Allow any build-id length between 4 and 20 bytes inclusive

Build-id support is being added to lld and by default it may produce a
64-bit build-id.

Prior to this change lldb would reject such a build-id. However, it then
falls back to a 4-byte crc32, which is a poorer quality identifier.

Differential Revision:	http://reviews.llvm.org/D18096

llvm-svn: 263432

diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index acde882..e20f994 100644 (file)
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -1410,8 +1410,9 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
                     // Only bother processing this if we don't already have the uuid set.
                     if (!uuid.IsValid())
                     {
-                        // 16 bytes is UUID|MD5, 20 bytes is SHA1
-                        if ((note.n_descsz == 16 || note.n_descsz == 20))
+                        // 16 bytes is UUID|MD5, 20 bytes is SHA1. Other linkers may produce a build-id of a different
+                        // length. Accept it as long as it's at least 4 bytes as it will be better than our own crc32.
+                        if (note.n_descsz >= 4 && note.n_descsz <= 20)
                         {
                             uint8_t uuidbuf[20];
                             if (data.GetU8 (&offset, &uuidbuf, note.n_descsz) == nullptr)