[Lldb-commits] [lldb] [lldb] Add SB API to access static constexpr member values (PR #89730)
via lldb-commits
lldb-commits at lists.llvm.org
Tue Apr 23 02:46:42 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lldb
Author: Pavel Labath (labath)
<details>
<summary>Changes</summary>
The main change is the addition of a new SBTypeStaticField class, representing a static member of a class. It can be retrieved created through SBType::GetStaticFieldWithName. It contains several methods (GetName, GetMangledName, etc.) whose meaning is hopefully obvious. The most interesting method is
lldb::SBValue GetConstantValue(lldb::SBTarget)
which returns a the value of the field -- if it is a compile time constant. The reason for that is that only constants have their values represented in the clang AST.
For non-constants, we need to go back to the module containing that constant, and ask retrieve the associated ValueObjectVariable. That's easy enough if the we are still in the type system of the module (because then the type system will contain the pointer to the module symbol file), but it's hard when the type has been copied into another AST (e.g. during expression evaluation). To do that we would need to walk the ast import chain backwards to find the source TypeSystem, and I haven't found a nice way to do that.
Another possibility would be to use the mangled name of the variable to perform a lookup (in all modules). That is sort of what happens when evaluating the variable in an expression (which does work), but I did not want to commit to that implementation as it's not necessary for my use case (and if anyone wants to, he can use the GetMangledName function and perform the lookup manually).
The patch adds a couple of new TypeSystem functions to surface the information needed to implement this functionality.
---
Full diff: https://github.com/llvm/llvm-project/pull/89730.diff
13 Files Affected:
- (modified) lldb/include/lldb/API/SBTarget.h (+1)
- (modified) lldb/include/lldb/API/SBType.h (+32)
- (modified) lldb/include/lldb/API/SBValue.h (+1)
- (modified) lldb/include/lldb/Symbol/CompilerDecl.h (+7)
- (modified) lldb/include/lldb/Symbol/CompilerType.h (+2)
- (modified) lldb/include/lldb/Symbol/TypeSystem.h (+9)
- (modified) lldb/source/API/SBType.cpp (+88)
- (modified) lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp (+52)
- (modified) lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h (+8)
- (modified) lldb/source/Symbol/CompilerDecl.cpp (+9)
- (modified) lldb/source/Symbol/CompilerType.cpp (+6)
- (modified) lldb/test/API/python_api/type/TestTypeList.py (+26)
- (modified) lldb/test/API/python_api/type/main.cpp (+1)
``````````diff
diff --git a/lldb/include/lldb/API/SBTarget.h b/lldb/include/lldb/API/SBTarget.h
index 3644ac056da3dc..823615e6a36df5 100644
--- a/lldb/include/lldb/API/SBTarget.h
+++ b/lldb/include/lldb/API/SBTarget.h
@@ -954,6 +954,7 @@ class LLDB_API SBTarget {
friend class SBSection;
friend class SBSourceManager;
friend class SBSymbol;
+ friend class SBTypeStaticField;
friend class SBValue;
friend class SBVariablesOptions;
diff --git a/lldb/include/lldb/API/SBType.h b/lldb/include/lldb/API/SBType.h
index 9980fe1218305b..7767eace0cebfe 100644
--- a/lldb/include/lldb/API/SBType.h
+++ b/lldb/include/lldb/API/SBType.h
@@ -107,6 +107,35 @@ class SBTypeMemberFunction {
lldb::TypeMemberFunctionImplSP m_opaque_sp;
};
+class LLDB_API SBTypeStaticField {
+public:
+ SBTypeStaticField();
+
+ SBTypeStaticField(const lldb::SBTypeStaticField &rhs);
+ lldb::SBTypeStaticField &operator=(const lldb::SBTypeStaticField &rhs);
+
+ ~SBTypeStaticField();
+
+ explicit operator bool() const;
+
+ bool IsValid() const;
+
+ const char *GetName();
+
+ const char *GetMangledName();
+
+ lldb::SBType GetType();
+
+ lldb::SBValue GetConstantValue(lldb::SBTarget target);
+
+protected:
+ friend class SBType;
+
+ SBTypeStaticField(lldb_private::CompilerDecl decl);
+
+ std::unique_ptr<lldb_private::CompilerDecl> m_opaque_up;
+};
+
class SBType {
public:
SBType();
@@ -182,6 +211,8 @@ class SBType {
lldb::SBTypeMember GetVirtualBaseClassAtIndex(uint32_t idx);
+ lldb::SBTypeStaticField GetStaticFieldWithName(const char *name);
+
lldb::SBTypeEnumMemberList GetEnumMembers();
uint32_t GetNumberOfTemplateArguments();
@@ -242,6 +273,7 @@ class SBType {
friend class SBTypeNameSpecifier;
friend class SBTypeMember;
friend class SBTypeMemberFunction;
+ friend class SBTypeStaticField;
friend class SBTypeList;
friend class SBValue;
friend class SBWatchpoint;
diff --git a/lldb/include/lldb/API/SBValue.h b/lldb/include/lldb/API/SBValue.h
index bbcccaab51aaee..67f55ce7da2877 100644
--- a/lldb/include/lldb/API/SBValue.h
+++ b/lldb/include/lldb/API/SBValue.h
@@ -426,6 +426,7 @@ class LLDB_API SBValue {
friend class SBModule;
friend class SBTarget;
friend class SBThread;
+ friend class SBTypeStaticField;
friend class SBTypeSummary;
friend class SBValueList;
diff --git a/lldb/include/lldb/Symbol/CompilerDecl.h b/lldb/include/lldb/Symbol/CompilerDecl.h
index 825a4f15836fce..5c99cae3781c58 100644
--- a/lldb/include/lldb/Symbol/CompilerDecl.h
+++ b/lldb/include/lldb/Symbol/CompilerDecl.h
@@ -73,6 +73,9 @@ class CompilerDecl {
CompilerDeclContext GetDeclContext() const;
+ // If this decl has a type, return it.
+ CompilerType GetType() const;
+
// If this decl represents a function, return the return type
CompilerType GetFunctionReturnType() const;
@@ -91,6 +94,10 @@ class CompilerDecl {
/// the subsequent entry, so the topmost entry is the global namespace.
std::vector<lldb_private::CompilerContext> GetCompilerContext() const;
+ // If decl represents a constant value, return it. Otherwise, return an
+ // invalid/empty Scalar.
+ Scalar GetConstantValue() const;
+
private:
TypeSystem *m_type_system = nullptr;
void *m_opaque_decl = nullptr;
diff --git a/lldb/include/lldb/Symbol/CompilerType.h b/lldb/include/lldb/Symbol/CompilerType.h
index b71c531f21633a..9e889a53086b2a 100644
--- a/lldb/include/lldb/Symbol/CompilerType.h
+++ b/lldb/include/lldb/Symbol/CompilerType.h
@@ -416,6 +416,8 @@ class CompilerType {
CompilerType GetVirtualBaseClassAtIndex(size_t idx,
uint32_t *bit_offset_ptr) const;
+ CompilerDecl GetStaticFieldWithName(llvm::StringRef name) const;
+
uint32_t GetIndexOfFieldWithName(const char *name,
CompilerType *field_compiler_type = nullptr,
uint64_t *bit_offset_ptr = nullptr,
diff --git a/lldb/include/lldb/Symbol/TypeSystem.h b/lldb/include/lldb/Symbol/TypeSystem.h
index 3a927d313b823d..ad3b853227a9f6 100644
--- a/lldb/include/lldb/Symbol/TypeSystem.h
+++ b/lldb/include/lldb/Symbol/TypeSystem.h
@@ -27,6 +27,8 @@
#include "lldb/Symbol/CompilerDecl.h"
#include "lldb/Symbol/CompilerDeclContext.h"
#include "lldb/Symbol/Type.h"
+#include "lldb/Utility/Scalar.h"
+#include "lldb/lldb-forward.h"
#include "lldb/lldb-private.h"
#include "lldb/lldb-types.h"
@@ -110,6 +112,8 @@ class TypeSystem : public PluginInterface,
virtual std::vector<lldb_private::CompilerContext>
DeclGetCompilerContext(void *opaque_decl);
+ virtual Scalar DeclGetConstantValue(void *opaque_decl) { return Scalar(); }
+
virtual CompilerType GetTypeForDecl(void *opaque_decl) = 0;
// CompilerDeclContext functions
@@ -339,6 +343,11 @@ class TypeSystem : public PluginInterface,
GetVirtualBaseClassAtIndex(lldb::opaque_compiler_type_t type, size_t idx,
uint32_t *bit_offset_ptr) = 0;
+ virtual CompilerDecl GetStaticFieldWithName(lldb::opaque_compiler_type_t type,
+ llvm::StringRef name) {
+ return CompilerDecl();
+ }
+
virtual CompilerType GetChildCompilerTypeAtIndex(
lldb::opaque_compiler_type_t type, ExecutionContext *exe_ctx, size_t idx,
bool transparent_pointers, bool omit_empty_base_classes,
diff --git a/lldb/source/API/SBType.cpp b/lldb/source/API/SBType.cpp
index ac0e56303fae3e..23bfb5536e86c7 100644
--- a/lldb/source/API/SBType.cpp
+++ b/lldb/source/API/SBType.cpp
@@ -7,16 +7,21 @@
//===----------------------------------------------------------------------===//
#include "lldb/API/SBType.h"
+#include "Utils.h"
#include "lldb/API/SBDefines.h"
#include "lldb/API/SBModule.h"
#include "lldb/API/SBStream.h"
#include "lldb/API/SBTypeEnumMember.h"
#include "lldb/Core/Mangled.h"
+#include "lldb/Core/ValueObjectConstResult.h"
+#include "lldb/Symbol/CompilerDecl.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Symbol/TypeSystem.h"
#include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/Instrumentation.h"
+#include "lldb/Utility/Scalar.h"
#include "lldb/Utility/Stream.h"
#include "llvm/ADT/APSInt.h"
@@ -325,6 +330,79 @@ lldb::SBTypeMemberFunction SBType::GetMemberFunctionAtIndex(uint32_t idx) {
return sb_func_type;
}
+SBTypeStaticField::SBTypeStaticField() { LLDB_INSTRUMENT_VA(this); }
+
+SBTypeStaticField::SBTypeStaticField(lldb_private::CompilerDecl decl)
+ : m_opaque_up(decl ? std::make_unique<CompilerDecl>(decl) : nullptr) {}
+
+SBTypeStaticField::SBTypeStaticField(const SBTypeStaticField &rhs) {
+ LLDB_INSTRUMENT_VA(this, rhs);
+
+ m_opaque_up = clone(rhs.m_opaque_up);
+}
+
+SBTypeStaticField &SBTypeStaticField::operator=(const SBTypeStaticField &rhs) {
+ LLDB_INSTRUMENT_VA(this, rhs);
+
+ m_opaque_up = clone(rhs.m_opaque_up);
+ return *this;
+}
+
+SBTypeStaticField::~SBTypeStaticField() { LLDB_INSTRUMENT_VA(this); }
+
+SBTypeStaticField::operator bool() const {
+ LLDB_INSTRUMENT_VA(this);
+
+ return IsValid();
+}
+
+bool SBTypeStaticField::IsValid() const {
+ LLDB_INSTRUMENT_VA(this);
+
+ return m_opaque_up != nullptr;
+}
+
+const char *SBTypeStaticField::GetName() {
+ LLDB_INSTRUMENT_VA(this);
+
+ if (!IsValid())
+ return "";
+ return m_opaque_up->GetName().GetCString();
+}
+
+const char *SBTypeStaticField::GetMangledName() {
+ LLDB_INSTRUMENT_VA(this);
+
+ if (!IsValid())
+ return "";
+ return m_opaque_up->GetMangledName().GetCString();
+}
+
+SBType SBTypeStaticField::GetType() {
+ LLDB_INSTRUMENT_VA(this);
+
+ if (!IsValid())
+ return SBType();
+ return SBType(m_opaque_up->GetType());
+}
+
+SBValue SBTypeStaticField::GetConstantValue(lldb::SBTarget target) {
+ LLDB_INSTRUMENT_VA(this);
+
+ if (!IsValid())
+ return SBValue();
+
+ Scalar value = m_opaque_up->GetConstantValue();
+ if (!value.IsValid())
+ return SBValue();
+ DataExtractor data;
+ value.GetData(data);
+ auto value_obj_sp = ValueObjectConstResult::Create(
+ target.GetSP().get(), m_opaque_up->GetType(), m_opaque_up->GetName(),
+ data);
+ return SBValue(std::move(value_obj_sp));
+}
+
lldb::SBType SBType::GetUnqualifiedType() {
LLDB_INSTRUMENT_VA(this);
@@ -438,6 +516,16 @@ SBTypeMember SBType::GetVirtualBaseClassAtIndex(uint32_t idx) {
return sb_type_member;
}
+SBTypeStaticField SBType::GetStaticFieldWithName(const char *name) {
+ LLDB_INSTRUMENT_VA(this, name);
+
+ if (!IsValid() || !name)
+ return SBTypeStaticField();
+
+ return SBTypeStaticField(m_opaque_sp->GetCompilerType(/*prefer_dynamic=*/true)
+ .GetStaticFieldWithName(name));
+}
+
SBTypeEnumMemberList SBType::GetEnumMembers() {
LLDB_INSTRUMENT_VA(this);
diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
index 2621f682011b41..93359a9df9170a 100644
--- a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
+++ b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
@@ -9,6 +9,7 @@
#include "TypeSystemClang.h"
#include "clang/AST/DeclBase.h"
+#include "clang/AST/ExprCXX.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/FormatAdapters.h"
#include "llvm/Support/FormatVariadic.h"
@@ -1145,6 +1146,8 @@ CompilerType TypeSystemClang::GetTypeForDecl(clang::NamedDecl *decl) {
return GetTypeForDecl(interface_decl);
if (clang::TagDecl *tag_decl = llvm::dyn_cast<clang::TagDecl>(decl))
return GetTypeForDecl(tag_decl);
+ if (clang::ValueDecl *value_decl = llvm::dyn_cast<clang::ValueDecl>(decl))
+ return GetTypeForDecl(value_decl);
return CompilerType();
}
@@ -1156,6 +1159,10 @@ CompilerType TypeSystemClang::GetTypeForDecl(ObjCInterfaceDecl *decl) {
return GetType(getASTContext().getObjCInterfaceType(decl));
}
+CompilerType TypeSystemClang::GetTypeForDecl(clang::ValueDecl *value_decl) {
+ return GetType(value_decl->getType());
+}
+
#pragma mark Structure, Unions, Classes
void TypeSystemClang::SetOwningModule(clang::Decl *decl,
@@ -5900,6 +5907,36 @@ CompilerType TypeSystemClang::GetVirtualBaseClassAtIndex(
return CompilerType();
}
+CompilerDecl
+TypeSystemClang::GetStaticFieldWithName(lldb::opaque_compiler_type_t type,
+ llvm::StringRef name) {
+ clang::QualType qual_type = RemoveWrappingTypes(GetCanonicalQualType(type));
+ switch (qual_type->getTypeClass()) {
+ case clang::Type::Record: {
+ if (!GetCompleteType(type))
+ return CompilerDecl();
+
+ const clang::RecordType *record_type =
+ llvm::cast<clang::RecordType>(qual_type.getTypePtr());
+ const clang::RecordDecl *record_decl = record_type->getDecl();
+
+ clang::DeclarationName decl_name(&getASTContext().Idents.get(name));
+ for (NamedDecl *decl : record_decl->lookup(decl_name)) {
+ auto *var_decl = dyn_cast<clang::VarDecl>(decl);
+ if (!var_decl || var_decl->getStorageClass() != clang::SC_Static)
+ continue;
+
+ return CompilerDecl(this, var_decl);
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ return CompilerDecl();
+}
+
// If a pointer to a pointee type (the clang_type arg) says that it has no
// children, then we either need to trust it, or override it and return a
// different result. For example, an "int *" has one child that is an integer,
@@ -9074,6 +9111,21 @@ CompilerType TypeSystemClang::DeclGetFunctionArgumentType(void *opaque_decl,
return CompilerType();
}
+Scalar TypeSystemClang::DeclGetConstantValue(void *opaque_decl) {
+ clang::Decl *decl = static_cast<clang::Decl *>(opaque_decl);
+ if (clang::VarDecl *var_decl = llvm::dyn_cast<clang::VarDecl>(decl)) {
+ clang::Expr *init_expr = var_decl->getInit();
+ if (!init_expr)
+ return Scalar();
+ std::optional<llvm::APSInt> value =
+ init_expr->getIntegerConstantExpr(getASTContext());
+ if (!value)
+ return Scalar();
+ return Scalar(*value);
+ }
+ return Scalar();
+}
+
// CompilerDeclContext functions
std::vector<CompilerDecl> TypeSystemClang::DeclContextFindDeclByName(
diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h
index 68b82e9688f12b..62f14df7638dce 100644
--- a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h
+++ b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h
@@ -22,6 +22,7 @@
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTFwd.h"
+#include "clang/AST/Decl.h"
#include "clang/AST/TemplateBase.h"
#include "clang/AST/Type.h"
#include "clang/Basic/TargetInfo.h"
@@ -251,6 +252,8 @@ class TypeSystemClang : public TypeSystem {
CompilerType GetTypeForDecl(clang::ObjCInterfaceDecl *objc_decl);
+ CompilerType GetTypeForDecl(clang::ValueDecl *value_decl);
+
template <typename RecordDeclType>
CompilerType
GetTypeForIdentifier(llvm::StringRef type_name,
@@ -559,6 +562,8 @@ class TypeSystemClang : public TypeSystem {
std::vector<lldb_private::CompilerContext>
DeclGetCompilerContext(void *opaque_decl) override;
+ Scalar DeclGetConstantValue(void *opaque_decl) override;
+
CompilerType GetTypeForDecl(void *opaque_decl) override;
// CompilerDeclContext override functions
@@ -868,6 +873,9 @@ class TypeSystemClang : public TypeSystem {
size_t idx,
uint32_t *bit_offset_ptr) override;
+ CompilerDecl GetStaticFieldWithName(lldb::opaque_compiler_type_t type,
+ llvm::StringRef name) override;
+
static uint32_t GetNumPointeeChildren(clang::QualType type);
CompilerType GetChildCompilerTypeAtIndex(
diff --git a/lldb/source/Symbol/CompilerDecl.cpp b/lldb/source/Symbol/CompilerDecl.cpp
index 0eb630e5b9e113..5fa0a32f041ad7 100644
--- a/lldb/source/Symbol/CompilerDecl.cpp
+++ b/lldb/source/Symbol/CompilerDecl.cpp
@@ -9,6 +9,7 @@
#include "lldb/Symbol/CompilerDecl.h"
#include "lldb/Symbol/CompilerDeclContext.h"
#include "lldb/Symbol/TypeSystem.h"
+#include "lldb/Utility/Scalar.h"
using namespace lldb_private;
@@ -24,6 +25,10 @@ CompilerDeclContext CompilerDecl::GetDeclContext() const {
return m_type_system->DeclGetDeclContext(m_opaque_decl);
}
+CompilerType CompilerDecl::GetType() const {
+ return m_type_system->GetTypeForDecl(m_opaque_decl);
+}
+
CompilerType CompilerDecl::GetFunctionReturnType() const {
return m_type_system->DeclGetFunctionReturnType(m_opaque_decl);
}
@@ -52,3 +57,7 @@ std::vector<lldb_private::CompilerContext>
CompilerDecl::GetCompilerContext() const {
return m_type_system->DeclGetCompilerContext(m_opaque_decl);
}
+
+Scalar CompilerDecl::GetConstantValue() const {
+ return m_type_system->DeclGetConstantValue(m_opaque_decl);
+}
diff --git a/lldb/source/Symbol/CompilerType.cpp b/lldb/source/Symbol/CompilerType.cpp
index 96e74b890d2d90..9523fb6ea77c20 100644
--- a/lldb/source/Symbol/CompilerType.cpp
+++ b/lldb/source/Symbol/CompilerType.cpp
@@ -849,6 +849,12 @@ CompilerType::GetVirtualBaseClassAtIndex(size_t idx,
return CompilerType();
}
+CompilerDecl CompilerType::GetStaticFieldWithName(llvm::StringRef name) const {
+ if (IsValid())
+ return GetTypeSystem()->GetStaticFieldWithName(m_type, name);
+ return CompilerDecl();
+}
+
uint32_t CompilerType::GetIndexOfFieldWithName(
const char *name, CompilerType *field_compiler_type_ptr,
uint64_t *bit_offset_ptr, uint32_t *bitfield_bit_size_ptr,
diff --git a/lldb/test/API/python_api/type/TestTypeList.py b/lldb/test/API/python_api/type/TestTypeList.py
index c647c2bcdccb6f..db1d93f63213a8 100644
--- a/lldb/test/API/python_api/type/TestTypeList.py
+++ b/lldb/test/API/python_api/type/TestTypeList.py
@@ -33,6 +33,25 @@ def _find_nested_type_in_Pointer_template_arg(self, pointer_type):
self.assertTrue(pointer_masks2_type)
self.DebugSBType(pointer_masks2_type)
+ def _find_static_constexpr_field_in_Task_pointer(self, task_pointer):
+ self.assertTrue(task_pointer)
+ self.DebugSBType(task_pointer)
+
+ task_type = task_pointer.GetPointeeType()
+ self.assertTrue(task_type)
+ self.DebugSBType(task_type)
+
+ static_constexpr_field = task_type.GetStaticFieldWithName(
+ "static_constexpr_field"
+ )
+ self.assertTrue(static_constexpr_field)
+ self.assertEqual(static_constexpr_field.GetName(), "static_constexpr_field")
+ self.assertEqual(static_constexpr_field.GetType().GetName(), "const long")
+
+ value = static_constexpr_field.GetConstantValue(self.target())
+ self.DebugSBValue(value)
+ self.assertEqual(value.GetValueAsSigned(), 47)
+
@skipIf(compiler="clang", compiler_version=["<", "17.0"])
def test(self):
"""Exercise SBType and SBTypeList API."""
@@ -175,6 +194,13 @@ def test(self):
frame0.EvaluateExpression("pointer").GetType()
)
+ self._find_static_constexpr_field_in_Task_pointer(
+ frame0.FindVariable("task_head").GetType()
+ )
+ self._find_static_constexpr_field_in_Task_pointer(
+ frame0.EvaluateExpression("task_head").GetType()
+ )
+
# We'll now get the child member 'id' from 'task_head'.
id = task_head.GetChildMemberWithName("id")
self.DebugSBValue(id)
diff --git a/lldb/test/API/python_api/type/main.cpp b/lldb/test/API/python_api/type/main.cpp
index 391f58e3e5871c..b3fefaf9a92985 100644
--- a/lldb/test/API/python_api/type/main.cpp
+++ b/lldb/test/API/python_api/type/main.cpp
@@ -27,6 +27,7 @@ class Task {
enum E : unsigned char {} e;
union U {
} u;
+ static constexpr long static_constexpr_field = 47;
Task(int i, Task *n):
id(i),
next(n),
``````````
</details>
https://github.com/llvm/llvm-project/pull/89730
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