[lld-link] initialize targets and asmparsers before invoking lib

Summary:
When using lld-link to build static libraries containing object files
with module assembly, the program would crash with "Assertion `T &&
T->hasMCAsmParser()' failed". This change causes the code in lld-link
that initialized Targets, TargetInfos, and AsmParsers (which already
existed) to be run before entering the lib building path (which needs
it). This avoids the error (and is what llvm-lib and llvm-ar do, too).

Fixes PR41803.

Reviewers: ruiu, rnk, hans

Reviewed By: ruiu

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61699

llvm-svn: 360295

2 files changed, 28 insertions, 7 deletions

diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index ef0c4a91168..807bd6f71c9 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -975,6 +975,13 @@ void LinkerDriver::maybeExportMinGWSymbols(const opt::InputArgList &Args) {
 }
 
 void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
+  // Needed for LTO.
+  InitializeAllTargetInfos();
+  InitializeAllTargets();
+  InitializeAllTargetMCs();
+  InitializeAllAsmParsers();
+  InitializeAllAsmPrinters();
+
   // If the first command line argument is "/lib", link.exe acts like lib.exe.
   // We call our own implementation of lib.exe that understands bitcode files.
   if (ArgsArr.size() > 1 && StringRef(ArgsArr[1]).equals_lower("/lib")) {
@@ -983,13 +990,6 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
     return;
   }
 
-  // Needed for LTO.
-  InitializeAllTargetInfos();
-  InitializeAllTargets();
-  InitializeAllTargetMCs();
-  InitializeAllAsmParsers();
-  InitializeAllAsmPrinters();
-
   // Parse command line options.
   ArgParser Parser;
   opt::InputArgList Args = Parser.parseLINK(ArgsArr);
diff --git a/lld/test/COFF/lib-module-asm.ll b/lld/test/COFF/lib-module-asm.ll
new file mode 100644
index 00000000000..2b2beba3aef
--- /dev/null
+++ b/lld/test/COFF/lib-module-asm.ll
@@ -0,0 +1,21 @@
+; PR41803: llvm-link /lib on object with module asm crashes
+; RUN: rm -f %t.lib
+; RUN: llvm-as -o %t.obj %s
+; RUN: lld-link /lib /out:%t.lib %t.obj
+; RUN: llvm-nm -M %t.lib | FileCheck %s
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i386-pc-windows-msvc19.11.0"
+
+module asm ".global global_asm_sym"
+module asm "global_asm_sym:"
+module asm "local_asm_sym:"
+module asm ".long undef_asm_sym"
+
+; CHECK: Archive map
+; CHECK-NEXT: global_asm_sym in {{.*}}lib-module-asm.ll.tmp.obj
+
+; CHECK: lib-module-asm.ll.tmp.obj:{{$}}
+; CHECK-NEXT:         T global_asm_sym
+; CHECK-NEXT:         t local_asm_sym
+; CHECK-NEXT:         U undef_asm_sym