https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89100
Bug ID: 89100 Summary: Default widths for i, f and g format specifiers in format strings Product: gcc Version: 9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: mark.eggleston at codethink dot com Target Milestone: --- Created attachment 45548 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45548&action=edit Patch to support default widths for f, g and i gfortran as of revision: svn+ssh://gcc.gnu.org/svn/gcc/trunk@268360 Fortran currently rejects format specifiers i, f and g without widths, e.g: 24 | write(buffer, "(A, F, A)") ':',real_4,':' | 1 Error: Nonnegative width required in format string at (1) The PGI Fortran compiler 18.10 silently accepts this with no compiler options. Jakub Jelinek provided this link https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-default-widths-for-data-edit-descriptors showing that ifort also defaults the widths of i, f and g. Please find attach a patch that provides default widths for f, g and i. As this feature is non-standard and most likely originated with DEC Fortran it is only available using the option -fdec-format-defaults which is also enabled by -fdec. For trunk and supported versions.