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Emit a DW_OP_deref for global variables in a fixed size buffer. #16342

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May 3, 2018
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Emit a DW_OP_deref for global variables in a fixed size buffer. #16342

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25 changes: 14 additions & 11 deletions lib/IRGen/GenDecl.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1948,7 +1948,7 @@ bool LinkInfo::isUsed(llvm::GlobalValue::LinkageTypes Linkage,
llvm::GlobalVariable *swift::irgen::createVariable(
IRGenModule &IGM, LinkInfo &linkInfo, llvm::Type *storageType,
Alignment alignment, DebugTypeInfo DbgTy, Optional<SILLocation> DebugLoc,
StringRef DebugName) {
StringRef DebugName, bool inFixedBuffer) {
auto name = linkInfo.getName();
llvm::GlobalValue *existingValue = IGM.Module.getNamedGlobal(name);
if (existingValue) {
Expand Down Expand Up @@ -1980,7 +1980,7 @@ llvm::GlobalVariable *swift::irgen::createVariable(
if (IGM.DebugInfo && !DbgTy.isNull() && linkInfo.isForDefinition())
IGM.DebugInfo->emitGlobalVariableDeclaration(
var, DebugName.empty() ? name : DebugName, name, DbgTy,
var->hasInternalLinkage(), DebugLoc);
var->hasInternalLinkage(), inFixedBuffer, DebugLoc);

return var;
}
Expand Down Expand Up @@ -2116,6 +2116,7 @@ Address IRGenModule::getAddrOfSILGlobalVariable(SILGlobalVariable *var,
llvm::Type *storageType;
Size fixedSize;
Alignment fixedAlignment;
bool inFixedBuffer = false;

if (var->isInitializedObject()) {
assert(ti.isFixedSize(expansion));
Expand Down Expand Up @@ -2145,6 +2146,7 @@ Address IRGenModule::getAddrOfSILGlobalVariable(SILGlobalVariable *var,
} else {
// Allocate a fixed-size buffer and possibly heap-allocate a payload at
// runtime if the runtime size of the type does not fit in the buffer.
inFixedBuffer = true;
storageType = getFixedBufferTy();
fixedSize = Size(DataLayout.getTypeAllocSize(storageType));
fixedAlignment = Alignment(DataLayout.getABITypeAlignment(storageType));
Expand Down Expand Up @@ -2175,20 +2177,21 @@ Address IRGenModule::getAddrOfSILGlobalVariable(SILGlobalVariable *var,
gvar = createVariable(*this, link, storageTypeWithContainer,
fixedAlignment);
} else {
auto DbgTy = DebugTypeInfo::getGlobal(var, storageTypeWithContainer,
fixedSize, fixedAlignment);
StringRef name;
Optional<SILLocation> loc;
if (var->getDecl()) {
// If we have the VarDecl, use it for more accurate debugging information.
gvar = createVariable(*this, link, storageTypeWithContainer,
fixedAlignment, DbgTy, SILLocation(var->getDecl()),
var->getDecl()->getName().str());
// Use the VarDecl for more accurate debugging information.
loc = var->getDecl();
name = var->getDecl()->getName().str();
} else {
Optional<SILLocation> loc;
if (var->hasLocation())
loc = var->getLocation();
gvar = createVariable(*this, link, storageTypeWithContainer,
fixedAlignment, DbgTy, loc, var->getName());
name = var->getName();
}
auto DbgTy = DebugTypeInfo::getGlobal(var, storageTypeWithContainer,
fixedSize, fixedAlignment);
gvar = createVariable(*this, link, storageTypeWithContainer,
fixedAlignment, DbgTy, loc, name, inFixedBuffer);
}
/// Add a zero initializer.
if (forDefinition)
Expand Down
12 changes: 5 additions & 7 deletions lib/IRGen/GenDecl.h
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Expand Up @@ -46,13 +46,11 @@ namespace irgen {
OptimizationMode FuncOptMode =
OptimizationMode::NotSet);

llvm::GlobalVariable *createVariable(IRGenModule &IGM,
LinkInfo &linkInfo,
llvm::Type *objectType,
Alignment alignment,
DebugTypeInfo DebugType=DebugTypeInfo(),
Optional<SILLocation> DebugLoc = None,
StringRef DebugName = StringRef());
llvm::GlobalVariable *
createVariable(IRGenModule &IGM, LinkInfo &linkInfo, llvm::Type *objectType,
Alignment alignment, DebugTypeInfo DebugType = DebugTypeInfo(),
Optional<SILLocation> DebugLoc = None,
StringRef DebugName = StringRef(), bool heapAllocated = false);

void disableAddressSanitizer(IRGenModule &IGM, llvm::GlobalVariable *var);
}
Expand Down
3 changes: 2 additions & 1 deletion lib/IRGen/GenInit.cpp
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Expand Up @@ -45,7 +45,8 @@ void IRGenModule::emitSILGlobalVariable(SILGlobalVariable *var) {
auto DbgTy = DebugTypeInfo::getGlobal(var, Int8Ty, Size(0), Alignment(1));
DebugInfo->emitGlobalVariableDeclaration(
nullptr, var->getDecl()->getName().str(), "", DbgTy,
var->getLinkage() != SILLinkage::Public, SILLocation(var->getDecl()));
var->getLinkage() != SILLinkage::Public,
IRGenDebugInfo::NotHeapAllocated, SILLocation(var->getDecl()));
}
return;
}
Expand Down
21 changes: 16 additions & 5 deletions lib/IRGen/IRGenDebugInfo.cpp
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Expand Up @@ -154,7 +154,7 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
void emitGlobalVariableDeclaration(llvm::GlobalVariable *Storage,
StringRef Name, StringRef LinkageName,
DebugTypeInfo DebugType,
bool IsLocalToUnit,
bool IsLocalToUnit, bool InFixedBuffer,
Optional<SILLocation> Loc);
void emitTypeMetadata(IRGenFunction &IGF, llvm::Value *Metadata,
StringRef Name);
Expand Down Expand Up @@ -1989,7 +1989,8 @@ void IRGenDebugInfoImpl::emitDbgIntrinsic(

void IRGenDebugInfoImpl::emitGlobalVariableDeclaration(
llvm::GlobalVariable *Var, StringRef Name, StringRef LinkageName,
DebugTypeInfo DbgTy, bool IsLocalToUnit, Optional<SILLocation> Loc) {
DebugTypeInfo DbgTy, bool IsLocalToUnit, bool InFixedBuffer,
Optional<SILLocation> Loc) {
if (Opts.DebugInfoKind <= IRGenDebugInfoKind::LineTables)
return;

Expand All @@ -2005,7 +2006,16 @@ void IRGenDebugInfoImpl::emitGlobalVariableDeclaration(
auto File = getOrCreateFile(L.Filename);

// Emit it as global variable of the current module.
auto *Expr = Var ? nullptr : DBuilder.createConstantValueExpression(0);
llvm::DIExpression *Expr = nullptr;
if (!Var)
Expr = DBuilder.createConstantValueExpression(0);
else if (InFixedBuffer)
// FIXME: This is *not* generally correct, but LLDB at the moment cannot
// poke to runtime to figure out whether a resilient value has inline
// storage, so this is assuming that it doesn't to get the majority of
// resilient Foundation types.
Expr =
DBuilder.createExpression(ArrayRef<uint64_t>(llvm::dwarf::DW_OP_deref));
auto *GV = DBuilder.createGlobalVariableExpression(
MainModule, Name, LinkageName, File, L.Line, Ty, IsLocalToUnit, Expr);
if (Var)
Expand Down Expand Up @@ -2129,9 +2139,10 @@ void IRGenDebugInfo::emitDbgIntrinsic(IRBuilder &Builder, llvm::Value *Storage,

void IRGenDebugInfo::emitGlobalVariableDeclaration(
llvm::GlobalVariable *Storage, StringRef Name, StringRef LinkageName,
DebugTypeInfo DebugType, bool IsLocalToUnit, Optional<SILLocation> Loc) {
DebugTypeInfo DebugType, bool IsLocalToUnit, bool InFixedBuffer,
Optional<SILLocation> Loc) {
static_cast<IRGenDebugInfoImpl *>(this)->emitGlobalVariableDeclaration(
Storage, Name, LinkageName, DebugType, IsLocalToUnit, Loc);
Storage, Name, LinkageName, DebugType, IsLocalToUnit, InFixedBuffer, Loc);
}

void IRGenDebugInfo::emitTypeMetadata(IRGenFunction &IGF, llvm::Value *Metadata,
Expand Down
4 changes: 3 additions & 1 deletion lib/IRGen/IRGenDebugInfo.h
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Expand Up @@ -136,11 +136,13 @@ class IRGenDebugInfo {
unsigned Line, unsigned Col, llvm::DILocalScope *Scope,
const SILDebugScope *DS);

enum { NotHeapAllocated = false };

/// Create debug metadata for a global variable.
void emitGlobalVariableDeclaration(llvm::GlobalVariable *Storage,
StringRef Name, StringRef LinkageName,
DebugTypeInfo DebugType,
bool IsLocalToUnit,
bool IsLocalToUnit, bool InFixedBuffer,
Optional<SILLocation> Loc);

/// Emit debug metadata for type metadata (for generic types). So meta.
Expand Down
44 changes: 33 additions & 11 deletions test/DebugInfo/resilience.swift
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Expand Up @@ -13,9 +13,25 @@
// RUN: -enable-resilience-bypass | %FileCheck %s --check-prefix=CHECK-LLDB
import resilient_struct

// CHECK-LABEL: define{{( protected)?}} swiftcc void @"$S10resilience1fyyF"()
// CHECK-LLDB-LABEL: define{{( protected)?}} swiftcc void @"$S10resilience1fyyF"()
public func f() {
let fixed = Point(x: 1, y: 2)
let non_fixed = Size(w: 1, h: 2)
let int = ResilientInt(i: 1)
// CHECK: @"$S10resilience5fixed16resilient_struct5PointVvp" =
// CHECK-SAME: !dbg ![[FIXED:[0-9]+]]
// CHECK: @"$S10resilience9non_fixed16resilient_struct4SizeVvp" =
// CHECK-SAME: !dbg ![[NON_FIXED:[0-9]+]]
// CHECK: @"$S10resilience3int16resilient_struct12ResilientIntVvp" =
// CHECK-SAME: !dbg ![[INT:[0-9]+]]
// CHECK-LABEL: define{{.*}}main

// CHECK-LABEL: define{{.*}} swiftcc void @"$S10resilience9takesSizeyy16resilient_struct0C0VF"(%swift.opaque* noalias nocapture)
// CHECK-LLDB-LABEL: define{{.*}} swiftcc void @"$S10resilience9takesSizeyy16resilient_struct0C0VF"(%T16resilient_struct4SizeV* noalias nocapture dereferenceable({{8|16}}))
public func takesSize(_ s: Size) {}


// CHECK-LABEL: define{{.*}} swiftcc void @"$S10resilience1fyyF"()
// CHECK-LLDB-LABEL: define{{.*}} swiftcc void @"$S10resilience1fyyF"()
func f() {
let s1 = Size(w: 1, h: 2)
takesSize(s1)
// CHECK: %[[ADDR:.*]] = alloca i8*
Expand All @@ -30,15 +46,21 @@ public func f() {
// CHECK-LLDB-SAME: metadata ![[V1:[0-9]+]],
// CHECK-LLDB-SAME: metadata !DIExpression())
}
f()

// Note that these DW_OP_deref are not necessarily correct, but it's the best
// approxmiation we have until LLDB can query the runtime for whether a relient
// type's storage is inline or not.
// CHECK: ![[FIXED]] = !DIGlobalVariableExpression(
// CHECK-SAME: expr: !DIExpression())
// CHECK: ![[NON_FIXED]] = !DIGlobalVariableExpression(
// CHECK-SAME: expr: !DIExpression(DW_OP_deref))
// CHECK: ![[TY:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Size",
// CHECK: ![[INT]] = !DIGlobalVariableExpression(
// CHECK-SAME: expr: !DIExpression(DW_OP_deref))

// CHECK-LABEL: define{{( protected)?}} swiftcc void @"$S10resilience9takesSizeyy16resilient_struct0C0VF"(%swift.opaque* noalias nocapture)
// CHECK-LLDB-LABEL: define{{( protected)?}} swiftcc void @"$S10resilience9takesSizeyy16resilient_struct0C0VF"(%T16resilient_struct4SizeV* noalias nocapture dereferenceable({{8|16}}))
public func takesSize(_ s: Size) {}

// CHECK: ![[V1]] = !DILocalVariable(name: "s1", {{.*}}type: ![[TY]])

// CHECK: ![[V1]] = !DILocalVariable(name: "s1", {{.*}}type: ![[TY:[0-9]+]])
// CHECK: ![[TY]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Size",
// CHECK-LLDB: ![[TY:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Size",
// CHECK-LLDB: ![[V1]] = !DILocalVariable(name: "s1", {{.*}}type: ![[TY]])

// CHECK-LLDB: ![[V1]] = !DILocalVariable(name: "s1", {{.*}}type: ![[TY:[0-9]+]])
// CHECK-LLDB: ![[TY]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Size",