From 168146e84b6b96d17093807189d069a4a04e8d06 Mon Sep 17 00:00:00 2001
From: Pavel Labath <labath@google.com>
Date: Mon, 16 Nov 2015 10:40:38 +0000
Subject: [PATCH] Don't generate discriminators for calls to debug intrinsics

Summary:
This fails a check in Verifier.cpp, which checks for location matches between the declared
variable and the !dbg attachments.

Reviewers: dnovillo, dblaikie, danielcdh

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14657

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253194 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Utils/AddDiscriminators.cpp    | 36 ++++++++++---------
 .../dbg-declare-discriminator.ll              | 30 ++++++++++++++++
 2 files changed, 49 insertions(+), 17 deletions(-)
 create mode 100644 test/Transforms/AddDiscriminators/dbg-declare-discriminator.ll

diff --git a/lib/Transforms/Utils/AddDiscriminators.cpp b/lib/Transforms/Utils/AddDiscriminators.cpp
index 9125b583212..db2bf6a2a9f 100644
--- a/lib/Transforms/Utils/AddDiscriminators.cpp
+++ b/lib/Transforms/Utils/AddDiscriminators.cpp
@@ -58,6 +58,7 @@
 #include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Pass.h"
@@ -233,26 +234,27 @@ bool AddDiscriminators::runOnFunction(Function &F) {
     const DILocation *FirstDIL = NULL;
     for (auto &I : B.getInstList()) {
       CallInst *Current = dyn_cast<CallInst>(&I);
-      if (Current) {
-        DILocation *CurrentDIL = Current->getDebugLoc();
-        if (FirstDIL) {
-          if (CurrentDIL && CurrentDIL->getLine() == FirstDIL->getLine() &&
-              CurrentDIL->getFilename() == FirstDIL->getFilename()) {
-            auto *Scope = FirstDIL->getScope();
-            auto *File = Builder.createFile(FirstDIL->getFilename(),
-                                            Scope->getDirectory());
-            auto *NewScope = Builder.createLexicalBlockFile(
-                Scope, File, FirstDIL->computeNewDiscriminator());
-            Current->setDebugLoc(DILocation::get(
-                Ctx, CurrentDIL->getLine(), CurrentDIL->getColumn(), NewScope,
-                CurrentDIL->getInlinedAt()));
-            Changed = true;
-          } else {
-            FirstDIL = CurrentDIL;
-          }
+      if (!Current || isa<DbgInfoIntrinsic>(&I))
+        continue;
+
+      DILocation *CurrentDIL = Current->getDebugLoc();
+      if (FirstDIL) {
+        if (CurrentDIL && CurrentDIL->getLine() == FirstDIL->getLine() &&
+            CurrentDIL->getFilename() == FirstDIL->getFilename()) {
+          auto *Scope = FirstDIL->getScope();
+          auto *File = Builder.createFile(FirstDIL->getFilename(),
+                                          Scope->getDirectory());
+          auto *NewScope = Builder.createLexicalBlockFile(
+              Scope, File, FirstDIL->computeNewDiscriminator());
+          Current->setDebugLoc(DILocation::get(
+              Ctx, CurrentDIL->getLine(), CurrentDIL->getColumn(), NewScope,
+              CurrentDIL->getInlinedAt()));
+          Changed = true;
         } else {
           FirstDIL = CurrentDIL;
         }
+      } else {
+        FirstDIL = CurrentDIL;
       }
     }
   }
diff --git a/test/Transforms/AddDiscriminators/dbg-declare-discriminator.ll b/test/Transforms/AddDiscriminators/dbg-declare-discriminator.ll
new file mode 100644
index 00000000000..5e90d32a62e
--- /dev/null
+++ b/test/Transforms/AddDiscriminators/dbg-declare-discriminator.ll
@@ -0,0 +1,30 @@
+; RUN: opt -S -add-discriminators < %s | FileCheck %s
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+; This checks whether the add-discriminators pass producess valid metadata on
+; llvm.dbg.declare instructions
+;
+; CHECK-LABEL: @test_valid_metadata
+define void @test_valid_metadata() {
+  %a = alloca i8
+  call void @llvm.dbg.declare(metadata i8* %a, metadata !2, metadata !5), !dbg !6
+  %b = alloca i8
+  call void @llvm.dbg.declare(metadata i8* %b, metadata !9, metadata !5), !dbg !11
+  ret void
+}
+
+!llvm.module.flags = !{!0, !1}
+
+!0 = !{i32 2, !"Dwarf Version", i32 4}
+!1 = !{i32 2, !"Debug Info Version", i32 3}
+!2 = !DILocalVariable(scope: !3)
+!3 = distinct !DISubprogram(scope: null, file: !4, isLocal: false, isDefinition: true, isOptimized: false)
+!4 = !DIFile(filename: "a.cpp", directory: "/tmp")
+!5 = !DIExpression()
+!6 = !DILocation(line: 0, scope: !3, inlinedAt: !7)
+!7 = distinct !DILocation(line: 0, scope: !8)
+!8 = distinct !DISubprogram(linkageName: "test_valid_metadata", scope: null, isLocal: false, isDefinition: true, isOptimized: false)
+!9 = !DILocalVariable(scope: !10)
+!10 = distinct !DISubprogram(scope: null, file: !4, isLocal: false, isDefinition: true, isOptimized: false)
+!11 = !DILocation(line: 0, scope: !10)
-- 
2.34.1