[binutils-gdb] Add attribute::value_as_string method

[Tom Tromey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f800b00e51f81a3ccbc62f53eaa36e2996f33b9f

commit f800b00e51f81a3ccbc62f53eaa36e2996f33b9f
Author: Tom Tromey <tom@tromey.com>
Date:   Tue Sep 29 18:49:08 2020 -0600

    Add attribute::value_as_string method
    
    The full DIE reader checks that an attribute has a "string" form in
    some spots, but the partial DIE reader does not.  This patch brings
    the two readers in sync for one specific case, namely when examining
    the linkage name.  This avoids regressions in an existing DWARF test
    case.
    
    A full fix for this problem would be preferable.  An accessor like
    DW_STRING should always check the form.  However, I haven't attempted
    that in this series.
    
    Also the fact that the partial and full readers can disagree like this
    is a design flaw.
    
    gdb/ChangeLog
    2020-09-29  Tom Tromey  <tom@tromey.com>
    
            * dwarf2/read.c (partial_die_info::read) <case
            DW_AT_linkage_name>: Use value_as_string.
            (dwarf2_string_attr): Use value_as_string.
            * dwarf2/attribute.h (struct attribute) <value_as_string>: Declare
            method.
            * dwarf2/attribute.c (attribute::value_as_string): New method.

Diff:
---
 gdb/ChangeLog     | 9 +++++++++
 gdb/dwarf2/read.c | 5 -----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 28e34fba04f..cd5958ccc44 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2020-09-29  Tom Tromey  <tom@tromey.com>
+
+	* dwarf2/read.c (partial_die_info::read) <case
+	DW_AT_linkage_name>: Use value_as_string.
+	(dwarf2_string_attr): Use value_as_string.
+	* dwarf2/attribute.h (struct attribute) <value_as_string>: Declare
+	method.
+	* dwarf2/attribute.c (attribute::value_as_string): New method.
+
 2020-09-29  Pedro Alves  <pedro@palves.net>
 
 	* unittests/enum-flags-selftests.c: Check whether __GNUC__ is
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 977bdb85689..3a2a918f4ed 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -19031,11 +19031,6 @@ 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 = attr.value_as_string ();
-	  /* 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;