gfortran's command line options are indexed here without any initial ‘-’ or ‘--’. Where an option has both positive and negative forms (such as -foption and -fno-option), relevant entries in the manual are indexed under the most appropriate form; it may sometimes be useful to look up both forms.
A-predicate=answer: Preprocessing OptionsApredicate=answer: Preprocessing Optionsbackslash: Fortran Dialect OptionsC: Preprocessing OptionsCC: Preprocessing Optionscpp: Preprocessing OptionsdD: Preprocessing OptionsdI: Preprocessing OptionsdM: Preprocessing OptionsdN: Preprocessing OptionsDname: Preprocessing OptionsDname=definition: Preprocessing OptionsdU: Preprocessing Optionsfaggressive-function-elimination: Code Gen Optionsfalign-commons: Code Gen Optionsfall-intrinsics: Fortran Dialect Optionsfblas-matmul-limit: Code Gen Optionsfbounds-check: Code Gen Optionsfcheck: Code Gen Optionsfcheck-array-temporaries: Code Gen Optionsfcoarray: Code Gen Optionsfconvert=conversion: Runtime Optionsfcray-pointer: Fortran Dialect Optionsfd-lines-as-code: Fortran Dialect Optionsfd-lines-as-comments: Fortran Dialect Optionsfdefault-double-8: Fortran Dialect Optionsfdefault-integer-8: Fortran Dialect Optionsfdefault-real-8: Fortran Dialect Optionsfdollar-ok: Fortran Dialect Optionsfdump-fortran-optimized: Debugging Optionsfdump-fortran-original: Debugging Optionsfdump-parse-tree: Debugging Optionsfexternal-blas: Code Gen Optionsff2c: Code Gen Optionsffixed-line-length-n: Fortran Dialect Optionsffpe-summary=list: Debugging Optionsffpe-trap=list: Debugging Optionsffree-form: Fortran Dialect Optionsffree-line-length-n: Fortran Dialect Optionsfimplicit-none: Fortran Dialect Optionsfinit-character: Code Gen Optionsfinit-integer: Code Gen Optionsfinit-local-zero: Code Gen Optionsfinit-logical: Code Gen Optionsfinit-real: Code Gen Optionsfinteger-4-integer-8: Fortran Dialect Optionsfintrinsic-modules-path dir: Directory Optionsfmax-array-constructor: Code Gen Optionsfmax-errors=n: Error and Warning Optionsfmax-identifier-length=n: Fortran Dialect Optionsfmax-stack-var-size: Code Gen Optionsfmax-subrecord-length=length: Runtime Optionsfmodule-private: Fortran Dialect Optionsfno-automatic: Code Gen Optionsfno-backtrace: Debugging Optionsfno-fixed-form: Fortran Dialect Optionsfno-protect-parens: Code Gen Optionsfno-underscoring: Code Gen Optionsfopenmp: Fortran Dialect Optionsfpack-derived: Code Gen Optionsfpp: Preprocessing Optionsfrange-check: Fortran Dialect Optionsfreal-4-real-10: Fortran Dialect Optionsfreal-4-real-16: Fortran Dialect Optionsfreal-4-real-8: Fortran Dialect Optionsfreal-8-real-10: Fortran Dialect Optionsfreal-8-real-16: Fortran Dialect Optionsfreal-8-real-4: Fortran Dialect Optionsfrealloc-lhs: Code Gen Optionsfrecord-marker=length: Runtime Optionsfrecursive: Code Gen Optionsfrepack-arrays: Code Gen Optionsfrontend-optimize: Code Gen Optionsfsecond-underscore: Code Gen Optionsfshort-enums: Fortran 2003 statusfshort-enums: Code Gen Optionsfsign-zero: Runtime Optionsfstack-arrays: Code Gen Optionsfsyntax-only: Error and Warning Optionsfworking-directory: Preprocessing OptionsH: Preprocessing OptionsIdir: Directory Optionsidirafter dir: Preprocessing Optionsimultilib dir: Preprocessing Optionsiprefix prefix: Preprocessing Optionsiquote dir: Preprocessing Optionsisysroot dir: Preprocessing Optionsisystem dir: Preprocessing OptionsJdir: Directory OptionsMdir: Directory Optionsnostdinc: Preprocessing OptionsP: Preprocessing Optionspedantic: Error and Warning Optionspedantic-errors: Error and Warning Optionsstatic-libgfortran: Link Optionsstd=std option: Fortran Dialect OptionsUname: Preprocessing Optionsundef: Preprocessing OptionsWaliasing: Error and Warning OptionsWalign-commons: Error and Warning OptionsWall: Error and Warning OptionsWampersand: Error and Warning OptionsWarray-temporaries: Error and Warning OptionsWc-binding-type: Error and Warning OptionsWcharacter-truncation: Error and Warning OptionsWcompare-reals: Error and Warning OptionsWconversion: Error and Warning OptionsWconversion-extra: Error and Warning OptionsWerror: Error and Warning OptionsWextra: Error and Warning OptionsWfunction-elimination: Error and Warning OptionsWimplicit-interface: Error and Warning OptionsWimplicit-procedure: Error and Warning OptionsWintrinsic-shadow: Error and Warning OptionsWintrinsics-std: Error and Warning OptionsWline-truncation: Error and Warning OptionsWreal-q-constant: Error and Warning OptionsWrealloc-lhs: Error and Warning OptionsWrealloc-lhs-all: Error and Warning OptionsWsurprising: Error and Warning OptionsWtabs: Error and Warning OptionsWtargt-lifetime: Error and Warning OptionsWunderflow: Error and Warning OptionsWunused-dummy-argument: Error and Warning OptionsWunused-parameter: Error and Warning OptionsWzerotrip: Error and Warning Options