vsk created this revision.
Herald added a subscriber: JDevlieghere.
This is a prototype of tail call frame support for lldb based on
compiler support from https://reviews.llvm.org/D49887. It isn't ready for
review. I'm sharing the
proof-of-concept to give a heads-up about this coming down the pipeline,
and/or to answer any early questions.
Demo (see the included tail5.cc test case):
+ /Users/vsk/src/builds/llvm-project-tailcall-RA/bin//clang++ tail5.cc -o
tail5.cc.out -g -mllvm -callsite-debuginfo-experimental=true -O2
+ xcrun lldb -o 'b sink' -o r -o bt -o quit tail5.cc.out
(lldb) target create "tail5.cc.out"
Current executable set to 'tail5.cc.out' (x86_64).
(lldb) b sink
Breakpoint 1: where = tail5.cc.out`sink() + 4 at tail5.cc:2, address =
0x0000000100000f64
(lldb) r
tail5.cc.out was compiled with optimization - stepping may behave oddly;
variables may not be available.
Process 21540 stopped
- thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
frame #0: 0x0000000100000f64 tail5.cc.out`sink() at tail5.cc:2 [opt] 1
volatile int x;
-> 2 void __attribute__((noinline)) sink() { x++; }
3 void __attribute__((noinline)) D() { sink(); /* tail */ }
4 void __attribute__((disable_tail_calls, noinline)) C() { D(); /* regular
*/ }
5 void __attribute__((noinline)) B() { C(); /* tail */ }
6 int __attribute__((disable_tail_calls)) main() { B(); /* regular */ }
Target 0: (tail5.cc.out) stopped.
Process 21540 launched:
'/Users/vsk/src/llvm-project-tailcall/lldb/test/testcases/functionalities/tail_call_frames/tail5.cc.out'
(x86_64)
(lldb) bt
- thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
- frame #0: 0x0000000100000f64 tail5.cc.out`sink() at tail5.cc:2 [opt] frame
#1: 0x0000000100000f89 tail5.cc.out`C() at tail5.cc:4 [opt] frame #2:
0x0000000100000fa9 tail5.cc.out`main at tail5.cc:6 [opt] frame #3:
0x00007fff57147015 libdyld.dylib`start + 1 frame #4: 0x00007fff57147015
libdyld.dylib`start + 1
(lldb) quit
+ /Users/vsk/src/builds/llvm-project-tailcall-RA/bin//lldb -o 'b sink' -o r -o
'log enable -f tail5.cc.log lldb step' -o bt -o quit tail5.cc.out
(lldb) target create "tail5.cc.out"
Current executable set to 'tail5.cc.out' (x86_64).
(lldb) b sink
Breakpoint 1: where = tail5.cc.out`sink() + 4 at tail5.cc:2, address =
0x0000000100000f64
(lldb) r
tail5.cc.out was compiled with optimization - stepping may behave oddly;
variables may not be available.
Process 21544 stopped
- thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
frame #0: 0x0000000100000f64 tail5.cc.out`sink() at tail5.cc:2 [opt] 1
volatile int x;
-> 2 void __attribute__((noinline)) sink() { x++; }
3 void __attribute__((noinline)) D() { sink(); /* tail */ }
4 void __attribute__((disable_tail_calls, noinline)) C() { D(); /* regular
*/ }
5 void __attribute__((noinline)) B() { C(); /* tail */ }
6 int __attribute__((disable_tail_calls)) main() { B(); /* regular */ }
Process 21544 launched:
'/Users/vsk/src/llvm-project-tailcall/lldb/test/testcases/functionalities/tail_call_frames/tail5.cc.out'
(x86_64)
(lldb) log enable -f tail5.cc.log lldb step
(lldb) bt
- thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
- frame #0: 0x0000000100000f64 tail5.cc.out`sink() at tail5.cc:2 [opt] frame
#1: 0x0000000000000010 tail5.cc.out`D() - 4294971232 [opt] frame #2:
0x0000000100000f89 tail5.cc.out`C() at tail5.cc:4 [opt] frame #3:
0x0000000000000030 tail5.cc.out`B() - 4294971232 [opt] frame #4:
0x0000000100000fa9 tail5.cc.out`main at tail5.cc:6 [opt] frame #5:
0x00007fff57147015 libdyld.dylib`start + 1 frame #6: 0x00007fff57147015
libdyld.dylib`start + 1
https://reviews.llvm.org/D50478
Files:
lldb/include/lldb/Symbol/Block.h
lldb/include/lldb/Symbol/Function.h
lldb/include/lldb/Symbol/SymbolFile.h
lldb/include/lldb/Target/StackFrame.h
lldb/include/lldb/Target/StackFrameList.h
lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail.cc
lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail2.cc
lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail3.cc
lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail4.cc
lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail5.cc
lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/test.sh
lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
lldb/source/Symbol/Block.cpp
lldb/source/Symbol/Function.cpp
lldb/source/Target/StackFrameList.cpp
Index: lldb/source/Target/StackFrameList.cpp
===================================================================
--- lldb/source/Target/StackFrameList.cpp
+++ lldb/source/Target/StackFrameList.cpp
@@ -27,6 +27,7 @@
#include "lldb/Target/Thread.h"
#include "lldb/Target/Unwind.h"
#include "lldb/Utility/Log.h"
+#include "llvm/ADT/SmallPtrSet.h"
//#define DEBUG_STACK_FRAMES 1
@@ -240,6 +241,124 @@
m_frames.resize(num_frames);
}
+/// Find the unique path through the call graph which led from \p begin to \p
+/// end. On success this path is stored into \p path, and on failure \p path is
+/// unchanged.
+static void FindInterveningFrames(Function &begin, Function &end,
+ std::vector<Function *> &path,
+ ModuleList &images, Log *log) {
+ LLDB_LOG(log, "SynthesizeTailCallFrames: Finding frames between {0} and {1}",
+ begin.GetDisplayName(), end.GetDisplayName());
+
+ struct dfs {
+ std::vector<Function *> active_path;
+ std::vector<Function *> solution_path;
+ llvm::SmallPtrSet<Function *, 8> visited;
+ bool ambiguous = false;
+ Function &end;
+ ModuleList &images;
+ Log *log;
+
+ dfs(Function &end, ModuleList &images, Log *log)
+ : end(end), images(images), log(log) {}
+
+ void search(Function &caller) {
+ if (&caller == &end) {
+ // Found a solution path. If a solution path has already been found, it
+ // must be ambiguous. If not, store the path.
+ if (!solution_path.empty())
+ ambiguous = true;
+ else
+ solution_path = active_path;
+ return;
+ }
+
+ // Scan the outgoing call edges from the caller.
+ for (CallEdge edge : caller.GetCallEdges()) {
+ Function *callee = edge.GetCallee(images);
+ if (!callee) {
+ LLDB_LOG(log, "SynthesizeTailCallFrames: Incomplete call edge");
+ continue;
+ }
+
+ // Recursively search unvisited callees.
+ bool unvisited = visited.insert(callee).second;
+ if (unvisited) {
+ LLDB_LOG(log, "SynthesizeTailCallFrames: Visiting edge {0} -> {1}",
+ caller.GetDisplayName(), callee->GetDisplayName());
+
+ active_path.push_back(callee);
+ search(*callee);
+ if (ambiguous)
+ return;
+ active_path.pop_back();
+ } else {
+ ambiguous = true;
+ return;
+ }
+ }
+ }
+ };
+
+ dfs dfs{end, images, log};
+ dfs.search(begin);
+
+ // Return an unambiguous solution if one exists.
+ if (!dfs.ambiguous && !dfs.solution_path.empty()) {
+ path = std::move(dfs.solution_path);
+
+ // Pop off the end node, as it's already on the stack frame list.
+ path.pop_back();
+ }
+}
+
+/// Given that \p next_frame will be appended to the frame list, synthesize
+/// tail call frames between the current end of the list and \p next_frame.
+/// If any frames are added, adjust the frame index of \p next_frame.
+void StackFrameList::SynthesizeTailCallFrames(StackFrame &next_frame) {
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+
+ assert(!m_frames.empty() && "Cannot synthesize frames in an empty stack");
+ StackFrame &prev_frame = *m_frames.back().get();
+
+ // Find the functions prev_frame and next_frame are stopped in. The function
+ // objects are needed to access the lazy call graph for intervening frames.
+ Function *prev_func =
+ prev_frame.GetSymbolContext(eSymbolContextFunction).function;
+ Function *next_func =
+ next_frame.GetSymbolContext(eSymbolContextFunction).function;
+ if (!prev_func || !next_func) {
+ LLDB_LOG(log, "SynthesizeTailCallFrames: Function lookup failed");
+ return;
+ }
+
+ // Try to find the unique sequence of (tail) calls which led from next_frame
+ // to prev_frame.
+ std::vector<Function *> path;
+ ModuleList &images = next_frame.CalculateTarget()->GetImages();
+ FindInterveningFrames(*next_func, *prev_func, path, images, log);
+ for (Function *callee : llvm::reverse(path)) {
+ uint32_t frame_idx = m_frames.size();
+ uint32_t concrete_frame_idx = next_frame.GetConcreteFrameIndex();
+ addr_t cfa = LLDB_INVALID_ADDRESS;
+ bool cfa_is_valid = false;
+ addr_t pc = callee->GetAddressRange().GetBaseAddress().GetOffset();
+ uint32_t stop_id = 0;
+ bool stop_id_is_valid = false;
+ bool is_history_frame = false;
+ SymbolContext sc;
+ callee->CalculateSymbolContext(&sc);
+ StackFrameSP synth_frame{new StackFrame(
+ m_thread.shared_from_this(), frame_idx, concrete_frame_idx, cfa,
+ cfa_is_valid, pc, stop_id, stop_id_is_valid, is_history_frame, &sc)};
+ m_frames.push_back(synth_frame);
+ LLDB_LOG(log, "SynthesizeTailCallFrames: Pushed frame {0}",
+ callee->GetDisplayName());
+ }
+ if (!path.empty())
+ next_frame.SetFrameIndex(m_frames.size());
+}
+
void StackFrameList::GetFramesUpTo(uint32_t end_idx) {
// Do not fetch frames for an invalid thread.
if (!m_thread.IsValid())
@@ -320,6 +439,12 @@
unwind_frame_sp.reset(new StackFrame(
m_thread.shared_from_this(), m_frames.size(), idx, cfa, cfa_is_valid,
pc, 0, stop_id_is_valid, is_history_frame, nullptr));
+
+ // Create synthetic tail call frames between the previous frame and the
+ // newly-found frame. The new frame's index may change after this call,
+ // although its concrete index will stay the same.
+ SynthesizeTailCallFrames(*unwind_frame_sp.get());
+
m_frames.push_back(unwind_frame_sp);
}
Index: lldb/source/Symbol/Function.cpp
===================================================================
--- lldb/source/Symbol/Function.cpp
+++ lldb/source/Symbol/Function.cpp
@@ -10,14 +10,16 @@
#include "lldb/Symbol/Function.h"
#include "lldb/Core/Disassembler.h"
#include "lldb/Core/Module.h"
+#include "lldb/Core/ModuleList.h"
#include "lldb/Core/Section.h"
#include "lldb/Host/Host.h"
#include "lldb/Symbol/CompileUnit.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Symbol/LineTable.h"
#include "lldb/Symbol/SymbolFile.h"
#include "lldb/Symbol/SymbolVendor.h"
#include "lldb/Target/Language.h"
+#include "lldb/Utility/Log.h"
#include "llvm/Support/Casting.h"
using namespace lldb;
@@ -128,6 +130,49 @@
return FunctionInfo::MemorySize() + m_mangled.MemorySize();
}
+//----------------------------------------------------------------------
+//
+//----------------------------------------------------------------------
+CallEdge::CallEdge(const char *mangled_name) : resolved(false) {
+ lazy_target.mangled_name = mangled_name;
+}
+
+Function *CallEdge::GetCallee(ModuleList &images) {
+ if (resolved)
+ return lazy_target.callee;
+
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ LLDB_LOG(log, "CallEdge::GetCallee: Lazily parsing the call graph for {0}",
+ lazy_target.mangled_name);
+
+ lazy_target.callee = [&]() -> Function * {
+ ConstString callee_name{lazy_target.mangled_name};
+ SymbolContextList sc_list;
+ size_t num_matches =
+ images.FindFunctionSymbols(callee_name, eFunctionNameTypeAuto, sc_list);
+ if (num_matches != 1 || !sc_list[0].symbol) {
+ LLDB_LOG(log,
+ "CallEdge::GetCallee: Found {0} matches for {1}, but needed "
+ "exactly 1 non-null match",
+ num_matches, callee_name);
+ return nullptr;
+ }
+ Address callee_addr = sc_list[0].symbol->GetAddress();
+ if (!callee_addr.IsValid()) {
+ LLDB_LOG(log, "CallEdge::GetCallee: Invalid symbol address");
+ return nullptr;
+ }
+ Function *f = callee_addr.CalculateSymbolContextFunction();
+ if (!f) {
+ LLDB_LOG(log, "CallEdge::GetCallee: Could not find complete function");
+ return nullptr;
+ }
+ return f;
+ }();
+ resolved = true;
+ return lazy_target.callee;
+}
+
//----------------------------------------------------------------------
//
//----------------------------------------------------------------------
@@ -192,6 +237,22 @@
}
}
+llvm::ArrayRef<CallEdge> Function::GetCallEdges() {
+ if (m_call_edges_resolved)
+ return m_call_edges;
+
+ // Attempt to parse call edges at most once.
+ m_call_edges_resolved = true;
+
+ Block &block = GetBlock(/*can_create*/true);
+ SymbolFile *sym_file = block.GetSymbolFile();
+ if (!sym_file)
+ return llvm::None;
+
+ m_call_edges = sym_file->ParseCallEdgesInFunction(GetID());
+ return m_call_edges;
+}
+
Block &Function::GetBlock(bool can_create) {
if (!m_block.BlockInfoHasBeenParsed() && can_create) {
SymbolContext sc;
Index: lldb/source/Symbol/Block.cpp
===================================================================
--- lldb/source/Symbol/Block.cpp
+++ lldb/source/Symbol/Block.cpp
@@ -444,19 +444,16 @@
return num_variables_added;
}
-CompilerDeclContext Block::GetDeclContext() {
- ModuleSP module_sp = CalculateSymbolContextModule();
-
- if (module_sp) {
- SymbolVendor *sym_vendor = module_sp->GetSymbolVendor();
-
- if (sym_vendor) {
- SymbolFile *sym_file = sym_vendor->GetSymbolFile();
+SymbolFile *Block::GetSymbolFile() {
+ if (ModuleSP module_sp = CalculateSymbolContextModule())
+ if (SymbolVendor *sym_vendor = module_sp->GetSymbolVendor())
+ return sym_vendor->GetSymbolFile();
+ return nullptr;
+}
- if (sym_file)
- return sym_file->GetDeclContextForUID(GetID());
- }
- }
+CompilerDeclContext Block::GetDeclContext() {
+ if (SymbolFile *sym_file = GetSymbolFile())
+ return sym_file->GetDeclContextForUID(GetID());
return CompilerDeclContext();
}
Index: lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
+++ lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
@@ -316,6 +316,9 @@
DIEInDeclContext(const lldb_private::CompilerDeclContext *parent_decl_ctx,
const DWARFDIE &die);
+ std::vector<lldb_private::CallEdge>
+ ParseCallEdgesInFunction(UserID func_id) override;
+
void Dump(lldb_private::Stream &s) override;
protected:
Index: lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -3736,6 +3736,54 @@
return vars_added;
}
+/// Collect call graph edges present in a function DIE.
+static std::vector<lldb_private::CallEdge>
+CollectCallEdges(DWARFDIE function_die) {
+ // Check if the function has a supported call site-related attribute.
+ // TODO: In the future it may be worthwhile to support call_all_source_calls.
+ uint64_t has_call_edges =
+ function_die.GetAttributeValueAsUnsigned(DW_AT_call_all_calls, 0);
+ if (!has_call_edges)
+ return {};
+
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ LLDB_LOG(log, "CollectCallEdges: Found call site info in {0}",
+ function_die.GetPubname());
+
+ // Scan the DIE for TAG_call_site entries.
+ // TODO: A recursive scan of all blocks in the subprogram is needed in order
+ // to be DWARF5-compliant. This may need to be done lazily to be performant.
+ // For now, assume that all entries are nested directly under the subprogram
+ // (this is the kind of DWARF LLVM produces) and parse them eagerly.
+ std::vector<CallEdge> call_edges;
+ for (DWARFDIE child = function_die.GetFirstChild(); child.IsValid();
+ child = child.GetSibling()) {
+ if (child.Tag() != DW_TAG_call_site)
+ continue;
+
+ // Extract DW_AT_call_origin (the call target's DIE).
+ DWARFDIE call_origin = child.GetReferencedDIE(DW_AT_call_origin);
+ if (!call_origin.IsValid()) {
+ LLDB_LOG(log, "CollectCallEdges: Invalid call origin in {0}",
+ function_die.GetPubname());
+ continue;
+ }
+
+ LLDB_LOG(log, "CollectCallEdges: Found call origin -> {0}",
+ call_origin.GetPubname());
+ call_edges.emplace_back(call_origin.GetMangledName());
+ }
+ return call_edges;
+}
+
+std::vector<lldb_private::CallEdge>
+SymbolFileDWARF::ParseCallEdgesInFunction(UserID func_id) {
+ DWARFDIE func_die = GetDIEFromUID(func_id.GetID());
+ if (func_die.IsValid())
+ return CollectCallEdges(func_die);
+ return {};
+}
+
//------------------------------------------------------------------
// PluginInterface protocol
//------------------------------------------------------------------
Index: lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/test.sh
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/test.sh
@@ -0,0 +1,13 @@
+#!/bin/bash -x
+
+BIN=/Users/vsk/src/builds/llvm-project-tailcall-RA/bin/
+CXX=$BIN/clang++
+LLDB=$BIN/lldb
+
+for F in $(ls *.cc); do
+ $CXX $F -o $F.out \
+ -g -mllvm -callsite-debuginfo-experimental=true -O2
+
+ xcrun lldb -o "b sink" -o "r" -o "bt" -o "quit" $F.out
+ $LLDB -o "b sink" -o "r" -o "log enable -f $F.log lldb step" -o "bt" -o "quit" $F.out
+done
Index: lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail5.cc
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail5.cc
@@ -0,0 +1,6 @@
+volatile int x;
+void __attribute__((noinline)) sink() { x++; }
+void __attribute__((noinline)) D() { sink(); /* tail */ }
+void __attribute__((disable_tail_calls, noinline)) C() { D(); /* regular */ }
+void __attribute__((noinline)) B() { C(); /* tail */ }
+int __attribute__((disable_tail_calls)) main() { B(); /* regular */ }
Index: lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail4.cc
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail4.cc
@@ -0,0 +1,5 @@
+volatile int x;
+void __attribute__((noinline)) sink() { x++; } // Two possible paths to sink.
+void __attribute__((noinline)) foo() { sink(); /* tail */ }
+void __attribute__((noinline)) bar() { sink(); /* tail */ }
+int __attribute__((disable_tail_calls)) main() { foo(); bar(); /* regular */ }
Index: lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail3.cc
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail3.cc
@@ -0,0 +1,5 @@
+volatile int x;
+void __attribute__((noinline)) sink() { x++; }
+void __attribute__((disable_tail_calls, noinline)) bar() { sink(); /* regular */ }
+void __attribute__((noinline)) foo() { bar(); /* tail */ }
+int __attribute__((disable_tail_calls)) main() { foo(); /* regular */ }
Index: lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail2.cc
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail2.cc
@@ -0,0 +1,8 @@
+volatile int x;
+void __attribute__((noinline)) sink() { x++; }
+void __attribute__((noinline)) bar() { x++; }
+void __attribute__((noinline)) foo() {
+ bar(); /* tail */
+ sink(); /* tail */
+}
+int __attribute__((disable_tail_calls)) main() { foo(); /* regular */}
Index: lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail.cc
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/functionalities/tail_call_frames/tail.cc
@@ -0,0 +1,20 @@
+volatile int x;
+
+void __attribute__((noinline)) sink() {
+ // The stack just contains a return address inside of main().
+ //
+ // Note that it wouldn't be possible to disambiguate sink() from another
+ // immediate callee of bar() without DW_AT_return_pc.
+ x++;
+}
+
+void __attribute__((noinline)) bar() {
+ // Note that no return address in sink() is pushed onto the stack.
+ sink(); // tail (`jmp _sink`)
+}
+
+int main() {
+ bar(); // tail (`callq _bar`)
+ bar(); // tail (`callq _bar`)
+ return 0;
+}
Index: lldb/include/lldb/Target/StackFrameList.h
===================================================================
--- lldb/include/lldb/Target/StackFrameList.h
+++ lldb/include/lldb/Target/StackFrameList.h
@@ -99,6 +99,8 @@
void GetOnlyConcreteFramesUpTo(uint32_t end_idx, Unwind *unwinder);
+ void SynthesizeTailCallFrames(StackFrame &next_frame);
+
bool GetAllFramesFetched() { return m_concrete_frames_fetched == UINT32_MAX; }
void SetAllFramesFetched() { m_concrete_frames_fetched = UINT32_MAX; }
Index: lldb/include/lldb/Target/StackFrame.h
===================================================================
--- lldb/include/lldb/Target/StackFrame.h
+++ lldb/include/lldb/Target/StackFrame.h
@@ -412,6 +412,11 @@
//------------------------------------------------------------------
uint32_t GetFrameIndex() const;
+ //------------------------------------------------------------------
+ /// Set this frame's synthetic frame index.
+ //------------------------------------------------------------------
+ void SetFrameIndex(uint32_t index) { m_frame_index = index; }
+
//------------------------------------------------------------------
/// Query this frame to find what frame it is in this Thread's
/// StackFrameList, not counting inlined frames.
Index: lldb/include/lldb/Symbol/SymbolFile.h
===================================================================
--- lldb/include/lldb/Symbol/SymbolFile.h
+++ lldb/include/lldb/Symbol/SymbolFile.h
@@ -14,6 +14,7 @@
#include "lldb/Symbol/CompilerDecl.h"
#include "lldb/Symbol/CompilerDeclContext.h"
#include "lldb/Symbol/CompilerType.h"
+#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/Type.h"
#include "lldb/lldb-private.h"
@@ -194,6 +195,10 @@
ObjectFile *GetObjectFile() { return m_obj_file; }
const ObjectFile *GetObjectFile() const { return m_obj_file; }
+ virtual std::vector<CallEdge> ParseCallEdgesInFunction(UserID func_id) {
+ return {};
+ }
+
//------------------------------------------------------------------
/// Notify the SymbolFile that the file addresses in the Sections
/// for this module have been changed.
Index: lldb/include/lldb/Symbol/Function.h
===================================================================
--- lldb/include/lldb/Symbol/Function.h
+++ lldb/include/lldb/Symbol/Function.h
@@ -16,6 +16,7 @@
#include "lldb/Symbol/Block.h"
#include "lldb/Symbol/Declaration.h"
#include "lldb/Utility/UserID.h"
+#include "llvm/ADT/ArrayRef.h"
namespace lldb_private {
@@ -290,6 +291,35 @@
Declaration m_call_decl;
};
+class Function;
+
+//----------------------------------------------------------------------
+/// @class CallEdge Function.h "lldb/Symbol/Function.h"
+///
+/// Represent a call made within a Function. This can be used to find a path
+/// in the call graph between two functions.
+//----------------------------------------------------------------------
+class CallEdge {
+ /// Whether or not an attempt was made to find the callee's definition.
+ bool resolved;
+
+ union {
+ const char *mangled_name; //< The mangled name of the callee.
+ Function *callee; //< The definition of the callee.
+ } lazy_target;
+
+ // TODO: Include the call return PC address here to disambiguate multiple
+ // paths from a caller to a leaf function.
+
+public:
+ CallEdge(const char *mangled_name);
+
+ /// Get the callee's definition.
+ ///
+ /// Note that this might lazily invoke the DWARF parser.
+ Function *GetCallee(ModuleList &images);
+};
+
//----------------------------------------------------------------------
/// @class Function Function.h "lldb/Symbol/Function.h"
/// A class that describes a function.
@@ -396,6 +426,13 @@
//------------------------------------------------------------------
void GetEndLineSourceInfo(FileSpec &source_file, uint32_t &line_no);
+ //------------------------------------------------------------------
+ /// Get the outgoing call edges from this function.
+ ///
+ /// @return An immutable array reference with the same lifetime as `this`.
+ //------------------------------------------------------------------
+ llvm::ArrayRef<CallEdge> GetCallEdges();
+
//------------------------------------------------------------------
/// Get accessor for the block list.
///
@@ -587,6 +624,10 @@
Flags m_flags;
uint32_t
m_prologue_byte_size; ///< Compute the prologue size once and cache it
+
+ bool m_call_edges_resolved = false; ///< Whether call site info has been
+ /// parsed.
+ std::vector<CallEdge> m_call_edges; ///< Outgoing call edges.
private:
DISALLOW_COPY_AND_ASSIGN(Function);
};
Index: lldb/include/lldb/Symbol/Block.h
===================================================================
--- lldb/include/lldb/Symbol/Block.h
+++ lldb/include/lldb/Symbol/Block.h
@@ -327,6 +327,14 @@
return m_inlineInfoSP.get();
}
+ //------------------------------------------------------------------
+ /// Get the symbol file which contains debug info for this block's
+ /// symbol context module.
+ ///
+ /// @return A pointer to the symbol file or nullptr.
+ //------------------------------------------------------------------
+ SymbolFile *GetSymbolFile();
+
CompilerDeclContext GetDeclContext();
//------------------------------------------------------------------
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