class Instruction;
class CallInst;
class DbgDeclareInst;
+class DbgValueInst;
class StoreInst;
class LoadInst;
class Value;
template<typename T> class SmallVectorImpl;
+typedef SmallVector<DbgValueInst *, 1> DbgValueList;
+
//===----------------------------------------------------------------------===//
// Local constant propagation.
//
bool ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
LoadInst *LI, DIBuilder &Builder);
+/// Inserts a llvm.dbg.value intrinsic after a phi of an alloca'd value
+/// that has an associated llvm.dbg.decl intrinsic.
+bool ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
+ PHINode *LI, DIBuilder &Builder);
+
/// Lowers llvm.dbg.declare intrinsics into appropriate set of
/// llvm.dbg.value intrinsics.
bool LowerDbgDeclare(Function &F);
/// Finds the llvm.dbg.declare intrinsic corresponding to an alloca, if any.
DbgDeclareInst *FindAllocaDbgDeclare(Value *V);
+/// Finds the llvm.dbg.value intrinsics corresponding to an alloca, if any.
+void FindAllocaDbgValues(DbgValueList &DbgValues, Value *V);
+
/// Replaces llvm.dbg.declare instruction when the address it describes
/// is replaced with a new value. If Deref is true, an additional DW_OP_deref is
/// prepended to the expression. If Offset is non-zero, a constant displacement
return false;
}
+/// See if there is a dbg.value intrinsic for DIVar for the PHI node.
+static bool PhiHasDebugValue(DILocalVariable *DIVar,
+ DIExpression *DIExpr,
+ PHINode *APN) {
+ // Since we can't guarantee that the original dbg.declare instrinsic
+ // is removed by LowerDbgDeclare(), we need to make sure that we are
+ // not inserting the same dbg.value intrinsic over and over.
+ DbgValueList DbgValues;
+ FindAllocaDbgValues(DbgValues, APN);
+ for (auto DVI : DbgValues) {
+ assert (DVI->getValue() == APN);
+ assert (DVI->getOffset() == 0);
+ if ((DVI->getVariable() == DIVar) && (DVI->getExpression() == DIExpr))
+ return true;
+ }
+ return false;
+}
+
/// Inserts a llvm.dbg.value intrinsic before a store to an alloca'd value
/// that has an associated llvm.dbg.decl intrinsic.
bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
return true;
}
+/// Inserts a llvm.dbg.value intrinsic after a phi
+/// that has an associated llvm.dbg.decl intrinsic.
+bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
+ PHINode *APN, DIBuilder &Builder) {
+ auto *DIVar = DDI->getVariable();
+ auto *DIExpr = DDI->getExpression();
+ assert(DIVar && "Missing variable");
+
+ if (PhiHasDebugValue(DIVar, DIExpr, APN))
+ return true;
+
+ Instruction *DbgValue = Builder.insertDbgValueIntrinsic(
+ APN, 0, DIVar, DIExpr, DDI->getDebugLoc(), (Instruction *)nullptr);
+ DbgValue->insertBefore(&*APN->getParent()->getFirstInsertionPt());
+ return true;
+}
+
/// Determine whether this alloca is either a VLA or an array.
static bool isArray(AllocaInst *AI) {
return AI->isArrayAllocation() ||
return nullptr;
}
+/// FindAllocaDbgValues - Finds the llvm.dbg.value intrinsics describing the
+/// alloca 'V', if any.
+void llvm::FindAllocaDbgValues(DbgValueList &DbgValues, Value *V) {
+ if (auto *L = LocalAsMetadata::getIfExists(V))
+ if (auto *MDV = MetadataAsValue::getIfExists(V->getContext(), L))
+ for (User *U : MDV->users())
+ if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(U))
+ DbgValues.push_back(DVI);
+}
+
static void DIExprAddDeref(SmallVectorImpl<uint64_t> &Expr) {
Expr.push_back(dwarf::DW_OP_deref);
}
--- /dev/null
+; RUN: opt -mem2reg -S < %s | FileCheck %s
+
+; Test that a @llvm.dbg.value node is created to describe the value returned by a phi node when
+; lowering a @llvm.dbg.declare node
+
+; Created from the C code, compiled with -O0 -g:
+;
+; int func(int a)
+; {
+; int c = 1;
+; if (a < 0 ) {
+; c = 12;
+; }
+; return c;
+; }
+
+; Function Attrs: nounwind
+define i32 @func(i32 %a) #0 !dbg !8 {
+entry:
+ %a.addr = alloca i32, align 4
+ %c = alloca i32, align 4
+ store i32 %a, i32* %a.addr, align 4
+ call void @llvm.dbg.declare(metadata i32* %a.addr, metadata !12, metadata !13), !dbg !14
+ call void @llvm.dbg.declare(metadata i32* %c, metadata !15, metadata !13), !dbg !16
+ store i32 1, i32* %c, align 4, !dbg !16
+ %0 = load i32, i32* %a.addr, align 4, !dbg !17
+ %cmp = icmp slt i32 %0, 0, !dbg !19
+ br i1 %cmp, label %if.then, label %if.end, !dbg !20
+
+if.then: ; preds = %entry
+ store i32 12, i32* %c, align 4, !dbg !21
+ br label %if.end, !dbg !23
+
+if.end: ; preds = %if.then, %entry
+ %1 = load i32, i32* %c, align 4, !dbg !24
+; CHECK: [[PHI:%.*]] = phi i32 [ 12, {{.*}} ], [ 1, {{.*}} ]
+; CHECK-NEXT: call void @llvm.dbg.value(metadata i32 [[PHI]], i64 0, metadata !15, metadata !13), !dbg !16
+ ret i32 %1, !dbg !25
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+attributes #1 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "a.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{i32 1, !"min_enum_size", i32 4}
+!7 = !{!"clang"}
+!8 = distinct !DISubprogram(name: "func", scope: !1, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!9 = !DISubroutineType(types: !10)
+!10 = !{!11, !11}
+!11 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!12 = !DILocalVariable(name: "a", arg: 1, scope: !8, file: !1, line: 1, type: !11)
+!13 = !DIExpression()
+!14 = !DILocation(line: 1, column: 14, scope: !8)
+!15 = !DILocalVariable(name: "c", scope: !8, file: !1, line: 3, type: !11)
+!16 = !DILocation(line: 3, column: 6, scope: !8)
+!17 = !DILocation(line: 4, column: 6, scope: !18)
+!18 = distinct !DILexicalBlock(scope: !8, file: !1, line: 4, column: 6)
+!19 = !DILocation(line: 4, column: 8, scope: !18)
+!20 = !DILocation(line: 4, column: 6, scope: !8)
+!21 = !DILocation(line: 5, column: 5, scope: !22)
+!22 = distinct !DILexicalBlock(scope: !18, file: !1, line: 4, column: 14)
+!23 = !DILocation(line: 6, column: 2, scope: !22)
+!24 = !DILocation(line: 7, column: 9, scope: !8)
+!25 = !DILocation(line: 7, column: 2, scope: !8)
+