[binutils-gdb] Add new overload of dwarf5_djb_hash

[Tom Tromey <tromey@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4e9e4fcda5e820d770369824669d86d3fadcad04

commit 4e9e4fcda5e820d770369824669d86d3fadcad04
Author: Tom Tromey <tom@tromey.com>
Date:   Sun Mar 21 11:15:57 2021 -0600

    Add new overload of dwarf5_djb_hash
    
    This adds a new overload of dwarf5_djb_hash.  This is used in
    subsequent patches.

Diff:
---
 gdb/dwarf2/index-common.c | 14 ++++++++++++++
 gdb/dwarf2/index-common.h |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/gdb/dwarf2/index-common.c b/gdb/dwarf2/index-common.c
index c2bb1c6f78e..d8f9973d6cc 100644
--- a/gdb/dwarf2/index-common.c
+++ b/gdb/dwarf2/index-common.c
@@ -54,3 +54,17 @@ dwarf5_djb_hash (const char *str_)
     hash = hash * 33 + tolower (c);
   return hash;
 }
+
+/* See dwarf-index-common.h.  */
+
+uint32_t
+dwarf5_djb_hash (gdb::string_view str)
+{
+  /* Note: tolower here ignores UTF-8, which isn't fully compliant.
+     See http://dwarfstd.org/ShowIssue.php?issue=161027.1.  */
+
+  uint32_t hash = 5381;
+  for (char c : str)
+    hash = hash * 33 + tolower (c & 0xff);
+  return hash;
+}
diff --git a/gdb/dwarf2/index-common.h b/gdb/dwarf2/index-common.h
index 049e1d894f1..cbfb88a4e98 100644
--- a/gdb/dwarf2/index-common.h
+++ b/gdb/dwarf2/index-common.h
@@ -52,4 +52,8 @@ hashval_t mapped_index_string_hash (int index_version, const void *p);
 
 uint32_t dwarf5_djb_hash (const char *str_);
 
+/* Symbol name hashing function as specified by DWARF-5.  */
+
+uint32_t dwarf5_djb_hash (gdb::string_view str_);
+
 #endif /* DWARF_INDEX_COMMON_H */