Merge 'remotes/trunk'

[0ad.git] / source / lib / debug.cpp

/* Copyright (C) 2023 Wildfire Games.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "precompiled.h"
#include "lib/debug.h"

#include "lib/alignment.h"
#include "lib/app_hooks.h"
#include "lib/fnv_hash.h"
#include "lib/sysdep/cpu.h"     // cpu_CAS
#include "lib/sysdep/sysdep.h"
#include "lib/sysdep/vm.h"

#include <cstdarg>
#include <cstring>
#include <cstdio>

namespace
{

// (NB: this may appear obscene, but deep stack traces have been
// observed to take up > 256 KiB)
constexpr std::size_t MESSAGE_SIZE = 512 * KiB / sizeof(wchar_t);
wchar_t g_MessageBuffer[MESSAGE_SIZE];

} // anonymous namespace

static const StatusDefinition debugStatusDefinitions[] = {
        { ERR::SYM_NO_STACK_FRAMES_FOUND, L"No stack frames found" },
        { ERR::SYM_UNRETRIEVABLE_STATIC, L"Value unretrievable (stored in external module)" },
        { ERR::SYM_UNRETRIEVABLE, L"Value unretrievable" },
        { ERR::SYM_TYPE_INFO_UNAVAILABLE, L"Error getting type_info" },
        { ERR::SYM_INTERNAL_ERROR, L"Exception raised while processing a symbol" },
        { ERR::SYM_UNSUPPORTED, L"Symbol type not (fully) supported" },
        { ERR::SYM_CHILD_NOT_FOUND, L"Symbol does not have the given child" },
        { ERR::SYM_NESTING_LIMIT, L"Symbol nesting too deep or infinite recursion" },
        { ERR::SYM_SINGLE_SYMBOL_LIMIT, L"Symbol has produced too much output" },
        { INFO::SYM_SUPPRESS_OUTPUT, L"Symbol was suppressed" }
};
STATUS_ADD_DEFINITIONS(debugStatusDefinitions);


// need to shoehorn printf-style variable params into
// the OutputDebugString call.
// - don't want to split into multiple calls - would add newlines to output.
// - fixing Win32 _vsnprintf to return # characters that would be written,
//   as required by C99, looks difficult and unnecessary. if any other code
//   needs that, implement GNU vasprintf.
// - fixed size buffers aren't nice, but much simpler than vasprintf-style
//   allocate+expand_until_it_fits. these calls are for quick debug output,
//   not loads of data, anyway.

// rationale: static data instead of std::set to allow setting at any time.
// we store FNV hash of tag strings for fast comparison; collisions are
// extremely unlikely and can only result in displaying more/less text.
static const size_t MAX_TAGS = 20;
static u32 tags[MAX_TAGS];
static size_t num_tags;

void debug_filter_add(const char* tag)
{
        const u32 hash = fnv_hash(tag, strlen(tag)*sizeof(tag[0]));

        // make sure it isn't already in the list
        for(size_t i = 0; i < MAX_TAGS; i++)
                if(tags[i] == hash)
                        return;

        // too many already?
        if(num_tags == MAX_TAGS)
        {
                DEBUG_WARN_ERR(ERR::LOGIC);     // increase MAX_TAGS
                return;
        }

        tags[num_tags++] = hash;
}

void debug_filter_remove(const char* tag)
{
        const u32 hash = fnv_hash(tag, strlen(tag)*sizeof(tag[0]));

        for(size_t i = 0; i < MAX_TAGS; i++)
        {
                if(tags[i] == hash)     // found it
                {
                        // replace with last element (avoid holes)
                        tags[i] = tags[MAX_TAGS-1];
                        num_tags--;

                        // can only happen once, so we're done.
                        return;
                }
        }
}

void debug_filter_clear()
{
        std::fill(tags, tags+MAX_TAGS, 0);
}

bool debug_filter_allows(const char* text)
{
        size_t i;
        for(i = 0; ; i++)
        {
                // no | found => no tag => should always be displayed
                if(text[i] == ' ' || text[i] == '\0')
                        return true;
                if(text[i] == '|' && i != 0)
                        break;
        }

        const u32 hash = fnv_hash(text, i*sizeof(text[0]));

        // check if entry allowing this tag is found
        for(i = 0; i < MAX_TAGS; i++)
                if(tags[i] == hash)
                        return true;

        return false;
}

#undef debug_printf     // allowing #defining it out
void debug_printf(const char* fmt, ...)
{
        char buf[16384];

        va_list ap;
        va_start(ap, fmt);
        const int numChars = vsprintf_s(buf, ARRAY_SIZE(buf), fmt, ap);
        if (numChars < 0)
                debug_break();  // poor man's assert - avoid infinite loop because ENSURE also uses debug_printf
        va_end(ap);

        debug_puts_filtered(buf);
}

void debug_puts_filtered(const char* text)
{
        if(debug_filter_allows(text))
                debug_puts(text);
}


//-----------------------------------------------------------------------------

Status debug_WriteCrashlog(const wchar_t* text)
{
        // (avoid infinite recursion and/or reentering this function if it
        // fails/reports an error)
        enum State
        {
                IDLE,
                BUSY,
                FAILED
        };
        // note: the initial state is IDLE. we rely on zero-init because
        // initializing local static objects from constants may happen when
        // this is first called, which isn't thread-safe. (see C++ 6.7.4)
        cassert(IDLE == 0);
        static volatile intptr_t state;

        if(!cpu_CAS(&state, IDLE, BUSY))
                return ERR::REENTERED;  // NOWARN

        OsPath pathname = ah_get_log_dir()/"crashlog.txt";
        FILE* f = sys_OpenFile(pathname, "w");
        if(!f)
        {
                state = FAILED; // must come before DEBUG_DISPLAY_ERROR
                DEBUG_DISPLAY_ERROR(L"Unable to open crashlog.txt for writing (please ensure the log directory is writable)");
                return ERR::FAIL;       // NOWARN (the above text is more helpful than a generic error code)
        }

        fputwc(0xFEFF, f);      // BOM
        fwprintf(f, L"%ls\n", text);
        fwprintf(f, L"\n\n====================================\n\n");

        // allow user to bundle whatever information they want
        ah_bundle_logs(f);

        fclose(f);
        state = IDLE;
        return INFO::OK;
}


//-----------------------------------------------------------------------------
// error message
//-----------------------------------------------------------------------------


// a stream with printf-style varargs and the possibility of
// writing directly to the output buffer.
class PrintfWriter
{
public:
        PrintfWriter(wchar_t* buf, size_t maxChars)
                : m_pos(buf), m_charsLeft(maxChars)
        {
        }

        bool operator()(const wchar_t* fmt, ...) WPRINTF_ARGS(2)
        {
                va_list ap;
                va_start(ap, fmt);
                const int len = vswprintf(m_pos, m_charsLeft, fmt, ap);
                va_end(ap);
                if(len < 0)
                        return false;
                m_pos += len;
                m_charsLeft -= len;
                return true;
        }

        wchar_t* Position() const
        {
                return m_pos;
        }

        size_t CharsLeft() const
        {
                return m_charsLeft;
        }

        void CountAddedChars()
        {
                const size_t len = wcslen(m_pos);
                m_pos += len;
                m_charsLeft -= len;
        }

private:
        wchar_t* m_pos;
        size_t m_charsLeft;
};


// split out of debug_DisplayError because it's used by the self-test.
const wchar_t* debug_BuildErrorMessage(
        const wchar_t* description,
        const wchar_t* filename, int line, const char* func,
        void* context, const wchar_t* lastFuncToSkip)
{
        // retrieve errno (might be relevant) before doing anything else
        // that might overwrite it.
        wchar_t description_buf[100] = L"?";
        wchar_t os_error[100] = L"?";
        Status errno_equiv = StatusFromErrno(); // NOWARN
        if(errno_equiv != ERR::FAIL)    // meaningful translation
                StatusDescription(errno_equiv, description_buf, ARRAY_SIZE(description_buf));
        sys_StatusDescription(0, os_error, ARRAY_SIZE(os_error));

        PrintfWriter writer(g_MessageBuffer, MESSAGE_SIZE);

        // header
        if(!writer(
                L"%ls\r\n"
                L"Location: %ls:%d (%hs)\r\n"
                L"\r\n"
                L"Call stack:\r\n"
                L"\r\n",
                description, filename, line, func
        ))
        {
fail:
                return L"(error while formatting error message)";
        }

        // append stack trace
        Status ret = debug_DumpStack(writer.Position(), writer.CharsLeft(), context, lastFuncToSkip);
        if(ret == ERR::REENTERED)
        {
                if(!writer(
                        L"While generating an error report, we encountered a second "
                        L"problem. Please be sure to report both this and the subsequent "
                        L"error messages."
                ))
                        goto fail;
        }
        else if(ret != INFO::OK)
        {
                wchar_t error_buf[100] = {'?'};
                if(!writer(
                        L"(error while dumping stack: %ls)",
                        StatusDescription(ret, error_buf, ARRAY_SIZE(error_buf))
                ))
                        goto fail;
        }
        else    // success
        {
                writer.CountAddedChars();
        }

        // append errno
        if(!writer(
                L"\r\n"
                L"errno = %d (%ls)\r\n"
                L"OS error = %ls\r\n",
                errno, description_buf, os_error
        ))
                goto fail;

        return g_MessageBuffer;
}


//-----------------------------------------------------------------------------
// display error messages
//-----------------------------------------------------------------------------

// translates and displays the given strings in a dialog.
// this is typically only used when debug_DisplayError has failed or
// is unavailable because that function is much more capable.
// implemented via sys_display_msg; see documentation there.
void debug_DisplayMessage(const wchar_t* caption, const wchar_t* msg)
{
        sys_display_msg(caption, msg);
}


// when an error has come up and user clicks Exit, we don't want any further
// errors (e.g. caused by atexit handlers) to come up, possibly causing an
// infinite loop. hiding errors isn't good, but we assume that whoever clicked
// exit really doesn't want to see any more messages.
static atomic_bool isExiting;

// this logic is applicable to any type of error. special cases such as
// suppressing certain expected WARN_ERRs are done there.
static bool ShouldSuppressError(atomic_bool* suppress)
{
        if(isExiting)
                return true;

        if(!suppress)
                return false;

        if(*suppress == DEBUG_SUPPRESS)
                return true;

        return false;
}

static ErrorReactionInternal CallDisplayError(const wchar_t* text, size_t flags)
{
        // first try app hook implementation
        ErrorReactionInternal er = ah_display_error(text, flags);
        // .. it's only a stub: default to normal implementation
        if(er == ERI_NOT_IMPLEMENTED)
                er = sys_display_error(text, flags);

        return er;
}

static ErrorReaction PerformErrorReaction(ErrorReactionInternal er, size_t flags, atomic_bool* suppress)
{
        const bool shouldHandleBreak = (flags & DE_MANUAL_BREAK) == 0;

        switch(er)
        {
        case ERI_CONTINUE:
                return ER_CONTINUE;

        case ERI_BREAK:
                // handle "break" request unless the caller wants to (doing so here
                // instead of within the dlgproc yields a correct call stack)
                if(shouldHandleBreak)
                {
                        debug_break();
                        return ER_CONTINUE;
                }
                else
                        return ER_BREAK;

        case ERI_SUPPRESS:
                (void)cpu_CAS(suppress, 0, DEBUG_SUPPRESS);
                return ER_CONTINUE;

        case ERI_EXIT:
                isExiting = 1;  // see declaration
                COMPILER_FENCE;

                exit(EXIT_FAILURE);

        case ERI_NOT_IMPLEMENTED:
        default:
                debug_break();  // not expected to be reached
                return ER_CONTINUE;
        }
}

ErrorReaction debug_DisplayError(const wchar_t* description,
        size_t flags, void* context, const wchar_t* lastFuncToSkip,
        const wchar_t* pathname, int line, const char* func,
        atomic_bool* suppress)
{
        // "suppressing" this error means doing nothing and returning ER_CONTINUE.
        if(ShouldSuppressError(suppress))
                return ER_CONTINUE;

        // fix up params
        // .. caller supports a suppress flag; set the corresponding flag so that
        //    the error display implementation enables the Suppress option.
        if(suppress)
                flags |= DE_ALLOW_SUPPRESS;

        if(flags & DE_NO_DEBUG_INFO)
        {
                // in non-debug-info mode, simply display the given description
                // and then return immediately
                ErrorReactionInternal er = CallDisplayError(description, flags);
                return PerformErrorReaction(er, flags, suppress);
        }

        // .. deal with incomplete file/line info
        if(!pathname || pathname[0] == '\0')
                pathname = L"unknown";
        if(line <= 0)
                line = 0;
        if(!func || func[0] == '\0')
                func = "?";
        // .. _FILE__ evaluates to the full path (albeit without drive letter)
        //    which is rather long. we only display the base name for clarity.
        const wchar_t* filename = path_name_only(pathname);

        // display in output window; double-click will navigate to error location.
        const wchar_t* text = debug_BuildErrorMessage(description, filename, line, func, context, lastFuncToSkip);

        (void)debug_WriteCrashlog(text);
        ErrorReactionInternal er = CallDisplayError(text, flags);

        // TODO: use utf8 conversion without internal allocations.
        debug_printf("%s(%d): %s\n", utf8_from_wstring(filename).c_str(), line, utf8_from_wstring(description).c_str());

        // note: debug_break-ing here to make sure the app doesn't continue
        // running is no longer necessary. debug_DisplayError now determines our
        // window handle and is modal.

        return PerformErrorReaction(er, flags, suppress);
}


// is errorToSkip valid? (also guarantees mutual exclusion)
enum SkipStatus
{
        INVALID, VALID, BUSY
};
static intptr_t skipStatus = INVALID;
static Status errorToSkip;
static size_t numSkipped;

void debug_SkipErrors(Status err)
{
        if(cpu_CAS(&skipStatus, INVALID, BUSY))
        {
                errorToSkip = err;
                numSkipped = 0;
                COMPILER_FENCE;
                skipStatus = VALID;     // linearization point
        }
        else
                DEBUG_WARN_ERR(ERR::REENTERED);
}

size_t debug_StopSkippingErrors()
{
        if(cpu_CAS(&skipStatus, VALID, BUSY))
        {
                const size_t ret = numSkipped;
                COMPILER_FENCE;
                skipStatus = INVALID;   // linearization point
                return ret;
        }
        else
        {
                DEBUG_WARN_ERR(ERR::REENTERED);
                return 0;
        }
}

static bool ShouldSkipError(Status err)
{
        if(cpu_CAS(&skipStatus, VALID, BUSY))
        {
                numSkipped++;
                const bool ret = (err == errorToSkip);
                COMPILER_FENCE;
                skipStatus = VALID;
                return ret;
        }
        return false;
}

ErrorReaction debug_OnError(Status err, atomic_bool* suppress, const wchar_t* file, int line, const char* func)
{
        CACHE_ALIGNED(u8) context[DEBUG_CONTEXT_SIZE];
        (void)debug_CaptureContext(context);

        if(ShouldSkipError(err))
                return ER_CONTINUE;

        const wchar_t* lastFuncToSkip = L"debug_OnError";
        wchar_t buf[400];
        wchar_t err_buf[200]; StatusDescription(err, err_buf, ARRAY_SIZE(err_buf));
        swprintf_s(buf, ARRAY_SIZE(buf), L"Function call failed: return value was %lld (%ls)", (long long)err, err_buf);
        return debug_DisplayError(buf, DE_MANUAL_BREAK, context, lastFuncToSkip, file,line,func, suppress);
}

ErrorReaction debug_OnAssertionFailure(const wchar_t* expr, atomic_bool* suppress, const wchar_t* file, int line, const char* func)
{
        CACHE_ALIGNED(u8) context[DEBUG_CONTEXT_SIZE];
        (void)debug_CaptureContext(context);

        const wchar_t* lastFuncToSkip = L"debug_OnAssertionFailure";
        wchar_t buf[400];
        swprintf_s(buf, ARRAY_SIZE(buf), L"Assertion failed: \"%ls\"", expr);
        return debug_DisplayError(buf, DE_MANUAL_BREAK, context, lastFuncToSkip, file,line,func, suppress);
}