/**
* =========================================================================
* File : wdbg_sym.cpp
* Project : 0 A.D.
* Description : Win32 stack trace and symbol engine.
* =========================================================================
*/
// license: GPL; see lib/license.txt
#include "precompiled.h"
#include "wdbg_sym.h"
#include <stdlib.h>
#include <stdio.h>
#include <set>
#include "lib/byte_order.h"
#include "lib/sysdep/cpu.h"
#include "lib/debug_stl.h"
#include "lib/app_hooks.h"
#include "lib/path_util.h"
#if CPU_IA32
#include "lib/sysdep/ia32/ia32.h"
#endif
#include "win.h"
#include "winit.h"
#include "wutil.h"
#define _NO_CVCONST_H // request SymTagEnum be defined
#include <dbghelp.h> // must come after win_internal
#include <OAIdl.h> // VARIANT
#if MSC_VERSION
#pragma comment(lib, "dbghelp.lib")
#pragma comment(lib, "oleaut32.lib") // VariantChangeType
#endif
WINIT_REGISTER_MAIN_INIT(wdbg_sym_Init);
WINIT_REGISTER_MAIN_SHUTDOWN(wdbg_sym_Shutdown);
// note: it is safe to use debug_assert/debug_warn/CHECK_ERR even during a
// stack trace (which is triggered by debug_assert et al. in app code) because
// nested stack traces are ignored and only the error is displayed.
// protects the non-reentrant dbghelp library.
static void lock()
{
win_lock(WDBG_SYM_CS);
}
static void unlock()
{
win_unlock(WDBG_SYM_CS);
}
//----------------------------------------------------------------------------
// dbghelp
//----------------------------------------------------------------------------
// passed to all dbghelp symbol query functions. we're not interested in
// resolving symbols in other processes; the purpose here is only to
// generate a stack trace. if that changes, we need to init a local copy
// of these in dump_sym_cb and pass them to all subsequent dump_*.
static HANDLE hProcess;
static ULONG64 mod_base;
// for StackWalk64; taken from PE header by wdbg_init.
static WORD machine;
// call on-demand (allows handling exceptions raised before win.cpp
// init functions are called); no effect if already initialized.
static LibError sym_init()
{
// bail if already initialized (there's nothing to do).
// don't use pthread_once because we need to return success/error code.
static uintptr_t already_initialized = 0;
if(!CAS(&already_initialized, 0, 1))
return INFO::OK;
hProcess = GetCurrentProcess();
// set options
// notes:
// - can be done before SymInitialize; we do so in case
// any of the options affect it.
// - do not set directly - that would zero any existing flags.
DWORD opts = SymGetOptions();
opts |= SYMOPT_DEFERRED_LOADS; // the "fastest, most efficient way"
//opts |= SYMOPT_DEBUG; // lots of debug spew in output window
SymSetOptions(opts);
// initialize dbghelp.
// .. request symbols from all currently active modules be loaded.
const BOOL fInvadeProcess = TRUE;
// .. use default *symbol* search path. we don't use this to locate
// our PDB file because its absolute path is stored inside the EXE.
PCSTR UserSearchPath = 0;
BOOL ok = SymInitialize(hProcess, UserSearchPath, fInvadeProcess);
WARN_IF_FALSE(ok);
mod_base = SymGetModuleBase64(hProcess, (u64)&sym_init);
IMAGE_NT_HEADERS* header = ImageNtHeader((void*)mod_base);
machine = header->FileHeader.Machine;
return INFO::OK;
}
// called from wdbg_sym_Shutdown.
static LibError sym_shutdown()
{
SymCleanup(hProcess);
return INFO::OK;
}
struct SYMBOL_INFO_PACKAGEW2 : public SYMBOL_INFO_PACKAGEW
{
SYMBOL_INFO_PACKAGEW2()
{
si.SizeOfStruct = sizeof(si);
si.MaxNameLen = MAX_SYM_NAME;
}
};
// note: we can't derive from TI_FINDCHILDREN_PARAMS because its members
// aren't guaranteed to precede ours (although they do in practice).
struct TI_FINDCHILDREN_PARAMS2
{
TI_FINDCHILDREN_PARAMS2(DWORD num_children)
{
p.Start = 0;
p.Count = std::min(num_children, MAX_CHILDREN);
}
static const DWORD MAX_CHILDREN = 400;
TI_FINDCHILDREN_PARAMS p;
DWORD additional_children[MAX_CHILDREN-1];
};
// actual implementation; made available so that functions already under
// the lock don't have to unlock (slow) to avoid recursive locking.
static LibError debug_resolve_symbol_lk(void* ptr_of_interest, char* sym_name, char* file, int* line)
{
sym_init();
const DWORD64 addr = (DWORD64)ptr_of_interest;
int successes = 0;
// get symbol name (if requested)
if(sym_name)
{
sym_name[0] = '\0';
SYMBOL_INFO_PACKAGEW2 sp;
SYMBOL_INFOW* sym = &sp.si;
if(SymFromAddrW(hProcess, addr, 0, sym))
{
snprintf(sym_name, DBG_SYMBOL_LEN, "%ws", sym->Name);
successes++;
}
}
// get source file and/or line number (if requested)
if(file || line)
{
file[0] = '\0';
*line = 0;
IMAGEHLP_LINE64 line_info = { sizeof(IMAGEHLP_LINE64) };
DWORD displacement; // unused but required by SymGetLineFromAddr64!
if(SymGetLineFromAddr64(hProcess, addr, &displacement, &line_info))
{
if(file)
{
// strip full path down to base name only.
// this loses information, but that isn't expected to be a
// problem and is balanced by not having to do this from every
// call site (full path is too long to display nicely).
const char* base_name = path_name_only(line_info.FileName);
snprintf(file, DBG_FILE_LEN, "%s", base_name);
successes++;
}
if(line)
{
*line = line_info.LineNumber;
successes++;
}
}
}
return (successes != 0)? INFO::OK : ERR::FAIL;
}
// read and return symbol information for the given address. all of the
// output parameters are optional; we pass back as much information as is
// available and desired. return 0 iff any information was successfully
// retrieved and stored.
// sym_name and file must hold at least the number of chars above;
// file is the base name only, not path (see rationale in wdbg_sym).
// the PDB implementation is rather slow (~500µs).
LibError debug_resolve_symbol(void* ptr_of_interest, char* sym_name, char* file, int* line)
{
lock();
LibError ret = debug_resolve_symbol_lk(ptr_of_interest, sym_name, file, line);
unlock();
return ret;
}
//----------------------------------------------------------------------------
// stack walk
//----------------------------------------------------------------------------
static VOID (*pRtlCaptureContext)(PCONTEXT*);
/*
Subroutine linkage example code:
push param2
push param1
call func
ret_addr:
[..]
func:
push ebp
mov ebp, esp
sub esp, local_size
[..]
Stack contents (down = decreasing address)
[param2]
[param1]
ret_addr
prev_ebp (<- current ebp points at this value)
[local_variables]
*/
/*
call func1
ret1:
func1:
push ebp
mov ebp, esp
call func2
ret2:
func2:
push ebp
mov ebp, esp
STARTHERE
*/
#if CPU_IA32 && !CONFIG_OMIT_FP
static LibError ia32_walk_stack(STACKFRAME64* sf)
{
// read previous values from STACKFRAME64
void* prev_fp = (void*)sf->AddrFrame .Offset;
void* prev_ip = (void*)sf->AddrPC .Offset;
void* prev_ret = (void*)sf->AddrReturn.Offset;
if(!debug_is_stack_ptr(prev_fp))
WARN_RETURN(ERR::_11);
if(prev_ip && !debug_is_code_ptr(prev_ip))
WARN_RETURN(ERR::_12);
if(prev_ret && !debug_is_code_ptr(prev_ret))
WARN_RETURN(ERR::_13);
// read stack frame
void* fp = ((void**)prev_fp)[0];
void* ret_addr = ((void**)prev_fp)[1];
if(!fp)
return INFO::ALL_COMPLETE;
if(!debug_is_stack_ptr(fp))
WARN_RETURN(ERR::_14);
if(!debug_is_code_ptr(ret_addr))
WARN_RETURN(ERR::_15);
void* target;
LibError err = ia32_GetCallTarget(ret_addr, &target);
RETURN_ERR(err);
if(target) // were able to determine it from the call instruction
debug_assert(debug_is_code_ptr(target));
sf->AddrFrame .Offset = (DWORD64)fp;
sf->AddrPC .Offset = (DWORD64)target;
sf->AddrReturn.Offset = (DWORD64)ret_addr;
return INFO::OK;
}
#endif // #if CPU_IA32 && !CONFIG_OMIT_FP
// called for each stack frame found by walk_stack, passing information
// about the frame and <user_arg>.
// return INFO::CB_CONTINUE to continue, anything else to stop immediately
// and return that value to walk_stack's caller.
//
// rationale: we can't just pass function's address to the callback -
// dump_frame_cb needs the frame pointer for reg-relative variables.
typedef LibError (*StackFrameCallback)(const STACKFRAME64*, void*);
static void skip_this_frame(uint& skip, void* context)
{
if(!context)
skip++;
}
// iterate over a call stack, calling back for each frame encountered.
// if <pcontext> != 0, we start there; otherwise, at the current context.
// return an error if callback never succeeded (returned 0).
//
// lock must be held.
static LibError walk_stack(StackFrameCallback cb, void* user_arg = 0, uint skip = 0, const CONTEXT* pcontext = 0)
{
// to function properly, StackWalk64 requires a CONTEXT on
// non-x86 systems (documented) or when in release mode (observed).
// exception handlers can call walk_stack with their context record;
// otherwise (e.g. dump_stack from debug_assert), we need to query it.
CONTEXT context;
// .. caller knows the context (most likely from an exception);
// since StackWalk64 may modify it, copy to a local variable.
if(pcontext)
context = *pcontext;
// .. need to determine context ourselves.
else
{
skip_this_frame(skip, (void*)pcontext);
// there are 4 ways to do so, in order of preference:
// - asm (easy to use but currently only implemented on IA32)
// - RtlCaptureContext (only available on WinXP or above)
// - intentionally raise an SEH exception and capture its context
// (spams us with "first chance exception")
// - GetThreadContext while suspended* (a bit tricky + slow).
//
// * it used to be common practice to query the current thread's context,
// but WinXP SP2 and above require it be suspended.
//
// this MUST be done inline and not in an external function because
// compiler-generated prolog code trashes some registers.
#if CPU_IA32
ia32_asm_GetCurrentContext(&context);
#else
// preferred implementation (was imported during module init)
if(pRtlCaptureContext)
pRtlCaptureContext(&context);
// not available: raise+handle an exception; grab the reported context.
else
{
__try
{
RaiseException(0xF001, 0, 0, 0);
}
__except(context = (GetExceptionInformation())->ContextRecord, EXCEPTION_CONTINUE_EXECUTION)
{
}
}
#endif
}
pcontext = &context;
STACKFRAME64 sf;
memset(&sf, 0, sizeof(sf));
sf.AddrPC.Offset = pcontext->PC_;
sf.AddrPC.Mode = AddrModeFlat;
sf.AddrFrame.Offset = pcontext->FP_;
sf.AddrFrame.Mode = AddrModeFlat;
sf.AddrStack.Offset = pcontext->SP_;
sf.AddrStack.Mode = AddrModeFlat;
// for each stack frame found:
LibError ret = ERR::SYM_NO_STACK_FRAMES_FOUND;
for(;;)
{
// rationale:
// - provide a separate ia32 implementation so that simple
// stack walks (e.g. to determine callers of malloc) do not
// require firing up dbghelp. that takes tens of seconds when
// OS symbols are installed (because symserv is wanting to access
// inet), which is entirely unacceptable.
// - VC7.1 sometimes generates stack frames despite /Oy ;
// ia32_walk_stack may appear to work, but it isn't reliable in
// this case and therefore must not be used!
// - don't switch between ia32_stack_walk and StackWalk64 when one
// of them fails: this needlessly complicates things. the ia32
// code is authoritative provided its prerequisite (FP not omitted)
// is met, otherwise totally unusable.
LibError err;
#if CPU_IA32 && !CONFIG_OMIT_FP
err = ia32_walk_stack(&sf);
#else
sym_init();
// note: unfortunately StackWalk64 doesn't always SetLastError,
// so we have to reset it and check for 0. *sigh*
SetLastError(0);
const HANDLE hThread = GetCurrentThread();
BOOL ok = StackWalk64(machine, hProcess, hThread, &sf, (PVOID)pcontext,
0, SymFunctionTableAccess64, SymGetModuleBase64, 0);
// note: don't use LibError_from_win32 because it raises a warning,
// and this "fails" commonly (when no stack frames are left).
err = ok? INFO::OK : ERR::FAIL;
#endif
// no more frames found - abort. note: also test FP because
// StackWalk64 sometimes erroneously reports success.
void* fp = (void*)(uintptr_t)sf.AddrFrame.Offset;
if(err != INFO::OK || !fp)
return ret;
if(skip)
{
skip--;
continue;
}
ret = cb(&sf, user_arg);
// callback is allowing us to continue
if(ret == INFO::CB_CONTINUE)
ret = INFO::OK; // make sure this is never returned
// callback reports it's done; stop calling it and return that value.
// (can be either success or failure)
else
{
debug_assert(ret <= 0); // shouldn't return > 0
return ret;
}
}
}
//
// get address of Nth function above us on the call stack (uses walk_stack)
//
// called by walk_stack for each stack frame
static LibError nth_caller_cb(const STACKFRAME64* sf, void* user_arg)
{
void** pfunc = (void**)user_arg;
// return its address
*pfunc = (void*)sf->AddrPC.Offset;
return INFO::OK;
}
// return address of the Nth function on the call stack.
// if <context> is nonzero, it is assumed to be a platform-specific
// representation of execution state (e.g. Win32 CONTEXT) and tracing
// starts there; this is useful for exceptions.
// otherwise, tracing starts at the current stack position, and the given
// number of stack frames (i.e. functions) above the caller are skipped.
// used by mmgr to determine what function requested each allocation;
// this is fast enough to allow that.
void* debug_get_nth_caller(uint skip, void* pcontext)
{
lock();
void* func;
skip_this_frame(skip, pcontext);
LibError err = walk_stack(nth_caller_cb, &func, skip, (const CONTEXT*)pcontext);
unlock();
return (err == INFO::OK)? func : 0;
}
//////////////////////////////////////////////////////////////////////////////
//
// helper routines for symbol value dump
//
//////////////////////////////////////////////////////////////////////////////
// overflow is impossible in practice, but check for robustness.
// keep in sync with DumpState.
static const uint MAX_INDIRECTION = 255;
static const uint MAX_LEVEL = 255;
struct DumpState
{
// keep in sync with MAX_* above
uint level : 8;
uint indirection : 8;
DumpState()
{
level = 0;
indirection = 0;
}
};
//----------------------------------------------------------------------------
static size_t out_chars_left;
static bool out_have_warned_of_overflow;
// only do so once until next out_init to avoid flood of messages.
static wchar_t* out_pos;
// some top-level (*) symbols cause tons of output - so much that they may
// single-handedly overflow the buffer (e.g. pointer to a tree of huge UDTs).
// we can't have that, so there is a limit in place as to how much a
// single top-level symbol can output. after that is reached, dumping is
// aborted for that symbol but continues for the subsequent top-level symbols.
//
// this is implemented as follows: dump_sym_cb latches the current output
// position; each dump_sym (through which all symbols go) checks if the
// new position exceeds the limit and aborts if so.
// slight wrinkle: since we don't want each level of UDTs to successively
// realize the limit has been hit and display the error message, we
// return ERR::SYM_SINGLE_SYMBOL_LIMIT once and thereafter INFO::SYM_SUPPRESS_OUTPUT.
//
// * example: local variables, as opposed to child symbols in a UDT.
static wchar_t* out_latched_pos;
static bool out_have_warned_of_limit;
static void out_init(wchar_t* buf, size_t max_chars)
{
out_pos = buf;
out_chars_left = max_chars;
out_have_warned_of_overflow = false;
out_have_warned_of_limit = false;
}
static void out(const wchar_t* fmt, ...)
{
va_list args;
va_start(args, fmt);
int len = vswprintf(out_pos, out_chars_left, fmt, args);
va_end(args);
// success
if(len >= 0)
{
out_pos += len;
// make sure out_chars_left remains nonnegative
if((size_t)len > out_chars_left)
{
debug_warn("apparently wrote more than out_chars_left");
len = (int)out_chars_left;
}
out_chars_left -= len;
}
// no more room left
else
{
// the buffer really is full yet out_chars_left may not be 0
// (since it isn't updated if vswprintf returns -1).
// must be set so subsequent calls don't try to squeeze stuff in.
out_chars_left = 0;
// write a warning into the output buffer (once) so it isn't
// abruptly cut off (which looks like an error)
if(!out_have_warned_of_overflow)
{
out_have_warned_of_overflow = true;
// with the current out_pos / out_chars_left variables, there's
// no way of knowing where the buffer actually ends. no matter;
// we'll just put the warning before out_pos and eat into the
// second newest text.
const wchar_t text[] = L"(no more room in buffer)";
wcscpy(out_pos-ARRAY_SIZE(text), text); // safe
}
}
}
static void out_erase(size_t num_chars)
{
// don't do anything if end of buffer was hit (prevents repeatedly
// scribbling over the last few bytes).
if(out_have_warned_of_overflow)
return;
out_chars_left += (ssize_t)num_chars;
out_pos -= num_chars;
*out_pos = '\0';
// make sure it's 0-terminated in case there is no further output.
}
// (see above)
static void out_latch_pos()
{
out_have_warned_of_limit = false;
out_latched_pos = out_pos;
}
// (see above)
static LibError out_check_limit()
{
if(out_have_warned_of_limit)
return INFO::SYM_SUPPRESS_OUTPUT;
if(out_pos -out_latched_pos > 3000) // ~30 lines
{
out_have_warned_of_limit = true;
return ERR::SYM_SINGLE_SYMBOL_LIMIT; // NOWARN
}
// no limit hit, proceed normally
return INFO::OK;
}
//----------------------------------------------------------------------------
#define INDENT STMT(for(uint i = 0; i <= state.level; i++) out(L" ");)
#define UNINDENT STMT(out_erase((state.level+1)*4);)
// does it look like an ASCII string is located at <addr>?
// set <stride> to 2 to search for WCS-2 strings (of western characters!).
// called by dump_sequence for its string special-case.
//
// algorithm: scan the "string" and count # text chars vs. garbage.
static bool is_string(const u8* p, size_t stride)
{
// note: access violations are caught by dump_sym; output is "?".
int score = 0;
for(;;)
{
// current character is:
const int c = *p & 0xff; // prevent sign extension
p += stride;
// .. text
if(isalnum(c))
score += 5;
// .. end of string
else if(!c)
break;
// .. garbage
else if(!isprint(c))
score -= 4;
// got enough information either way => done.
// (we don't want to unnecessarily scan huge binary arrays)
if(abs(score) >= 10)
break;
}
return (score > 0);
}
// forward decl; called by dump_sequence and some of dump_sym_*.
static LibError dump_sym(DWORD id, const u8* p, DumpState state);
// from cvconst.h
//
// rationale: we don't provide a get_register routine, since only the
// value of FP is known to dump_frame_cb (via STACKFRAME64).
// displaying variables stored in registers is out of the question;
// all we can do is display FP-relative variables.
enum CV_HREG_e
{
CV_REG_EAX = 17,
CV_REG_ECX = 18,
CV_REG_EDX = 19,
CV_REG_EBX = 20,
CV_REG_ESP = 21,
CV_REG_EBP = 22,
CV_REG_ESI = 23,
CV_REG_EDI = 24
};
static const wchar_t* string_for_register(CV_HREG_e reg)
{
switch(reg)
{
case CV_REG_EAX:
return L"eax";
case CV_REG_ECX:
return L"ecx";
case CV_REG_EDX:
return L"edx";
case CV_REG_EBX:
return L"ebx";
case CV_REG_ESP:
return L"esp";
case CV_REG_EBP:
return L"ebp";
case CV_REG_ESI:
return L"esi";
case CV_REG_EDI:
return L"edi";
default:
{
static wchar_t buf[19];
swprintf(buf, ARRAY_SIZE(buf), L"0x%x", reg);
return buf;
}
}
}
static void dump_error(LibError err, const u8* p)
{
switch(err)
{
case 0:
// no error => no output
break;
case ERR::SYM_SINGLE_SYMBOL_LIMIT:
out(L"(too much output; skipping to next top-level symbol)");
break;
case ERR::SYM_UNRETRIEVABLE_STATIC:
out(L"(unavailable - located in another module)");
break;
case ERR::SYM_UNRETRIEVABLE_REG:
out(L"(unavailable - stored in register %s)", string_for_register((CV_HREG_e)(uintptr_t)p));
break;
case ERR::SYM_TYPE_INFO_UNAVAILABLE:
out(L"(unavailable - type info request failed (GLE=%d))", GetLastError());
break;
case ERR::SYM_INTERNAL_ERROR:
out(L"(unavailable - internal error)\r\n");
break;
case INFO::SYM_SUPPRESS_OUTPUT:
// not an error; do not output anything. handled by caller.
break;
default:
out(L"(unavailable - unspecified error 0x%X (%d))", err, err);
break;
}
}
// split out of dump_sequence.
static LibError dump_string(const u8* p, size_t el_size)
{
// not char or wchar_t string
if(el_size != sizeof(char) && el_size != sizeof(wchar_t))
return INFO::CANNOT_HANDLE;
// not text
if(!is_string(p, el_size))
return INFO::CANNOT_HANDLE;
wchar_t buf[512];
if(el_size == sizeof(wchar_t))
wcscpy_s(buf, ARRAY_SIZE(buf), (const wchar_t*)p);
// convert to wchar_t
else
{
size_t i;
for(i = 0; i < ARRAY_SIZE(buf)-1; i++)
{
buf[i] = (wchar_t)p[i];
if(buf[i] == '\0')
break;
}
buf[i] = '\0';
}
out(L"\"%s\"", buf);
return INFO::OK;
}
// split out of dump_sequence.
static void seq_determine_formatting(size_t el_size, size_t el_count,
bool* fits_on_one_line, size_t* num_elements_to_show)
{
if(el_size == sizeof(char))
{
*fits_on_one_line = el_count <= 16;
*num_elements_to_show = std::min(16u, el_count);
}
else if(el_size <= sizeof(int))
{
*fits_on_one_line = el_count <= 8;
*num_elements_to_show = std::min(12u, el_count);
}
else
{
*fits_on_one_line = false;
*num_elements_to_show = std::min(8u, el_count);
}
// make sure empty containers are displayed with [0] {}, otherwise
// the lack of output looks like an error.
if(!el_count)
*fits_on_one_line = true;
}
static LibError dump_sequence(DebugIterator el_iterator, void* internal,
size_t el_count, DWORD el_type_id, size_t el_size, DumpState state)
{
const u8* el_p = 0; // avoid "uninitialized" warning
// special case: display as a string if the sequence looks to be text.
// do this only if container isn't empty because the otherwise the
// iterator may crash.
if(el_count)
{
el_p = el_iterator(internal, el_size);
LibError ret = dump_string(el_p, el_size);
if(ret == INFO::OK)
return ret;
}
// choose formatting based on element size and count
bool fits_on_one_line;
size_t num_elements_to_show;
seq_determine_formatting(el_size, el_count, &fits_on_one_line, &num_elements_to_show);
out(L"[%d] ", el_count);
state.level++;
out(fits_on_one_line? L"{ " : L"\r\n");
for(size_t i = 0; i < num_elements_to_show; i++)
{
if(!fits_on_one_line)
INDENT;
LibError err = dump_sym(el_type_id, el_p, state);
el_p = el_iterator(internal, el_size);
// there was no output for this child; undo its indentation (if any),
// skip everything below and proceed with the next child.
if(err == INFO::SYM_SUPPRESS_OUTPUT)
{
if(!fits_on_one_line)
UNINDENT;
continue;
}
dump_error(err, el_p); // nop if err == INFO::OK
// add separator unless this is the last element (can't just
// erase below due to additional "...").
if(i != num_elements_to_show-1)
out(fits_on_one_line? L", " : L"\r\n");
if(err == ERR::SYM_SINGLE_SYMBOL_LIMIT)
break;
} // for each child
// indicate some elements were skipped
if(el_count != num_elements_to_show)
out(L" ...");
state.level--;
if(fits_on_one_line)
out(L" }");
return INFO::OK;
}
static const u8* array_iterator(void* internal, size_t el_size)
{
const u8*& pos = *(const u8**)internal;
const u8* cur_pos = pos;
pos += el_size;
return cur_pos;
}
static LibError dump_array(const u8* p,
size_t el_count, DWORD el_type_id, size_t el_size, DumpState state)
{
const u8* iterator_internal_pos = p;
return dump_sequence(array_iterator, &iterator_internal_pos,
el_count, el_type_id, el_size, state);
}
static const STACKFRAME64* current_stackframe64;
static LibError determine_symbol_address(DWORD id, DWORD UNUSED(type_id), const u8** pp)
{
const STACKFRAME64* sf = current_stackframe64;
DWORD data_kind;
if(!SymGetTypeInfo(hProcess, mod_base, id, TI_GET_DATAKIND, &data_kind))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
switch(data_kind)
{
// SymFromIndex will fail
case DataIsMember:
// pp is already correct (udt_dump_normal retrieved the offset;
// we do it that way so we can check it against the total
// UDT size for safety).
return INFO::OK;
// this symbol is defined as static in another module =>
// there's nothing we can do.
case DataIsStaticMember:
return ERR::SYM_UNRETRIEVABLE_STATIC; // NOWARN
// ok; will handle below
case DataIsLocal:
case DataIsStaticLocal:
case DataIsParam:
case DataIsObjectPtr:
case DataIsFileStatic:
case DataIsGlobal:
break;
default:
debug_warn("unexpected data_kind");
//case DataIsConstant
}
// get SYMBOL_INFO (we need .Flags)
SYMBOL_INFO_PACKAGEW2 sp;
SYMBOL_INFOW* sym = &sp.si;
if(!SymFromIndexW(hProcess, mod_base, id, sym))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
DWORD addrofs = 0;
ULONG64 addr2 = 0;
DWORD ofs2 = 0;
SymGetTypeInfo(hProcess, mod_base, id, TI_GET_ADDRESSOFFSET, &addrofs);
SymGetTypeInfo(hProcess, mod_base, id, TI_GET_ADDRESS, &addr2);
SymGetTypeInfo(hProcess, mod_base, id, TI_GET_OFFSET, &ofs2);
// get address
ULONG64 addr = sym->Address;
// .. relative to a register
// note: we only have the FP (not SP)
if(sym->Flags & SYMFLAG_REGREL)
{
if(sym->Register == CV_REG_EBP)
goto fp_rel;
else
goto in_register;
}
// .. relative to FP (appears to be obsolete)
else if(sym->Flags & SYMFLAG_FRAMEREL)
{
fp_rel:
addr += sf->AddrFrame.Offset;
// HACK: reg-relative symbols (params and locals, but not
// static) appear to be off by 4 bytes in release builds.
// no idea as to the cause, but this "fixes" it.
#ifdef NDEBUG
addr += sizeof(void*);
#endif
}
// .. in register (this happens when optimization is enabled,
// but we can't do anything; see SymbolInfoRegister)
else if(sym->Flags & SYMFLAG_REGISTER)
{
in_register:
*pp = (const u8*)(uintptr_t)sym->Register;
return ERR::SYM_UNRETRIEVABLE_REG; // NOWARN
}
*pp = (const u8*)addr;
debug_printf("SYM| %ws at %p flags=%X dk=%d sym->addr=%I64X addrofs=%X addr2=%I64X ofs2=%X\n", sym->Name, *pp, sym->Flags, data_kind, sym->Address, addrofs, addr2, ofs2);
return INFO::OK;
}
//-----------------------------------------------------------------------------
// dump routines for each dbghelp symbol type
//-----------------------------------------------------------------------------
// these functions return != 0 if they're not able to produce any
// reasonable output at all; the caller (dump_sym_data, dump_sequence, etc.)
// will display the appropriate error message via dump_error.
// called by dump_sym; lock is held.
static LibError dump_sym_array(DWORD type_id, const u8* p, DumpState state)
{
ULONG64 size_ = 0;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_LENGTH, &size_))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
const size_t size = (size_t)size_;
// get element count and size
DWORD el_type_id = 0;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_TYPEID, &el_type_id))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
// .. workaround: TI_GET_COUNT returns total struct size for
// arrays-of-struct. therefore, calculate as size / el_size.
ULONG64 el_size_;
if(!SymGetTypeInfo(hProcess, mod_base, el_type_id, TI_GET_LENGTH, &el_size_))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
const size_t el_size = (size_t)el_size_;
debug_assert(el_size != 0);
const size_t num_elements = size/el_size;
debug_assert(num_elements != 0);
return dump_array(p, num_elements, el_type_id, el_size, state);
}
//-----------------------------------------------------------------------------
static LibError dump_sym_base_type(DWORD type_id, const u8* p, DumpState state)
{
DWORD base_type;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_BASETYPE, &base_type))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
ULONG64 size_ = 0;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_LENGTH, &size_))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
const size_t size = (size_t)size_;
// single out() call. note: we pass a single u64 for all sizes,
// which will only work on little-endian systems.
// must be declared before goto to avoid W4 warning.
const wchar_t* fmt = L"";
u64 data = movzx_le64(p, size);
// if value is 0xCC..CC (uninitialized mem), we display as hex.
// the output would otherwise be garbage; this makes it obvious.
// note: be very careful to correctly handle size=0 (e.g. void*).
for(size_t i = 0; i < size; i++)
{
if(p[i] != 0xCC)
break;
if(i == size-1)
goto display_as_hex;
}
switch(base_type)
{
// boolean
case btBool:
debug_assert(size == sizeof(bool));
fmt = L"%hs";
data = (u64)(data? "true " : "false");
break;
// floating-point
case btFloat:
// C calling convention casts float params to doubles, so printf
// expects one when we indicate %g. there are no width flags,
// so we have to manually convert the float data to double.
if(size == sizeof(float))
*(double*)&data = (double)*(float*)&data;
else if(size != sizeof(double))
debug_warn("dump_sym_base_type: invalid float size");
fmt = L"%g";
break;
// signed integers (displayed as decimal)
case btInt:
case btLong:
if(size != 1 && size != 2 && size != 4 && size != 8)
debug_warn("dump_sym_base_type: invalid int size");
// need to re-load and sign-extend, because we output 64 bits.
data = movsx_le64(p, size);
fmt = L"%I64d";
break;
// unsigned integers (displayed as hex)
// note: 0x00000000 can get annoying (0 would be nicer),
// but it indicates the variable size and makes for consistently
// formatted structs/arrays. (0x1234 0 0x5678 is ugly)
case btUInt:
case btULong:
display_as_hex:
if(size == 1)
{
// _TUCHAR
if(state.indirection)
{
state.indirection = 0;
return dump_array(p, 8, type_id, size, state);
}
fmt = L"0x%02X";
}
else if(size == 2)
fmt = L"0x%04X";
else if(size == 4)
fmt = L"0x%08X";
else if(size == 8)
fmt = L"0x%016I64X";
else
debug_warn("dump_sym_base_type: invalid uint size");
break;
// character
case btChar:
case btWChar:
debug_assert(size == sizeof(char) || size == sizeof(wchar_t));
// char*, wchar_t*
if(state.indirection)
{
state.indirection = 0;
return dump_array(p, 8, type_id, size, state);
}
// either integer or character;
// if printable, the character will be appended below.
fmt = L"%d";
break;
// note: void* is sometimes indicated as (pointer, btNoType).
case btVoid:
case btNoType:
// void* - cannot display what it's pointing to (type unknown).
if(state.indirection)
{
out_erase(4); // " -> "
fmt = L"";
}
else
debug_warn("dump_sym_base_type: non-pointer btVoid or btNoType");
break;
default:
debug_warn("dump_sym_base_type: unknown type");
//-fallthrough
// unsupported complex types
case btBCD:
case btCurrency:
case btDate:
case btVariant:
case btComplex:
case btBit:
case btBSTR:
case btHresult:
return ERR::SYM_UNSUPPORTED; // NOWARN
}
out(fmt, data);
// if the current value is a printable character, display in that form.
// this isn't only done in btChar because sometimes ints store characters.
if(data < 0x100)
{
int c = (int)data;
if(isprint(c))
out(L" ('%hc')", c);
}
return INFO::OK;
}
//-----------------------------------------------------------------------------
static LibError dump_sym_base_class(DWORD type_id, const u8* p, DumpState state)
{
DWORD base_class_type_id;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_TYPEID, &base_class_type_id))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
// this is a virtual base class. we can't display those because it'd
// require reading the VTbl, which is difficult given lack of documentation
// and just not worth it.
DWORD vptr_ofs;
if(SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_VIRTUALBASEPOINTEROFFSET, &vptr_ofs))
return ERR::SYM_UNSUPPORTED; // NOWARN
return dump_sym(base_class_type_id, p, state);
}
//-----------------------------------------------------------------------------
static LibError dump_sym_data(DWORD id, const u8* p, DumpState state)
{
// display name (of variable/member)
const wchar_t* name;
if(!SymGetTypeInfo(hProcess, mod_base, id, TI_GET_SYMNAME, &name))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
out(L"%s = ", name);
LocalFree((HLOCAL)name);
__try
{
// get type_id and address
DWORD type_id;
if(!SymGetTypeInfo(hProcess, mod_base, id, TI_GET_TYPEID, &type_id))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
RETURN_ERR(determine_symbol_address(id, type_id, &p));
// display value recursively
return dump_sym(type_id, p, state);
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
return ERR::SYM_INTERNAL_ERROR; // NOWARN
}
}
//-----------------------------------------------------------------------------
static LibError dump_sym_enum(DWORD type_id, const u8* p, DumpState UNUSED(state))
{
ULONG64 size_ = 0;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_LENGTH, &size_))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
const size_t size = (size_t)size_;
const i64 enum_value = movsx_le64(p, size);
// get array of child symbols (enumerants).
DWORD num_children;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_CHILDRENCOUNT, &num_children))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
TI_FINDCHILDREN_PARAMS2 fcp(num_children);
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_FINDCHILDREN, &fcp))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
num_children = fcp.p.Count; // was truncated to MAX_CHILDREN
const DWORD* children = fcp.p.ChildId;
// for each child (enumerant):
for(uint i = 0; i < num_children; i++)
{
DWORD child_data_id = children[i];
// get this enumerant's value. we can't make any assumptions about
// the variant's type or size - no restriction is documented.
// rationale: VariantChangeType is much less tedious than doing
// it manually and guarantees we cover everything. the OLE DLL is
// already pulled in by e.g. OpenGL anyway.
VARIANT v;
if(!SymGetTypeInfo(hProcess, mod_base, child_data_id, TI_GET_VALUE, &v))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
if(VariantChangeType(&v, &v, 0, VT_I8) != S_OK)
continue;
// it's the one we want - output its name.
if(enum_value == v.llVal)
{
const wchar_t* name;
if(!SymGetTypeInfo(hProcess, mod_base, child_data_id, TI_GET_SYMNAME, &name))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
out(L"%s", name);
LocalFree((HLOCAL)name);
return INFO::OK;
}
}
// we weren't able to retrieve a matching enum value, but can still
// produce reasonable output (the numeric value).
// note: could goto here after a SGTI fails, but we fail instead
// to make sure those errors are noticed.
out(L"%I64d", enum_value);
return INFO::OK;
}
//-----------------------------------------------------------------------------
static LibError dump_sym_function(DWORD UNUSED(type_id), const u8* UNUSED(p),
DumpState UNUSED(state))
{
return INFO::SYM_SUPPRESS_OUTPUT;
}
//-----------------------------------------------------------------------------
static LibError dump_sym_function_type(DWORD UNUSED(type_id), const u8* p, DumpState UNUSED(state))
{
// this symbol gives class parent, return type, and parameter count.
// unfortunately the one thing we care about, its name,
// isn't exposed via TI_GET_SYMNAME, so we resolve it ourselves.
char name[DBG_SYMBOL_LEN];
LibError err = debug_resolve_symbol_lk((void*)p, name, 0, 0);
out(L"0x%p", p);
if(err == INFO::OK)
out(L" (%hs)", name);
return INFO::OK;
}
//-----------------------------------------------------------------------------
// do not follow pointers that we have already displayed. this reduces
// clutter a bit and prevents infinite recursion for cyclical references
// (e.g. via struct S { S* p; } s; s.p = &s;)
typedef std::set<const u8*> PtrSet;
static PtrSet* already_visited_ptrs;
// allocated on-demand by ptr_already_visited. this cannot be a NLSO
// because it may be used before _cinit.
// if we put it in a function, construction still fails on VC7 because
// the atexit table will not have been initialized yet.
// called by debug_dump_stack and wdbg_sym_Shutdown
static void ptr_reset_visited()
{
delete already_visited_ptrs;
already_visited_ptrs = 0;
}
static bool ptr_already_visited(const u8* p)
{
if(!already_visited_ptrs)
already_visited_ptrs = new PtrSet;
std::pair<PtrSet::iterator, bool> ret = already_visited_ptrs->insert(p);
return !ret.second;
}
static LibError dump_sym_pointer(DWORD type_id, const u8* p, DumpState state)
{
ULONG64 size_ = 0;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_LENGTH, &size_))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
const size_t size = (size_t)size_;
// read+output pointer's value.
p = (const u8*)movzx_le64(p, size);
out(L"0x%p", p);
// bail if it's obvious the pointer is bogus
// (=> can't display what it's pointing to)
if(debug_is_pointer_bogus(p))
return INFO::OK;
// avoid duplicates and circular references
if(ptr_already_visited(p))
{
out(L" (see above)");
return INFO::OK;
}
// display what the pointer is pointing to.
// if the pointer is invalid (despite "bogus" check above),
// dump_data_sym recovers via SEH and prints an error message.
// if the pointed-to value turns out to uninteresting (e.g. void*),
// the responsible dump_sym* will erase "->", leaving only address.
out(L" -> ");
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_TYPEID, &type_id))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
// prevent infinite recursion just to be safe (shouldn't happen)
if(state.indirection >= MAX_INDIRECTION)
WARN_RETURN(ERR::SYM_NESTING_LIMIT);
state.indirection++;
return dump_sym(type_id, p, state);
}
//-----------------------------------------------------------------------------
static LibError dump_sym_typedef(DWORD type_id, const u8* p, DumpState state)
{
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_TYPEID, &type_id))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
return dump_sym(type_id, p, state);
}
//-----------------------------------------------------------------------------
// determine type and size of the given child in a UDT.
// useful for UDTs that contain typedefs describing their contents,
// e.g. value_type in STL containers.
static LibError udt_get_child_type(const wchar_t* child_name,
ULONG num_children, const DWORD* children,
DWORD* el_type_id, size_t* el_size)
{
*el_type_id = 0;
*el_size = 0;
for(ULONG i = 0; i < num_children; i++)
{
DWORD child_id = children[i];
// find the desired child
wchar_t* this_child_name;
if(!SymGetTypeInfo(hProcess, mod_base, child_id, TI_GET_SYMNAME, &this_child_name))
continue;
const bool found_it = !wcscmp(this_child_name, child_name);
LocalFree(this_child_name);
if(!found_it)
continue;
// .. its type information is what we want.
DWORD type_id;
if(!SymGetTypeInfo(hProcess, mod_base, child_id, TI_GET_TYPEID, &type_id))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
ULONG64 size;
if(!SymGetTypeInfo(hProcess, mod_base, child_id, TI_GET_LENGTH, &size))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
*el_type_id = type_id;
*el_size = (size_t)size;
return INFO::OK;
}
// (happens if called for containers that are treated as STL but are not)
return ERR::SYM_CHILD_NOT_FOUND; // NOWARN
}
static LibError udt_dump_std(const wchar_t* wtype_name, const u8* p, size_t size, DumpState state,
ULONG num_children, const DWORD* children)
{
LibError err;
// not a C++ standard library object; can't handle it.
if(wcsncmp(wtype_name, L"std::", 5) != 0)
return INFO::CANNOT_HANDLE;
// check for C++ objects that should be displayed via udt_dump_normal.
// STL containers are special-cased and the rest (apart from those here)
// are ignored, because for the most part they are spew.
if(!wcsncmp(wtype_name, L"std::pair", 9))
return INFO::CANNOT_HANDLE;
// convert to char since debug_stl doesn't support wchar_t.
char ctype_name[DBG_SYMBOL_LEN];
snprintf(ctype_name, ARRAY_SIZE(ctype_name), "%ws", wtype_name);
// display contents of STL containers
// .. get element type
DWORD el_type_id;
size_t el_size;
err = udt_get_child_type(L"value_type", num_children, children, &el_type_id, &el_size);
if(err != INFO::OK)
goto not_valid_container;
// .. get iterator and # elements
size_t el_count;
DebugIterator el_iterator;
u8 it_mem[DEBUG_STL_MAX_ITERATOR_SIZE];
err = debug_stl_get_container_info(ctype_name, p, size, el_size, &el_count, &el_iterator, it_mem);
if(err != INFO::OK)
goto not_valid_container;
return dump_sequence(el_iterator, it_mem, el_count, el_type_id, el_size, state);
not_valid_container:
// build and display detailed "error" message.
char buf[100];
const char* text;
// .. object named std::* but doesn't include a "value_type" child =>
// it's a non-STL C++ stdlib object. wasn't handled by the
// special case above, so we just display its simplified type name
// (the contents are usually spew).
if(err == ERR::SYM_CHILD_NOT_FOUND)
text = "";
// .. not one of the containers we can analyse.
if(err == ERR::STL_CNT_UNKNOWN)
text = "unsupported ";
// .. container of a known type but contents are invalid.
if(err == ERR::STL_CNT_INVALID)
text = "uninitialized/invalid ";
// .. some other error encountered
else
{
snprintf(buf, ARRAY_SIZE(buf), "error %d while analyzing ", err);
text = buf;
}
out(L"(%hs%hs)", text, debug_stl_simplify_name(ctype_name));
return INFO::OK;
}
static bool udt_should_suppress(const wchar_t* type_name)
{
// specialized HANDLEs are defined as pointers to structs by
// DECLARE_HANDLE. we only want the numerical value (pointer address),
// so prevent these structs from being displayed.
// note: no need to check for indirection; these are only found in
// HANDLEs (which are pointers).
// removed obsolete defs: HEVENT, HFILE, HUMPD
if(type_name[0] != 'H')
goto not_handle;
#define SUPPRESS_HANDLE(name) if(!wcscmp(type_name, L#name L"__")) return true;
SUPPRESS_HANDLE(HACCEL);
SUPPRESS_HANDLE(HBITMAP);
SUPPRESS_HANDLE(HBRUSH);
SUPPRESS_HANDLE(HCOLORSPACE);
SUPPRESS_HANDLE(HCURSOR);
SUPPRESS_HANDLE(HDC);
SUPPRESS_HANDLE(HENHMETAFILE);
SUPPRESS_HANDLE(HFONT);
SUPPRESS_HANDLE(HGDIOBJ);
SUPPRESS_HANDLE(HGLOBAL);
SUPPRESS_HANDLE(HGLRC);
SUPPRESS_HANDLE(HHOOK);
SUPPRESS_HANDLE(HICON);
SUPPRESS_HANDLE(HIMAGELIST);
SUPPRESS_HANDLE(HIMC);
SUPPRESS_HANDLE(HINSTANCE);
SUPPRESS_HANDLE(HKEY);
SUPPRESS_HANDLE(HKL);
SUPPRESS_HANDLE(HKLOCAL);
SUPPRESS_HANDLE(HMENU);
SUPPRESS_HANDLE(HMETAFILE);
SUPPRESS_HANDLE(HMODULE);
SUPPRESS_HANDLE(HMONITOR);
SUPPRESS_HANDLE(HPALETTE);
SUPPRESS_HANDLE(HPEN);
SUPPRESS_HANDLE(HRGN);
SUPPRESS_HANDLE(HRSRC);
SUPPRESS_HANDLE(HSTR);
SUPPRESS_HANDLE(HTASK);
SUPPRESS_HANDLE(HWINEVENTHOOK);
SUPPRESS_HANDLE(HWINSTA);
SUPPRESS_HANDLE(HWND);
not_handle:
return false;
}
static LibError udt_dump_suppressed(const wchar_t* type_name, const u8* UNUSED(p), size_t UNUSED(size),
DumpState state, ULONG UNUSED(num_children), const DWORD* UNUSED(children))
{
if(!udt_should_suppress(type_name))
return INFO::CANNOT_HANDLE;
// the data symbol is pointer-to-UDT. since we won't display its
// contents, leave only the pointer's value.
if(state.indirection)
out_erase(4); // " -> "
// indicate something was deliberately left out
// (otherwise, lack of output may be taken for an error)
out(L" (..)");
return INFO::OK;
}
// (by now) non-trivial heuristic to determine if a UDT should be
// displayed on one line or several. split out of udt_dump_normal.
static bool udt_fits_on_one_line(const wchar_t* type_name, size_t child_count, size_t total_size)
{
// special case: always put CStr* on one line
// (std::*string are displayed directly, but these go through
// udt_dump_normal. we want to avoid the ensuing 3-line output)
if(!wcscmp(type_name, L"CStr") || !wcscmp(type_name, L"CStr8") || !wcscmp(type_name, L"CStrW"))
return true;
// try to get actual number of relevant children
// (typedefs etc. are never displayed, but are included in child_count.
// we have to balance that vs. tons of static members, which aren't
// reflected in total_size).
// .. prevent division by 0.
if(child_count == 0)
child_count = 1;
// special-case a few types that would otherwise be classified incorrectly
// (due to having more or less than expected relevant children)
if(!wcsncmp(type_name, L"std::pair", 9))
child_count = 2;
const size_t avg_size = total_size / child_count;
// (if 0, no worries - child_count will probably be large and
// we return false, which is a safe default)
// small UDT with a few (small) members: fits on one line.
if(child_count <= 3 && avg_size <= sizeof(int))
return true;
return false;
}
static LibError udt_dump_normal(const wchar_t* type_name, const u8* p, size_t size,
DumpState state, ULONG num_children, const DWORD* children)
{
const bool fits_on_one_line = udt_fits_on_one_line(type_name, num_children, size);
// prevent infinite recursion just to be safe (shouldn't happen)
if(state.level >= MAX_LEVEL)
WARN_RETURN(ERR::SYM_NESTING_LIMIT);
state.level++;
out(fits_on_one_line? L"{ " : L"\r\n");
bool displayed_anything = false;
for(ULONG i = 0; i < num_children; i++)
{
const DWORD child_id = children[i];
// get offset. if not available, skip this child
// (we only display data here, not e.g. typedefs)
DWORD ofs = 0;
if(!SymGetTypeInfo(hProcess, mod_base, child_id, TI_GET_OFFSET, &ofs))
continue;
debug_assert(ofs < size);
if(!fits_on_one_line)
INDENT;
const u8* el_p = p+ofs;
LibError err = dump_sym(child_id, el_p, state);
// there was no output for this child; undo its indentation (if any),
// skip everything below and proceed with the next child.
if(err == INFO::SYM_SUPPRESS_OUTPUT)
{
if(!fits_on_one_line)
UNINDENT;
continue;
}
displayed_anything = true;
dump_error(err, el_p); // nop if err == INFO::OK
out(fits_on_one_line? L", " : L"\r\n");
if(err == ERR::SYM_SINGLE_SYMBOL_LIMIT)
break;
} // for each child
state.level--;
if(!displayed_anything)
{
out_erase(2); // "{ " or "\r\n"
out(L"(%s)", type_name);
return INFO::OK;
}
// remove trailing comma separator
// note: we can't avoid writing it by checking if i == num_children-1:
// each child might be the last valid data member.
if(fits_on_one_line)
{
out_erase(2); // ", "
out(L" }");
}
return INFO::OK;
}
static LibError dump_sym_udt(DWORD type_id, const u8* p, DumpState state)
{
ULONG64 size_ = 0;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_LENGTH, &size_))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
const size_t size = (size_t)size_;
// get array of child symbols (members/functions/base classes).
DWORD num_children;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_CHILDRENCOUNT, &num_children))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
TI_FINDCHILDREN_PARAMS2 fcp(num_children);
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_FINDCHILDREN, &fcp))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
num_children = fcp.p.Count; // was truncated to MAX_CHILDREN
const DWORD* children = fcp.p.ChildId;
const wchar_t* type_name;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_SYMNAME, &type_name))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
LibError ret;
// note: order is important (e.g. STL special-case must come before
// suppressing UDTs, which tosses out most other C++ stdlib classes)
ret = udt_dump_std (type_name, p, size, state, num_children, children);
if(ret != INFO::CANNOT_HANDLE)
goto done;
ret = udt_dump_suppressed(type_name, p, size, state, num_children, children);
if(ret != INFO::CANNOT_HANDLE)
goto done;
ret = udt_dump_normal (type_name, p, size, state, num_children, children);
if(ret != INFO::CANNOT_HANDLE)
goto done;
done:
LocalFree((HLOCAL)type_name);
return ret;
}
//-----------------------------------------------------------------------------
static LibError dump_sym_vtable(DWORD UNUSED(type_id), const u8* UNUSED(p), DumpState UNUSED(state))
{
// unsupported (vtable internals are undocumented; too much work).
return INFO::SYM_SUPPRESS_OUTPUT;
}
//-----------------------------------------------------------------------------
static LibError dump_sym_unknown(DWORD type_id, const u8* UNUSED(p), DumpState UNUSED(state))
{
// redundant (already done in dump_sym), but this is rare.
DWORD type_tag;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_SYMTAG, &type_tag))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
debug_printf("SYM| unknown tag: %d\n", type_tag);
out(L"(unknown symbol type)");
return INFO::OK;
}
//-----------------------------------------------------------------------------
// write name and value of the symbol <type_id> to the output buffer.
// delegates to dump_sym_* depending on the symbol's tag.
static LibError dump_sym(DWORD type_id, const u8* p, DumpState state)
{
RETURN_ERR(out_check_limit());
DWORD type_tag;
if(!SymGetTypeInfo(hProcess, mod_base, type_id, TI_GET_SYMTAG, &type_tag))
WARN_RETURN(ERR::SYM_TYPE_INFO_UNAVAILABLE);
switch(type_tag)
{
case SymTagArrayType:
return dump_sym_array (type_id, p, state);
case SymTagBaseType:
return dump_sym_base_type (type_id, p, state);
case SymTagBaseClass:
return dump_sym_base_class (type_id, p, state);
case SymTagData:
return dump_sym_data (type_id, p, state);
case SymTagEnum:
return dump_sym_enum (type_id, p, state);
case SymTagFunction:
return dump_sym_function (type_id, p, state);
case SymTagFunctionType:
return dump_sym_function_type (type_id, p, state);
case SymTagPointerType:
return dump_sym_pointer (type_id, p, state);
case SymTagTypedef:
return dump_sym_typedef (type_id, p, state);
case SymTagUDT:
return dump_sym_udt (type_id, p, state);
case SymTagVTable:
return dump_sym_vtable (type_id, p, state);
default:
return dump_sym_unknown (type_id, p, state);
}
}
//////////////////////////////////////////////////////////////////////////////
//
// stack trace
//
//////////////////////////////////////////////////////////////////////////////
// output the symbol's name and value via dump_sym*.
// called from dump_frame_cb for each local symbol; lock is held.
static BOOL CALLBACK dump_sym_cb(SYMBOL_INFO* sym, ULONG UNUSED(size), void* UNUSED(ctx))
{
out_latch_pos(); // see decl
mod_base = sym->ModBase;
const u8* p = (const u8*)sym->Address;
DumpState state;
INDENT;
LibError err = dump_sym(sym->Index, p, state);
dump_error(err, p);
if(err == INFO::SYM_SUPPRESS_OUTPUT)
UNINDENT;
else
out(L"\r\n");
return TRUE; // continue
}
//////////////////////////////////////////////////////////////////////////////
struct IMAGEHLP_STACK_FRAME2 : public IMAGEHLP_STACK_FRAME
{
IMAGEHLP_STACK_FRAME2(const STACKFRAME64* sf)
{
// apparently only PC, FP and SP are necessary, but
// we go whole-hog to be safe.
memset(this, 0, sizeof(IMAGEHLP_STACK_FRAME2));
InstructionOffset = sf->AddrPC.Offset;
ReturnOffset = sf->AddrReturn.Offset;
FrameOffset = sf->AddrFrame.Offset;
StackOffset = sf->AddrStack.Offset;
BackingStoreOffset = sf->AddrBStore.Offset;
FuncTableEntry = (ULONG64)sf->FuncTableEntry;
Virtual = sf->Virtual;
// (note: array of different types, can't copy directly)
for(int i = 0; i < 4; i++)
Params[i] = sf->Params[i];
}
};
// called by walk_stack for each stack frame
static LibError dump_frame_cb(const STACKFRAME64* sf, void* UNUSED(user_arg))
{
current_stackframe64 = sf;
void* func = (void*)sf->AddrPC.Offset;
char func_name[DBG_SYMBOL_LEN]; char file[DBG_FILE_LEN]; int line;
LibError ret = debug_resolve_symbol_lk(func, func_name, file, &line);
if(ret == INFO::OK)
{
// don't trace back further than the app's entry point
// (no one wants to see this frame). checking for the
// function name isn't future-proof, but not stopping is no big deal.
// an alternative would be to check if module=kernel32, but
// that would cut off callbacks as well.
if(!strcmp(func_name, "_BaseProcessStart@4"))
return INFO::OK;
out(L"%hs (%hs:%d)\r\n", func_name, file, line);
}
else
out(L"%p\r\n", func);
// only enumerate symbols for this stack frame
// (i.e. its locals and parameters)
// problem: debug info is scope-aware, so we won't see any variables
// declared in sub-blocks. we'd have to pass an address in that block,
// which isn't worth the trouble. since
IMAGEHLP_STACK_FRAME2 imghlp_frame(sf);
SymSetContext(hProcess, &imghlp_frame, 0); // last param is ignored
SymEnumSymbols(hProcess, 0, 0, dump_sym_cb, 0);
// 2nd and 3rd params indicate scope set by SymSetContext
// should be used.
out(L"\r\n");
return INFO::CB_CONTINUE;
}
LibError debug_dump_stack(wchar_t* buf, size_t max_chars, uint skip, void* pcontext)
{
static uintptr_t already_in_progress;
if(!CAS(&already_in_progress, 0, 1))
return ERR::REENTERED; // NOWARN
lock();
out_init(buf, max_chars);
ptr_reset_visited();
skip_this_frame(skip, pcontext);
LibError ret = walk_stack(dump_frame_cb, 0, skip, (const CONTEXT*)pcontext);
unlock();
already_in_progress = 0;
return ret;
}
// write out a "minidump" containing register and stack state; this enables
// examining the crash in a debugger. called by wdbg_exception_filter.
// heavily modified from http://www.codeproject.com/debug/XCrashReportPt3.asp
// lock must be held.
void wdbg_sym_write_minidump(EXCEPTION_POINTERS* exception_pointers)
{
lock();
// note: we go through some gyrations here (strcpy+strcat) to avoid
// dependency on file code (path_append).
char N_path[PATH_MAX];
strcpy_s(N_path, ARRAY_SIZE(N_path), ah_get_log_dir());
strcat_s(N_path, ARRAY_SIZE(N_path), "crashlog.dmp");
HANDLE hFile = CreateFile(N_path, GENERIC_WRITE, FILE_SHARE_WRITE, 0, CREATE_ALWAYS, 0, 0);
if(hFile == INVALID_HANDLE_VALUE)
goto fail;
MINIDUMP_EXCEPTION_INFORMATION mei;
mei.ThreadId = GetCurrentThreadId();
mei.ExceptionPointers = exception_pointers;
mei.ClientPointers = FALSE;
// exception_pointers is not in our address space.
// note: we don't store other crashlog info within the dump file
// (UserStreamParam), since we will need to generate a plain text file on
// non-Windows platforms. users will just have to send us both files.
HANDLE hProcess = GetCurrentProcess(); DWORD pid = GetCurrentProcessId();
if(!MiniDumpWriteDump(hProcess, pid, hFile, MiniDumpNormal, &mei, 0, 0))
{
fail:
DISPLAY_ERROR(L"Unable to generate minidump.");
}
CloseHandle(hFile);
unlock();
}
static LibError wdbg_sym_Init()
{
// try to import RtlCaptureContext (available on WinXP and later).
// it's used in walk_stack; import here to avoid overhead of doing so
// on every call. if not available, walk_stack emulates it.
//
// note: kernel32 is always loaded into every process, so we
// don't need LoadLibrary/FreeLibrary.
HMODULE hKernel32Dll = GetModuleHandle("kernel32.dll");
*(void**)&pRtlCaptureContext = GetProcAddress(hKernel32Dll, "RtlCaptureContext");
return INFO::OK;
}
static LibError wdbg_sym_Shutdown()
{
ptr_reset_visited();
return sym_shutdown();
}