dmd.chkformat

Check the arguments to printf and scanf against the format string.

Authors

Walter Bright

License

Boost License 1.0

Source: chkformat.d

Documentation: https://dlang.org/phobos/dmd_chkformat.html

Coverage: https://codecov.io/gh/dlang/dmd/src/master/src/dmd/chkformat.d

  • checkPrintfFormat

    Declaration

    bool checkPrintfFormat(const ref Loc loc, scope const char[] format, scope Expression[] args, bool isVa_list);

    Check that arguments to a printf format string are compatible with that string. Issue errors for incompatibilities.

    Discussion

    Follows the C99 specification for printf.

    Takes a generous, rather than strict, view of compatiblity. For example, an unsigned value can be formatted with a signed specifier.

    Diagnosed incompatibilities are:

    1. incompatible sizes which will cause argument misalignment
    2. deferencing arguments that are not pointers
    3. insufficient number of arguments
    4. struct arguments
    5. array and slice arguments
    6. non-pointer arguments to s specifier
    7. non-standard formats
    8. undefined behavior per C99
    Per the C Standard, extra arguments are ignored.

    No attempt is made to fix the arguments or the format string.

    Parameters

    Loc loc

    location for error messages

    char[] format

    format string

    Expression[] args

    arguments to match with format string

    bool isVa_list

    if a "v" function (format check only)

    Return Value

    true if errors occurred

    References: C99 7.19.6.1 https://www.cplusplus.com/reference/cstdio/printf/

  • checkScanfFormat

    Declaration

    bool checkScanfFormat(const ref Loc loc, scope const char[] format, scope Expression[] args, bool isVa_list);

    Check that arguments to a scanf format string are compatible with that string. Issue errors for incompatibilities.

    Discussion

    Follows the C99 specification for scanf.

    Takes a generous, rather than strict, view of compatiblity. For example, an unsigned value can be formatted with a signed specifier.

    Diagnosed incompatibilities are:

    1. incompatible sizes which will cause argument misalignment
    2. deferencing arguments that are not pointers
    3. insufficient number of arguments
    4. struct arguments
    5. array and slice arguments
    6. non-standard formats
    7. undefined behavior per C99
    Per the C Standard, extra arguments are ignored.

    No attempt is made to fix the arguments or the format string.

    Parameters

    Loc loc

    location for error messages

    char[] format

    format string

    Expression[] args

    arguments to match with format string

    bool isVa_list

    if a "v" function (format check only)

    Return Value

    true if errors occurred

    References: C99 7.19.6.2 https://www.cplusplus.com/reference/cstdio/scanf/