r205952 - Add global static variables for anonymous union fields. This makes
Eric Christopher
echristo at gmail.com
Wed Apr 9 22:20:01 PDT 2014
Author: echristo
Date: Thu Apr 10 00:20:00 2014
New Revision: 205952
URL: http://llvm.org/viewvc/llvm-project?rev=205952&view=rev
Log:
Add global static variables for anonymous union fields. This makes
sure that a debugger can find them when stepping through code,
for example from the included testcase:
12 int test_it() {
13 c = 1;
14 d = 2;
-> 15 a = 4;
16 return (c == 1);
17 }
18
(lldb) p a
(int) $0 = 2
(lldb) p c
(int) $1 = 2
(lldb) p d
(int) $2 = 2
and a, c, d are all part of the file static anonymous union:
static union {
int c;
int d;
union {
int a;
};
struct {
int b;
};
};
Fixes PR19221.
Added:
cfe/trunk/test/CodeGenCXX/debug-info-anon-union-vars.cpp
Modified:
cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
cfe/trunk/lib/CodeGen/CGDebugInfo.h
Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=205952&r1=205951&r2=205952&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Thu Apr 10 00:20:00 2014
@@ -3180,6 +3180,37 @@ CGDebugInfo::getOrCreateStaticDataMember
return T;
}
+/// Recursively collect all of the member fields of a global anonymous decl and
+/// create static variables for them. The first time this is called it needs
+/// to be on a union and then from there we can have additional unnamed fields.
+llvm::DIGlobalVariable
+CGDebugInfo::CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile Unit,
+ unsigned LineNo, StringRef LinkageName,
+ llvm::GlobalVariable *Var,
+ llvm::DIDescriptor DContext) {
+ llvm::DIGlobalVariable GV;
+
+ for (const auto *Field : RD->fields()) {
+ llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
+ StringRef FieldName = Field->getName();
+
+ // Ignore unnamed fields, but recurse into anonymous records.
+ if (FieldName.empty()) {
+ const RecordType *RT = dyn_cast<RecordType>(Field->getType());
+ if (RT)
+ GV = CollectAnonRecordDecls(RT->getDecl(), Unit, LineNo, LinkageName,
+ Var, DContext);
+ continue;
+ }
+ // Use VarDecl's Tag, Scope and Line number.
+ GV = DBuilder.createStaticVariable(DContext, FieldName, LinkageName, Unit,
+ LineNo, FieldTy,
+ Var->hasInternalLinkage(), Var,
+ llvm::DIDerivedType());
+ }
+ return GV;
+}
+
/// EmitGlobalVariable - Emit information about a global variable.
void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
const VarDecl *D) {
@@ -3200,19 +3231,35 @@ void CGDebugInfo::EmitGlobalVariable(llv
T = CGM.getContext().getConstantArrayType(ET, ConstVal,
ArrayType::Normal, 0);
}
+
StringRef DeclName = D->getName();
StringRef LinkageName;
- if (D->getDeclContext() && !isa<FunctionDecl>(D->getDeclContext())
- && !isa<ObjCMethodDecl>(D->getDeclContext()))
+ if (D->getDeclContext() && !isa<FunctionDecl>(D->getDeclContext()) &&
+ !isa<ObjCMethodDecl>(D->getDeclContext()))
LinkageName = Var->getName();
if (LinkageName == DeclName)
LinkageName = StringRef();
+
llvm::DIDescriptor DContext =
getContextDescriptor(dyn_cast<Decl>(D->getDeclContext()));
- llvm::DIGlobalVariable GV = DBuilder.createStaticVariable(
- DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
- Var->hasInternalLinkage(), Var,
- getOrCreateStaticDataMemberDeclarationOrNull(D));
+
+ // Attempt to store one global variable for the declaration - even if we
+ // emit a lot of fields.
+ llvm::DIGlobalVariable GV;
+
+ // If this is an anonymous union then we'll want to emit a global
+ // variable for each member of the anonymous union so that it's possible
+ // to find the name of any field in the union.
+ if (T->isUnionType() && DeclName.empty()) {
+ const RecordDecl *RD = cast<RecordType>(T)->getDecl();
+ assert(RD->isAnonymousStructOrUnion() && "unnamed non-anonymous struct or union?");
+ GV = CollectAnonRecordDecls(RD, Unit, LineNo, LinkageName, Var, DContext);
+ } else {
+ GV = DBuilder.createStaticVariable(
+ DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
+ Var->hasInternalLinkage(), Var,
+ getOrCreateStaticDataMemberDeclarationOrNull(D));
+ }
DeclCache.insert(std::make_pair(D->getCanonicalDecl(), llvm::WeakVH(GV)));
}
Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.h?rev=205952&r1=205951&r2=205952&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.h (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.h Thu Apr 10 00:20:00 2014
@@ -358,6 +358,13 @@ private:
llvm::DIDerivedType
getOrCreateStaticDataMemberDeclarationOrNull(const VarDecl *D);
+ /// Return a global variable that represents one of the collection of
+ /// global variables created for an anonmyous union.
+ llvm::DIGlobalVariable
+ CollectAnonRecordDecls(const RecordDecl *RD, llvm::DIFile Unit, unsigned LineNo,
+ StringRef LinkageName, llvm::GlobalVariable *Var,
+ llvm::DIDescriptor DContext);
+
/// getFunctionName - Get function name for the given FunctionDecl. If the
/// name is constructed on demand (e.g. C++ destructor) then the name
/// is stored on the side.
Added: cfe/trunk/test/CodeGenCXX/debug-info-anon-union-vars.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-anon-union-vars.cpp?rev=205952&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-anon-union-vars.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/debug-info-anon-union-vars.cpp Thu Apr 10 00:20:00 2014
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -emit-llvm -gdwarf-4 -triple x86_64-linux-gnu %s -o - | FileCheck %s
+
+// Make sure that we emit a global variable for each of the members of the
+// anonymous union.
+
+static union {
+ int c;
+ int d;
+ union {
+ int a;
+ };
+ struct {
+ int b;
+ };
+};
+
+int test_it() {
+ c = 1;
+ d = 2;
+ a = 4;
+ return (c == 1);
+}
+
+// CHECK: [[FILE:.*]] = {{.*}}[ DW_TAG_file_type ] [{{.*}}debug-info-anon-union-vars.cpp]
+// CHECK: [[FILE]]{{.*}}[ DW_TAG_variable ] [c] [line 6] [local] [def]
+// CHECK: [[FILE]]{{.*}}[ DW_TAG_variable ] [d] [line 6] [local] [def]
+// CHECK: [[FILE]]{{.*}}[ DW_TAG_variable ] [a] [line 6] [local] [def]
+// CHECK: [[FILE]]{{.*}}[ DW_TAG_variable ] [b] [line 6] [local] [def]
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