[llvm] r240243 - AsmPrinter: Rewrite initialization of DbgVariable, NFC
Duncan P. N. Exon Smith
dexonsmith at apple.com
Sun Jun 21 09:50:43 PDT 2015
Author: dexonsmith
Date: Sun Jun 21 11:50:43 2015
New Revision: 240243
URL: http://llvm.org/viewvc/llvm-project?rev=240243&view=rev
Log:
AsmPrinter: Rewrite initialization of DbgVariable, NFC
There are three types of `DbgVariable`:
- alloca variables, created based on the MMI table,
- register variables, created based on DBG_VALUE instructions, and
- optimized-out variables.
This commit reconfigures `DbgVariable` to make it easier to tell which
kind we have, and make initialization a little clearer.
For MMI/alloca variables, `FrameIndex.size()` must always equal
`Expr.size()`, and there shouldn't be an `MInsn`. For register
variables (with a `MInsn`), `FrameIndex` must be empty, and `Expr`
should have 0 or 1 element depending on whether it has a complex
expression (registers with multiple locations use `DebugLocListIndex`).
Optimized-out variables shouldn't have any of these fields.
Moreover, this separates DBG_VALUE initialization until after the
variable is created, simplifying logic in a future commit that changes
`collectVariableInfo()` to stop creating empty .debug_loc entries/lists.
Modified:
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp?rev=240243&r1=240242&r2=240243&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp Sun Jun 21 11:50:43 2015
@@ -508,7 +508,7 @@ DwarfCompileUnit::constructVariableDIEIm
}
// .. else use frame index.
- if (DV.getFrameIndex().back() == ~0)
+ if (DV.getFrameIndex().empty())
return VariableDie;
auto Expr = DV.getExpression().begin();
@@ -686,7 +686,7 @@ void DwarfCompileUnit::collectDeadVariab
SPDIE = getDIE(SP);
assert(SPDIE);
for (const DILocalVariable *DV : Variables) {
- DbgVariable NewVar(DV, /* IA */ nullptr, /* Expr */ nullptr, DD);
+ DbgVariable NewVar(DV, /* IA */ nullptr, DD);
auto VariableDie = constructVariableDIE(NewVar);
applyVariableAttributes(NewVar, *VariableDie);
SPDIE->addChild(std::move(VariableDie));
@@ -725,7 +725,7 @@ void DwarfCompileUnit::addGlobalType(con
/// DbgVariable based on provided MachineLocation.
void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
MachineLocation Location) {
- if (DV.variableHasComplexAddress())
+ if (DV.hasComplexAddress())
addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
else if (DV.isBlockByrefVariable())
addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=240243&r1=240242&r2=240243&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Sun Jun 21 11:50:43 2015
@@ -678,8 +678,7 @@ DbgVariable *DwarfDebug::getExistingAbst
void DwarfDebug::createAbstractVariable(const DILocalVariable *Var,
LexicalScope *Scope) {
- auto AbsDbgVariable =
- make_unique<DbgVariable>(Var, /* IA */ nullptr, /* Expr */ nullptr, this);
+ auto AbsDbgVariable = make_unique<DbgVariable>(Var, /* IA */ nullptr, this);
InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
AbstractVariables[Var] = std::move(AbsDbgVariable);
}
@@ -722,10 +721,9 @@ void DwarfDebug::collectVariableInfoFrom
if (!Scope)
continue;
- const DIExpression *Expr = cast_or_null<DIExpression>(VI.Expr);
ensureAbstractVariableIsCreatedIfScoped(Var, Scope->getScopeNode());
- auto RegVar =
- make_unique<DbgVariable>(Var.first, Var.second, Expr, this, VI.Slot);
+ auto RegVar = make_unique<DbgVariable>(Var.first, Var.second, this);
+ RegVar->initializeMMI(VI.Expr, VI.Slot);
if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
ConcreteVariables.push_back(std::move(RegVar));
}
@@ -870,6 +868,14 @@ DwarfDebug::buildLocationList(SmallVecto
}
}
+DbgVariable *DwarfDebug::createConcreteVariable(LexicalScope &Scope,
+ InlinedVariable IV) {
+ ensureAbstractVariableIsCreatedIfScoped(IV, Scope.getScopeNode());
+ ConcreteVariables.push_back(
+ make_unique<DbgVariable>(IV.first, IV.second, this));
+ InfoHolder.addScopeVariable(&Scope, ConcreteVariables.back().get());
+ return ConcreteVariables.back().get();
+}
// Find variables for each lexical scope.
void DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU,
@@ -898,12 +904,11 @@ void DwarfDebug::collectVariableInfo(Dwa
continue;
Processed.insert(IV);
+ DbgVariable *RegVar = createConcreteVariable(*Scope, IV);
+
const MachineInstr *MInsn = Ranges.front().first;
assert(MInsn->isDebugValue() && "History must begin with debug value");
- ensureAbstractVariableIsCreatedIfScoped(IV, Scope->getScopeNode());
- ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
- DbgVariable *RegVar = ConcreteVariables.back().get();
- InfoHolder.addScopeVariable(Scope, RegVar);
+ RegVar->initializeDbgValue(MInsn);
// Check if the first DBG_VALUE is valid for the rest of the function.
if (Ranges.size() == 1 && Ranges.front().second == nullptr)
@@ -930,15 +935,9 @@ void DwarfDebug::collectVariableInfo(Dwa
// Collect info for variables that were optimized out.
for (const DILocalVariable *DV : SP->getVariables()) {
- if (!Processed.insert(InlinedVariable(DV, nullptr)).second)
- continue;
- if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope())) {
- ensureAbstractVariableIsCreatedIfScoped(InlinedVariable(DV, nullptr),
- Scope->getScopeNode());
- ConcreteVariables.push_back(make_unique<DbgVariable>(
- DV, /* IA */ nullptr, /* Expr */ nullptr, this));
- InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
- }
+ if (Processed.insert(InlinedVariable(DV, nullptr)).second)
+ if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope()))
+ createConcreteVariable(*Scope, InlinedVariable(DV, nullptr));
}
}
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h?rev=240243&r1=240242&r2=240243&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h Sun Jun 21 11:50:43 2015
@@ -67,42 +67,61 @@ public:
};
//===----------------------------------------------------------------------===//
-/// \brief This class is used to track local variable information.
+/// This class is used to track local variable information.
///
-/// - Variables whose location changes over time have a DebugLocListIndex and
-/// the other fields are not used.
+/// Variables can be created from allocas, in which case they're generated from
+/// the MMI table. Such variables can have multiple expressions and frame
+/// indices. The \a Expr and \a FrameIndices array must match.
///
-/// - Variables that are described by multiple MMI table entries have multiple
-/// expressions and frame indices.
+/// Variables can be created from \c DBG_VALUE instructions. Those whose
+/// location changes over time use \a DebugLocListIndex, while those with a
+/// single instruction use \a MInsn and (optionally) a single entry of \a Expr.
+///
+/// Variables that have been optimized out use none of these fields.
class DbgVariable {
- const DILocalVariable *Var; /// Variable Descriptor.
- const DILocation *IA; /// Inlined at location.
- SmallVector<const DIExpression *, 1>
- Expr; /// Complex address location expression.
- DIE *TheDIE; /// Variable DIE.
- unsigned DebugLocListIndex; /// Offset in DebugLocs.
- const MachineInstr *MInsn; /// DBG_VALUE instruction of the variable.
- SmallVector<int, 1> FrameIndex; /// Frame index of the variable.
+ const DILocalVariable *Var; /// Variable Descriptor.
+ const DILocation *IA; /// Inlined at location.
+ SmallVector<const DIExpression *, 1> Expr; /// Complex address.
+ DIE *TheDIE = nullptr; /// Variable DIE.
+ unsigned DebugLocListIndex = ~0u; /// Offset in DebugLocs.
+ const MachineInstr *MInsn = nullptr; /// DBG_VALUE instruction.
+ SmallVector<int, 1> FrameIndex; /// Frame index.
DwarfDebug *DD;
public:
- /// Construct a DbgVariable from a variable.
- DbgVariable(const DILocalVariable *V, const DILocation *IA,
- const DIExpression *E, DwarfDebug *DD, int FI = ~0)
- : Var(V), IA(IA), Expr(1, E), TheDIE(nullptr), DebugLocListIndex(~0U),
- MInsn(nullptr), DD(DD) {
+ /// Construct a DbgVariable.
+ ///
+ /// Creates a variable without any DW_AT_location. Call \a initializeMMI()
+ /// for MMI entries, or \a initializeDbgValue() for DBG_VALUE instructions.
+ DbgVariable(const DILocalVariable *V, const DILocation *IA, DwarfDebug *DD)
+ : Var(V), IA(IA), DD(DD) {}
+
+ /// Initialize from the MMI table.
+ void initializeMMI(const DIExpression *E, int FI) {
+ assert(Expr.empty() && "Already initialized?");
+ assert(FrameIndex.empty() && "Already initialized?");
+ assert(!MInsn && "Already initialized?");
+
+ assert((!E || E->isValid()) && "Expected valid expression");
+ assert(~FI && "Expected valid index");
+
+ Expr.push_back(E);
FrameIndex.push_back(FI);
- assert(!E || E->isValid());
}
- /// Construct a DbgVariable from a DEBUG_VALUE.
- /// AbstractVar may be NULL.
- DbgVariable(const MachineInstr *DbgValue, DwarfDebug *DD)
- : Var(DbgValue->getDebugVariable()),
- IA(DbgValue->getDebugLoc()->getInlinedAt()),
- Expr(1, DbgValue->getDebugExpression()), TheDIE(nullptr),
- DebugLocListIndex(~0U), MInsn(DbgValue), DD(DD) {
- FrameIndex.push_back(~0);
+ /// Initialize from a DBG_VALUE instruction.
+ void initializeDbgValue(const MachineInstr *DbgValue) {
+ assert(Expr.empty() && "Already initialized?");
+ assert(FrameIndex.empty() && "Already initialized?");
+ assert(!MInsn && "Already initialized?");
+
+ assert(Var == DbgValue->getDebugVariable() && "Wrong variable");
+ assert(IA == DbgValue->getDebugLoc()->getInlinedAt() && "Wrong inlined-at");
+
+ MInsn = DbgValue;
+ if (auto *E = DbgValue->getDebugExpression())
+ if (E->getNumElements())
+ Expr.push_back(E);
}
// Accessors.
@@ -123,17 +142,16 @@ public:
assert(V.Var == Var && "conflicting variable");
assert(V.IA == IA && "conflicting inlined-at location");
- if (V.getFrameIndex().back() != ~0) {
- auto E = V.getExpression();
- auto FI = V.getFrameIndex();
- Expr.append(E.begin(), E.end());
- FrameIndex.append(FI.begin(), FI.end());
- }
- assert(Expr.size() > 1 ? std::all_of(Expr.begin(), Expr.end(),
- [](const DIExpression *E) {
- return E->isBitPiece();
- })
- : (true && "conflicting locations for variable"));
+ assert(!FrameIndex.empty() && "Expected an MMI entry");
+ assert(!V.FrameIndex.empty() && "Expected an MMI entry");
+ assert(Expr.size() == FrameIndex.size() && "Mismatched expressions");
+ assert(V.Expr.size() == V.FrameIndex.size() && "Mismatched expressions");
+
+ Expr.append(V.Expr.begin(), V.Expr.end());
+ FrameIndex.append(V.FrameIndex.begin(), V.FrameIndex.end());
+ assert(std::all_of(Expr.begin(), Expr.end(), [](const DIExpression *E) {
+ return E && E->isBitPiece();
+ }) && "conflicting locations for variable");
}
// Translate tag to proper Dwarf tag.
@@ -160,11 +178,13 @@ public:
return false;
}
- bool variableHasComplexAddress() const {
- assert(Var && "Invalid complex DbgVariable!");
- assert(Expr.size() == 1 &&
- "variableHasComplexAddress() invoked on multi-FI variable");
- return Expr.back()->getNumElements() > 0;
+ bool hasComplexAddress() const {
+ assert(MInsn && "Expected DBG_VALUE, not MMI variable");
+ assert(FrameIndex.empty() && "Expected DBG_VALUE, not MMI variable");
+ assert(
+ (Expr.empty() || (Expr.size() == 1 && Expr.back()->getNumElements())) &&
+ "Invalid Expr for DBG_VALUE");
+ return !Expr.empty();
}
bool isBlockByrefVariable() const;
const DIType *getType() const;
@@ -344,6 +364,8 @@ class DwarfDebug : public AsmPrinterHand
void ensureAbstractVariableIsCreatedIfScoped(InlinedVariable Var,
const MDNode *Scope);
+ DbgVariable *createConcreteVariable(LexicalScope &Scope, InlinedVariable IV);
+
/// \brief Construct a DIE for this abstract scope.
void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
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