Lint Rules

fobis lint has 105 rules. Rules marked default run unless a selection is given; opt-in rules run only when selected (--select COR003, a prefix like --select COR, or ALL). Run fobis lint --explain <ID> for the same documentation in the terminal. How to run, select and suppress rules: Code quality.

Correctness (COR)

Rule	Name	Severity	Default	Fortitude	Reports
COR001	implicit-typing	warning	yes	C001	A module, program or external procedure has no implicit none.
COR002	interface-implicit-typing	warning	yes	C002	An interface body has no implicit none.
COR003	implicit-external-procedures	warning	opt-in	C003	implicit none does not forbid implicit external procedures (implicit none (type, external)).
COR010	missing-intent	warning	yes	C061	A dummy argument has no intent.
COR011	assumed-size	warning	yes	C071	A dummy array is assumed-size (a(*), a(n,*)).
COR020	initialisation-in-declaration	warning	yes	C081	A procedure's local variable is initialised in its declaration, which implies save.
COR021	pointer-initialisation-in-declaration	warning	yes	C082	A procedure's local pointer is initialised in its declaration (=> null()), which implies save.
COR022	missing-default-pointer-initialisation	warning	yes	C101	A pointer component of a derived type has no default initialisation (=> null()).
COR030	external-procedure	warning	yes	C091	A procedure is declared external.
COR031	procedure-not-in-module	warning	yes	C092	A subroutine or function is defined outside a module (an external procedure).
COR040	use-all	warning	yes	C121	A use statement imports everything (no only: list).
COR041	missing-intrinsic	warning	yes	C122	An intrinsic module is used without the intrinsic keyword.
COR050	missing-accessibility-statement	warning	yes	C131	A module has no default accessibility statement (private or public).
COR060	unchecked-stat	warning	yes	C181	The stat= variable of an allocate/deallocate is never read afterwards.
COR061	multiple-allocations-with-stat	warning	yes	C182	One allocate/deallocate with stat= handles several objects.
COR062	stat-without-errmsg	warning	opt-in	C183	An allocate/deallocate has stat= but no errmsg=.
COR070	missing-default-case	warning	yes	C011	A select case construct has no case default.
COR071	missing-class-default	warning	opt-in	-	A select type construct has no class default.
COR072	missing-rank-default	warning	opt-in	-	A select rank construct has no rank default.
COR080	magic-number-in-array-size	warning	opt-in	C031	An array is declared with a literal size other than 0 or 1.
COR081	magic-io-unit	warning	opt-in	C032	An I/O statement uses a literal unit number.
COR082	missing-action-specifier	warning	opt-in	C043	An open statement has no action= specifier.
COR090	missing-exit-or-cycle-label	warning	yes	C141	An exit or cycle inside a named DO loop does not name the loop.
COR091	exit-or-cycle-in-unlabelled-loop	warning	opt-in	C142	An exit or cycle appears in a DO loop that has no construct name.
COR092	missing-end-label	error	yes	C143	The end statement of a named construct does not repeat the construct name.
COR100	misleading-inline-if-semicolon	warning	yes	C151	A statement follows a one-line if after a semicolon: it is not conditional.
COR101	misleading-inline-if-continuation	warning	yes	C152	A one-line if continues its action on the next line.
COR110	nonportable-shortcircuit-inquiry	warning	yes	C161	A condition tests present/allocated/associated and uses the same entity in one expression.
COR120	unreachable-statement	warning	yes	C191	A statement follows return, stop, exit, cycle or go to in the same block: it never runs.

Obsolescent (OBS)

Rule	Name	Severity	Default	Fortitude	Reports
OBS001	common-block	warning	yes	OB011	A common block.
OBS002	equivalence-statement	warning	yes	OB012	An equivalence statement.
OBS003	block-data	warning	yes	OB013	A block data program unit.
OBS004	entry-statement	warning	yes	OB021	An entry statement.
OBS005	specific-intrinsic-name	warning	yes	OB031	A specific intrinsic name (dsqrt, dabs, amax1, float ...) instead of the generic one.
OBS006	computed-go-to	warning	yes	OB041	A computed go to (l1, l2, ...), i.
OBS007	pause-statement	warning	yes	OB051	A pause statement.
OBS008	deprecated-character-syntax	warning	yes	OB061	Old-style character length character*n / character*(*).
OBS009	forall	warning	yes	OB071	A forall statement or construct.
OBS010	arithmetic-if	warning	yes	OB081	An arithmetic if (x) l1, l2, l3.
OBS011	labelled-do-loop	warning	yes	OB091	A labelled do 10 i = ... loop.
OBS012	shared-do-termination	warning	yes	OB092	Several do loops end on the same labelled statement.
OBS013	bad-do-termination	warning	yes	OB093	A labelled do loop ends on a statement other than continue or end do.
OBS014	goto-end-do	warning	yes	OB094	A go to jumps to the end do of a loop.
OBS020	deprecated-mpi-include	warning	yes	OB201	include 'mpif.h' instead of the mpi_f08 module.
OBS021	deprecated-omp-include	warning	yes	OB211	include 'omp_lib.h' instead of the omp_lib module.

Modernisation (MDN)

Rule	Name	Severity	Default	Fortitude	Reports
MDN001	double-precision	warning	opt-in	MOD001	A double precision (or double complex) declaration.
MDN002	double-precision-literal	warning	opt-in	MOD002	A double precision literal with exponent letter d (1.0d0).
MDN011	old-style-array-constructor	warning	yes	MOD011	An array constructor written (/ ... /) instead of [ ... ].
MDN021	deprecated-relational-operator	warning	yes	MOD021	A relational operator written .eq., .ne., .lt., .le., .gt., .ge..
MDN031	include-statement	warning	opt-in	MOD031	A Fortran include line.
MDN041	out-of-line-attribute	warning	yes	MOD041	An attribute given in a separate statement (dimension a(n), intent(in) :: x, parameter (...)).
MDN051	superfluous-save	warning	yes	MOD051	save in a module specification part.
MDN201	old-mpi-module	warning	opt-in	MOD201	use mpi instead of use mpi_f08.

Portability (PRT)

Rule	Name	Severity	Default	Fortitude	Reports
PRT011	literal-kind	warning	yes	PORT011	A kind given as a number in a type declaration (real(8), integer(kind=4)).
PRT012	literal-kind-suffix	warning	yes	PORT012	A literal with a numeric kind suffix (1.0_8, 10_4).
PRT021	star-kind	warning	yes	PORT021	A non-standard type*size declaration (real*8, integer*4).
PRT031	invalid-tab	warning	yes	PORT031	Tab characters in Fortran code (reported once per file).
PRT061	non-portable-system-call	warning	opt-in	PORT061	system() (a compiler extension) runs a shell command.
PRT062	gfortran-random-extension	warning	opt-in	PORT062	The extensions rand, srand, irand generate random numbers.

Style (STY)

Rule	Name	Severity	Default	Fortitude	Reports
STY001	multiple-modules	warning	opt-in	S211	A file defines more than one module or submodule.
STY002	program-with-module	warning	opt-in	S212	A file defines both a program and a module.
STY003	function-missing-result	warning	opt-in	S221	A function has no result(...) clause.
STY010	inconsistent-array-declaration	warning	yes	S261	A declaration has a dimension attribute and an entity with its own shape.
STY011	mixed-scalar-array-declaration	warning	opt-in	S262	One declaration statement declares both scalars and arrays.
STY020	too-complex	warning	opt-in	S901	A procedure's cyclomatic complexity exceeds 10.
STY021	too-many-arguments	warning	opt-in	S902	A procedure has more than 8 dummy arguments.

Fortran practice (FOR)

Rule	Name	Severity	Default	Fortitude	Reports
FOR001	saved-local-in-parallel-procedure	warning	yes	-	A procedure that runs in parallel has a saved local variable (one copy shared by all threads).
FOR002	loop-order-not-column-major	warning	opt-in	-	The innermost loop runs over a non-leading array dimension while an outer loop runs over the leading one.
FOR003	lower-bounds-lost-in-assumed-shape	warning	opt-in	-	An array with non-default lower bounds is passed to an assumed-shape dummy: inside, its bounds restart at 1.
FOR004	function-result-component	error	yes	-	A component of a function result is referenced directly: f(x)%c.
FOR005	cpu-time-for-wall-clock	warning	yes	-	cpu_time measures time in code that runs in parallel (OpenMP, OpenACC, MPI).
FOR006	array-of-finalizable-type-not-finalised	warning	yes	-	An array of a derived type with final procedures, none of which finalises arrays of that rank.
FOR007	default-real-literal-precision-loss	warning	yes	-	A real literal without kind is assigned to a higher-precision real and cannot be represented in default precision.

OpenMP (OMP)

Rule	Name	Severity	Default	Fortitude	Reports
OMP001	shared-scalar-written-in-parallel-region	warning	yes	-	A shared scalar is assigned inside an OpenMP parallel region: a data race.
OMP002	accumulation-without-reduction	warning	yes	-	A shared scalar is accumulated inside an OpenMP parallel region without reduction.
OMP003	collapse-imperfect-nest	error	yes	-	collapse(n) on OpenMP loops that are not tightly nested.
OMP004	nowait-dependent-read	warning	opt-in	-	Data written by a nowait worksharing construct is read before the next barrier.
OMP005	serialisation-in-innermost-loop	warning	yes	-	An OpenMP critical or atomic is inside the innermost loop of a parallel loop.
OMP006	target-map-in-loop	warning	opt-in	-	An OpenMP target region inside a loop maps data on every iteration, with no target data around it.
OMP007	mpi-in-threaded-region-without-thread-support	warning	yes	-	MPI is called inside an OpenMP parallel region but initialised with mpi_init, not mpi_init_thread.
OMP008	implicit-target-map	warning	yes	-	The compiler maps data implicitly for an OpenMP target region (nvfortran: 'Generating implicit map').

OpenACC (ACC)

Rule	Name	Severity	Default	Fortitude	Reports
ACC001	implicit-data-movement	warning	yes	-	The compiler moves data implicitly for an OpenACC compute region (nvfortran: 'Generating implicit copy').
ACC002	atomic-in-compute-region	warning	yes	-	An !$acc atomic inside an OpenACC compute region or device routine.
ACC003	firstprivate-associate-name	warning	yes	-	An associate name appears in an OpenACC firstprivate clause.
ACC004	reduction-into-device-module-variable	error	yes	-	An OpenACC reduction targets a module allocatable declared !$acc declare create.
ACC005	strided-section-argument-in-kernel	warning	yes	-	A non-contiguous section of a shared array is passed to a procedure inside OpenACC device code.
ACC006	missing-acc-routine	warning	yes	-	A project procedure is called inside an OpenACC compute region but has no !$acc routine.
ACC007	device-routine-assumed-shape-lower-bound	warning	opt-in	-	A device routine has an assumed-shape dummy with a non-default lower bound (q(0:), q(1-ng:)).
ACC008	timer-without-acc-wait	warning	yes	-	A timer is read while asynchronous OpenACC work may still be running.
ACC009	mpi-on-device-data-without-update	warning	opt-in	-	MPI sends or receives a device-resident array with no host update around the call and no host_data.
ACC010	private-array-in-contained-kernel	info	opt-in	-	A compute region of a contained (internal) procedure has a private array.
ACC011	acc-collapse-imperfect-nest	error	yes	-	collapse(n) on OpenACC loops that are not tightly nested.
ACC012	sequential-device-loop	warning	yes	-	A loop in an OpenACC compute region runs sequentially: the compiler found a loop-carried dependence.

MPI (MPI)

Rule	Name	Severity	Default	Fortitude	Reports
MPI001	request-never-completed	warning	yes	-	A non-blocking MPI operation stores its request in a local variable that is never completed.
MPI002	isend-buffer-modified-before-completion	warning	yes	-	The buffer of a pending mpi_isend is written before the request is completed.
MPI003	irecv-buffer-used-before-completion	warning	yes	-	The buffer of a pending mpi_irecv is used before the request is completed.
MPI004	collective-in-rank-branch	warning	yes	-	An MPI collective is called inside a branch that depends on the rank.
MPI005	blocking-send-before-receive	warning	opt-in	-	Every rank does a blocking mpi_send and then the matching mpi_recv: a deadlock for large messages.
MPI006	any-source-order-dependent-sum	info	opt-in	-	Messages received from MPI_ANY_SOURCE are summed in arrival order: the result is not reproducible.

Performance (PRF)

Rule	Name	Severity	Default	Fortitude	Reports
PRF001	loop-not-vectorized	info	opt-in	-	gfortran could not vectorise a loop (-fopt-info-vec-missed).

Numerics (NUM)

Rule	Name	Severity	Default	Fortitude	Reports
NUM001	uncompensated-global-sum	info	opt-in	-	A diagnostic quantity (residual, norm, mass, energy ...) is summed across ranks with MPI_SUM.

Linter (LNT)

Rule	Name	Severity	Default	Fortitude	Reports
LNT001	suppression-without-reason	warning	yes	-	An inline suppression ! fobis: ignore[ID] gives no reason.
LNT002	unused-suppression	warning	yes	-	An inline suppression silences nothing.
LNT003	unknown-rule-in-suppression	warning	yes	-	An inline suppression names a rule that does not exist.
LNT004	preprocessor-assumption	info	yes	-	A preprocessor condition could not be evaluated and was assumed true.

Relation to Fortitude

The generic rules (COR, OBS, MDN, PRT, STY) are a native reimplementation, in FoBiS's own words and on its own source analysis, of rules catalogued by Fortitude (PlasmaFAIR, MIT licence), whose rule set served as the reference. The Fortitude column gives the matching Fortitude code, for users who know it. FoBiS does not depend on Fortitude. The FOR, NUM, OMP, ACC, MPI and PRF rules are FoBiS's own, distilled from the OpenMP, OpenACC and MPI specifications and from HPC practice.

Not reimplemented: Fortitude's formatting rules (line length, whitespace, keyword case, quotes: formatters own them) and S263 (a project-configured preference between dimension(n) and x(n)). The thresholds of STY020 and STY021 are fixed (complexity 10, 8 arguments).