From 4669cf27508ba00274367d62b295e1a7ca20c7ba Mon Sep 17 00:00:00 2001
From: Igor Kudrin <ikudrin@accesssoftek.com>
Date: Thu, 16 May 2019 05:23:25 +0000
Subject: [PATCH] [LTO] Improve readability of module IDs

Module IDs can appear in diagnostic messages.
This patch adds some auxiliary symbols to improve their readability.

Differential Revision: https://reviews.llvm.org/D61857

llvm-svn: 360858
---
 lld/ELF/InputFiles.cpp                     |  9 +++++----
 lld/test/ELF/lto/Inputs/irmover-warning.ll | 10 ++++++++++
 lld/test/ELF/lto/irmover-warning.ll        | 22 ++++++++++++++++++++++
 3 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 lld/test/ELF/lto/Inputs/irmover-warning.ll
 create mode 100644 lld/test/ELF/lto/irmover-warning.ll

diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index d22fa74..5917cb9 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -1241,10 +1241,11 @@ BitcodeFile::BitcodeFile(MemoryBufferRef MB, StringRef ArchiveName,
   // into consideration at LTO time (which very likely causes undefined
   // symbols later in the link stage). So we append file offset to make
   // filename unique.
-  MemoryBufferRef MBRef(
-      MB.getBuffer(),
-      Saver.save(ArchiveName + Path +
-                 (ArchiveName.empty() ? "" : utostr(OffsetInArchive))));
+  StringRef Name = ArchiveName.empty()
+                       ? Saver.save(Path)
+                       : Saver.save(ArchiveName + "(" + Path + " at " +
+                                    utostr(OffsetInArchive) + ")");
+  MemoryBufferRef MBRef(MB.getBuffer(), Name);
 
   Obj = CHECK(lto::InputFile::create(MBRef), this);
 
diff --git a/lld/test/ELF/lto/Inputs/irmover-warning.ll b/lld/test/ELF/lto/Inputs/irmover-warning.ll
new file mode 100644
index 0000000..72d437f
--- /dev/null
+++ b/lld/test/ELF/lto/Inputs/irmover-warning.ll
@@ -0,0 +1,10 @@
+target triple = "x86_64-unknown-linux-gnu"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @f() {
+  ret void
+}
+
+!0 = !{ i32 2, !"foo", i32 2 }
+
+!llvm.module.flags = !{ !0 }
diff --git a/lld/test/ELF/lto/irmover-warning.ll b/lld/test/ELF/lto/irmover-warning.ll
new file mode 100644
index 0000000..8774687
--- /dev/null
+++ b/lld/test/ELF/lto/irmover-warning.ll
@@ -0,0 +1,22 @@
+; RUN: llvm-as -o %t1.bc %s
+; RUN: llvm-as -o %t2.bc %S/Inputs/irmover-warning.ll
+; RUN: rm -f %t.a
+; RUN: llvm-ar rcs %t.a %t2.bc
+; RUN: ld.lld %t1.bc %t.a -o %t 2>&1 | FileCheck %s
+
+; CHECK: warning: linking module flags 'foo': IDs have conflicting values
+; CHECK-SAME: irmover-warning.ll.tmp.a(irmover-warning.ll.tmp2.bc at {{[0-9]+}})
+
+target triple = "x86_64-unknown-linux-gnu"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+declare void @f()
+
+define void @g() {
+  call void @f()
+  ret void
+}
+
+!0 = !{ i32 2, !"foo", i32 1 }
+
+!llvm.module.flags = !{ !0 }
-- 
2.7.4