>
+
+	* dwarf2read.c (write_psymtabs_to_index): Construct file_closer
+	after gdb::unlinker.
+
 2017-06-19  Sergio Durigan Junior  <sergiodj@redhat.com>
 
 	* mi/mi-cm-env.c (_initialize_mi_cmd_env): Use getenv instead of
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index abe14b2..2369d4b 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -23776,8 +23776,12 @@ write_psymtabs_to_index (struct objfile *objfile, const char *dir)
   if (!out_file)
     error (_("Can't open `%s' for writing"), filename.c_str ());
 
-  file_closer close_out_file (out_file);
+  /* Order matters here; we want FILE to be closed before FILENAME is
+     unlinked, because on MS-Windows one cannot delete a file that is
+     still open.  (Don't call anything here that might throw until
+     file_closer is created.)  */
   gdb::unlinker unlink_file (filename.c_str ());
+  file_closer close_out_file (out_file);
 
   mapped_symtab symtab;
   data_buf cu_list;