[PATCH 02/10] Move the rust "{" hack

[Tom Tromey]

The DWARF reader has a special case to work around a bug in some
versions of the Rust compiler -- it ignores mangled names that contain
a "{" character.

I noticed that this check should probably be in dw2_linkage_name
rather than only in dwarf2_physname.  The former is called in some
cases that the latter is not.

Also, I noticed that this work is not done for the partial DIE reader,
so this patch adds the check there as well.

gdb/ChangeLog
2020-03-25  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.c (dw2_linkage_name): Move Rust "{" hack here...
	(dwarf2_physname): ... from here.
	(partial_die_info::read): Add Rust "{" hack.
---
 gdb/ChangeLog     |  6 ++++++
 gdb/dwarf2/read.c | 17 +++++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 69ad352b6a7..d5cdd49a086 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -10020,6 +10020,12 @@ dw2_linkage_name (struct die_info *die, struct dwarf2_cu *cu)
   if (linkage_name == NULL)
     linkage_name = dwarf2_string_attr (die, DW_AT_MIPS_linkage_name, cu);
 
+  /* rustc emits invalid values for DW_AT_linkage_name.  Ignore these.
+     See https://github.com/rust-lang/rust/issues/32925.  */
+  if (cu->language == language_rust && linkage_name != NULL
+      && strchr (linkage_name, '{') != NULL)
+    linkage_name = NULL;
+
   return linkage_name;
 }
 
@@ -10296,12 +10302,6 @@ dwarf2_physname (const char *name, struct die_info *die, struct dwarf2_cu *cu)
 
   mangled = dw2_linkage_name (die, cu);
 
-  /* rustc emits invalid values for DW_AT_linkage_name.  Ignore these.
-     See https://github.com/rust-lang/rust/issues/32925.  */
-  if (cu->language == language_rust && mangled != NULL
-      && strchr (mangled, '{') != NULL)
-    mangled = NULL;
-
   /* DW_AT_linkage_name is missing in some cases - depend on what GDB
      has computed.  */
   gdb::unique_xmalloc_ptr<char> demangled;
@@ -18032,6 +18032,11 @@ partial_die_info::read (const struct die_reader_specs *reader,
 	     assume they will be the same, and we only store the last
 	     one we see.  */
 	  linkage_name = DW_STRING (&attr);
+	  /* rustc emits invalid values for DW_AT_linkage_name.  Ignore these.
+	     See https://github.com/rust-lang/rust/issues/32925.  */
+	  if (cu->language == language_rust && linkage_name != NULL
+	      && strchr (linkage_name, '{') != NULL)
+	    linkage_name = NULL;
 	  break;
 	case DW_AT_low_pc:
 	  has_low_pc_attr = 1;
-- 
2.17.2