The GNU Fortran Compiler
Short Table of Contents
- 1 Introduction
- 2 GNU Fortran Command Options
- 3 Runtime: Influencing runtime behavior with environment variables
- 4 Fortran 2003 and 2008 Status
- 5 Compiler Characteristics
- 6 Extensions
- 7 Mixed-Language Programming
- 8 Coarray Programming
- 9 Intrinsic Procedures
- 10 Intrinsic Modules
- Contributing
- GNU General Public License
- GNU Free Documentation License
- Funding Free Software
- Option Index
- Keyword Index
Table of Contents
- 1 Introduction
-
2 GNU Fortran Command Options
- 2.1 Option summary
- 2.2 Options controlling Fortran dialect
- 2.3 Enable and customize preprocessing
- 2.4 Options to request or suppress errors and warnings
- 2.5 Options for debugging your program or GNU Fortran
- 2.6 Options for directory search
- 2.7 Influencing the linking step
- 2.8 Influencing runtime behavior
- 2.9 Options for code generation conventions
- 2.10 Environment variables affecting
gfortran
-
3 Runtime: Influencing runtime behavior with environment variables
- 3.1
TMPDIR—Directory for scratch files - 3.2
GFORTRAN_STDIN_UNIT—Unit number for standard input - 3.3
GFORTRAN_STDOUT_UNIT—Unit number for standard output - 3.4
GFORTRAN_STDERR_UNIT—Unit number for standard error - 3.5
GFORTRAN_UNBUFFERED_ALL—Do not buffer I/O on all units - 3.6
GFORTRAN_UNBUFFERED_PRECONNECTED—Do not buffer I/O on preconnected units - 3.7
GFORTRAN_SHOW_LOCUS—Show location for runtime errors - 3.8
GFORTRAN_OPTIONAL_PLUS—Print leading + where permitted - 3.9
GFORTRAN_DEFAULT_RECL—Default record length for new files - 3.10
GFORTRAN_LIST_SEPARATOR—Separator for list output - 3.11
GFORTRAN_CONVERT_UNIT—Set endianness for unformatted I/O - 3.12
GFORTRAN_ERROR_BACKTRACE—Show backtrace on run-time errors
- 3.1
- 4 Fortran 2003 and 2008 Status
- 5 Compiler Characteristics
-
6 Extensions
-
6.1 Extensions implemented in GNU Fortran
- 6.1.1 Old-style kind specifications
- 6.1.2 Old-style variable initialization
- 6.1.3 Extensions to namelist
- 6.1.4
Xformat descriptor without count field - 6.1.5 Commas in
FORMATspecifications - 6.1.6 Missing period in
FORMATspecifications - 6.1.7 I/O item lists
- 6.1.8
Qexponent-letter - 6.1.9 BOZ literal constants
- 6.1.10 Real array indices
- 6.1.11 Unary operators
- 6.1.12 Implicitly convert
LOGICALandINTEGERvalues - 6.1.13 Hollerith constants support
- 6.1.14 Cray pointers
- 6.1.15
CONVERTspecifier - 6.1.16 OpenMP
- 6.1.17 OpenACC
- 6.1.18 Argument list functions
%VAL,%REFand%LOC - 6.1.19 Read/Write after EOF marker
- 6.1.20
STRUCTUREandRECORD - 6.1.21
UNIONandMAP - 6.1.22 Type variants for integer intrinsics
- 6.1.23
AUTOMATICandSTATICattributes - 6.1.24 Extended math intrinsics
- 6.1.25 Form feed as whitespace
- 6.1.26 TYPE as an alias for PRINT
- 6.1.27 %LOC as an rvalue
- 6.1.28 .XOR. operator
- 6.1.29 Bitwise logical operators
- 6.1.30 Extended I/O specifiers
- 6.1.31 Legacy PARAMETER statements
- 6.1.32 Default exponents
- 6.2 Extensions not implemented in GNU Fortran
-
6.1 Extensions implemented in GNU Fortran
-
7 Mixed-Language Programming
- 7.1 Interoperability with C
- 7.2 GNU Fortran Compiler Directives
-
7.3 Non-Fortran Main Program
- 7.3.1
_gfortran_set_args— Save command-line arguments - 7.3.2
_gfortran_set_options— Set library option flags - 7.3.3
_gfortran_set_convert— Set endian conversion - 7.3.4
_gfortran_set_record_marker— Set length of record markers - 7.3.5
_gfortran_set_fpe— Enable floating point exception traps - 7.3.6
_gfortran_set_max_subrecord_length— Set subrecord length
- 7.3.1
- 7.4 Naming and argument-passing conventions
-
8 Coarray Programming
- 8.1 Type and enum ABI Documentation
-
8.2 Function ABI Documentation
- 8.2.1
_gfortran_caf_init— Initialiation function - 8.2.2
_gfortran_caf_finish— Finalization function - 8.2.3
_gfortran_caf_this_image— Querying the image number - 8.2.4
_gfortran_caf_num_images— Querying the maximal number of images - 8.2.5
_gfortran_caf_image_status— Query the status of an image - 8.2.6
_gfortran_caf_failed_images— Get an array of the indexes of the failed images - 8.2.7
_gfortran_caf_stopped_images— Get an array of the indexes of the stopped images - 8.2.8
_gfortran_caf_register— Registering coarrays - 8.2.9
_gfortran_caf_deregister— Deregistering coarrays - 8.2.10
_gfortran_caf_is_present— Query whether an allocatable or pointer component in a derived type coarray is allocated - 8.2.11
_gfortran_caf_send— Sending data from a local image to a remote image - 8.2.12
_gfortran_caf_get— Getting data from a remote image - 8.2.13
_gfortran_caf_sendget— Sending data between remote images - 8.2.14
_gfortran_caf_send_by_ref— Sending data from a local image to a remote image with enhanced referencing options - 8.2.15
_gfortran_caf_get_by_ref— Getting data from a remote image using enhanced references - 8.2.16
_gfortran_caf_sendget_by_ref— Sending data between remote images using enhanced references on both sides - 8.2.17
_gfortran_caf_lock— Locking a lock variable - 8.2.18
_gfortran_caf_lock— Unlocking a lock variable - 8.2.19
_gfortran_caf_event_post— Post an event - 8.2.20
_gfortran_caf_event_wait— Wait that an event occurred - 8.2.21
_gfortran_caf_event_query— Query event count - 8.2.22
_gfortran_caf_sync_all— All-image barrier - 8.2.23
_gfortran_caf_sync_images— Barrier for selected images - 8.2.24
_gfortran_caf_sync_memory— Wait for completion of segment-memory operations - 8.2.25
_gfortran_caf_error_stop— Error termination with exit code - 8.2.26
_gfortran_caf_error_stop_str— Error termination with string - 8.2.27
_gfortran_caf_fail_image— Mark the image failed and end its execution - 8.2.28
_gfortran_caf_atomic_define— Atomic variable assignment - 8.2.29
_gfortran_caf_atomic_ref— Atomic variable reference - 8.2.30
_gfortran_caf_atomic_cas— Atomic compare and swap - 8.2.31
_gfortran_caf_atomic_op— Atomic operation - 8.2.32
_gfortran_caf_co_broadcast— Sending data to all images - 8.2.33
_gfortran_caf_co_max— Collective maximum reduction - 8.2.34
_gfortran_caf_co_min— Collective minimum reduction - 8.2.35
_gfortran_caf_co_sum— Collective summing reduction - 8.2.36
_gfortran_caf_co_reduce— Generic collective reduction
- 8.2.1
-
9 Intrinsic Procedures
- 9.1 Introduction to intrinsic procedures
- 9.2
ABORT— Abort the program - 9.3
ABS— Absolute value - 9.4
ACCESS— Checks file access modes - 9.5
ACHAR— Character in ASCII collating sequence - 9.6
ACOS— Arccosine function - 9.7
ACOSD— Arccosine function, degrees - 9.8
ACOSH— Inverse hyperbolic cosine function - 9.9
ADJUSTL— Left adjust a string - 9.10
ADJUSTR— Right adjust a string - 9.11
AIMAG— Imaginary part of complex number - 9.12
AINT— Truncate to a whole number - 9.13
ALARM— Execute a routine after a given delay - 9.14
ALL— All values in MASK along DIM are true - 9.15
ALLOCATED— Status of an allocatable entity - 9.16
AND— Bitwise logical AND - 9.17
ANINT— Nearest whole number - 9.18
ANY— Any value in MASK along DIM is true - 9.19
ASIN— Arcsine function - 9.20
ASIND— Arcsine function, degrees - 9.21
ASINH— Inverse hyperbolic sine function - 9.22
ASSOCIATED— Status of a pointer or pointer/target pair - 9.23
ATAN— Arctangent function - 9.24
ATAND— Arctangent function, degrees - 9.25
ATAN2— Arctangent function - 9.26
ATAN2D— Arctangent function, degrees - 9.27
ATANH— Inverse hyperbolic tangent function - 9.28
ATOMIC_ADD— Atomic ADD operation - 9.29
ATOMIC_AND— Atomic bitwise AND operation - 9.30
ATOMIC_CAS— Atomic compare and swap - 9.31
ATOMIC_DEFINE— Setting a variable atomically - 9.32
ATOMIC_FETCH_ADD— Atomic ADD operation with prior fetch - 9.33
ATOMIC_FETCH_AND— Atomic bitwise AND operation with prior fetch - 9.34
ATOMIC_FETCH_OR— Atomic bitwise OR operation with prior fetch - 9.35
ATOMIC_FETCH_XOR— Atomic bitwise XOR operation with prior fetch - 9.36
ATOMIC_OR— Atomic bitwise OR operation - 9.37
ATOMIC_REF— Obtaining the value of a variable atomically - 9.38
ATOMIC_XOR— Atomic bitwise OR operation - 9.39
BACKTRACE— Show a backtrace - 9.40
BESSEL_J0— Bessel function of the first kind of order 0 - 9.41
BESSEL_J1— Bessel function of the first kind of order 1 - 9.42
BESSEL_JN— Bessel function of the first kind - 9.43
BESSEL_Y0— Bessel function of the second kind of order 0 - 9.44
BESSEL_Y1— Bessel function of the second kind of order 1 - 9.45
BESSEL_YN— Bessel function of the second kind - 9.46
BGE— Bitwise greater than or equal to - 9.47
BGT— Bitwise greater than - 9.48
BIT_SIZE— Bit size inquiry function - 9.49
BLE— Bitwise less than or equal to - 9.50
BLT— Bitwise less than - 9.51
BTEST— Bit test function - 9.52
C_ASSOCIATED— Status of a C pointer - 9.53
C_F_POINTER— Convert C into Fortran pointer - 9.54
C_F_PROCPOINTER— Convert C into Fortran procedure pointer - 9.55
C_FUNLOC— Obtain the C address of a procedure - 9.56
C_LOC— Obtain the C address of an object - 9.57
C_SIZEOF— Size in bytes of an expression - 9.58
CEILING— Integer ceiling function - 9.59
CHAR— Character conversion function - 9.60
CHDIR— Change working directory - 9.61
CHMOD— Change access permissions of files - 9.62
CMPLX— Complex conversion function - 9.63
CO_BROADCAST— Copy a value to all images the current set of images - 9.64
CO_MAX— Maximal value on the current set of images - 9.65
CO_MIN— Minimal value on the current set of images - 9.66
CO_REDUCE— Reduction of values on the current set of images - 9.67
CO_SUM— Sum of values on the current set of images - 9.68
COMMAND_ARGUMENT_COUNT— Get number of command line arguments - 9.69
COMPILER_OPTIONS— Options passed to the compiler - 9.70
COMPILER_VERSION— Compiler version string - 9.71
COMPLEX— Complex conversion function - 9.72
CONJG— Complex conjugate function - 9.73
COS— Cosine function - 9.74
COSD— Cosine function, degrees - 9.75
COSH— Hyperbolic cosine function - 9.76
COTAN— Cotangent function - 9.77
COTAND— Cotangent function, degrees - 9.78
COUNT— Count function - 9.79
CPU_TIME— CPU elapsed time in seconds - 9.80
CSHIFT— Circular shift elements of an array - 9.81
CTIME— Convert a time into a string - 9.82
DATE_AND_TIME— Date and time subroutine - 9.83
DBLE— Double conversion function - 9.84
DCMPLX— Double complex conversion function - 9.85
DIGITS— Significant binary digits function - 9.86
DIM— Positive difference - 9.87
DOT_PRODUCT— Dot product function - 9.88
DPROD— Double product function - 9.89
DREAL— Double real part function - 9.90
DSHIFTL— Combined left shift - 9.91
DSHIFTR— Combined right shift - 9.92
DTIME— Execution time subroutine (or function) - 9.93
EOSHIFT— End-off shift elements of an array - 9.94
EPSILON— Epsilon function - 9.95
ERF— Error function - 9.96
ERFC— Error function - 9.97
ERFC_SCALED— Error function - 9.98
ETIME— Execution time subroutine (or function) - 9.99
EVENT_QUERY— Query whether a coarray event has occurred - 9.100
EXECUTE_COMMAND_LINE— Execute a shell command - 9.101
EXIT— Exit the program with status. - 9.102
EXP— Exponential function - 9.103
EXPONENT— Exponent function - 9.104
EXTENDS_TYPE_OF— Query dynamic type for extension - 9.105
FDATE— Get the current time as a string - 9.106
FGET— Read a single character in stream mode from stdin - 9.107
FGETC— Read a single character in stream mode - 9.108
FLOOR— Integer floor function - 9.109
FLUSH— Flush I/O unit(s) - 9.110
FNUM— File number function - 9.111
FPUT— Write a single character in stream mode to stdout - 9.112
FPUTC— Write a single character in stream mode - 9.113
FRACTION— Fractional part of the model representation - 9.114
FREE— Frees memory - 9.115
FSEEK— Low level file positioning subroutine - 9.116
FSTAT— Get file status - 9.117
FTELL— Current stream position - 9.118
GAMMA— Gamma function - 9.119
GERROR— Get last system error message - 9.120
GETARG— Get command line arguments - 9.121
GET_COMMAND— Get the entire command line - 9.122
GET_COMMAND_ARGUMENT— Get command line arguments - 9.123
GETCWD— Get current working directory - 9.124
GETENV— Get an environmental variable - 9.125
GET_ENVIRONMENT_VARIABLE— Get an environmental variable - 9.126
GETGID— Group ID function - 9.127
GETLOG— Get login name - 9.128
GETPID— Process ID function - 9.129
GETUID— User ID function - 9.130
GMTIME— Convert time to GMT info - 9.131
HOSTNM— Get system host name - 9.132
HUGE— Largest number of a kind - 9.133
HYPOT— Euclidean distance function - 9.134
IACHAR— Code in ASCII collating sequence - 9.135
IALL— Bitwise AND of array elements - 9.136
IAND— Bitwise logical and - 9.137
IANY— Bitwise OR of array elements - 9.138
IARGC— Get the number of command line arguments - 9.139
IBCLR— Clear bit - 9.140
IBITS— Bit extraction - 9.141
IBSET— Set bit - 9.142
ICHAR— Character-to-integer conversion function - 9.143
IDATE— Get current local time subroutine (day/month/year) - 9.144
IEOR— Bitwise logical exclusive or - 9.145
IERRNO— Get the last system error number - 9.146
IMAGE_INDEX— Function that converts a cosubscript to an image index - 9.147
INDEX— Position of a substring within a string - 9.148
INT— Convert to integer type - 9.149
INT2— Convert to 16-bit integer type - 9.150
INT8— Convert to 64-bit integer type - 9.151
IOR— Bitwise logical or - 9.152
IPARITY— Bitwise XOR of array elements - 9.153
IRAND— Integer pseudo-random number - 9.154
IS_IOSTAT_END— Test for end-of-file value - 9.155
IS_IOSTAT_EOR— Test for end-of-record value - 9.156
ISATTY— Whether a unit is a terminal device. - 9.157
ISHFT— Shift bits - 9.158
ISHFTC— Shift bits circularly - 9.159
ISNAN— Test for a NaN - 9.160
ITIME— Get current local time subroutine (hour/minutes/seconds) - 9.161
KILL— Send a signal to a process - 9.162
KIND— Kind of an entity - 9.163
LBOUND— Lower dimension bounds of an array - 9.164
LCOBOUND— Lower codimension bounds of an array - 9.165
LEADZ— Number of leading zero bits of an integer - 9.166
LEN— Length of a character entity - 9.167
LEN_TRIM— Length of a character entity without trailing blank characters - 9.168
LGE— Lexical greater than or equal - 9.169
LGT— Lexical greater than - 9.170
LINK— Create a hard link - 9.171
LLE— Lexical less than or equal - 9.172
LLT— Lexical less than - 9.173
LNBLNK— Index of the last non-blank character in a string - 9.174
LOC— Returns the address of a variable - 9.175
LOG— Natural logarithm function - 9.176
LOG10— Base 10 logarithm function - 9.177
LOG_GAMMA— Logarithm of the Gamma function - 9.178
LOGICAL— Convert to logical type - 9.179
LONG— Convert to integer type - 9.180
LSHIFT— Left shift bits - 9.181
LSTAT— Get file status - 9.182
LTIME— Convert time to local time info - 9.183
MALLOC— Allocate dynamic memory - 9.184
MASKL— Left justified mask - 9.185
MASKR— Right justified mask - 9.186
MATMUL— matrix multiplication - 9.187
MAX— Maximum value of an argument list - 9.188
MAXEXPONENT— Maximum exponent of a real kind - 9.189
MAXLOC— Location of the maximum value within an array - 9.190
MAXVAL— Maximum value of an array - 9.191
MCLOCK— Time function - 9.192
MCLOCK8— Time function (64-bit) - 9.193
MERGE— Merge variables - 9.194
MERGE_BITS— Merge of bits under mask - 9.195
MIN— Minimum value of an argument list - 9.196
MINEXPONENT— Minimum exponent of a real kind - 9.197
MINLOC— Location of the minimum value within an array - 9.198
MINVAL— Minimum value of an array - 9.199
MOD— Remainder function - 9.200
MODULO— Modulo function - 9.201
MOVE_ALLOC— Move allocation from one object to another - 9.202
MVBITS— Move bits from one integer to another - 9.203
NEAREST— Nearest representable number - 9.204
NEW_LINE— New line character - 9.205
NINT— Nearest whole number - 9.206
NORM2— Euclidean vector norms - 9.207
NOT— Logical negation - 9.208
NULL— Function that returns an disassociated pointer - 9.209
NUM_IMAGES— Function that returns the number of images - 9.210
OR— Bitwise logical OR - 9.211
PACK— Pack an array into an array of rank one - 9.212
PARITY— Reduction with exclusive OR - 9.213
PERROR— Print system error message - 9.214
POPCNT— Number of bits set - 9.215
POPPAR— Parity of the number of bits set - 9.216
PRECISION— Decimal precision of a real kind - 9.217
PRESENT— Determine whether an optional dummy argument is specified - 9.218
PRODUCT— Product of array elements - 9.219
RADIX— Base of a model number - 9.220
RAN— Real pseudo-random number - 9.221
RAND— Real pseudo-random number - 9.222
RANDOM_NUMBER— Pseudo-random number - 9.223
RANDOM_SEED— Initialize a pseudo-random number sequence - 9.224
RANGE— Decimal exponent range - 9.225
RANK— Rank of a data object - 9.226
REAL— Convert to real type - 9.227
RENAME— Rename a file - 9.228
REPEAT— Repeated string concatenation - 9.229
RESHAPE— Function to reshape an array - 9.230
RRSPACING— Reciprocal of the relative spacing - 9.231
RSHIFT— Right shift bits - 9.232
SAME_TYPE_AS— Query dynamic types for equality - 9.233
SCALE— Scale a real value - 9.234
SCAN— Scan a string for the presence of a set of characters - 9.235
SECNDS— Time function - 9.236
SECOND— CPU time function - 9.237
SELECTED_CHAR_KIND— Choose character kind - 9.238
SELECTED_INT_KIND— Choose integer kind - 9.239
SELECTED_REAL_KIND— Choose real kind - 9.240
SET_EXPONENT— Set the exponent of the model - 9.241
SHAPE— Determine the shape of an array - 9.242
SHIFTA— Right shift with fill - 9.243
SHIFTL— Left shift - 9.244
SHIFTR— Right shift - 9.245
SIGN— Sign copying function - 9.246
SIGNAL— Signal handling subroutine (or function) - 9.247
SIN— Sine function - 9.248
SIND— Sine function, degrees - 9.249
SINH— Hyperbolic sine function - 9.250
SIZE— Determine the size of an array - 9.251
SIZEOF— Size in bytes of an expression - 9.252
SLEEP— Sleep for the specified number of seconds - 9.253
SPACING— Smallest distance between two numbers of a given type - 9.254
SPREAD— Add a dimension to an array - 9.255
SQRT— Square-root function - 9.256
SRAND— Reinitialize the random number generator - 9.257
STAT— Get file status - 9.258
STORAGE_SIZE— Storage size in bits - 9.259
SUM— Sum of array elements - 9.260
SYMLNK— Create a symbolic link - 9.261
SYSTEM— Execute a shell command - 9.262
SYSTEM_CLOCK— Time function - 9.263
TAN— Tangent function - 9.264
TAND— Tangent function, degrees - 9.265
TANH— Hyperbolic tangent function - 9.266
THIS_IMAGE— Function that returns the cosubscript index of this image - 9.267
TIME— Time function - 9.268
TIME8— Time function (64-bit) - 9.269
TINY— Smallest positive number of a real kind - 9.270
TRAILZ— Number of trailing zero bits of an integer - 9.271
TRANSFER— Transfer bit patterns - 9.272
TRANSPOSE— Transpose an array of rank two - 9.273
TRIM— Remove trailing blank characters of a string - 9.274
TTYNAM— Get the name of a terminal device. - 9.275
UBOUND— Upper dimension bounds of an array - 9.276
UCOBOUND— Upper codimension bounds of an array - 9.277
UMASK— Set the file creation mask - 9.278
UNLINK— Remove a file from the file system - 9.279
UNPACK— Unpack an array of rank one into an array - 9.280
VERIFY— Scan a string for characters not a given set - 9.281
XOR— Bitwise logical exclusive OR
- 10 Intrinsic Modules
- Contributing
- GNU General Public License
- GNU Free Documentation License
- Funding Free Software
- Option Index
- Keyword Index
Introduction
This manual documents the use of gfortran, the GNU Fortran compiler. You can find in this manual how to invoke gfortran, as well as its features and incompatibilities.
| • Introduction: | ||
| Part I: Invoking GNU Fortran | ||
|---|---|---|
| • Invoking GNU Fortran: | Command options supported by gfortran. |
|
| • Runtime: | Influencing runtime behavior with environment variables. | |
| Part II: Language Reference | ||
| • Fortran 2003 and 2008 status: | Fortran 2003 and 2008 features supported by GNU Fortran. | |
| • Compiler Characteristics: | User-visible implementation details. | |
| • Extensions: | Language extensions implemented by GNU Fortran. | |
| • Mixed-Language Programming: | Interoperability with C | |
| • Coarray Programming: | ||
| • Intrinsic Procedures: | Intrinsic procedures supported by GNU Fortran. | |
| • Intrinsic Modules: | Intrinsic modules supported by GNU Fortran. | |
| • Contributing: | How you can help. | |
| • Copying: | GNU General Public License says how you can copy and share GNU Fortran. | |
| • GNU Free Documentation License: | How you can copy and share this manual. | |
| • Funding: | How to help assure continued work for free software. | |
| • Option Index: | Index of command line options | |
| • Keyword Index: | Index of concepts | |
Next: Introduction, Up: (dir) [Contents][Index]
© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-7.2.0/gfortran/index.html