Edited some module descriptions

[deark.git] / src / deark-win.c

// This file is part of Deark.
// Copyright (C) 2016 Jason Summers
// See the file COPYING for terms of use.

// Functions specific to Microsoft Windows, especially those that require
// windows.h.

#define DE_NOT_IN_MODULE
#include "deark-config.h"

#ifdef DE_WINDOWS

#include <windows.h>

#include <sys/stat.h>
#include <sys/types.h>

// This file is overloaded, in that it contains functions intended to only
// be used internally, as well as functions intended only for the
// command-line utility. That's why we need both deark-user.h and
// deark-private.h.
#include "deark-private.h"
#include "deark-user.h"

#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
#endif

// Windows-specific contextual data, mainly for console settings.
struct de_platform_data {
        HANDLE msgs_HANDLE;
        int msgs_HANDLE_is_console;
        WORD orig_console_attribs;
        WORD inverse_console_attribs;
};

void de_vsnprintf(char *buf, size_t buflen, const char *fmt, va_list ap)
{
        _vsnprintf_s(buf, buflen, _TRUNCATE, fmt, ap);
}

char *de_strdup(deark *c, const char *s)
{
        char *s2;

        s2 = _strdup(s);
        if(!s2) {
                de_err(c, "Memory allocation failed");
                de_fatalerror(c);
                return NULL;
        }
        return s2;
}

i64 de_strtoll(const char *string, char **endptr, int base)
{
        return _strtoi64(string, endptr, base);
}

void de_utf8_to_oem(deark *c, const char *src, char *dst, size_t dstlen)
{
        WCHAR *srcW;
        int ret;

        srcW = de_utf8_to_utf16_strdup(c, src);

        // FIXME: An issue is that WideCharToMultiByte translates some printable
        // Unicode characters to OEM graphics characters below 0x20. For example, for
        // CP437, U+000A (LINE FEED) and U+25D9 (INVERSE WHITE CIRCLE) are both
        // translated to 0x0a.
        // The printf-like functions we will use on the translated string interpret
        // bytes below 0x20 as ASCII control characters, so U+25D9 will end up being
        // misinterpreted as a newline.
        // I am not sure what to do about this. It might be possible to change the
        // mode that printf uses, but we at least need newlines to work.
        // Ideally, we should probably redesign some things so that de_utf8_to_oem()
        // is not used with strings that contain newlines. But that's a lot of work
        // for an obscure feature.
        ret = WideCharToMultiByte(CP_OEMCP, 0, srcW, -1, dst, (int)dstlen, NULL, NULL);
        if(ret<1) {
                dst[0]='\0';
        }

        de_free(c, srcW);
}

static char *de_utf16_to_utf8_strdup(deark *c, const WCHAR *src)
{
        char *dst;
        int dstlen;
        int ret;

        // Calculate the size required by the target string.
        ret = WideCharToMultiByte(CP_UTF8, 0, src, -1, NULL, 0, NULL, NULL);
        if(ret<1) return NULL;

        dstlen = ret;
        dst = (char*)de_malloc(c, dstlen);

        ret = WideCharToMultiByte(CP_UTF8, 0, src, -1, dst, dstlen, NULL, NULL);
        if(ret<1) {
                de_free(c, dst);
                return NULL;
        }
        return dst;
}

wchar_t *de_utf8_to_utf16_strdup(deark *c, const char *src)
{
        WCHAR *dst;
        int dstlen;
        int ret;

        // Calculate the size required by the target string.
        ret = MultiByteToWideChar(CP_UTF8, 0, src, -1, NULL, 0);
        if(ret<1) {
                de_err(c, "Encoding conversion failed");
                de_fatalerror(c);
                return NULL;
        }

        dstlen = ret;
        dst = (WCHAR*)de_mallocarray(c, dstlen, sizeof(WCHAR));

        ret = MultiByteToWideChar(CP_UTF8, 0, src, -1, dst, dstlen);
        if(ret<1) {
                de_free(c, dst);
                de_err(c, "Encoding conversion failed");
                de_fatalerror(c);
                return NULL;
        }
        return dst;
}

// Convert a string from utf8 to utf16, then write it to a FILE
// (e.g. using fputws).
void de_utf8_to_utf16_to_FILE(deark *c, const char *src, FILE *f)
{
#define DST_SMALL_SIZE 1024
        WCHAR dst_small[DST_SMALL_SIZE];
        WCHAR *dst_large;
        int ret;

        ret = MultiByteToWideChar(CP_UTF8, 0, src, -1, dst_small, DST_SMALL_SIZE);
        if(ret>=1) {
                // Our "small" buffer was big enough for the converted string.
                fputws(dst_small, f);
                return;
        }

        // Our "small" buffer was not big enough. Do it the slow way.
        // (Unfortunately, MultiByteToWideChar doesn't have a way to automatically
        // tell us the required buffer size in the case that the supplied buffer
        // was not big enough. So we end up calling it three times, when two should
        // have been sufficient. But this is a rare code path.)
        dst_large = de_utf8_to_utf16_strdup(c, src);
        fputws(dst_large, f);
        de_free(c, dst_large);
}

static FILE* de_fopenW(deark *c, const WCHAR *fnW, const WCHAR *modeW,
        char *errmsg, size_t errmsg_len)
{
        FILE *f = NULL;
        errno_t errcode;

        errcode = _wfopen_s(&f, fnW, modeW);

        errmsg[0] = '\0';

        if(errcode!=0) {
                strerror_s(errmsg, (size_t)errmsg_len, (int)errcode);
                f=NULL;
        }
        return f;
}

static int de_examine_file_by_fd(deark *c, int fd, i64 *len,
        char *errmsg, size_t errmsg_len, unsigned int *returned_flags)
{
        struct __stat64 stbuf;
        int retval = 0;

        *returned_flags = 0;

        de_zeromem(&stbuf, sizeof(struct __stat64));

        if(0 != _fstat64(fd, &stbuf)) {
                strerror_s(errmsg, (size_t)errmsg_len, errno);
                goto done;
        }

        if(!(stbuf.st_mode & _S_IFREG)) {
                de_strlcpy(errmsg, "Not a regular file", errmsg_len);
                return 0;
        }

        *len = (i64)stbuf.st_size;

        retval = 1;

done:
        return retval;
}

FILE* de_fopen_for_read(deark *c, const char *fn, i64 *len,
        char *errmsg, size_t errmsg_len, unsigned int *returned_flags)
{
        int ret;
        FILE *f;
        WCHAR *fnW;

        fnW = de_utf8_to_utf16_strdup(c, fn);

        f = de_fopenW(c, fnW, L"rb", errmsg, errmsg_len);

        de_free(c, fnW);

        if(!f) {
                return NULL;
        }

        ret = de_examine_file_by_fd(c, _fileno(f), len, errmsg, errmsg_len,
                returned_flags);
        if(!ret) {
                de_fclose(f);
                return NULL;
        }

        return f;
}

// flags: 0x1 = append instead of overwriting
FILE* de_fopen_for_write(deark *c, const char *fn,
        char *errmsg, size_t errmsg_len, int overwrite_mode,
        unsigned int flags)
{
        const WCHAR *modeW;
        WCHAR *fnW = NULL;
        FILE *f_ret = NULL;

        // A simple check to make it harder to accidentally overwrite the input
        // file. (But it can easily be defeated.)
        // TODO?: Make this more robust.
        if(c->input_filename && !de_strcasecmp(fn, c->input_filename)) {
                de_err(c, "Refusing to write to %s: Same as input filename", fn);
                de_fatalerror(c);
                de_strlcpy(errmsg, "", errmsg_len);
                goto done;
        }

        modeW = (flags&0x1) ? L"ab" : L"wb";
        fnW = de_utf8_to_utf16_strdup(c, fn);

        if(overwrite_mode==DE_OVERWRITEMODE_NEVER) {
                DWORD fa = GetFileAttributesW(fnW);
                if(fa != INVALID_FILE_ATTRIBUTES) {
                        de_strlcpy(errmsg, "Output file already exists", errmsg_len);
                        goto done;
                }
        }

        f_ret = de_fopenW(c, fnW, modeW, errmsg, errmsg_len);

done:
        de_free(c, fnW);
        return f_ret;
}

int de_fseek(FILE *fp, i64 offs, int whence)
{
        return _fseeki64(fp, (__int64)offs, whence);
}

i64 de_ftell(FILE *fp)
{
        return (i64)_ftelli64(fp);
}

int de_fclose(FILE *fp)
{
        return fclose(fp);
}

static void update_file_time(dbuf *f)
{
        WCHAR *fnW = NULL;
        HANDLE fh = INVALID_HANDLE_VALUE;
        i64 ft;
        FILETIME wrtime;
        deark *c;

        if(f->btype!=DBUF_TYPE_OFILE) return;
        if(!f->fi_copy) return;
        if(!f->fi_copy->timestamp[DE_TIMESTAMPIDX_MODIFY].is_valid) return;
        if(!f->name) return;
        c = f->c;

        ft = de_timestamp_to_FILETIME(&f->fi_copy->timestamp[DE_TIMESTAMPIDX_MODIFY]);
        if(ft==0) goto done;
        fnW = de_utf8_to_utf16_strdup(c, f->name);
        fh = CreateFileW(fnW, FILE_WRITE_ATTRIBUTES, FILE_SHARE_READ, NULL,
                OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
        if(fh==INVALID_HANDLE_VALUE) goto done;

        wrtime.dwHighDateTime = (DWORD)(((u64)ft)>>32);
        wrtime.dwLowDateTime = (DWORD)(((u64)ft)&0xffffffffULL);
        SetFileTime(fh, NULL, NULL, &wrtime);

done:
        if(fh != INVALID_HANDLE_VALUE) {
                CloseHandle(fh);
        }
        de_free(c, fnW);
}

void de_update_file_attribs(dbuf *f, u8 preserve_file_times)
{
        // [Updating file permissions not implemented on Windows.]

        if(preserve_file_times) {
                update_file_time(f);
        }
}

char **de_convert_args_to_utf8(int argc, wchar_t **argvW)
{
        int i;
        char **argvUTF8;

        argvUTF8 = (char**)de_mallocarray(NULL, argc, sizeof(char*));

        // Convert parameters to UTF-8
        for(i=0;i<argc;i++) {
                argvUTF8[i] = de_utf16_to_utf8_strdup(NULL, argvW[i]);
        }

        return argvUTF8;
}

void de_free_utf8_args(int argc, char **argv)
{
        int i;

        for(i=0;i<argc;i++) {
                de_free(NULL, argv[i]);
        }
        de_free(NULL, argv);
}

struct de_platform_data *de_platformdata_create(void)
{
        struct de_platform_data *plctx;

        plctx = de_malloc(NULL, sizeof(struct de_platform_data));
        return plctx;
}

void de_platformdata_destroy(struct de_platform_data *plctx)
{
        if(!plctx) return;
        de_free(NULL, plctx);
}

// Set the plctx->msgs_HANDLE field, for later use.
// n: 1=stdout, 2=stderr
void de_winconsole_init_handle(struct de_platform_data *plctx, int n)
{
        DWORD consolemode=0;
        BOOL b;

        plctx->msgs_HANDLE = GetStdHandle((n==2)?STD_ERROR_HANDLE:STD_OUTPUT_HANDLE);

        b = GetConsoleMode(plctx->msgs_HANDLE, &consolemode);
        plctx->msgs_HANDLE_is_console = b ? 1 : 0;
}

// Does plctx->msgs_HANDLE seem to be a Windows console?
int de_winconsole_is_console(struct de_platform_data *plctx)
{
        return plctx->msgs_HANDLE_is_console;
}

void de_winconsole_set_UTF8_CP(struct de_platform_data *plctx)
{
        // I hate to do this, but it's the least-bad fix I've found for some issues
        // that have cropped up in the wake of Cygwin+Mintty using Windows 10's
        // ConPTY features (as of Cygwin 3.1.0 - Dec. 2019).

        // Note that, somewhat ironically, we only change the console code page if
        // the output is *not* going directly to a console.

        // Unfortunately, rude as it is not to do so, we can't restore the original
        // code page settings when we're done. If we restore the code page, we have to
        // do it after all of the output has reached the console. But if our output
        // is being piped through a pager, some of it likely won't reach the console
        // until after our program ends.
        SetConsoleCP(65001);
        SetConsoleOutputCP(65001);
}

// Save current attribs to plctx.
// Returns 1 on success.
void de_winconsole_record_current_attributes(struct de_platform_data *plctx)
{
        CONSOLE_SCREEN_BUFFER_INFO csbi;

        if(GetConsoleScreenBufferInfo(plctx->msgs_HANDLE, &csbi)) {
                plctx->orig_console_attribs = csbi.wAttributes;
        }
        else {
                plctx->orig_console_attribs = 0x0007;
        }

        plctx->inverse_console_attribs =
                (plctx->orig_console_attribs&0xff00) |
                ((plctx->orig_console_attribs&0x000f)<<4) |
                ((plctx->orig_console_attribs&0x00f0)>>4);
}

// If we think this computer supports 24-bit color ANSI, enable it (if needed)
// and return 1.
// Otherwise return 0.
int de_winconsole_try_enable_ansi24(struct de_platform_data *plctx)
{
        // Note: Maybe we should check for Windows 10 (e.g. using
        // IsWindows10OrGreater()) before calling SetConsoleMode(), but maybe that's
        // just be a waste of time. Also, IsWindows10OrGreater() is fragile because
        // it requires a .manifest file with certain properties.

        // TODO: This is not correct. AFAIK, there is a range of Windows 10 builds
        // that support ANSI codes, but do not support 24-bit color ANSI.
        // I don't know a *good* way to detect 24-bit color support.
        // Querying the Windows build number is possible, but requires some hackery,
        // because Microsoft *really* does not want applications to do that.
        return de_winconsole_enable_ansi(plctx);
}

int de_winconsole_enable_ansi(struct de_platform_data *plctx)
{
        BOOL b;
        DWORD oldmode = 0;

        if(!plctx->msgs_HANDLE_is_console) return 1;

        b = GetConsoleMode(plctx->msgs_HANDLE, &oldmode);
        if(!b) return 0;
        if(oldmode & ENABLE_VIRTUAL_TERMINAL_PROCESSING) return 1; // Already enabled

        // The ENABLE_VIRTUAL_TERMINAL_PROCESSING mode is what enables interpretation
        // of ANSI escape codes.

        // Note: This mode seems to be specific to the console window, not to the specific
        // I/O handle that we pass to SetConsoleMode.
        // I.e. if both stderr and stdout refer to the console, it doesn't matter which
        // one we use here.
        // And if we write an ANSI code to stderr, it could also affect stdout.
        // That's not what we want, but it shouldn't cause much of a problem for us.

        // Note: This mode seems to get reset automatically when the process ends.
        // It doesn't affect future processes that run in the same console.
        // So we don't have to try to set it back when we're done.

        b = SetConsoleMode(plctx->msgs_HANDLE, oldmode | ENABLE_VIRTUAL_TERMINAL_PROCESSING);
        if(!b) return 0;
        return 1;
}

void de_winconsole_highlight(struct de_platform_data *plctx, int x)
{
        if(x) {
                SetConsoleTextAttribute(plctx->msgs_HANDLE, plctx->inverse_console_attribs);
        }
        else {
                SetConsoleTextAttribute(plctx->msgs_HANDLE, plctx->orig_console_attribs);
        }
}

// Note: Need to keep this function in sync with the implementation in deark-unix.c.
void de_current_time_to_timestamp(struct de_timestamp *ts)
{
        FILETIME ft1;
        i64 ft;

        GetSystemTimeAsFileTime(&ft1);
        ft = (i64)(((u64)ft1.dwHighDateTime)<<32 | ft1.dwLowDateTime);
        de_FILETIME_to_timestamp(ft, ts, 0x1);
}

void de_exitprocess(int s)
{
        exit(s);
}

#endif // DE_WINDOWS