reactos/drivers/bus/acpi/acpica/utilities/utstrtoul64.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: utstrtoul64 - string to 64-bit integer support
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2017, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include "acpi.h"
  45 #include "accommon.h"
  46
  47
  48 /*******************************************************************************
  49  *
  50  * The functions in this module satisfy the need for 64-bit string-to-integer
  51  * conversions on both 32-bit and 64-bit platforms.
  52  *
  53  ******************************************************************************/
  54
  55 #define _COMPONENT          ACPI_UTILITIES
  56         ACPI_MODULE_NAME    ("utstrtoul64")
  57
  58 /* Local prototypes */
  59
  60 static UINT64
  61 AcpiUtStrtoulBase10 (
  62     char                    *String,
  63     UINT32                  Flags);
  64
  65 static UINT64
  66 AcpiUtStrtoulBase16 (
  67     char                    *String,
  68     UINT32                  Flags);
  69
  70
  71 /*******************************************************************************
  72  *
  73  * String conversion rules as written in the ACPI specification. The error
  74  * conditions and behavior are different depending on the type of conversion.
  75  *
  76  *
  77  * Implicit data type conversion: string-to-integer
  78  * --------------------------------------------------
  79  *
  80  * Base is always 16. This is the ACPI_STRTOUL_BASE16 case.
  81  *
  82  * Example:
  83  *      Add ("BA98", Arg0, Local0)
  84  *
  85  * The integer is initialized to the value zero.
  86  * The ASCII string is interpreted as a hexadecimal constant.
  87  *
  88  *  1)  A "0x" prefix is not allowed. However, ACPICA allows this for
  89  *      compatibility with previous ACPICA. (NO ERROR)
  90  *
  91  *  2)  Terminates when the size of an integer is reached (32 or 64 bits).
  92  *      (NO ERROR)
  93  *
  94  *  3)  The first non-hex character terminates the conversion without error.
  95  *      (NO ERROR)
  96  *
  97  *  4)  Conversion of a null (zero-length) string to an integer is not
  98  *      allowed. However, ACPICA allows this for compatibility with previous
  99  *      ACPICA. This conversion returns the value 0. (NO ERROR)
 100  *
 101  *
 102  * Explicit data type conversion:  ToInteger() with string operand
 103  * ---------------------------------------------------------------
 104  *
 105  * Base is either 10 (default) or 16 (with 0x prefix)
 106  *
 107  * Examples:
 108  *      ToInteger ("1000")
 109  *      ToInteger ("0xABCD")
 110  *
 111  *  1)  Can be (must be) either a decimal or hexadecimal numeric string.
 112  *      A hex value must be prefixed by "0x" or it is interpreted as a decimal.
 113  *
 114  *  2)  The value must not exceed the maximum of an integer value. ACPI spec
 115  *      states the behavior is "unpredictable", so ACPICA matches the behavior
 116  *      of the implicit conversion case.(NO ERROR)
 117  *
 118  *  3)  Behavior on the first non-hex character is not specified by the ACPI
 119  *      spec, so ACPICA matches the behavior of the implicit conversion case
 120  *      and terminates. (NO ERROR)
 121  *
 122  *  4)  A null (zero-length) string is illegal.
 123  *      However, ACPICA allows this for compatibility with previous ACPICA.
 124  *      This conversion returns the value 0. (NO ERROR)
 125  *
 126  ******************************************************************************/
 127
 128
 129 /*******************************************************************************
 130  *
 131  * FUNCTION:    AcpiUtStrtoul64
 132  *
 133  * PARAMETERS:  String                  - Null terminated input string
 134  *              Flags                   - Conversion info, see below
 135  *              ReturnValue             - Where the converted integer is
 136  *                                        returned
 137  *
 138  * RETURN:      Status and Converted value
 139  *
 140  * DESCRIPTION: Convert a string into an unsigned value. Performs either a
 141  *              32-bit or 64-bit conversion, depending on the input integer
 142  *              size in Flags (often the current mode of the interpreter).
 143  *
 144  * Values for Flags:
 145  *      ACPI_STRTOUL_32BIT      - Max integer value is 32 bits
 146  *      ACPI_STRTOUL_64BIT      - Max integer value is 64 bits
 147  *      ACPI_STRTOUL_BASE16     - Input string is hexadecimal. Default
 148  *                                is 10/16 based on string prefix (0x).
 149  *
 150  * NOTES:
 151  *   Negative numbers are not supported, as they are not supported by ACPI.
 152  *
 153  *   Supports only base 16 or base 10 strings/values. Does not
 154  *   support Octal strings, as these are not supported by ACPI.
 155  *
 156  * Current users of this support:
 157  *
 158  *  Interpreter - Implicit and explicit conversions, GPE method names
 159  *  Debugger    - Command line input string conversion
 160  *  iASL        - Main parser, conversion of constants to integers
 161  *  iASL        - Data Table Compiler parser (constant math expressions)
 162  *  iASL        - Preprocessor (constant math expressions)
 163  *  AcpiDump    - Input table addresses
 164  *  AcpiExec    - Testing of the AcpiUtStrtoul64 function
 165  *
 166  * Note concerning callers:
 167  *   AcpiGbl_IntegerByteWidth can be used to set the 32/64 limit. If used,
 168  *   this global should be set to the proper width. For the core ACPICA code,
 169  *   this width depends on the DSDT version. For iASL, the default byte
 170  *   width is always 8 for the parser, but error checking is performed later
 171  *   to flag cases where a 64-bit constant is defined in a 32-bit DSDT/SSDT.
 172  *
 173  ******************************************************************************/
 174
 175 ACPI_STATUS
 176 AcpiUtStrtoul64 (
 177     char                    *String,
 178     UINT32                  Flags,
 179     UINT64                  *ReturnValue)
 180 {
 181     ACPI_STATUS             Status = AE_OK;
 182     UINT32                  Base;
 183
 184
 185     ACPI_FUNCTION_TRACE_STR (UtStrtoul64, String);
 186
 187
 188     /* Parameter validation */
 189
 190     if (!String || !ReturnValue)
 191     {
 192         return_ACPI_STATUS (AE_BAD_PARAMETER);
 193     }
 194
 195     *ReturnValue = 0;
 196
 197     /* Check for zero-length string, returns 0 */
 198
 199     if (*String == 0)
 200     {
 201         return_ACPI_STATUS (AE_OK);
 202     }
 203
 204     /* Skip over any white space at start of string */
 205
 206     while (isspace ((int) *String))
 207     {
 208         String++;
 209     }
 210
 211     /* End of string? return 0 */
 212
 213     if (*String == 0)
 214     {
 215         return_ACPI_STATUS (AE_OK);
 216     }
 217
 218     /*
 219      * 1) The "0x" prefix indicates base 16. Per the ACPI specification,
 220      * the "0x" prefix is only allowed for implicit (non-strict) conversions.
 221      * However, we always allow it for compatibility with older ACPICA.
 222      */
 223     if ((*String == ACPI_ASCII_ZERO) &&
 224         (tolower ((int) *(String + 1)) == 'x'))
 225     {
 226         String += 2;    /* Go past the 0x */
 227         if (*String == 0)
 228         {
 229             return_ACPI_STATUS (AE_OK);     /* Return value 0 */
 230         }
 231
 232         Base = 16;
 233     }
 234
 235     /* 2) Force to base 16 (implicit conversion case) */
 236
 237     else if (Flags & ACPI_STRTOUL_BASE16)
 238     {
 239         Base = 16;
 240     }
 241
 242     /* 3) Default fallback is to Base 10 */
 243
 244     else
 245     {
 246         Base = 10;
 247     }
 248
 249     /* Skip all leading zeros */
 250
 251     while (*String == ACPI_ASCII_ZERO)
 252     {
 253         String++;
 254         if (*String == 0)
 255         {
 256             return_ACPI_STATUS (AE_OK);     /* Return value 0 */
 257         }
 258     }
 259
 260     /* Perform the base 16 or 10 conversion */
 261
 262     if (Base == 16)
 263     {
 264         *ReturnValue = AcpiUtStrtoulBase16 (String, Flags);
 265     }
 266     else
 267     {
 268         *ReturnValue = AcpiUtStrtoulBase10 (String, Flags);
 269     }
 270
 271     return_ACPI_STATUS (Status);
 272 }
 273
 274
 275 /*******************************************************************************
 276  *
 277  * FUNCTION:    AcpiUtStrtoulBase10
 278  *
 279  * PARAMETERS:  String                  - Null terminated input string
 280  *              Flags                   - Conversion info
 281  *
 282  * RETURN:      64-bit converted integer
 283  *
 284  * DESCRIPTION: Performs a base 10 conversion of the input string to an
 285  *              integer value, either 32 or 64 bits.
 286  *              Note: String must be valid and non-null.
 287  *
 288  ******************************************************************************/
 289
 290 static UINT64
 291 AcpiUtStrtoulBase10 (
 292     char                    *String,
 293     UINT32                  Flags)
 294 {
 295     int                     AsciiDigit;
 296     UINT64                  NextValue;
 297     UINT64                  ReturnValue = 0;
 298
 299
 300     /* Main loop: convert each ASCII byte in the input string */
 301
 302     while (*String)
 303     {
 304         AsciiDigit = *String;
 305         if (!isdigit (AsciiDigit))
 306         {
 307             /* Not ASCII 0-9, terminate */
 308
 309             goto Exit;
 310         }
 311
 312         /* Convert and insert (add) the decimal digit */
 313
 314         AcpiUtShortMultiply (ReturnValue, 10, &NextValue);
 315         NextValue += (AsciiDigit - ACPI_ASCII_ZERO);
 316
 317         /* Check for overflow (32 or 64 bit) - return current converted value */
 318
 319         if (((Flags & ACPI_STRTOUL_32BIT) && (NextValue > ACPI_UINT32_MAX)) ||
 320             (NextValue < ReturnValue)) /* 64-bit overflow case */
 321         {
 322             goto Exit;
 323         }
 324
 325         ReturnValue = NextValue;
 326         String++;
 327     }
 328
 329 Exit:
 330     return (ReturnValue);
 331 }
 332
 333
 334 /*******************************************************************************
 335  *
 336  * FUNCTION:    AcpiUtStrtoulBase16
 337  *
 338  * PARAMETERS:  String                  - Null terminated input string
 339  *              Flags                   - conversion info
 340  *
 341  * RETURN:      64-bit converted integer
 342  *
 343  * DESCRIPTION: Performs a base 16 conversion of the input string to an
 344  *              integer value, either 32 or 64 bits.
 345  *              Note: String must be valid and non-null.
 346  *
 347  ******************************************************************************/
 348
 349 static UINT64
 350 AcpiUtStrtoulBase16 (
 351     char                    *String,
 352     UINT32                  Flags)
 353 {
 354     int                     AsciiDigit;
 355     UINT32                  ValidDigits = 1;
 356     UINT64                  ReturnValue = 0;
 357
 358
 359     /* Main loop: convert each ASCII byte in the input string */
 360
 361     while (*String)
 362     {
 363         /* Check for overflow (32 or 64 bit) - return current converted value */
 364
 365         if ((ValidDigits > 16) ||
 366             ((ValidDigits > 8) && (Flags & ACPI_STRTOUL_32BIT)))
 367         {
 368             goto Exit;
 369         }
 370
 371         AsciiDigit = *String;
 372         if (!isxdigit (AsciiDigit))
 373         {
 374             /* Not Hex ASCII A-F, a-f, or 0-9, terminate */
 375
 376             goto Exit;
 377         }
 378
 379         /* Convert and insert the hex digit */
 380
 381         AcpiUtShortShiftLeft (ReturnValue, 4, &ReturnValue);
 382         ReturnValue |= AcpiUtAsciiCharToHex (AsciiDigit);
 383
 384         String++;
 385         ValidDigits++;
 386     }
 387
 388 Exit:
 389     return (ReturnValue);
 390 }