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ACPICA: String conversions: Cleanup/format comments. No functional ch…
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ACPICA commit 33e38cd2406709b13fa0a7821e588505b3771163

Cleanup some of the language used in the large comments, especially
the ones that reference the rules in the ACPI spec.
Fixed some typos.

Link: https://github.com/acpica/acpica/commit/33e38cd24067
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Bob Moore authored and Rafael J. Wysocki committed Oct 3, 2017
1 parent fe97d28 commit 72a2935
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Showing 2 changed files with 74 additions and 78 deletions.
48 changes: 22 additions & 26 deletions drivers/acpi/acpica/utstrsuppt.c
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
/*******************************************************************************
*
* Module Name: utstrsuppt - string-to-integer conversion support functions
* Module Name: utstrsuppt - Support functions for string-to-integer conversion
*
******************************************************************************/

Expand Down Expand Up @@ -83,7 +83,7 @@ acpi_status acpi_ut_convert_octal_string(char *string, u64 *return_value_ptr)

while (*string) {

/* Must be ASCII 0-7, otherwise terminate with no error */
/* Character must be ASCII 0-7, otherwise terminate with no error */

if (!(ACPI_IS_OCTAL_DIGIT(*string))) {
break;
Expand Down Expand Up @@ -132,7 +132,7 @@ acpi_status acpi_ut_convert_decimal_string(char *string, u64 *return_value_ptr)

while (*string) {

/* Must be ASCII 0-9, otherwise terminate with no error */
/* Character must be ASCII 0-9, otherwise terminate with no error */

if (!isdigit(*string)) {
break;
Expand Down Expand Up @@ -210,18 +210,17 @@ acpi_status acpi_ut_convert_hex_string(char *string, u64 *return_value_ptr)
*
* PARAMETERS: string - Pointer to input ASCII string
*
* RETURN: Next character after the leading zeros. This behavior may be
* Used by the caller to detect end-of-string.
* RETURN: Next character after any leading zeros. This character may be
* used by the caller to detect end-of-string.
*
* DESCRIPTION: Remove all leading zeros in the input string. Return the
* next character after the final zero to check for the end
* of the string (NULL terminator).
* DESCRIPTION: Remove any leading zeros in the input string. Return the
* next character after the final ASCII zero to enable the caller
* to check for the end of the string (NULL terminator).
*
******************************************************************************/

char acpi_ut_remove_leading_zeros(char **string)
{
/* Skip all leading zeros */

while (**string == ACPI_ASCII_ZERO) {
*string += 1;
Expand All @@ -236,9 +235,9 @@ char acpi_ut_remove_leading_zeros(char **string)
*
* PARAMETERS: string - Pointer to input ASCII string
*
* RETURN: TRUE if a 0x prefix was found
* RETURN: TRUE if a "0x" prefix was found at the start of the string
*
* DESCRIPTION: Detect and remove a hex 0x prefix
* DESCRIPTION: Detect and remove a hex "0x" prefix
*
******************************************************************************/

Expand All @@ -260,7 +259,8 @@ u8 acpi_ut_detect_hex_prefix(char **string)
*
* PARAMETERS: string - Pointer to input ASCII string
*
* RETURN: True if an octal 0 prefix was found
* RETURN: True if an octal "0" prefix was found at the start of the
* string
*
* DESCRIPTION: Detect and remove an octal prefix (zero)
*
Expand All @@ -282,23 +282,22 @@ u8 acpi_ut_detect_octal_prefix(char **string)
* FUNCTION: acpi_ut_insert_digit
*
* PARAMETERS: accumulated_value - Current value of the integer value
* accumulator. The New value is
* accumulator. The new value is
* returned here.
* base - Radix, either 8/10/16 supported
* base - Radix, either 8/10/16
* ascii_digit - ASCII single digit to be inserted
*
* RETURN: Status and result of convert/insert operation. The only
* exception is numeric overflow of either the multiply or the
* add operations.
* RETURN: Status and result of the convert/insert operation. The only
* possible returned exception code is numeric overflow of
* either the multiply or add conversion operations.
*
* DESCRIPTION: Generic conversion and insertion function for all bases:
*
* 1) Multiply the current accumulated converted value by the
* 1) Multiply the current accumulated/converted value by the
* base in order to make room for the new character.
*
* 2) Add the current accumulated/converted value the new
* character (after the character has been converted to a binary
* value).
* 2) Convert the new character to binary and add it to the
* current accumulated value.
*
* Note: The only possible exception indicates an integer
* overflow (AE_NUMERIC_OVERFLOW)
Expand All @@ -318,17 +317,14 @@ acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit)
return (status);
}

/* Add in the new digit, and store to the caller's accumulated value */
/* Add in the new digit, and store the sum to the accumulated value */

status =
acpi_ut_strtoul_add64(product,
acpi_ut_ascii_char_to_hex(ascii_digit),
accumulated_value);
if (ACPI_FAILURE(status)) {
return (status);
}

return (AE_OK);
return (status);
}

/*******************************************************************************
Expand Down
104 changes: 52 additions & 52 deletions drivers/acpi/acpica/utstrtoul64.c
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
/*******************************************************************************
*
* Module Name: utstrtoul64 - string-to-integer support for both 64-bit
* and 32-bit integers
* Module Name: utstrtoul64 - String-to-integer conversion support for both
* 64-bit and 32-bit integers
*
******************************************************************************/

Expand Down Expand Up @@ -50,21 +50,23 @@ ACPI_MODULE_NAME("utstrtoul64")

/*******************************************************************************
*
* This module contains the external string to 64/32-bit unsigned integer
* This module contains the top-level string to 64/32-bit unsigned integer
* conversion functions:
*
* 1) Standard strtoul() function with 64-bit support. This is mostly used by
* the iASL compiler.
* 1) A standard strtoul() function that supports 64-bit integers, base
* 8/10/16, with integer overflow support. This is used mainly by the
* iASL compiler, which implements tighter constraints on integer
* constants than the runtime (interpreter) integer-to-string conversions.
* 2) Runtime "Explicit conversion" as defined in the ACPI specification.
* 3) Runtime "Implicit conversion" as defined in the ACPI specification.
*
* Current users of this module:
*
* iASL - Preprocessor (constants and math expressions)
* iASL - Main parser, conversion of constants to integers
* iASL - Data Table Compiler parser (constants and math expressions)
* interpreter - Implicit and explicit conversions, GPE method names
* debugger - Command line input string conversion
* iASL - Main parser, conversion of constants to integers
* iASL - Data Table Compiler parser (constant math expressions)
* iASL - Preprocessor (constant math expressions)
* acpi_dump - Input table addresses
* acpi_exec - Testing of the acpi_ut_strtoul64 function
*
Expand All @@ -77,15 +79,17 @@ ACPI_MODULE_NAME("utstrtoul64")
* a 64-bit constant is wrongly defined in a 32-bit DSDT/SSDT.
*
* In ACPI, the only place where octal numbers are supported is within
* the ASL language itself. There is no runtime support for octal.
* the ASL language itself. This is implemented via the main acpi_ut_strtoul64
* interface. According the ACPI specification, there is no ACPI runtime
* support for octal string conversions.
*
******************************************************************************/
/*******************************************************************************
*
* FUNCTION: acpi_ut_strtoul64
*
* PARAMETERS: string - Null terminated input string.
* Must be a valid pointer
* PARAMETERS: string - Null terminated input string,
* must be a valid pointer
* return_value - Where the converted integer is
* returned. Must be a valid pointer
*
Expand All @@ -98,9 +102,9 @@ ACPI_MODULE_NAME("utstrtoul64")
*
* Current users of this function:
*
* iASL - Preprocessor (constant math expressions)
* iASL - Main parser, conversion of ASL constants to integers
* iASL - Data Table Compiler parser (constant math expressions)
* iASL - Preprocessor (constants and math expressions)
* iASL - Main ASL parser, conversion of ASL constants to integers
* iASL - Data Table Compiler parser (constants and math expressions)
*
******************************************************************************/
acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
Expand All @@ -112,25 +116,22 @@ acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)

*return_value = 0;

/* Null return string returns a value of zero */
/* A NULL return string returns a value of zero */

if (*string == 0) {
return_ACPI_STATUS(AE_OK);
}

/*
* 1) The "0x" prefix indicates base 16. Per the ACPI specification,
* the "0x" prefix is only allowed for implicit (non-strict) conversions.
* However, we always allow it for compatibility with older ACPICA and
* just plain on principle.
* 1) Check for a hex constant. A "0x" prefix indicates base 16.
*/
if (acpi_ut_detect_hex_prefix(&string)) {
base = 16;
}

/*
* 2) Check for an octal constant, defined to be a leading zero
* followed by an valid octal digit (0-7)
* followed by sequence of octal digits (0-7)
*/
else if (acpi_ut_detect_octal_prefix(&string)) {
base = 8;
Expand All @@ -142,7 +143,7 @@ acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)

/*
* Perform the base 8, 10, or 16 conversion. A numeric overflow will
* return an exception.
* return an exception (to allow iASL to flag the statement).
*/
switch (base) {
case 8:
Expand All @@ -154,11 +155,8 @@ acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
break;

case 16:
status = acpi_ut_convert_hex_string(string, return_value);
break;

default:
status = AE_AML_INTERNAL; /* Should never happen */
status = acpi_ut_convert_hex_string(string, return_value);
break;
}

Expand All @@ -169,51 +167,53 @@ acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
*
* FUNCTION: acpi_ut_implicit_strtoul64
*
* PARAMETERS: string - Null terminated input string.
* Must be a valid pointer
* PARAMETERS: string - Null terminated input string,
* must be a valid pointer
*
* RETURN: Converted integer
*
* DESCRIPTION: Perform a 64-bit conversion with restrictions placed upon
* an "implicit conversion" by the ACPI specification. Used by
* many ASL operators that require an integer operand, and support
* an automatic (implicit) conversion from a string operand
* to the final integer operand. The restriction is that only
* hex strings are supported.
* to the final integer operand. The major restriction is that
* only hex strings are supported.
*
* -----------------------------------------------------------------------------
*
* Base is always 16, either with or without the 0x prefix.
* Base is always 16, either with or without the 0x prefix. Decimal and
* Octal strings are not supported, as per the ACPI specification.
*
* Examples (both are hex values):
* Add ("BA98", Arg0, Local0)
* Subtract ("0x12345678", Arg1, Local1)
*
* Rules extracted from the ACPI specification:
* Conversion rules as extracted from the ACPI specification:
*
* The converted integer is initialized to the value zero.
* The ASCII string is interpreted as a hexadecimal constant.
* The ASCII string is always interpreted as a hexadecimal constant.
*
* 1) A "0x" prefix is not allowed. However, ACPICA allows this as an
* ACPI extension on general principle. (NO ERROR)
* 1) According to the ACPI specification, a "0x" prefix is not allowed.
* However, ACPICA allows this as an ACPI extension on general
* principle. (NO ERROR)
*
* 2) Terminates when the size of an integer is reached (32 or 64 bits).
* There are no numeric overflow conditions. (NO ERROR)
* 2) The conversion terminates when the size of an integer is reached
* (32 or 64 bits). There are no numeric overflow conditions. (NO ERROR)
*
* 3) The first non-hex character terminates the conversion and returns
* the current accumulated value of the converted integer (NO ERROR).
*
* 4) Conversion of a null (zero-length) string to an integer is
* technically allowed. However, ACPICA allows as an ACPI extension.
* The conversion returns the value 0. (NO ERROR)
* technically not allowed. However, ACPICA allows this as an ACPI
* extension. The conversion returns the value 0. (NO ERROR)
*
* Note: there are no error conditions returned by this function. At
* NOTE: There are no error conditions returned by this function. At
* the minimum, a value of zero is returned.
*
* Current users of this function:
*
* interpreter - All runtime implicit conversions, as per ACPI specification
* iASL - Data Table Compiler parser (constant math expressions)
* iASL - Data Table Compiler parser (constants and math expressions)
*
******************************************************************************/

Expand Down Expand Up @@ -247,8 +247,8 @@ u64 acpi_ut_implicit_strtoul64(char *string)
*
* FUNCTION: acpi_ut_explicit_strtoul64
*
* PARAMETERS: string - Null terminated input string.
* Must be a valid pointer
* PARAMETERS: string - Null terminated input string,
* must be a valid pointer
*
* RETURN: Converted integer
*
Expand All @@ -258,35 +258,35 @@ u64 acpi_ut_implicit_strtoul64(char *string)
*
* -----------------------------------------------------------------------------
*
* Base is either 10 (default) or 16 (with 0x prefix). There is no octal
* (base 8), as per the ACPI specification.
* Base is either 10 (default) or 16 (with 0x prefix). Octal (base 8) strings
* are not supported, as per the ACPI specification.
*
* Examples:
* to_integer ("1000") Decimal
* to_integer ("0xABCD") Hex
*
* Rules extracted from the ACPI specification:
* Conversion rules as extracted from the ACPI specification:
*
* 1) Thi input string is either a decimal or hexadecimal numeric string.
* 1) The input string is either a decimal or hexadecimal numeric string.
* A hex value must be prefixed by "0x" or it is interpreted as decimal.
*
* 2) The value must not exceed the maximum of an integer value
* (32 or 64 bits). The ACPI specification states the behavior is
* "unpredictable", so ACPICA matches the behavior of the implicit
* conversion case. There are no numeric overflow conditions. (NO ERROR)
*
* 3) Behavior on the first non-hex character is not specified by the ACPI
* 3) Behavior on the first non-hex character is not defined by the ACPI
* specification (for the to_integer operator), so ACPICA matches the
* behavior of the implicit conversion case. It terminates the
* conversion and returns the current accumulated value of the converted
* integer. (NO ERROR)
*
* 4) Conversion of a null (zero-length) string to an integer is
* technically allowed. However, ACPICA allows as an ACPI extension.
* The conversion returns the value 0. (NO ERROR)
* technically not allowed. However, ACPICA allows this as an ACPI
* extension. The conversion returns the value 0. (NO ERROR)
*
* Note: there are no error conditions returned by this function. At
* the minimum, a value of zero is returned.
* NOTE: There are no error conditions returned by this function. At the
* minimum, a value of zero is returned.
*
* Current users of this function:
*
Expand All @@ -303,7 +303,7 @@ u64 acpi_ut_explicit_strtoul64(char *string)

/*
* Only Hex and Decimal are supported, as per the ACPI specification.
* 0x prefix means hex; otherwise decimal is assumed.
* A "0x" prefix indicates hex; otherwise decimal is assumed.
*/
if (acpi_ut_detect_hex_prefix(&string)) {
base = 16;
Expand Down

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