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[lldb] Load embedded type summary section (#7859) (#8040) #113743

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[lldb] Load embedded type summary section (#7859) (#8040) #113743

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1 change: 1 addition & 0 deletions lldb/include/lldb/lldb-enumerations.h
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Expand Up @@ -761,6 +761,7 @@ enum SectionType {
eSectionTypeDWARFDebugLocListsDwo,
eSectionTypeDWARFDebugTuIndex,
eSectionTypeCTF,
eSectionTypeLLDBTypeSummaries,
eSectionTypeSwiftModules,
};

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3 changes: 3 additions & 0 deletions lldb/source/Core/Section.cpp
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Expand Up @@ -147,6 +147,8 @@ const char *Section::GetTypeAsCString() const {
return "dwarf-gnu-debugaltlink";
case eSectionTypeCTF:
return "ctf";
case eSectionTypeLLDBTypeSummaries:
return "lldb-type-summaries";
case eSectionTypeOther:
return "regular";
case eSectionTypeSwiftModules:
Expand Down Expand Up @@ -457,6 +459,7 @@ bool Section::ContainsOnlyDebugInfo() const {
case eSectionTypeDWARFAppleObjC:
case eSectionTypeDWARFGNUDebugAltLink:
case eSectionTypeCTF:
case eSectionTypeLLDBTypeSummaries:
case eSectionTypeSwiftModules:
return true;
}
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1 change: 1 addition & 0 deletions lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
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Expand Up @@ -1678,6 +1678,7 @@ static SectionType GetSectionTypeFromName(llvm::StringRef Name) {
.Case(".gnu_debugaltlink", eSectionTypeDWARFGNUDebugAltLink)
.Case(".gosymtab", eSectionTypeGoSymtab)
.Case(".text", eSectionTypeCode)
.Case(".lldbsummaries", lldb::eSectionTypeLLDBTypeSummaries)
.Case(".swift_ast", eSectionTypeSwiftModules)
.Default(eSectionTypeOther);
}
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4 changes: 4 additions & 0 deletions lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
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Expand Up @@ -1209,6 +1209,7 @@ AddressClass ObjectFileMachO::GetAddressClass(lldb::addr_t file_addr) {
case eSectionTypeDWARFAppleObjC:
case eSectionTypeDWARFGNUDebugAltLink:
case eSectionTypeCTF:
case eSectionTypeLLDBTypeSummaries:
case eSectionTypeSwiftModules:
return AddressClass::eDebug;

Expand Down Expand Up @@ -1484,6 +1485,7 @@ static lldb::SectionType GetSectionType(uint32_t flags,
static ConstString g_sect_name_data("__data");
static ConstString g_sect_name_go_symtab("__gosymtab");
static ConstString g_sect_name_ctf("__ctf");
static ConstString g_sect_name_lldb_summaries("__lldbsummaries");
static ConstString g_sect_name_swift_ast("__swift_ast");

if (section_name == g_sect_name_dwarf_debug_abbrev)
Expand Down Expand Up @@ -1564,6 +1566,8 @@ static lldb::SectionType GetSectionType(uint32_t flags,
return eSectionTypeGoSymtab;
if (section_name == g_sect_name_ctf)
return eSectionTypeCTF;
if (section_name == g_sect_name_lldb_summaries)
return lldb::eSectionTypeLLDBTypeSummaries;
if (section_name == g_sect_name_swift_ast)
return eSectionTypeSwiftModules;
if (section_name == g_sect_name_objc_data ||
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1 change: 1 addition & 0 deletions lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
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Expand Up @@ -1010,6 +1010,7 @@ SectionType ObjectFilePECOFF::GetSectionType(llvm::StringRef sect_name,
// .eh_frame can be truncated to 8 chars.
.Cases(".eh_frame", ".eh_fram", eSectionTypeEHFrame)
.Case(".gosymtab", eSectionTypeGoSymtab)
.Case(".lldbsummaries", lldb::eSectionTypeLLDBTypeSummaries)
.Case("swiftast", eSectionTypeSwiftModules)
.Default(eSectionTypeInvalid);
if (section_type != eSectionTypeInvalid)
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1 change: 1 addition & 0 deletions lldb/source/Symbol/ObjectFile.cpp
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Expand Up @@ -366,6 +366,7 @@ AddressClass ObjectFile::GetAddressClass(addr_t file_addr) {
case eSectionTypeDWARFAppleObjC:
case eSectionTypeDWARFGNUDebugAltLink:
case eSectionTypeCTF:
case eSectionTypeLLDBTypeSummaries:
case eSectionTypeSwiftModules:
return AddressClass::eDebug;
case eSectionTypeEHFrame:
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72 changes: 72 additions & 0 deletions lldb/source/Target/Target.cpp
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Expand Up @@ -26,6 +26,7 @@
#include "lldb/Core/StructuredDataImpl.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/DataFormatters/DataVisualization.h"
#include "lldb/Expression/DiagnosticManager.h"
#include "lldb/Expression/ExpressionVariable.h"
#include "lldb/Expression/REPL.h"
Expand Down Expand Up @@ -1537,6 +1538,76 @@ static void LoadScriptingResourceForModule(const ModuleSP &module_sp,
feedback_stream.GetData());
}

// Load type summaries embedded in the binary. These are type summaries provided
// by the authors of the code.
static void LoadTypeSummariesForModule(ModuleSP module_sp) {
auto *sections = module_sp->GetSectionList();
if (!sections)
return;

auto summaries_sp =
sections->FindSectionByType(eSectionTypeLLDBTypeSummaries, true);
if (!summaries_sp)
return;

Log *log = GetLog(LLDBLog::DataFormatters);
const char *module_name = module_sp->GetObjectName().GetCString();

TypeCategoryImplSP category;
DataVisualization::Categories::GetCategory(ConstString("default"), category);

// The type summary record is serialized as follows.
//
// Each record contains, in order:
// * Version number of the record format
// * The remaining size of the record
// * The size of the type identifier
// * The type identifier, either a type name, or a regex
// * The size of the summary string
// * The summary string
//
// Integers are encoded using ULEB.
//
// Strings are encoded with first a length (ULEB), then the string contents,
// and lastly a null terminator. The length includes the null.

DataExtractor extractor;
auto section_size = summaries_sp->GetSectionData(extractor);
lldb::offset_t offset = 0;
while (offset < section_size) {
uint64_t version = extractor.GetULEB128(&offset);
uint64_t record_size = extractor.GetULEB128(&offset);
if (version == 1) {
uint64_t type_size = extractor.GetULEB128(&offset);
llvm::StringRef type_name = extractor.GetCStr(&offset, type_size);
uint64_t summary_size = extractor.GetULEB128(&offset);
llvm::StringRef summary_string = extractor.GetCStr(&offset, summary_size);
if (!type_name.empty() && !summary_string.empty()) {
TypeSummaryImpl::Flags flags;
auto summary_sp =
std::make_shared<StringSummaryFormat>(flags, summary_string.data());
FormatterMatchType match_type = eFormatterMatchExact;
if (summary_string.front() == '^' && summary_string.back() == '$')
match_type = eFormatterMatchRegex;
category->AddTypeSummary(type_name, match_type, summary_sp);
LLDB_LOGF(log, "Loaded embedded type summary for '%s' from %s.",
type_name.data(), module_name);
} else {
if (type_name.empty())
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Should this log message always be printed? It looks like you have to have both strings so if you get to the else, one of them is empty. This will only log if one of them is empty but not the other one.

Might as well put in what strings they are too. "Missing type or summary string in....".

LLDB_LOGF(log, "Missing string(s) in embedded type summary in %s.",
module_name);
}
} else {
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Could if version != 1: continue instead of putting this at the end of the loop.

Also you could if (type_name.empty() || summary_string.empty()): log(whatever); continue; to again exit this iteration early.

// Skip unsupported record.
offset += record_size;
LLDB_LOGF(
log,
"Skipping unsupported embedded type summary of version %llu in %s.",
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Use the PRIu64 and other generic 64 bit printf options so that I don't have to fix a warning on Arm 32 bit later :)

version, module_name);
}
}
}

void Target::ClearModules(bool delete_locations) {
ModulesDidUnload(m_images, delete_locations);
m_section_load_history.Clear();
Expand Down Expand Up @@ -1775,6 +1846,7 @@ void Target::ModulesDidLoad(ModuleList &module_list) {
for (size_t idx = 0; idx < num_images; ++idx) {
ModuleSP module_sp(module_list.GetModuleAtIndex(idx));
LoadScriptingResourceForModule(module_sp, this);
LoadTypeSummariesForModule(module_sp);
}
m_breakpoint_list.UpdateBreakpoints(module_list, true, false);
m_internal_breakpoint_list.UpdateBreakpoints(module_list, true, false);
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2 changes: 2 additions & 0 deletions lldb/test/API/functionalities/data-formatter/embedded-summary/Makefile
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@@ -0,0 +1,2 @@
C_SOURCES := main.c
include Makefile.rules
12 changes: 12 additions & 0 deletions lldb/test/API/functionalities/data-formatter/embedded-summary/TestEmbeddedTypeSummary.py
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@@ -0,0 +1,12 @@
import lldb
from lldbsuite.test.decorators import *
from lldbsuite.test.lldbtest import *
from lldbsuite.test import lldbutil


class TestCase(TestBase):
@skipUnlessDarwin
def test(self):
self.build()
lldbutil.run_to_source_breakpoint(self, "break here", lldb.SBFileSpec("main.c"))
self.expect("v player", substrs=['"Dirk" (41)'])
22 changes: 22 additions & 0 deletions lldb/test/API/functionalities/data-formatter/embedded-summary/main.c
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@@ -0,0 +1,22 @@
#include <stdio.h>

struct Player {
char *name;
int number;
};

__attribute__((used, section("__DATA_CONST,__lldbsummaries"))) unsigned char
_Player_type_summary[] = "\x01" // version
"\x25" // record size
"\x07" // type name size
"Player\0" // type name
"\x1c" // summary string size
"${var.name} (${var.number})"; // summary string

int main() {
struct Player player;
player.name = "Dirk";
player.number = 41;
puts("break here");
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Does this actually show up in the logs? If so return 0 // break here would be a bit more tidy.

return 0;
}
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