Revert "[asan] Catch initialization-order-fiasco in modules without globals" (#104665)

Reverts #104621

To many bots are broken, see #104621.

Author: vitalybuka

compiler-rt/test/asan/TestCases/initialization-bug-no-global.cpp

@@ -1,6 +1,9 @@
 // RUN: %clangxx_asan %min_macos_deployment_target=10.11 -O0 %s %p/Helpers/initialization-bug-extra.cpp -o %t
 // RUN: %env_asan_opts=check_initialization_order=true:strict_init_order=true not %run %t 2>&1 | FileCheck %s
 
+// Not implemented.
+// XFAIL: *
+
 // Do not test with optimization -- the error may be optimized away.
 
 // FIXME: https://code.google.com/p/address-sanitizer/issues/detail?id=186

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

@@ -2531,10 +2531,15 @@ void ModuleAddressSanitizer::instrumentGlobals(IRBuilder<> &IRB, Module &M,
   SmallVector<GlobalVariable *, 16> NewGlobals(n);
   SmallVector<Constant *, 16> Initializers(n);
 
+  bool HasDynamicallyInitializedGlobals = false;
+
   // We shouldn't merge same module names, as this string serves as unique
   // module ID in runtime.
-  GlobalVariable *ModuleName = createPrivateGlobalForString(
-      M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
+  GlobalVariable *ModuleName =
+      n != 0
+          ? createPrivateGlobalForString(M, M.getModuleIdentifier(),
+                                         /*AllowMerging*/ false, kAsanGenPrefix)
+          : nullptr;
 
   for (size_t i = 0; i < n; i++) {
     GlobalVariable *G = GlobalsToChange[i];
@@ -2641,6 +2646,9 @@ void ModuleAddressSanitizer::instrumentGlobals(IRBuilder<> &IRB, Module &M,
         Constant::getNullValue(IntptrTy),
         ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
 
+    if (ClInitializers && MD.IsDynInit)
+      HasDynamicallyInitializedGlobals = true;
+
     LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
 
     Initializers[i] = Initializer;
@@ -2680,7 +2688,7 @@ void ModuleAddressSanitizer::instrumentGlobals(IRBuilder<> &IRB, Module &M,
   }
 
   // Create calls for poisoning before initializers run and unpoisoning after.
-  if (ClInitializers)
+  if (HasDynamicallyInitializedGlobals)
     createInitializerPoisonCalls(M, ModuleName);
 
   LLVM_DEBUG(dbgs() << M);

llvm/test/Instrumentation/AddressSanitizer/instrument_initializer_without_global.ll

@@ -18,9 +18,7 @@ define internal void @__late_ctor() sanitize_address section ".text.startup" {
 ; CHECK-LABEL: define internal void @__late_ctor(
 ; CHECK-SAME: ) #[[ATTR1:[0-9]+]] section ".text.startup" {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
-; CHECK-NEXT:    call void @__asan_before_dynamic_init(i64 ptrtoint (ptr @___asan_gen_ to i64))
 ; CHECK-NEXT:    call void @initializer()
-; CHECK-NEXT:    call void @__asan_after_dynamic_init()
 ; CHECK-NEXT:    ret void
 ;
 ; NOINIT-LABEL: define internal void @__late_ctor(