[llvm] c0527ff - [DebugInfo] Upgrade `dbg.addr` to `dbg.value`

[J. Ryan Stinnett via llvm-commits]

Author: J. Ryan Stinnett
Date: 2023-03-02T09:29:42Z
New Revision: c0527fff030799bffd1d7bda01012f8b62363cb2

URL: https://github.com/llvm/llvm-project/commit/c0527fff030799bffd1d7bda01012f8b62363cb2
DIFF: https://github.com/llvm/llvm-project/commit/c0527fff030799bffd1d7bda01012f8b62363cb2.diff

LOG: [DebugInfo] Upgrade `dbg.addr` to `dbg.value`

As part of removing `dbg.addr`, this upgrades any calls to `dbg.value` with
`DW_OP_deref` prepended onto the value expression.

Part of `dbg.addr` removal
Discussed in https://discourse.llvm.org/t/what-is-the-status-of-dbg-addr/62898

Differential Revision: https://reviews.llvm.org/D144793

Added: 
    llvm/test/Bitcode/upgrade-dbg-addr.ll
    llvm/test/Bitcode/upgrade-dbg-addr.ll.bc

Modified: 
    llvm/lib/IR/AutoUpgrade.cpp
    llvm/test/Bitcode/upgrade-dbg-value.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index b395df573aaf..9ca86c978ecc 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -14,8 +14,10 @@
 
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
@@ -27,6 +29,7 @@
 #include "llvm/IR/IntrinsicsARM.h"
 #include "llvm/IR/IntrinsicsX86.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Metadata.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -844,6 +847,11 @@ static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
     break;
   }
   case 'd': {
+    if (Name == "dbg.addr") {
+      rename(F);
+      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::dbg_value);
+      return true;
+    }
     if (Name == "dbg.value" && F->arg_size() == 4) {
       rename(F);
       NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::dbg_value);
@@ -4128,7 +4136,20 @@ void llvm::UpgradeIntrinsicCall(CallBase *CI, Function *NewFn) {
     NewCall = Builder.CreateCall(NewFn, {CI->getArgOperand(0)});
     break;
 
-  case Intrinsic::dbg_value:
+  case Intrinsic::dbg_value: {
+    StringRef Name = F->getName();
+    Name = Name.substr(5); // Strip llvm.
+    // Upgrade `dbg.addr` to `dbg.value` with `DW_OP_deref`.
+    if (Name.startswith("dbg.addr")) {
+      DIExpression *Expr = cast<DIExpression>(
+          cast<MetadataAsValue>(CI->getArgOperand(2))->getMetadata());
+      Expr = DIExpression::append(Expr, dwarf::DW_OP_deref);
+      NewCall =
+          Builder.CreateCall(NewFn, {CI->getArgOperand(0), CI->getArgOperand(1),
+                                     MetadataAsValue::get(C, Expr)});
+      break;
+    }
+
     // Upgrade from the old version that had an extra offset argument.
     assert(CI->arg_size() == 4);
     // Drop nonzero offsets instead of attempting to upgrade them.
@@ -4141,6 +4162,7 @@ void llvm::UpgradeIntrinsicCall(CallBase *CI, Function *NewFn) {
       }
     CI->eraseFromParent();
     return;
+  }
 
   case Intrinsic::ptr_annotation:
     // Upgrade from versions that lacked the annotation attribute argument.

diff  --git a/llvm/test/Bitcode/upgrade-dbg-addr.ll b/llvm/test/Bitcode/upgrade-dbg-addr.ll
new file mode 100644
index 000000000000..40fd7db18948
--- /dev/null
+++ b/llvm/test/Bitcode/upgrade-dbg-addr.ll
@@ -0,0 +1,33 @@
+; Test upgrade of dbg.addr intrinsics into dbg.value with DW_OP_deref appended
+;
+; RUN: llvm-dis < %s.bc | FileCheck %s
+; RUN: verify-uselistorder < %s.bc
+
+define i32 @example(i32 %num) {
+entry:
+  %num.addr = alloca i32, align 4
+  store i32 %num, ptr %num.addr, align 4
+  ; CHECK-NOT: call void @llvm.dbg.addr
+  ; CHECK: call void @llvm.dbg.value(metadata ptr %num.addr, metadata ![[#]], metadata !DIExpression(DW_OP_plus_uconst, 0, DW_OP_deref))
+  call void @llvm.dbg.addr(metadata ptr %num.addr, metadata !16, metadata !DIExpression(DW_OP_plus_uconst, 0)), !dbg !17
+  %0 = load i32, ptr %num.addr, align 4
+  ret i32 %0
+}
+
+; CHECK: declare void @llvm.dbg.value(metadata, metadata, metadata)
+declare void @llvm.dbg.addr(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1)
+!1 = !DIFile(filename: "/app/example.c", directory: "/app")
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!10 = distinct !DISubprogram(name: "example", scope: !11, file: !11, line: 1, type: !12, scopeLine: 1, unit: !0, retainedNodes: !15)
+!11 = !DIFile(filename: "example.c", directory: "/app")
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !{}
+!16 = !DILocalVariable(name: "num", arg: 1, scope: !10, file: !11, line: 1, type: !14)
+!17 = !DILocation(line: 1, column: 17, scope: !10)

diff  --git a/llvm/test/Bitcode/upgrade-dbg-addr.ll.bc b/llvm/test/Bitcode/upgrade-dbg-addr.ll.bc
new file mode 100644
index 000000000000..10701592a1e6
Binary files /dev/null and b/llvm/test/Bitcode/upgrade-dbg-addr.ll.bc 
diff er

diff  --git a/llvm/test/Bitcode/upgrade-dbg-value.ll b/llvm/test/Bitcode/upgrade-dbg-value.ll
index 6e29e6f76b64..090f515bd3b6 100644
--- a/llvm/test/Bitcode/upgrade-dbg-value.ll
+++ b/llvm/test/Bitcode/upgrade-dbg-value.ll
@@ -1,4 +1,4 @@
-; Test upgrade of dbg.dvalue intrinsics with offsets.
+; Test upgrade of dbg.value intrinsics with offsets.
 ;
 ; RUN: llvm-dis < %s.bc | FileCheck %s
 ; RUN: verify-uselistorder < %s.bc