PR16214, PR14467: DebugInfo: use "RequireCompleteType" to decide when to emit the full definition of a type in -flimit-debug-info
This simplifies the core benefit of -flimit-debug-info by taking a more
systematic approach to avoid emitting debug info definitions for types
that only require declarations. The previous ad-hoc approach (3 cases
removed in this patch) had many holes.
The general approach (adding a bit to TagDecl and callback through
ASTConsumer) has been discussed with Richard Smith - though always open
to revision.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186262 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/ASTConsumer.h b/include/clang/AST/ASTConsumer.h
index 9109a67..7b6fa94 100644
--- a/include/clang/AST/ASTConsumer.h
+++ b/include/clang/AST/ASTConsumer.h
@@ -72,6 +72,10 @@
/// can be defined in declspecs).
virtual void HandleTagDeclDefinition(TagDecl *D) {}
+ /// \brief This callback is invoked the first time each TagDecl is required to
+ /// be complete.
+ virtual void HandleTagDeclRequiredDefinition(const TagDecl *D) {}
+
/// \brief Invoked when a function is implicitly instantiated.
/// Note that at this point point it does not have a body, its body is
/// instantiated at the end of the translation unit and passed to
diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index 2b2bf1a..cc9a907 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -2445,6 +2445,9 @@
/// This option is only enabled when modules are enabled.
bool MayHaveOutOfDateDef : 1;
+ /// Has the full definition of this type been required by a use somewhere in
+ /// the TU.
+ bool IsCompleteDefinitionRequired : 1;
private:
SourceLocation RBraceLoc;
@@ -2531,6 +2534,12 @@
return IsCompleteDefinition;
}
+ /// \brief Return true if this complete decl is
+ /// required to be complete for some existing use.
+ bool isCompleteDefinitionRequired() const {
+ return IsCompleteDefinitionRequired;
+ }
+
/// isBeingDefined - Return true if this decl is currently being defined.
bool isBeingDefined() const {
return IsBeingDefined;
@@ -2572,6 +2581,8 @@
void setCompleteDefinition(bool V) { IsCompleteDefinition = V; }
+ void setCompleteDefinitionRequired() { IsCompleteDefinitionRequired = true; }
+
// FIXME: Return StringRef;
const char *getKindName() const {
return TypeWithKeyword::getTagTypeKindName(getTagKind());
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index ab392b4..6b4079e 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -1182,6 +1182,10 @@
virtual ~BoundTypeDiagnoser3() { }
};
+private:
+ bool RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
+ TypeDiagnoser &Diagnoser);
+public:
bool RequireCompleteType(SourceLocation Loc, QualType T,
TypeDiagnoser &Diagnoser);
bool RequireCompleteType(SourceLocation Loc, QualType T,
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index c522059..2bb4455 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -1630,17 +1630,6 @@
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) {
-
- CGDebugInfo *DI = getDebugInfo();
- if (DI &&
- CGM.getCodeGenOpts().getDebugInfo() == CodeGenOptions::LimitedDebugInfo) {
- // If debug info for this class has not been emitted then this is the
- // right time to do so.
- const CXXRecordDecl *Parent = D->getParent();
- DI->getOrCreateRecordType(CGM.getContext().getTypeDeclType(Parent),
- Parent->getLocation());
- }
-
// If this is a trivial constructor, just emit what's needed.
if (D->isTrivial()) {
if (ArgBeg == ArgEnd) {
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 11149f4..4c27546 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1379,7 +1379,8 @@
RecordDecl *RD = Ty->getDecl();
// Limited debug info should only remove struct definitions that can
// safely be replaced by a forward declaration in the source code.
- if (DebugKind <= CodeGenOptions::LimitedDebugInfo && Declaration) {
+ if (DebugKind <= CodeGenOptions::LimitedDebugInfo && Declaration &&
+ !RD->isCompleteDefinitionRequired()) {
// FIXME: This implementation is problematic; there are some test
// cases where we violate the above principle, such as
// test/CodeGen/debug-info-records.c .
diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 438657a..672e86d 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -175,17 +175,6 @@
const MemberExpr *ME = cast<MemberExpr>(callee);
const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl());
- CGDebugInfo *DI = getDebugInfo();
- if (DI &&
- CGM.getCodeGenOpts().getDebugInfo() == CodeGenOptions::LimitedDebugInfo &&
- !isa<CallExpr>(ME->getBase())) {
- QualType PQTy = ME->getBase()->IgnoreParenImpCasts()->getType();
- if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) {
- DI->getOrCreateRecordType(PTy->getPointeeType(),
- MD->getParent()->getLocation());
- }
- }
-
if (MD->isStatic()) {
// The method is static, emit it as we would a regular call.
llvm::Value *Callee = CGM.GetAddrOfFunction(MD);
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index f055c67..8e81866 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -992,18 +992,6 @@
return Builder.getInt(Value);
}
- // Emit debug info for aggregate now, if it was delayed to reduce
- // debug info size.
- CGDebugInfo *DI = CGF.getDebugInfo();
- if (DI &&
- CGF.CGM.getCodeGenOpts().getDebugInfo()
- == CodeGenOptions::LimitedDebugInfo) {
- QualType PQTy = E->getBase()->IgnoreParenImpCasts()->getType();
- if (const PointerType * PTy = dyn_cast<PointerType>(PQTy))
- if (FieldDecl *M = dyn_cast<FieldDecl>(E->getMemberDecl()))
- DI->getOrCreateRecordType(PTy->getPointeeType(),
- M->getParent()->getLocation());
- }
return EmitLoadOfLValue(E);
}
diff --git a/lib/CodeGen/CodeGenAction.cpp b/lib/CodeGen/CodeGenAction.cpp
index 804af31..3072204 100644
--- a/lib/CodeGen/CodeGenAction.cpp
+++ b/lib/CodeGen/CodeGenAction.cpp
@@ -171,6 +171,10 @@
Gen->HandleTagDeclDefinition(D);
}
+ virtual void HandleTagDeclRequiredDefinition(const TagDecl *D) {
+ Gen->HandleTagDeclRequiredDefinition(D);
+ }
+
virtual void CompleteTentativeDefinition(VarDecl *D) {
Gen->CompleteTentativeDefinition(D);
}
diff --git a/lib/CodeGen/ModuleBuilder.cpp b/lib/CodeGen/ModuleBuilder.cpp
index 763aa12..7e0e3aa 100644
--- a/lib/CodeGen/ModuleBuilder.cpp
+++ b/lib/CodeGen/ModuleBuilder.cpp
@@ -13,6 +13,7 @@
#include "clang/CodeGen/ModuleBuilder.h"
#include "CodeGenModule.h"
+#include "CGDebugInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
@@ -93,6 +94,12 @@
}
}
+ virtual void HandleTagDeclRequiredDefinition(const TagDecl *D) LLVM_OVERRIDE {
+ if (CodeGen::CGDebugInfo *DI = Builder->getModuleDebugInfo())
+ if (const RecordDecl *RD = dyn_cast<RecordDecl>(D))
+ DI->completeFwdDecl(*RD);
+ }
+
virtual void HandleTranslationUnit(ASTContext &Ctx) {
if (Diags.hasErrorOccurred()) {
M.reset();
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 72a6d1a..80e9b2f 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -12,6 +12,7 @@
//===----------------------------------------------------------------------===//
#include "clang/Sema/SemaInternal.h"
+#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/CXXInheritance.h"
@@ -4844,6 +4845,20 @@
/// @c false otherwise.
bool Sema::RequireCompleteType(SourceLocation Loc, QualType T,
TypeDiagnoser &Diagnoser) {
+ if (RequireCompleteTypeImpl(Loc, T, Diagnoser))
+ return true;
+ if (const TagType *Tag = T->getAs<TagType>()) {
+ if (!Tag->getDecl()->isCompleteDefinitionRequired()) {
+ Tag->getDecl()->setCompleteDefinitionRequired();
+ Consumer.HandleTagDeclRequiredDefinition(Tag->getDecl());
+ }
+ }
+ return false;
+}
+
+/// \brief The implementation of RequireCompleteType
+bool Sema::RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
+ TypeDiagnoser &Diagnoser) {
// FIXME: Add this assertion to make sure we always get instantiation points.
// assert(!Loc.isInvalid() && "Invalid location in RequireCompleteType");
// FIXME: Add this assertion to help us flush out problems with
diff --git a/test/CodeGenCXX/debug-info-class-limited.cpp b/test/CodeGenCXX/debug-info-class-limited.cpp
index 26ee19f..a4b9f46 100644
--- a/test/CodeGenCXX/debug-info-class-limited.cpp
+++ b/test/CodeGenCXX/debug-info-class-limited.cpp
@@ -1,8 +1,7 @@
// RUN: %clang -emit-llvm -g -S %s -o - | FileCheck %s
namespace PR16214_1 {
-// CHECK: [[PR16214_1:![0-9]*]] = {{.*}} [ DW_TAG_namespace ] [PR16214_1]
-// CHECK: = metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata [[PR16214_1]], {{.*}} ; [ DW_TAG_structure_type ] [foo] {{.*}} [def]
+// CHECK-DAG: [ DW_TAG_structure_type ] [foo] [line [[@LINE+1]], {{.*}} [def]
struct foo {
int i;
};
@@ -13,9 +12,9 @@
bar b;
}
-namespace test1 {
+namespace PR14467 {
+// CHECK-DAG: [ DW_TAG_structure_type ] [foo] [line [[@LINE+1]], {{.*}} [def]
struct foo {
- int i;
};
foo *bar(foo *a) {
@@ -24,9 +23,9 @@
}
}
-namespace test2 {
+namespace test1 {
+// CHECK-DAG: [ DW_TAG_structure_type ] [foo] [line [[@LINE+1]], {{.*}} [decl]
struct foo {
- int i;
};
extern int bar(foo *a);
@@ -34,3 +33,20 @@
return bar(a);
}
}
+
+namespace test2 {
+// FIXME: if we were a bit fancier, we could realize that the 'foo' type is only
+// required because of the 'bar' type which is not required at all (or might
+// only be required to be declared)
+// CHECK-DAG: [ DW_TAG_structure_type ] [foo] [line [[@LINE+1]], {{.*}} [def]
+struct foo {
+};
+
+struct bar {
+ foo f;
+};
+
+void func() {
+ foo *f;
+}
+}
