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#include "debug_utils.h"
#include "node_internals.h"
#ifdef __POSIX__
#if defined(__linux__)
#include <features.h>
#endif
#if defined(__linux__) && !defined(__GLIBC__) || \
defined(__UCLIBC__) || \
defined(_AIX)
#define HAVE_EXECINFO_H 0
#else
#define HAVE_EXECINFO_H 1
#endif
#if HAVE_EXECINFO_H
#include <cxxabi.h>
#include <dlfcn.h>
#include <execinfo.h>
#include <unistd.h>
#include <sys/mman.h>
#include <stdio.h>
#endif
#else // __POSIX__
#include <windows.h>
#include <dbghelp.h>
#endif // __POSIX__
namespace node {
#ifdef __POSIX__
#if HAVE_EXECINFO_H
class PosixSymbolDebuggingContext final : public NativeSymbolDebuggingContext {
public:
PosixSymbolDebuggingContext() : pagesize_(getpagesize()) { }
SymbolInfo LookupSymbol(void* address) override {
Dl_info info;
const bool have_info = dladdr(address, &info);
SymbolInfo ret;
if (!have_info)
return ret;
if (info.dli_sname != nullptr) {
if (char* demangled = abi::__cxa_demangle(info.dli_sname, 0, 0, 0)) {
ret.name = demangled;
free(demangled);
} else {
ret.name = info.dli_sname;
}
}
if (info.dli_fname != nullptr) {
ret.filename = info.dli_fname;
}
return ret;
}
bool IsMapped(void* address) override {
void* page_aligned = reinterpret_cast<void*>(
reinterpret_cast<uintptr_t>(address) & ~(pagesize_ - 1));
return msync(page_aligned, pagesize_, MS_ASYNC) == 0;
}
int GetStackTrace(void** frames, int count) override {
return backtrace(frames, count);
}
private:
uintptr_t pagesize_;
};
std::unique_ptr<NativeSymbolDebuggingContext>
NativeSymbolDebuggingContext::New() {
return std::unique_ptr<NativeSymbolDebuggingContext>(
new PosixSymbolDebuggingContext());
}
#else // HAVE_EXECINFO_H
std::unique_ptr<NativeSymbolDebuggingContext>
NativeSymbolDebuggingContext::New() {
return std::unique_ptr<NativeSymbolDebuggingContext>(
new NativeSymbolDebuggingContext());
}
#endif // HAVE_EXECINFO_H
#else // __POSIX__
class Win32SymbolDebuggingContext final : public NativeSymbolDebuggingContext {
public:
Win32SymbolDebuggingContext() {
current_process_ = GetCurrentProcess();
USE(SymInitialize(current_process_, nullptr, true));
}
~Win32SymbolDebuggingContext() {
USE(SymCleanup(current_process_));
}
SymbolInfo LookupSymbol(void* address) override {
// Ref: https://msdn.microsoft.com/en-en/library/windows/desktop/ms680578(v=vs.85).aspx
char info_buf[sizeof(SYMBOL_INFO) + MAX_SYM_NAME];
SYMBOL_INFO* info = reinterpret_cast<SYMBOL_INFO*>(info_buf);
char demangled[MAX_SYM_NAME];
info->MaxNameLen = MAX_SYM_NAME;
info->SizeOfStruct = sizeof(SYMBOL_INFO);
SymbolInfo ret;
const bool have_info = SymFromAddr(current_process_,
reinterpret_cast<DWORD64>(address),
nullptr,
info);
if (have_info && strlen(info->Name) == 0) {
if (UnDecorateSymbolName(info->Name,
demangled,
sizeof(demangled),
UNDNAME_COMPLETE)) {
ret.name = demangled;
} else {
ret.name = info->Name;
}
}
return ret;
}
bool IsMapped(void* address) override {
MEMORY_BASIC_INFORMATION info;
if (VirtualQuery(address, &info, sizeof(info)) != sizeof(info))
return false;
return info.State == MEM_COMMIT && info.Protect != 0;
}
int GetStackTrace(void** frames, int count) override {
return CaptureStackBackTrace(0, count, frames, nullptr);
}
private:
HANDLE current_process_;
};
std::unique_ptr<NativeSymbolDebuggingContext>
NativeSymbolDebuggingContext::New() {
return std::unique_ptr<NativeSymbolDebuggingContext>(
new Win32SymbolDebuggingContext());
}
#endif // __POSIX__
std::string NativeSymbolDebuggingContext::SymbolInfo::Display() const {
std::string ret = name;
if (!filename.empty()) {
ret += " [";
ret += filename;
ret += ']';
}
return ret;
}
void DumpBacktrace(FILE* fp) {
auto sym_ctx = NativeSymbolDebuggingContext::New();
void* frames[256];
const int size = sym_ctx->GetStackTrace(frames, arraysize(frames));
for (int i = 1; i < size; i += 1) {
void* frame = frames[i];
fprintf(fp, "%2d: %p %s\n",
i, frame, sym_ctx->LookupSymbol(frame).Display().c_str());
}
}
void CheckedUvLoopClose(uv_loop_t* loop) {
if (uv_loop_close(loop) == 0) return;
auto sym_ctx = NativeSymbolDebuggingContext::New();
fprintf(stderr, "uv loop at [%p] has active handles\n", loop);
uv_walk(loop, [](uv_handle_t* handle, void* arg) {
auto sym_ctx = static_cast<NativeSymbolDebuggingContext*>(arg);
fprintf(stderr, "[%p] %s\n", handle, uv_handle_type_name(handle->type));
void* close_cb = reinterpret_cast<void*>(handle->close_cb);
fprintf(stderr, "\tClose callback: %p %s\n",
close_cb, sym_ctx->LookupSymbol(close_cb).Display().c_str());
fprintf(stderr, "\tData: %p %s\n",
handle->data, sym_ctx->LookupSymbol(handle->data).Display().c_str());
// We are also interested in the first field of what `handle->data`
// points to, because for C++ code that is usually the virtual table pointer
// and gives us information about the exact kind of object we're looking at.
void* first_field = nullptr;
// `handle->data` might be any value, including `nullptr`, or something
// cast from a completely different type; therefore, check that it’s
// dereferencable first.
if (sym_ctx->IsMapped(handle->data))
first_field = *reinterpret_cast<void**>(handle->data);
if (first_field != nullptr) {
fprintf(stderr, "\t(First field): %p %s\n",
first_field, sym_ctx->LookupSymbol(first_field).Display().c_str());
}
}, sym_ctx.get());
fflush(stderr);
// Finally, abort.
CHECK(0 && "uv_loop_close() while having open handles");
}
} // namespace node
extern "C" void __DumpBacktrace(FILE* fp) {
node::DumpBacktrace(fp);
}
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