[binutils-gdb] Fix bug in quirk_rust_enum

[Tom Tromey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a1520ad8fc5c5c1932d69e4685836cc1375bd850

commit a1520ad8fc5c5c1932d69e4685836cc1375bd850
Author: Tom Tromey <tromey@adacore.com>
Date:   Tue Jun 30 07:57:35 2020 -0600

    Fix bug in quirk_rust_enum
    
    Tom de Vries pointed out that some Rust tests were failing after the
    variant part rewrite.  He sent an executable, which helped track down
    this bug.
    
    quirk_rust_enum was passing 1 to alloc_rust_variant in one case.
    However, a comment earlier says:
    
          /* We don't need a range entry for the discriminant, but we do
             need one for every other field, as there is no default
             variant.  */
    
    In this case, we must pass -1 for this parameter.  That is what this
    patch implements.
    
    gdb/ChangeLog
    2020-06-30  Tom Tromey  <tromey@adacore.com>
    
            * dwarf2/read.c (quirk_rust_enum): Correctly call
            alloc_rust_variant for default-less enum.

Diff:
---
 gdb/ChangeLog     | 5 +++++
 gdb/dwarf2/read.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ddd831e7311..d64f572e071 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-06-30  Tom Tromey  <tromey@adacore.com>
+
+	* dwarf2/read.c (quirk_rust_enum): Correctly call
+	alloc_rust_variant for default-less enum.
+
 2020-06-30  Tom Tromey  <tromey@adacore.com>
 
 	PR build/26183:
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 4dc9ad6c99b..b097f624b6c 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -9691,7 +9691,7 @@ quirk_rust_enum (struct type *type, struct objfile *objfile)
 	}
 
       /* Indicate that this is a variant type.  */
-      alloc_rust_variant (&objfile->objfile_obstack, type, 0, 1,
+      alloc_rust_variant (&objfile->objfile_obstack, type, 0, -1,
 			  gdb::array_view<discriminant_range> (ranges,
 							       n_fields - 1));
     }