[AddressSanitizer] Add fallback DebugLocation for instrumented calls

When building the kernel with LTO, KASAN & debug information enabled,
multiple inlinable AddressSanitizer functions require debug information
present.

In such cases we repurpose the InstrumentationIRBuilder that ensures
the necessary debug information is added if necessary.

This has been done analogous to the work for the ThreadSanitizer
in D124937.

Bug: ClangBuiltLinux/linux#1721

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D155376

Author: Jakob-Koschel

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

@@ -1230,7 +1230,7 @@ Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
 
 // Instrument memset/memmove/memcpy
 void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
-  IRBuilder<> IRB(MI);
+  InstrumentationIRBuilder IRB(MI);
   if (isa<MemTransferInst>(MI)) {
     IRB.CreateCall(
         isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
@@ -1642,7 +1642,7 @@ Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
                                                  size_t AccessSizeIndex,
                                                  Value *SizeArgument,
                                                  uint32_t Exp) {
-  IRBuilder<> IRB(InsertBefore);
+  InstrumentationIRBuilder IRB(InsertBefore);
   Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
   CallInst *Call = nullptr;
   if (SizeArgument) {
@@ -1719,7 +1719,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
       return;
   }
 
-  IRBuilder<> IRB(InsertBefore);
+  InstrumentationIRBuilder IRB(InsertBefore);
   size_t AccessSizeIndex = TypeStoreSizeToSizeIndex(TypeStoreSize);
   const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
 
@@ -1781,7 +1781,8 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
 
   Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
                                          AccessSizeIndex, SizeArgument, Exp);
-  Crash->setDebugLoc(OrigIns->getDebugLoc());
+  if (OrigIns->getDebugLoc())
+    Crash->setDebugLoc(OrigIns->getDebugLoc());
 }
 
 // Instrument unusual size or unusual alignment.
@@ -1791,7 +1792,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
 void AddressSanitizer::instrumentUnusualSizeOrAlignment(
     Instruction *I, Instruction *InsertBefore, Value *Addr, TypeSize TypeStoreSize,
     bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
-  IRBuilder<> IRB(InsertBefore);
+  InstrumentationIRBuilder IRB(InsertBefore);
   Value *NumBits = IRB.CreateTypeSize(IntptrTy, TypeStoreSize);
   Value *Size = IRB.CreateLShr(NumBits, ConstantInt::get(IntptrTy, 3));
 

llvm/test/Instrumentation/AddressSanitizer/missing_dbg.ll

@@ -0,0 +1,37 @@
+; RUN: opt < %s -passes=asan -S | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+
+define i32 @with_dbg(ptr %a, ptr %b) sanitize_address !dbg !3 {
+entry:
+  %tmp1 = load i32, ptr %a, align 4
+  store i32 32, ptr %b
+  ret i32 %tmp1
+}
+; CHECK-LABEL: @with_dbg
+; CHECK-NEXT:  entry:
+; CHECK:       call void @__asan_report_load4(i64 %0) #3, !dbg [[DBG:![0-9]+]]
+; CHECK:       call void @__asan_report_store4(i64 %13) #3, !dbg [[DBG]]
+
+define i32 @without_dbg(ptr %a, ptr %b) sanitize_address {
+entry:
+  %tmp1 = load i32, ptr %a, align 4
+  store i32 32, ptr %b
+  ret i32 %tmp1
+}
+; CHECK-LABEL: @without_dbg
+; CHECK-NEXT:  entry:
+; CHECK:       call void @__asan_report_load4(i64 %0) #3
+; CHECK:       call void @__asan_report_store4(i64 %13) #3
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C89, file: !1, producer: "", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "foo.c", directory: "")
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 190, type: !4, scopeLine: 192, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0)
+!4 = !DISubroutineType(types: !5)
+!5 = !{}
+
+; CHECK:       [[DBG]] = !DILocation(line: 0, scope: !3)