Report a bug
If you spot a problem with this page, click here to create a Bugzilla issue.
Improve this page
Quickly fork, edit online, and submit a pull request for this page. Requires a signed-in GitHub account. This works well for small changes. If you'd like to make larger changes you may want to consider using a local clone.

dmd.chkformat

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

Source chkformat.d

bool checkPrintfFormat(ref const 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.
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)
Returns:
true if errors occurred
bool checkScanfFormat(ref const 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.
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)
Returns:
true if errors occurred