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diff --git a/gcc-4.9/gcc/doc/gfortran.1 b/gcc-4.9/gcc/doc/gfortran.1 deleted file mode 100644 index 285fdafd7..000000000 --- a/gcc-4.9/gcc/doc/gfortran.1 +++ /dev/null @@ -1,1411 +0,0 @@ -.\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28) -.\" -.\" Standard preamble: -.\" ======================================================================== -.de Sp \" Vertical space (when we can't use .PP) -.if t .sp .5v -.if n .sp -.. -.de Vb \" Begin verbatim text -.ft CW -.nf -.ne \\$1 -.. -.de Ve \" End verbatim text -.ft R -.fi -.. -.\" Set up some character translations and predefined strings. \*(-- will -.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left -.\" double quote, and \*(R" will give a right double quote. \*(C+ will -.\" give a nicer C++. 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Always turn off hyphenation; it makes -.\" way too many mistakes in technical documents. -.if n .ad l -.nh -.SH "NAME" -gfortran \- GNU Fortran compiler -.SH "SYNOPSIS" -.IX Header "SYNOPSIS" -gfortran [\fB\-c\fR|\fB\-S\fR|\fB\-E\fR] - [\fB\-g\fR] [\fB\-pg\fR] [\fB\-O\fR\fIlevel\fR] - [\fB\-W\fR\fIwarn\fR...] [\fB\-pedantic\fR] - [\fB\-I\fR\fIdir\fR...] [\fB\-L\fR\fIdir\fR...] - [\fB\-D\fR\fImacro\fR[=\fIdefn\fR]...] [\fB\-U\fR\fImacro\fR] - [\fB\-f\fR\fIoption\fR...] - [\fB\-m\fR\fImachine-option\fR...] - [\fB\-o\fR \fIoutfile\fR] \fIinfile\fR... -.PP -Only the most useful options are listed here; see below for the -remainder. -.SH "DESCRIPTION" -.IX Header "DESCRIPTION" -The \fBgfortran\fR command supports all the options supported by the -\&\fBgcc\fR command. Only options specific to \s-1GNU\s0 Fortran are documented -here. -.PP -All \s-1GCC\s0 and \s-1GNU\s0 Fortran options -are accepted both by \fBgfortran\fR and by \fBgcc\fR -(as well as any other drivers built at the same time, -such as \fBg++\fR), -since adding \s-1GNU\s0 Fortran to the \s-1GCC\s0 distribution -enables acceptance of \s-1GNU\s0 Fortran options -by all of the relevant drivers. -.PP -In some cases, options have positive and negative forms; -the negative form of \fB\-ffoo\fR would be \fB\-fno\-foo\fR. -This manual documents only one of these two forms, whichever -one is not the default. -.SH "OPTIONS" -.IX Header "OPTIONS" -Here is a summary of all the options specific to \s-1GNU\s0 Fortran, grouped -by type. Explanations are in the following sections. -.IP "\fIFortran Language Options\fR" 4 -.IX Item "Fortran Language Options" -\&\fB\-fall\-intrinsics \-fbackslash \-fcray\-pointer \-fd\-lines\-as\-code -\&\-fd\-lines\-as\-comments \-fdefault\-double\-8 \-fdefault\-integer\-8 -\&\-fdefault\-real\-8 \-fdollar\-ok \-ffixed\-line\-length\-\fR\fIn\fR -\&\fB\-ffixed\-line\-length\-none \-ffree\-form \-ffree\-line\-length\-\fR\fIn\fR -\&\fB\-ffree\-line\-length\-none \-fimplicit\-none \-finteger\-4\-integer\-8 -\&\-fmax\-identifier\-length \-fmodule\-private \-fno\-fixed\-form \-fno\-range\-check -\&\-fopenmp \-freal\-4\-real\-10 \-freal\-4\-real\-16 \-freal\-4\-real\-8 -\&\-freal\-8\-real\-10 \-freal\-8\-real\-16 \-freal\-8\-real\-4 \-std=\fR\fIstd\fR\fB \fR -.IP "\fIPreprocessing Options\fR" 4 -.IX Item "Preprocessing Options" -\&\fB\-A\-\fR\fIquestion\fR[\fB=\fR\fIanswer\fR] -\&\fB\-A\fR\fIquestion\fR\fB=\fR\fIanswer\fR \fB\-C \-CC \-D\fR\fImacro\fR[\fB=\fR\fIdefn\fR] -\&\fB\-H \-P -\&\-U\fR\fImacro\fR \fB\-cpp \-dD \-dI \-dM \-dN \-dU \-fworking\-directory -\&\-imultilib\fR \fIdir\fR -\&\fB\-iprefix\fR \fIfile\fR \fB\-iquote \-isysroot\fR \fIdir\fR \fB\-isystem\fR \fIdir\fR \fB\-nocpp -\&\-nostdinc -\&\-undef\fR -.IP "\fIError and Warning Options\fR" 4 -.IX Item "Error and Warning Options" -\&\fB\-Waliasing \-Wall \-Wampersand \-Warray\-bounds -\&\-Wc\-binding\-type \-Wcharacter\-truncation -\&\-Wconversion \-Wfunction\-elimination \-Wimplicit\-interface -\&\-Wimplicit\-procedure \-Wintrinsic\-shadow \-Wintrinsics\-std -\&\-Wline\-truncation \-Wno\-align\-commons \-Wno\-tabs \-Wreal\-q\-constant -\&\-Wsurprising \-Wunderflow \-Wunused\-parameter \-Wrealloc\-lhs \-Wrealloc\-lhs\-all -\&\-Wtarget\-lifetime \-fmax\-errors=\fR\fIn\fR \fB\-fsyntax\-only \-pedantic \-pedantic\-errors\fR -.IP "\fIDebugging Options\fR" 4 -.IX Item "Debugging Options" -\&\fB\-fbacktrace \-fdump\-fortran\-optimized \-fdump\-fortran\-original -\&\-fdump\-parse\-tree \-ffpe\-trap=\fR\fIlist\fR \fB\-ffpe\-summary=\fR\fIlist\fR\fB \fR -.IP "\fIDirectory Options\fR" 4 -.IX Item "Directory Options" -\&\fB\-I\fR\fIdir\fR \fB\-J\fR\fIdir\fR \fB\-fintrinsic\-modules\-path\fR \fIdir\fR -.IP "\fILink Options\fR" 4 -.IX Item "Link Options" -\&\fB\-static\-libgfortran\fR -.IP "\fIRuntime Options\fR" 4 -.IX Item "Runtime Options" -\&\fB\-fconvert=\fR\fIconversion\fR \fB\-fmax\-subrecord\-length=\fR\fIlength\fR -\&\fB\-frecord\-marker=\fR\fIlength\fR \fB\-fsign\-zero\fR -.IP "\fICode Generation Options\fR" 4 -.IX Item "Code Generation Options" -\&\fB\-faggressive\-function\-elimination \-fblas\-matmul\-limit=\fR\fIn\fR -\&\fB\-fbounds\-check \-fcheck\-array\-temporaries -\&\-fcheck=\fR\fI<all|array\-temps|bounds|do|mem|pointer|recursion>\fR -\&\fB\-fcoarray=\fR\fI<none|single|lib>\fR \fB\-fexternal\-blas \-ff2c -\&\-ffrontend\-optimize -\&\-finit\-character=\fR\fIn\fR \fB\-finit\-integer=\fR\fIn\fR \fB\-finit\-local\-zero -\&\-finit\-logical=\fR\fI<true|false>\fR -\&\fB\-finit\-real=\fR\fI<zero|inf|\-inf|nan|snan>\fR -\&\fB\-fmax\-array\-constructor=\fR\fIn\fR \fB\-fmax\-stack\-var\-size=\fR\fIn\fR -\&\fB\-fno\-align\-commons -\&\-fno\-automatic \-fno\-protect\-parens \-fno\-underscoring -\&\-fsecond\-underscore \-fpack\-derived \-frealloc\-lhs \-frecursive -\&\-frepack\-arrays \-fshort\-enums \-fstack\-arrays\fR -.SS "Options controlling Fortran dialect" -.IX Subsection "Options controlling Fortran dialect" -The following options control the details of the Fortran dialect -accepted by the compiler: -.IP "\fB\-ffree\-form\fR" 4 -.IX Item "-ffree-form" -.PD 0 -.IP "\fB\-ffixed\-form\fR" 4 -.IX Item "-ffixed-form" -.PD -Specify the layout used by the source file. The free form layout -was introduced in Fortran 90. Fixed form was traditionally used in -older Fortran programs. When neither option is specified, the source -form is determined by the file extension. -.IP "\fB\-fall\-intrinsics\fR" 4 -.IX Item "-fall-intrinsics" -This option causes all intrinsic procedures (including the GNU-specific -extensions) to be accepted. This can be useful with \fB\-std=f95\fR to -force standard-compliance but get access to the full range of intrinsics -available with \fBgfortran\fR. As a consequence, \fB\-Wintrinsics\-std\fR -will be ignored and no user-defined procedure with the same name as any -intrinsic will be called except when it is explicitly declared \f(CW\*(C`EXTERNAL\*(C'\fR. -.IP "\fB\-fd\-lines\-as\-code\fR" 4 -.IX Item "-fd-lines-as-code" -.PD 0 -.IP "\fB\-fd\-lines\-as\-comments\fR" 4 -.IX Item "-fd-lines-as-comments" -.PD -Enable special treatment for lines beginning with \f(CW\*(C`d\*(C'\fR or \f(CW\*(C`D\*(C'\fR -in fixed form sources. If the \fB\-fd\-lines\-as\-code\fR option is -given they are treated as if the first column contained a blank. If the -\&\fB\-fd\-lines\-as\-comments\fR option is given, they are treated as -comment lines. -.IP "\fB\-fdollar\-ok\fR" 4 -.IX Item "-fdollar-ok" -Allow \fB$\fR as a valid non-first character in a symbol name. Symbols -that start with \fB$\fR are rejected since it is unclear which rules to -apply to implicit typing as different vendors implement different rules. -Using \fB$\fR in \f(CW\*(C`IMPLICIT\*(C'\fR statements is also rejected. -.IP "\fB\-fbackslash\fR" 4 -.IX Item "-fbackslash" -Change the interpretation of backslashes in string literals from a single -backslash character to \*(L"C\-style\*(R" escape characters. The following -combinations are expanded \f(CW\*(C`\ea\*(C'\fR, \f(CW\*(C`\eb\*(C'\fR, \f(CW\*(C`\ef\*(C'\fR, \f(CW\*(C`\en\*(C'\fR, -\&\f(CW\*(C`\er\*(C'\fR, \f(CW\*(C`\et\*(C'\fR, \f(CW\*(C`\ev\*(C'\fR, \f(CW\*(C`\e\e\*(C'\fR, and \f(CW\*(C`\e0\*(C'\fR to the \s-1ASCII\s0 -characters alert, backspace, form feed, newline, carriage return, -horizontal tab, vertical tab, backslash, and \s-1NUL,\s0 respectively. -Additionally, \f(CW\*(C`\ex\*(C'\fR\fInn\fR, \f(CW\*(C`\eu\*(C'\fR\fInnnn\fR and -\&\f(CW\*(C`\eU\*(C'\fR\fInnnnnnnn\fR (where each \fIn\fR is a hexadecimal digit) are -translated into the Unicode characters corresponding to the specified code -points. All other combinations of a character preceded by \e are -unexpanded. -.IP "\fB\-fmodule\-private\fR" 4 -.IX Item "-fmodule-private" -Set the default accessibility of module entities to \f(CW\*(C`PRIVATE\*(C'\fR. -Use-associated entities will not be accessible unless they are explicitly -declared as \f(CW\*(C`PUBLIC\*(C'\fR. -.IP "\fB\-ffixed\-line\-length\-\fR\fIn\fR" 4 -.IX Item "-ffixed-line-length-n" -Set column after which characters are ignored in typical fixed-form -lines in the source file, and through which spaces are assumed (as -if padded to that length) after the ends of short fixed-form lines. -.Sp -Popular values for \fIn\fR include 72 (the -standard and the default), 80 (card image), and 132 (corresponding -to \*(L"extended-source\*(R" options in some popular compilers). -\&\fIn\fR may also be \fBnone\fR, meaning that the entire line is meaningful -and that continued character constants never have implicit spaces appended -to them to fill out the line. -\&\fB\-ffixed\-line\-length\-0\fR means the same thing as -\&\fB\-ffixed\-line\-length\-none\fR. -.IP "\fB\-ffree\-line\-length\-\fR\fIn\fR" 4 -.IX Item "-ffree-line-length-n" -Set column after which characters are ignored in typical free-form -lines in the source file. The default value is 132. -\&\fIn\fR may be \fBnone\fR, meaning that the entire line is meaningful. -\&\fB\-ffree\-line\-length\-0\fR means the same thing as -\&\fB\-ffree\-line\-length\-none\fR. -.IP "\fB\-fmax\-identifier\-length=\fR\fIn\fR" 4 -.IX Item "-fmax-identifier-length=n" -Specify the maximum allowed identifier length. Typical values are -31 (Fortran 95) and 63 (Fortran 2003 and Fortran 2008). -.IP "\fB\-fimplicit\-none\fR" 4 -.IX Item "-fimplicit-none" -Specify that no implicit typing is allowed, unless overridden by explicit -\&\f(CW\*(C`IMPLICIT\*(C'\fR statements. This is the equivalent of adding -\&\f(CW\*(C`implicit none\*(C'\fR to the start of every procedure. -.IP "\fB\-fcray\-pointer\fR" 4 -.IX Item "-fcray-pointer" -Enable the Cray pointer extension, which provides C\-like pointer -functionality. -.IP "\fB\-fopenmp\fR" 4 -.IX Item "-fopenmp" -Enable the OpenMP extensions. This includes OpenMP \f(CW\*(C`!$omp\*(C'\fR directives -in free form -and \f(CW\*(C`c$omp\*(C'\fR, \f(CW*$omp\fR and \f(CW\*(C`!$omp\*(C'\fR directives in fixed form, -\&\f(CW\*(C`!$\*(C'\fR conditional compilation sentinels in free form -and \f(CW\*(C`c$\*(C'\fR, \f(CW\*(C`*$\*(C'\fR and \f(CW\*(C`!$\*(C'\fR sentinels in fixed form, -and when linking arranges for the OpenMP runtime library to be linked -in. The option \fB\-fopenmp\fR implies \fB\-frecursive\fR. -.IP "\fB\-fno\-range\-check\fR" 4 -.IX Item "-fno-range-check" -Disable range checking on results of simplification of constant -expressions during compilation. For example, \s-1GNU\s0 Fortran will give -an error at compile time when simplifying \f(CW\*(C`a = 1. / 0\*(C'\fR. -With this option, no error will be given and \f(CW\*(C`a\*(C'\fR will be assigned -the value \f(CW\*(C`+Infinity\*(C'\fR. If an expression evaluates to a value -outside of the relevant range of [\f(CW\*(C`\-HUGE()\*(C'\fR:\f(CW\*(C`HUGE()\*(C'\fR], -then the expression will be replaced by \f(CW\*(C`\-Inf\*(C'\fR or \f(CW\*(C`+Inf\*(C'\fR -as appropriate. -Similarly, \f(CW\*(C`DATA i/Z\*(AqFFFFFFFF\*(Aq/\*(C'\fR will result in an integer overflow -on most systems, but with \fB\-fno\-range\-check\fR the value will -\&\*(L"wrap around\*(R" and \f(CW\*(C`i\*(C'\fR will be initialized to \-1 instead. -.IP "\fB\-fdefault\-integer\-8\fR" 4 -.IX Item "-fdefault-integer-8" -Set the default integer and logical types to an 8 byte wide type. This option -also affects the kind of integer constants like \f(CW42\fR. Unlike -\&\fB\-finteger\-4\-integer\-8\fR, it does not promote variables with explicit -kind declaration. -.IP "\fB\-fdefault\-real\-8\fR" 4 -.IX Item "-fdefault-real-8" -Set the default real type to an 8 byte wide type. This option also affects -the kind of non-double real constants like \f(CW1.0\fR, and does promote -the default width of \f(CW\*(C`DOUBLE PRECISION\*(C'\fR to 16 bytes if possible, unless -\&\f(CW\*(C`\-fdefault\-double\-8\*(C'\fR is given, too. Unlike \fB\-freal\-4\-real\-8\fR, -it does not promote variables with explicit kind declaration. -.IP "\fB\-fdefault\-double\-8\fR" 4 -.IX Item "-fdefault-double-8" -Set the \f(CW\*(C`DOUBLE PRECISION\*(C'\fR type to an 8 byte wide type. Do nothing if this -is already the default. If \fB\-fdefault\-real\-8\fR is given, -\&\f(CW\*(C`DOUBLE PRECISION\*(C'\fR would instead be promoted to 16 bytes if possible, and -\&\fB\-fdefault\-double\-8\fR can be used to prevent this. The kind of real -constants like \f(CW\*(C`1.d0\*(C'\fR will not be changed by \fB\-fdefault\-real\-8\fR -though, so also \fB\-fdefault\-double\-8\fR does not affect it. -.IP "\fB\-finteger\-4\-integer\-8\fR" 4 -.IX Item "-finteger-4-integer-8" -Promote all \f(CW\*(C`INTEGER(KIND=4)\*(C'\fR entities to an \f(CW\*(C`INTEGER(KIND=8)\*(C'\fR -entities. If \f(CW\*(C`KIND=8\*(C'\fR is unavailable, then an error will be issued. -This option should be used with care and may not be suitable for your codes. -Areas of possible concern include calls to external procedures, -alignment in \f(CW\*(C`EQUIVALENCE\*(C'\fR and/or \f(CW\*(C`COMMON\*(C'\fR, generic interfaces, -\&\s-1BOZ\s0 literal constant conversion, and I/O. Inspection of the intermediate -representation of the translated Fortran code, produced by -\&\fB\-fdump\-tree\-original\fR, is suggested. -.IP "\fB\-freal\-4\-real\-8\fR" 4 -.IX Item "-freal-4-real-8" -.PD 0 -.IP "\fB\-freal\-4\-real\-10\fR" 4 -.IX Item "-freal-4-real-10" -.IP "\fB\-freal\-4\-real\-16\fR" 4 -.IX Item "-freal-4-real-16" -.IP "\fB\-freal\-8\-real\-4\fR" 4 -.IX Item "-freal-8-real-4" -.IP "\fB\-freal\-8\-real\-10\fR" 4 -.IX Item "-freal-8-real-10" -.IP "\fB\-freal\-8\-real\-16\fR" 4 -.IX Item "-freal-8-real-16" -.PD -Promote all \f(CW\*(C`REAL(KIND=M)\*(C'\fR entities to \f(CW\*(C`REAL(KIND=N)\*(C'\fR entities. -If \f(CW\*(C`REAL(KIND=N)\*(C'\fR is unavailable, then an error will be issued. -All other real kind types are unaffected by this option. -These options should be used with care and may not be suitable for your -codes. Areas of possible concern include calls to external procedures, -alignment in \f(CW\*(C`EQUIVALENCE\*(C'\fR and/or \f(CW\*(C`COMMON\*(C'\fR, generic interfaces, -\&\s-1BOZ\s0 literal constant conversion, and I/O. Inspection of the intermediate -representation of the translated Fortran code, produced by -\&\fB\-fdump\-tree\-original\fR, is suggested. -.IP "\fB\-std=\fR\fIstd\fR" 4 -.IX Item "-std=std" -Specify the standard to which the program is expected to conform, which -may be one of \fBf95\fR, \fBf2003\fR, \fBf2008\fR, \fBgnu\fR, or -\&\fBlegacy\fR. The default value for \fIstd\fR is \fBgnu\fR, which -specifies a superset of the Fortran 95 standard that includes all of the -extensions supported by \s-1GNU\s0 Fortran, although warnings will be given for -obsolete extensions not recommended for use in new code. The -\&\fBlegacy\fR value is equivalent but without the warnings for obsolete -extensions, and may be useful for old non-standard programs. The -\&\fBf95\fR, \fBf2003\fR and \fBf2008\fR values specify strict -conformance to the Fortran 95, Fortran 2003 and Fortran 2008 standards, -respectively; errors are given for all extensions beyond the relevant -language standard, and warnings are given for the Fortran 77 features -that are permitted but obsolescent in later standards. \fB\-std=f2008ts\fR -allows the Fortran 2008 standard including the additions of the -Technical Specification (\s-1TS\s0) 29113 on Further Interoperability of Fortran -with C. -.SS "Enable and customize preprocessing" -.IX Subsection "Enable and customize preprocessing" -Preprocessor related options. See section -\&\fBPreprocessing and conditional compilation\fR for more detailed -information on preprocessing in \fBgfortran\fR. -.IP "\fB\-cpp\fR" 4 -.IX Item "-cpp" -.PD 0 -.IP "\fB\-nocpp\fR" 4 -.IX Item "-nocpp" -.PD -Enable preprocessing. The preprocessor is automatically invoked if -the file extension is \fI.fpp\fR, \fI.FPP\fR, \fI.F\fR, \fI.FOR\fR, -\&\fI.FTN\fR, \fI.F90\fR, \fI.F95\fR, \fI.F03\fR or \fI.F08\fR. Use -this option to manually enable preprocessing of any kind of Fortran file. -.Sp -To disable preprocessing of files with any of the above listed extensions, -use the negative form: \fB\-nocpp\fR. -.Sp -The preprocessor is run in traditional mode. Any restrictions of the -file-format, especially the limits on line length, apply for -preprocessed output as well, so it might be advisable to use the -\&\fB\-ffree\-line\-length\-none\fR or \fB\-ffixed\-line\-length\-none\fR -options. -.IP "\fB\-dM\fR" 4 -.IX Item "-dM" -Instead of the normal output, generate a list of \f(CW\*(Aq#define\*(Aq\fR -directives for all the macros defined during the execution of the -preprocessor, including predefined macros. This gives you a way -of finding out what is predefined in your version of the preprocessor. -Assuming you have no file \fIfoo.f90\fR, the command -.Sp -.Vb 1 -\& touch foo.f90; gfortran \-cpp \-E \-dM foo.f90 -.Ve -.Sp -will show all the predefined macros. -.IP "\fB\-dD\fR" 4 -.IX Item "-dD" -Like \fB\-dM\fR except in two respects: it does not include the -predefined macros, and it outputs both the \f(CW\*(C`#define\*(C'\fR directives -and the result of preprocessing. Both kinds of output go to the -standard output file. -.IP "\fB\-dN\fR" 4 -.IX Item "-dN" -Like \fB\-dD\fR, but emit only the macro names, not their expansions. -.IP "\fB\-dU\fR" 4 -.IX Item "-dU" -Like \fBdD\fR except that only macros that are expanded, or whose -definedness is tested in preprocessor directives, are output; the -output is delayed until the use or test of the macro; and \f(CW\*(Aq#undef\*(Aq\fR -directives are also output for macros tested but undefined at the time. -.IP "\fB\-dI\fR" 4 -.IX Item "-dI" -Output \f(CW\*(Aq#include\*(Aq\fR directives in addition to the result -of preprocessing. -.IP "\fB\-fworking\-directory\fR" 4 -.IX Item "-fworking-directory" -Enable generation of linemarkers in the preprocessor output that will -let the compiler know the current working directory at the time of -preprocessing. When this option is enabled, the preprocessor will emit, -after the initial linemarker, a second linemarker with the current -working directory followed by two slashes. \s-1GCC\s0 will use this directory, -when it is present in the preprocessed input, as the directory emitted -as the current working directory in some debugging information formats. -This option is implicitly enabled if debugging information is enabled, -but this can be inhibited with the negated form -\&\fB\-fno\-working\-directory\fR. If the \fB\-P\fR flag is present -in the command line, this option has no effect, since no \f(CW\*(C`#line\*(C'\fR -directives are emitted whatsoever. -.IP "\fB\-idirafter\fR \fIdir\fR" 4 -.IX Item "-idirafter dir" -Search \fIdir\fR for include files, but do it after all directories -specified with \fB\-I\fR and the standard system directories have -been exhausted. \fIdir\fR is treated as a system include directory. -If dir begins with \f(CW\*(C`=\*(C'\fR, then the \f(CW\*(C`=\*(C'\fR will be replaced by -the sysroot prefix; see \fB\-\-sysroot\fR and \fB\-isysroot\fR. -.IP "\fB\-imultilib\fR \fIdir\fR" 4 -.IX Item "-imultilib dir" -Use \fIdir\fR as a subdirectory of the directory containing target-specific -\&\*(C+ headers. -.IP "\fB\-iprefix\fR \fIprefix\fR" 4 -.IX Item "-iprefix prefix" -Specify \fIprefix\fR as the prefix for subsequent \fB\-iwithprefix\fR -options. If the \fIprefix\fR represents a directory, you should include -the final \f(CW\*(Aq/\*(Aq\fR. -.IP "\fB\-isysroot\fR \fIdir\fR" 4 -.IX Item "-isysroot dir" -This option is like the \fB\-\-sysroot\fR option, but applies only to -header files. See the \fB\-\-sysroot\fR option for more information. -.IP "\fB\-iquote\fR \fIdir\fR" 4 -.IX Item "-iquote dir" -Search \fIdir\fR only for header files requested with \f(CW\*(C`#include "file"\*(C'\fR; -they are not searched for \f(CW\*(C`#include <file>\*(C'\fR, before all directories -specified by \fB\-I\fR and before the standard system directories. If -\&\fIdir\fR begins with \f(CW\*(C`=\*(C'\fR, then the \f(CW\*(C`=\*(C'\fR will be replaced by the -sysroot prefix; see \fB\-\-sysroot\fR and \fB\-isysroot\fR. -.IP "\fB\-isystem\fR \fIdir\fR" 4 -.IX Item "-isystem dir" -Search \fIdir\fR for header files, after all directories specified by -\&\fB\-I\fR but before the standard system directories. Mark it as a -system directory, so that it gets the same special treatment as is -applied to the standard system directories. If \fIdir\fR begins with -\&\f(CW\*(C`=\*(C'\fR, then the \f(CW\*(C`=\*(C'\fR will be replaced by the sysroot prefix; -see \fB\-\-sysroot\fR and \fB\-isysroot\fR. -.IP "\fB\-nostdinc\fR" 4 -.IX Item "-nostdinc" -Do not search the standard system directories for header files. Only -the directories you have specified with \fB\-I\fR options (and the -directory of the current file, if appropriate) are searched. -.IP "\fB\-undef\fR" 4 -.IX Item "-undef" -Do not predefine any system-specific or GCC-specific macros. -The standard predefined macros remain defined. -.IP "\fB\-A\fR\fIpredicate\fR\fB=\fR\fIanswer\fR" 4 -.IX Item "-Apredicate=answer" -Make an assertion with the predicate \fIpredicate\fR and answer \fIanswer\fR. -This form is preferred to the older form \-A predicate(answer), which is still -supported, because it does not use shell special characters. -.IP "\fB\-A\-\fR\fIpredicate\fR\fB=\fR\fIanswer\fR" 4 -.IX Item "-A-predicate=answer" -Cancel an assertion with the predicate \fIpredicate\fR and answer \fIanswer\fR. -.IP "\fB\-C\fR" 4 -.IX Item "-C" -Do not discard comments. All comments are passed through to the output -file, except for comments in processed directives, which are deleted -along with the directive. -.Sp -You should be prepared for side effects when using \fB\-C\fR; it causes -the preprocessor to treat comments as tokens in their own right. For example, -comments appearing at the start of what would be a directive line have the -effect of turning that line into an ordinary source line, since the first -token on the line is no longer a \f(CW\*(Aq#\*(Aq\fR. -.Sp -Warning: this currently handles C\-Style comments only. The preprocessor -does not yet recognize Fortran-style comments. -.IP "\fB\-CC\fR" 4 -.IX Item "-CC" -Do not discard comments, including during macro expansion. This is like -\&\fB\-C\fR, except that comments contained within macros are also passed -through to the output file where the macro is expanded. -.Sp -In addition to the side-effects of the \fB\-C\fR option, the \fB\-CC\fR -option causes all \*(C+\-style comments inside a macro to be converted to C\-style -comments. This is to prevent later use of that macro from inadvertently -commenting out the remainder of the source line. The \fB\-CC\fR option -is generally used to support lint comments. -.Sp -Warning: this currently handles C\- and \*(C+\-Style comments only. The -preprocessor does not yet recognize Fortran-style comments. -.IP "\fB\-D\fR\fIname\fR" 4 -.IX Item "-Dname" -Predefine name as a macro, with definition \f(CW1\fR. -.IP "\fB\-D\fR\fIname\fR\fB=\fR\fIdefinition\fR" 4 -.IX Item "-Dname=definition" -The contents of \fIdefinition\fR are tokenized and processed as if they -appeared during translation phase three in a \f(CW\*(Aq#define\*(Aq\fR directive. -In particular, the definition will be truncated by embedded newline -characters. -.Sp -If you are invoking the preprocessor from a shell or shell-like program -you may need to use the shell's quoting syntax to protect characters such -as spaces that have a meaning in the shell syntax. -.Sp -If you wish to define a function-like macro on the command line, write -its argument list with surrounding parentheses before the equals sign -(if any). Parentheses are meaningful to most shells, so you will need -to quote the option. With sh and csh, \f(CW\*(C`\-D\*(Aqname(args...)=definition\*(Aq\*(C'\fR -works. -.Sp -\&\fB\-D\fR and \fB\-U\fR options are processed in the order they are -given on the command line. All \-imacros file and \-include file options -are processed after all \-D and \-U options. -.IP "\fB\-H\fR" 4 -.IX Item "-H" -Print the name of each header file used, in addition to other normal -activities. Each name is indented to show how deep in the \f(CW\*(Aq#include\*(Aq\fR -stack it is. -.IP "\fB\-P\fR" 4 -.IX Item "-P" -Inhibit generation of linemarkers in the output from the preprocessor. -This might be useful when running the preprocessor on something that -is not C code, and will be sent to a program which might be confused -by the linemarkers. -.IP "\fB\-U\fR\fIname\fR" 4 -.IX Item "-Uname" -Cancel any previous definition of \fIname\fR, either built in or provided -with a \fB\-D\fR option. -.SS "Options to request or suppress errors and warnings" -.IX Subsection "Options to request or suppress errors and warnings" -Errors are diagnostic messages that report that the \s-1GNU\s0 Fortran compiler -cannot compile the relevant piece of source code. The compiler will -continue to process the program in an attempt to report further errors -to aid in debugging, but will not produce any compiled output. -.PP -Warnings are diagnostic messages that report constructions which -are not inherently erroneous but which are risky or suggest there is -likely to be a bug in the program. Unless \fB\-Werror\fR is specified, -they do not prevent compilation of the program. -.PP -You can request many specific warnings with options beginning \fB\-W\fR, -for example \fB\-Wimplicit\fR to request warnings on implicit -declarations. Each of these specific warning options also has a -negative form beginning \fB\-Wno\-\fR to turn off warnings; -for example, \fB\-Wno\-implicit\fR. This manual lists only one of the -two forms, whichever is not the default. -.PP -These options control the amount and kinds of errors and warnings produced -by \s-1GNU\s0 Fortran: -.IP "\fB\-fmax\-errors=\fR\fIn\fR" 4 -.IX Item "-fmax-errors=n" -Limits the maximum number of error messages to \fIn\fR, at which point -\&\s-1GNU\s0 Fortran bails out rather than attempting to continue processing the -source code. If \fIn\fR is 0, there is no limit on the number of error -messages produced. -.IP "\fB\-fsyntax\-only\fR" 4 -.IX Item "-fsyntax-only" -Check the code for syntax errors, but do not actually compile it. This -will generate module files for each module present in the code, but no -other output file. -.IP "\fB\-pedantic\fR" 4 -.IX Item "-pedantic" -Issue warnings for uses of extensions to Fortran 95. -\&\fB\-pedantic\fR also applies to C\-language constructs where they -occur in \s-1GNU\s0 Fortran source files, such as use of \fB\ee\fR in a -character constant within a directive like \f(CW\*(C`#include\*(C'\fR. -.Sp -Valid Fortran 95 programs should compile properly with or without -this option. -However, without this option, certain \s-1GNU\s0 extensions and traditional -Fortran features are supported as well. -With this option, many of them are rejected. -.Sp -Some users try to use \fB\-pedantic\fR to check programs for conformance. -They soon find that it does not do quite what they want\-\-\-it finds some -nonstandard practices, but not all. -However, improvements to \s-1GNU\s0 Fortran in this area are welcome. -.Sp -This should be used in conjunction with \fB\-std=f95\fR, -\&\fB\-std=f2003\fR or \fB\-std=f2008\fR. -.IP "\fB\-pedantic\-errors\fR" 4 -.IX Item "-pedantic-errors" -Like \fB\-pedantic\fR, except that errors are produced rather than -warnings. -.IP "\fB\-Wall\fR" 4 -.IX Item "-Wall" -Enables commonly used warning options pertaining to usage that -we recommend avoiding and that we believe are easy to avoid. -This currently includes \fB\-Waliasing\fR, \fB\-Wampersand\fR, -\&\fB\-Wconversion\fR, \fB\-Wsurprising\fR, \fB\-Wc\-binding\-type\fR, -\&\fB\-Wintrinsics\-std\fR, \fB\-Wno\-tabs\fR, \fB\-Wintrinsic\-shadow\fR, -\&\fB\-Wline\-truncation\fR, \fB\-Wtarget\-lifetime\fR, -\&\fB\-Wreal\-q\-constant\fR and \fB\-Wunused\fR. -.IP "\fB\-Waliasing\fR" 4 -.IX Item "-Waliasing" -Warn about possible aliasing of dummy arguments. Specifically, it warns -if the same actual argument is associated with a dummy argument with -\&\f(CW\*(C`INTENT(IN)\*(C'\fR and a dummy argument with \f(CW\*(C`INTENT(OUT)\*(C'\fR in a call -with an explicit interface. -.Sp -The following example will trigger the warning. -.Sp -.Vb 7 -\& interface -\& subroutine bar(a,b) -\& integer, intent(in) :: a -\& integer, intent(out) :: b -\& end subroutine -\& end interface -\& integer :: a -\& -\& call bar(a,a) -.Ve -.IP "\fB\-Wampersand\fR" 4 -.IX Item "-Wampersand" -Warn about missing ampersand in continued character constants. The warning is -given with \fB\-Wampersand\fR, \fB\-pedantic\fR, \fB\-std=f95\fR, -\&\fB\-std=f2003\fR and \fB\-std=f2008\fR. Note: With no ampersand -given in a continued character constant, \s-1GNU\s0 Fortran assumes continuation -at the first non-comment, non-whitespace character after the ampersand -that initiated the continuation. -.IP "\fB\-Warray\-temporaries\fR" 4 -.IX Item "-Warray-temporaries" -Warn about array temporaries generated by the compiler. The information -generated by this warning is sometimes useful in optimization, in order to -avoid such temporaries. -.IP "\fB\-Wc\-binding\-type\fR" 4 -.IX Item "-Wc-binding-type" -Warn if the a variable might not be C interoperable. In particular, warn if -the variable has been declared using an intrinsic type with default kind -instead of using a kind parameter defined for C interoperability in the -intrinsic \f(CW\*(C`ISO_C_Binding\*(C'\fR module. This option is implied by -\&\fB\-Wall\fR. -.IP "\fB\-Wcharacter\-truncation\fR" 4 -.IX Item "-Wcharacter-truncation" -Warn when a character assignment will truncate the assigned string. -.IP "\fB\-Wline\-truncation\fR" 4 -.IX Item "-Wline-truncation" -Warn when a source code line will be truncated. This option is -implied by \fB\-Wall\fR. -.IP "\fB\-Wconversion\fR" 4 -.IX Item "-Wconversion" -Warn about implicit conversions that are likely to change the value of -the expression after conversion. Implied by \fB\-Wall\fR. -.IP "\fB\-Wconversion\-extra\fR" 4 -.IX Item "-Wconversion-extra" -Warn about implicit conversions between different types and kinds. -.IP "\fB\-Wextra\fR" 4 -.IX Item "-Wextra" -Enables some warning options for usages of language features which -may be problematic. This currently includes \fB\-Wcompare\-reals\fR -and \fB\-Wunused\-parameter\fR. -.IP "\fB\-Wimplicit\-interface\fR" 4 -.IX Item "-Wimplicit-interface" -Warn if a procedure is called without an explicit interface. -Note this only checks that an explicit interface is present. It does not -check that the declared interfaces are consistent across program units. -.IP "\fB\-Wimplicit\-procedure\fR" 4 -.IX Item "-Wimplicit-procedure" -Warn if a procedure is called that has neither an explicit interface -nor has been declared as \f(CW\*(C`EXTERNAL\*(C'\fR. -.IP "\fB\-Wintrinsics\-std\fR" 4 -.IX Item "-Wintrinsics-std" -Warn if \fBgfortran\fR finds a procedure named like an intrinsic not -available in the currently selected standard (with \fB\-std\fR) and treats -it as \f(CW\*(C`EXTERNAL\*(C'\fR procedure because of this. \fB\-fall\-intrinsics\fR can -be used to never trigger this behavior and always link to the intrinsic -regardless of the selected standard. -.IP "\fB\-Wreal\-q\-constant\fR" 4 -.IX Item "-Wreal-q-constant" -Produce a warning if a real-literal-constant contains a \f(CW\*(C`q\*(C'\fR -exponent-letter. -.IP "\fB\-Wsurprising\fR" 4 -.IX Item "-Wsurprising" -Produce a warning when \*(L"suspicious\*(R" code constructs are encountered. -While technically legal these usually indicate that an error has been made. -.Sp -This currently produces a warning under the following circumstances: -.RS 4 -.IP "\(bu" 4 -An \s-1INTEGER SELECT\s0 construct has a \s-1CASE\s0 that can never be matched as its -lower value is greater than its upper value. -.IP "\(bu" 4 -A \s-1LOGICAL SELECT\s0 construct has three \s-1CASE\s0 statements. -.IP "\(bu" 4 -A \s-1TRANSFER\s0 specifies a source that is shorter than the destination. -.IP "\(bu" 4 -The type of a function result is declared more than once with the same type. If -\&\fB\-pedantic\fR or standard-conforming mode is enabled, this is an error. -.IP "\(bu" 4 -A \f(CW\*(C`CHARACTER\*(C'\fR variable is declared with negative length. -.RE -.RS 4 -.RE -.IP "\fB\-Wtabs\fR" 4 -.IX Item "-Wtabs" -By default, tabs are accepted as whitespace, but tabs are not members -of the Fortran Character Set. For continuation lines, a tab followed -by a digit between 1 and 9 is supported. \fB\-Wno\-tabs\fR will cause -a warning to be issued if a tab is encountered. Note, \fB\-Wno\-tabs\fR -is active for \fB\-pedantic\fR, \fB\-std=f95\fR, \fB\-std=f2003\fR, -\&\fB\-std=f2008\fR and \fB\-Wall\fR. -.IP "\fB\-Wunderflow\fR" 4 -.IX Item "-Wunderflow" -Produce a warning when numerical constant expressions are -encountered, which yield an \s-1UNDERFLOW\s0 during compilation. -.IP "\fB\-Wintrinsic\-shadow\fR" 4 -.IX Item "-Wintrinsic-shadow" -Warn if a user-defined procedure or module procedure has the same name as an -intrinsic; in this case, an explicit interface or \f(CW\*(C`EXTERNAL\*(C'\fR or -\&\f(CW\*(C`INTRINSIC\*(C'\fR declaration might be needed to get calls later resolved to -the desired intrinsic/procedure. This option is implied by \fB\-Wall\fR. -.IP "\fB\-Wunused\-dummy\-argument\fR" 4 -.IX Item "-Wunused-dummy-argument" -Warn about unused dummy arguments. This option is implied by \fB\-Wall\fR. -.IP "\fB\-Wunused\-parameter\fR" 4 -.IX Item "-Wunused-parameter" -Contrary to \fBgcc\fR's meaning of \fB\-Wunused\-parameter\fR, -\&\fBgfortran\fR's implementation of this option does not warn -about unused dummy arguments (see \fB\-Wunused\-dummy\-argument\fR), -but about unused \f(CW\*(C`PARAMETER\*(C'\fR values. \fB\-Wunused\-parameter\fR -is not included in \fB\-Wall\fR but is implied by \fB\-Wall \-Wextra\fR. -.IP "\fB\-Walign\-commons\fR" 4 -.IX Item "-Walign-commons" -By default, \fBgfortran\fR warns about any occasion of variables being -padded for proper alignment inside a \f(CW\*(C`COMMON\*(C'\fR block. This warning can be turned -off via \fB\-Wno\-align\-commons\fR. See also \fB\-falign\-commons\fR. -.IP "\fB\-Wfunction\-elimination\fR" 4 -.IX Item "-Wfunction-elimination" -Warn if any calls to functions are eliminated by the optimizations -enabled by the \fB\-ffrontend\-optimize\fR option. -.IP "\fB\-Wrealloc\-lhs\fR" 4 -.IX Item "-Wrealloc-lhs" -Warn when the compiler might insert code to for allocation or reallocation of -an allocatable array variable of intrinsic type in intrinsic assignments. In -hot loops, the Fortran 2003 reallocation feature may reduce the performance. -If the array is already allocated with the correct shape, consider using a -whole-array array-spec (e.g. \f(CW\*(C`(:,:,:)\*(C'\fR) for the variable on the left-hand -side to prevent the reallocation check. Note that in some cases the warning -is shown, even if the compiler will optimize reallocation checks away. For -instance, when the right-hand side contains the same variable multiplied by -a scalar. See also \fB\-frealloc\-lhs\fR. -.IP "\fB\-Wrealloc\-lhs\-all\fR" 4 -.IX Item "-Wrealloc-lhs-all" -Warn when the compiler inserts code to for allocation or reallocation of an -allocatable variable; this includes scalars and derived types. -.IP "\fB\-Wcompare\-reals\fR" 4 -.IX Item "-Wcompare-reals" -Warn when comparing real or complex types for equality or inequality. -This option is implied by \fB\-Wextra\fR. -.IP "\fB\-Wtarget\-lifetime\fR" 4 -.IX Item "-Wtarget-lifetime" -Warn if the pointer in a pointer assignment might be longer than the its -target. This option is implied by \fB\-Wall\fR. -.IP "\fB\-Wzerotrip\fR" 4 -.IX Item "-Wzerotrip" -Warn if a \f(CW\*(C`DO\*(C'\fR loop is known to execute zero times at compile -time. This option is implied by \fB\-Wall\fR. -.IP "\fB\-Werror\fR" 4 -.IX Item "-Werror" -Turns all warnings into errors. -.PP -Some of these have no effect when compiling programs written in Fortran. -.SS "Options for debugging your program or \s-1GNU\s0 Fortran" -.IX Subsection "Options for debugging your program or GNU Fortran" -\&\s-1GNU\s0 Fortran has various special options that are used for debugging -either your program or the \s-1GNU\s0 Fortran compiler. -.IP "\fB\-fdump\-fortran\-original\fR" 4 -.IX Item "-fdump-fortran-original" -Output the internal parse tree after translating the source program -into internal representation. Only really useful for debugging the -\&\s-1GNU\s0 Fortran compiler itself. -.IP "\fB\-fdump\-fortran\-optimized\fR" 4 -.IX Item "-fdump-fortran-optimized" -Output the parse tree after front-end optimization. Only really -useful for debugging the \s-1GNU\s0 Fortran compiler itself. -.IP "\fB\-fdump\-parse\-tree\fR" 4 -.IX Item "-fdump-parse-tree" -Output the internal parse tree after translating the source program -into internal representation. Only really useful for debugging the -\&\s-1GNU\s0 Fortran compiler itself. This option is deprecated; use -\&\f(CW\*(C`\-fdump\-fortran\-original\*(C'\fR instead. -.IP "\fB\-ffpe\-trap=\fR\fIlist\fR" 4 -.IX Item "-ffpe-trap=list" -Specify a list of floating point exception traps to enable. On most -systems, if a floating point exception occurs and the trap for that -exception is enabled, a \s-1SIGFPE\s0 signal will be sent and the program -being aborted, producing a core file useful for debugging. \fIlist\fR -is a (possibly empty) comma-separated list of the following -exceptions: \fBinvalid\fR (invalid floating point operation, such as -\&\f(CW\*(C`SQRT(\-1.0)\*(C'\fR), \fBzero\fR (division by zero), \fBoverflow\fR -(overflow in a floating point operation), \fBunderflow\fR (underflow -in a floating point operation), \fBinexact\fR (loss of precision -during operation), and \fBdenormal\fR (operation performed on a -denormal value). The first five exceptions correspond to the five -\&\s-1IEEE 754\s0 exceptions, whereas the last one (\fBdenormal\fR) is not -part of the \s-1IEEE 754\s0 standard but is available on some common -architectures such as x86. -.Sp -The first three exceptions (\fBinvalid\fR, \fBzero\fR, and -\&\fBoverflow\fR) often indicate serious errors, and unless the program -has provisions for dealing with these exceptions, enabling traps for -these three exceptions is probably a good idea. -.Sp -Many, if not most, floating point operations incur loss of precision -due to rounding, and hence the \f(CW\*(C`ffpe\-trap=inexact\*(C'\fR is likely to -be uninteresting in practice. -.Sp -By default no exception traps are enabled. -.IP "\fB\-ffpe\-summary=\fR\fIlist\fR" 4 -.IX Item "-ffpe-summary=list" -Specify a list of floating-point exceptions, whose flag status is printed -to \f(CW\*(C`ERROR_UNIT\*(C'\fR when invoking \f(CW\*(C`STOP\*(C'\fR and \f(CW\*(C`ERROR STOP\*(C'\fR. -\&\fIlist\fR can be either \fBnone\fR, \fBall\fR or a comma-separated list -of the following exceptions: \fBinvalid\fR, \fBzero\fR, \fBoverflow\fR, -\&\fBunderflow\fR, \fBinexact\fR and \fBdenormal\fR. (See -\&\fB\-ffpe\-trap\fR for a description of the exceptions.) -.Sp -By default, a summary for all exceptions but \fBinexact\fR is shown. -.IP "\fB\-fno\-backtrace\fR" 4 -.IX Item "-fno-backtrace" -When a serious runtime error is encountered or a deadly signal is -emitted (segmentation fault, illegal instruction, bus error, -floating-point exception, and the other \s-1POSIX\s0 signals that have the -action \fBcore\fR), the Fortran runtime library tries to output a -backtrace of the error. \f(CW\*(C`\-fno\-backtrace\*(C'\fR disables the backtrace -generation. This option only has influence for compilation of the -Fortran main program. -.SS "Options for directory search" -.IX Subsection "Options for directory search" -These options affect how \s-1GNU\s0 Fortran searches -for files specified by the \f(CW\*(C`INCLUDE\*(C'\fR directive and where it searches -for previously compiled modules. -.PP -It also affects the search paths used by \fBcpp\fR when used to preprocess -Fortran source. -.IP "\fB\-I\fR\fIdir\fR" 4 -.IX Item "-Idir" -These affect interpretation of the \f(CW\*(C`INCLUDE\*(C'\fR directive -(as well as of the \f(CW\*(C`#include\*(C'\fR directive of the \fBcpp\fR -preprocessor). -.Sp -Also note that the general behavior of \fB\-I\fR and -\&\f(CW\*(C`INCLUDE\*(C'\fR is pretty much the same as of \fB\-I\fR with -\&\f(CW\*(C`#include\*(C'\fR in the \fBcpp\fR preprocessor, with regard to -looking for \fIheader.gcc\fR files and other such things. -.Sp -This path is also used to search for \fI.mod\fR files when previously -compiled modules are required by a \f(CW\*(C`USE\*(C'\fR statement. -.IP "\fB\-J\fR\fIdir\fR" 4 -.IX Item "-Jdir" -This option specifies where to put \fI.mod\fR files for compiled modules. -It is also added to the list of directories to searched by an \f(CW\*(C`USE\*(C'\fR -statement. -.Sp -The default is the current directory. -.IP "\fB\-fintrinsic\-modules\-path\fR \fIdir\fR" 4 -.IX Item "-fintrinsic-modules-path dir" -This option specifies the location of pre-compiled intrinsic modules, if -they are not in the default location expected by the compiler. -.SS "Influencing the linking step" -.IX Subsection "Influencing the linking step" -These options come into play when the compiler links object files into an -executable output file. They are meaningless if the compiler is not doing -a link step. -.IP "\fB\-static\-libgfortran\fR" 4 -.IX Item "-static-libgfortran" -On systems that provide \fIlibgfortran\fR as a shared and a static -library, this option forces the use of the static version. If no -shared version of \fIlibgfortran\fR was built when the compiler was -configured, this option has no effect. -.SS "Influencing runtime behavior" -.IX Subsection "Influencing runtime behavior" -These options affect the runtime behavior of programs compiled with \s-1GNU\s0 Fortran. -.IP "\fB\-fconvert=\fR\fIconversion\fR" 4 -.IX Item "-fconvert=conversion" -Specify the representation of data for unformatted files. Valid -values for conversion are: \fBnative\fR, the default; \fBswap\fR, -swap between big\- and little-endian; \fBbig-endian\fR, use big-endian -representation for unformatted files; \fBlittle-endian\fR, use little-endian -representation for unformatted files. -.Sp -\&\fIThis option has an effect only when used in the main program. -The \f(CI\*(C`CONVERT\*(C'\fI specifier and the \s-1GFORTRAN_CONVERT_UNIT\s0 environment -variable override the default specified by \f(BI\-fconvert\fI.\fR -.IP "\fB\-frecord\-marker=\fR\fIlength\fR" 4 -.IX Item "-frecord-marker=length" -Specify the length of record markers for unformatted files. -Valid values for \fIlength\fR are 4 and 8. Default is 4. -\&\fIThis is different from previous versions of\fR \fBgfortran\fR, -which specified a default record marker length of 8 on most -systems. If you want to read or write files compatible -with earlier versions of \fBgfortran\fR, use \fB\-frecord\-marker=8\fR. -.IP "\fB\-fmax\-subrecord\-length=\fR\fIlength\fR" 4 -.IX Item "-fmax-subrecord-length=length" -Specify the maximum length for a subrecord. The maximum permitted -value for length is 2147483639, which is also the default. Only -really useful for use by the gfortran testsuite. -.IP "\fB\-fsign\-zero\fR" 4 -.IX Item "-fsign-zero" -When enabled, floating point numbers of value zero with the sign bit set -are written as negative number in formatted output and treated as -negative in the \f(CW\*(C`SIGN\*(C'\fR intrinsic. \fB\-fno\-sign\-zero\fR does not -print the negative sign of zero values (or values rounded to zero for I/O) -and regards zero as positive number in the \f(CW\*(C`SIGN\*(C'\fR intrinsic for -compatibility with Fortran 77. The default is \fB\-fsign\-zero\fR. -.SS "Options for code generation conventions" -.IX Subsection "Options for code generation conventions" -These machine-independent options control the interface conventions -used in code generation. -.PP -Most of them have both positive and negative forms; the negative form -of \fB\-ffoo\fR would be \fB\-fno\-foo\fR. In the table below, only -one of the forms is listed\-\-\-the one which is not the default. You -can figure out the other form by either removing \fBno\-\fR or adding -it. -.IP "\fB\-fno\-automatic\fR" 4 -.IX Item "-fno-automatic" -Treat each program unit (except those marked as \s-1RECURSIVE\s0) as if the -\&\f(CW\*(C`SAVE\*(C'\fR statement were specified for every local variable and array -referenced in it. Does not affect common blocks. (Some Fortran compilers -provide this option under the name \fB\-static\fR or \fB\-save\fR.) -The default, which is \fB\-fautomatic\fR, uses the stack for local -variables smaller than the value given by \fB\-fmax\-stack\-var\-size\fR. -Use the option \fB\-frecursive\fR to use no static memory. -.IP "\fB\-ff2c\fR" 4 -.IX Item "-ff2c" -Generate code designed to be compatible with code generated -by \fBg77\fR and \fBf2c\fR. -.Sp -The calling conventions used by \fBg77\fR (originally implemented -in \fBf2c\fR) require functions that return type -default \f(CW\*(C`REAL\*(C'\fR to actually return the C type \f(CW\*(C`double\*(C'\fR, and -functions that return type \f(CW\*(C`COMPLEX\*(C'\fR to return the values via an -extra argument in the calling sequence that points to where to -store the return value. Under the default \s-1GNU\s0 calling conventions, such -functions simply return their results as they would in \s-1GNU\s0 -C\-\-\-default \f(CW\*(C`REAL\*(C'\fR functions return the C type \f(CW\*(C`float\*(C'\fR, and -\&\f(CW\*(C`COMPLEX\*(C'\fR functions return the \s-1GNU C\s0 type \f(CW\*(C`complex\*(C'\fR. -Additionally, this option implies the \fB\-fsecond\-underscore\fR -option, unless \fB\-fno\-second\-underscore\fR is explicitly requested. -.Sp -This does not affect the generation of code that interfaces with -the \fBlibgfortran\fR library. -.Sp -\&\fICaution:\fR It is not a good idea to mix Fortran code compiled with -\&\fB\-ff2c\fR with code compiled with the default \fB\-fno\-f2c\fR -calling conventions as, calling \f(CW\*(C`COMPLEX\*(C'\fR or default \f(CW\*(C`REAL\*(C'\fR -functions between program parts which were compiled with different -calling conventions will break at execution time. -.Sp -\&\fICaution:\fR This will break code which passes intrinsic functions -of type default \f(CW\*(C`REAL\*(C'\fR or \f(CW\*(C`COMPLEX\*(C'\fR as actual arguments, as -the library implementations use the \fB\-fno\-f2c\fR calling conventions. -.IP "\fB\-fno\-underscoring\fR" 4 -.IX Item "-fno-underscoring" -Do not transform names of entities specified in the Fortran -source file by appending underscores to them. -.Sp -With \fB\-funderscoring\fR in effect, \s-1GNU\s0 Fortran appends one -underscore to external names with no underscores. This is done to ensure -compatibility with code produced by many \s-1UNIX\s0 Fortran compilers. -.Sp -\&\fICaution\fR: The default behavior of \s-1GNU\s0 Fortran is -incompatible with \fBf2c\fR and \fBg77\fR, please use the -\&\fB\-ff2c\fR option if you want object files compiled with -\&\s-1GNU\s0 Fortran to be compatible with object code created with these -tools. -.Sp -Use of \fB\-fno\-underscoring\fR is not recommended unless you are -experimenting with issues such as integration of \s-1GNU\s0 Fortran into -existing system environments (vis\-a\*`\-vis existing libraries, tools, -and so on). -.Sp -For example, with \fB\-funderscoring\fR, and assuming other defaults like -\&\fB\-fcase\-lower\fR and that \f(CW\*(C`j()\*(C'\fR and \f(CW\*(C`max_count()\*(C'\fR are -external functions while \f(CW\*(C`my_var\*(C'\fR and \f(CW\*(C`lvar\*(C'\fR are local variables, -a statement like -.Sp -.Vb 1 -\& I = J() + MAX_COUNT (MY_VAR, LVAR) -.Ve -.Sp -is implemented as something akin to: -.Sp -.Vb 1 -\& i = j_() + max_count_\|_(&my_var_\|_, &lvar); -.Ve -.Sp -With \fB\-fno\-underscoring\fR, the same statement is implemented as: -.Sp -.Vb 1 -\& i = j() + max_count(&my_var, &lvar); -.Ve -.Sp -Use of \fB\-fno\-underscoring\fR allows direct specification of -user-defined names while debugging and when interfacing \s-1GNU\s0 Fortran -code with other languages. -.Sp -Note that just because the names match does \fInot\fR mean that the -interface implemented by \s-1GNU\s0 Fortran for an external name matches the -interface implemented by some other language for that same name. -That is, getting code produced by \s-1GNU\s0 Fortran to link to code produced -by some other compiler using this or any other method can be only a -small part of the overall solution\-\-\-getting the code generated by -both compilers to agree on issues other than naming can require -significant effort, and, unlike naming disagreements, linkers normally -cannot detect disagreements in these other areas. -.Sp -Also, note that with \fB\-fno\-underscoring\fR, the lack of appended -underscores introduces the very real possibility that a user-defined -external name will conflict with a name in a system library, which -could make finding unresolved-reference bugs quite difficult in some -cases\-\-\-they might occur at program run time, and show up only as -buggy behavior at run time. -.Sp -In future versions of \s-1GNU\s0 Fortran we hope to improve naming and linking -issues so that debugging always involves using the names as they appear -in the source, even if the names as seen by the linker are mangled to -prevent accidental linking between procedures with incompatible -interfaces. -.IP "\fB\-fsecond\-underscore\fR" 4 -.IX Item "-fsecond-underscore" -By default, \s-1GNU\s0 Fortran appends an underscore to external -names. If this option is used \s-1GNU\s0 Fortran appends two -underscores to names with underscores and one underscore to external names -with no underscores. \s-1GNU\s0 Fortran also appends two underscores to -internal names with underscores to avoid naming collisions with external -names. -.Sp -This option has no effect if \fB\-fno\-underscoring\fR is -in effect. It is implied by the \fB\-ff2c\fR option. -.Sp -Otherwise, with this option, an external name such as \f(CW\*(C`MAX_COUNT\*(C'\fR -is implemented as a reference to the link-time external symbol -\&\f(CW\*(C`max_count_\|_\*(C'\fR, instead of \f(CW\*(C`max_count_\*(C'\fR. This is required -for compatibility with \fBg77\fR and \fBf2c\fR, and is implied -by use of the \fB\-ff2c\fR option. -.IP "\fB\-fcoarray=\fR\fI<keyword>\fR" 4 -.IX Item "-fcoarray=<keyword>" -.RS 4 -.PD 0 -.IP "\fBnone\fR" 4 -.IX Item "none" -.PD -Disable coarray support; using coarray declarations and image-control -statements will produce a compile-time error. (Default) -.IP "\fBsingle\fR" 4 -.IX Item "single" -Single-image mode, i.e. \f(CW\*(C`num_images()\*(C'\fR is always one. -.IP "\fBlib\fR" 4 -.IX Item "lib" -Library-based coarray parallelization; a suitable \s-1GNU\s0 Fortran coarray -library needs to be linked. -.RE -.RS 4 -.RE -.IP "\fB\-fcheck=\fR\fI<keyword>\fR" 4 -.IX Item "-fcheck=<keyword>" -Enable the generation of run-time checks; the argument shall be -a comma-delimited list of the following keywords. -.RS 4 -.IP "\fBall\fR" 4 -.IX Item "all" -Enable all run-time test of \fB\-fcheck\fR. -.IP "\fBarray-temps\fR" 4 -.IX Item "array-temps" -Warns at run time when for passing an actual argument a temporary array -had to be generated. The information generated by this warning is -sometimes useful in optimization, in order to avoid such temporaries. -.Sp -Note: The warning is only printed once per location. -.IP "\fBbounds\fR" 4 -.IX Item "bounds" -Enable generation of run-time checks for array subscripts -and against the declared minimum and maximum values. It also -checks array indices for assumed and deferred -shape arrays against the actual allocated bounds and ensures that all string -lengths are equal for character array constructors without an explicit -typespec. -.Sp -Some checks require that \fB\-fcheck=bounds\fR is set for -the compilation of the main program. -.Sp -Note: In the future this may also include other forms of checking, e.g., -checking substring references. -.IP "\fBdo\fR" 4 -.IX Item "do" -Enable generation of run-time checks for invalid modification of loop -iteration variables. -.IP "\fBmem\fR" 4 -.IX Item "mem" -Enable generation of run-time checks for memory allocation. -Note: This option does not affect explicit allocations using the -\&\f(CW\*(C`ALLOCATE\*(C'\fR statement, which will be always checked. -.IP "\fBpointer\fR" 4 -.IX Item "pointer" -Enable generation of run-time checks for pointers and allocatables. -.IP "\fBrecursion\fR" 4 -.IX Item "recursion" -Enable generation of run-time checks for recursively called subroutines and -functions which are not marked as recursive. See also \fB\-frecursive\fR. -Note: This check does not work for OpenMP programs and is disabled if used -together with \fB\-frecursive\fR and \fB\-fopenmp\fR. -.RE -.RS 4 -.RE -.IP "\fB\-fbounds\-check\fR" 4 -.IX Item "-fbounds-check" -Deprecated alias for \fB\-fcheck=bounds\fR. -.IP "\fB\-fcheck\-array\-temporaries\fR" 4 -.IX Item "-fcheck-array-temporaries" -Deprecated alias for \fB\-fcheck=array\-temps\fR. -.IP "\fB\-fmax\-array\-constructor=\fR\fIn\fR" 4 -.IX Item "-fmax-array-constructor=n" -This option can be used to increase the upper limit permitted in -array constructors. The code below requires this option to expand -the array at compile time. -.Sp -.Vb 7 -\& program test -\& implicit none -\& integer j -\& integer, parameter :: n = 100000 -\& integer, parameter :: i(n) = (/ (2*j, j = 1, n) /) -\& print \*(Aq(10(I0,1X))\*(Aq, i -\& end program test -.Ve -.Sp -\&\fICaution: This option can lead to long compile times and excessively -large object files.\fR -.Sp -The default value for \fIn\fR is 65535. -.IP "\fB\-fmax\-stack\-var\-size=\fR\fIn\fR" 4 -.IX Item "-fmax-stack-var-size=n" -This option specifies the size in bytes of the largest array that will be put -on the stack; if the size is exceeded static memory is used (except in -procedures marked as \s-1RECURSIVE\s0). Use the option \fB\-frecursive\fR to -allow for recursive procedures which do not have a \s-1RECURSIVE\s0 attribute or -for parallel programs. Use \fB\-fno\-automatic\fR to never use the stack. -.Sp -This option currently only affects local arrays declared with constant -bounds, and may not apply to all character variables. -Future versions of \s-1GNU\s0 Fortran may improve this behavior. -.Sp -The default value for \fIn\fR is 32768. -.IP "\fB\-fstack\-arrays\fR" 4 -.IX Item "-fstack-arrays" -Adding this option will make the Fortran compiler put all local arrays, -even those of unknown size onto stack memory. If your program uses very -large local arrays it is possible that you will have to extend your runtime -limits for stack memory on some operating systems. This flag is enabled -by default at optimization level \fB\-Ofast\fR. -.IP "\fB\-fpack\-derived\fR" 4 -.IX Item "-fpack-derived" -This option tells \s-1GNU\s0 Fortran to pack derived type members as closely as -possible. Code compiled with this option is likely to be incompatible -with code compiled without this option, and may execute slower. -.IP "\fB\-frepack\-arrays\fR" 4 -.IX Item "-frepack-arrays" -In some circumstances \s-1GNU\s0 Fortran may pass assumed shape array -sections via a descriptor describing a noncontiguous area of memory. -This option adds code to the function prologue to repack the data into -a contiguous block at runtime. -.Sp -This should result in faster accesses to the array. However it can introduce -significant overhead to the function call, especially when the passed data -is noncontiguous. -.IP "\fB\-fshort\-enums\fR" 4 -.IX Item "-fshort-enums" -This option is provided for interoperability with C code that was -compiled with the \fB\-fshort\-enums\fR option. It will make -\&\s-1GNU\s0 Fortran choose the smallest \f(CW\*(C`INTEGER\*(C'\fR kind a given -enumerator set will fit in, and give all its enumerators this kind. -.IP "\fB\-fexternal\-blas\fR" 4 -.IX Item "-fexternal-blas" -This option will make \fBgfortran\fR generate calls to \s-1BLAS\s0 functions -for some matrix operations like \f(CW\*(C`MATMUL\*(C'\fR, instead of using our own -algorithms, if the size of the matrices involved is larger than a given -limit (see \fB\-fblas\-matmul\-limit\fR). This may be profitable if an -optimized vendor \s-1BLAS\s0 library is available. The \s-1BLAS\s0 library will have -to be specified at link time. -.IP "\fB\-fblas\-matmul\-limit=\fR\fIn\fR" 4 -.IX Item "-fblas-matmul-limit=n" -Only significant when \fB\-fexternal\-blas\fR is in effect. -Matrix multiplication of matrices with size larger than (or equal to) \fIn\fR -will be performed by calls to \s-1BLAS\s0 functions, while others will be -handled by \fBgfortran\fR internal algorithms. If the matrices -involved are not square, the size comparison is performed using the -geometric mean of the dimensions of the argument and result matrices. -.Sp -The default value for \fIn\fR is 30. -.IP "\fB\-frecursive\fR" 4 -.IX Item "-frecursive" -Allow indirect recursion by forcing all local arrays to be allocated -on the stack. This flag cannot be used together with -\&\fB\-fmax\-stack\-var\-size=\fR or \fB\-fno\-automatic\fR. -.IP "\fB\-finit\-local\-zero\fR" 4 -.IX Item "-finit-local-zero" -.PD 0 -.IP "\fB\-finit\-integer=\fR\fIn\fR" 4 -.IX Item "-finit-integer=n" -.IP "\fB\-finit\-real=\fR\fI<zero|inf|\-inf|nan|snan>\fR" 4 -.IX Item "-finit-real=<zero|inf|-inf|nan|snan>" -.IP "\fB\-finit\-logical=\fR\fI<true|false>\fR" 4 -.IX Item "-finit-logical=<true|false>" -.IP "\fB\-finit\-character=\fR\fIn\fR" 4 -.IX Item "-finit-character=n" -.PD -The \fB\-finit\-local\-zero\fR option instructs the compiler to -initialize local \f(CW\*(C`INTEGER\*(C'\fR, \f(CW\*(C`REAL\*(C'\fR, and \f(CW\*(C`COMPLEX\*(C'\fR -variables to zero, \f(CW\*(C`LOGICAL\*(C'\fR variables to false, and -\&\f(CW\*(C`CHARACTER\*(C'\fR variables to a string of null bytes. Finer-grained -initialization options are provided by the -\&\fB\-finit\-integer=\fR\fIn\fR, -\&\fB\-finit\-real=\fR\fI<zero|inf|\-inf|nan|snan>\fR (which also initializes -the real and imaginary parts of local \f(CW\*(C`COMPLEX\*(C'\fR variables), -\&\fB\-finit\-logical=\fR\fI<true|false>\fR, and -\&\fB\-finit\-character=\fR\fIn\fR (where \fIn\fR is an \s-1ASCII\s0 character -value) options. These options do not initialize -.RS 4 -.IP "\(bu" 4 -allocatable arrays -.IP "\(bu" 4 -components of derived type variables -.IP "\(bu" 4 -variables that appear in an \f(CW\*(C`EQUIVALENCE\*(C'\fR statement. -.RE -.RS 4 -.Sp -(These limitations may be removed in future releases). -.Sp -Note that the \fB\-finit\-real=nan\fR option initializes \f(CW\*(C`REAL\*(C'\fR -and \f(CW\*(C`COMPLEX\*(C'\fR variables with a quiet NaN. For a signalling NaN -use \fB\-finit\-real=snan\fR; note, however, that compile-time -optimizations may convert them into quiet NaN and that trapping -needs to be enabled (e.g. via \fB\-ffpe\-trap\fR). -.Sp -Finally, note that enabling any of the \fB\-finit\-*\fR options will -silence warnings that would have been emitted by \fB\-Wuninitialized\fR -for the affected local variables. -.RE -.IP "\fB\-falign\-commons\fR" 4 -.IX Item "-falign-commons" -By default, \fBgfortran\fR enforces proper alignment of all variables in a -\&\f(CW\*(C`COMMON\*(C'\fR block by padding them as needed. On certain platforms this is mandatory, -on others it increases performance. If a \f(CW\*(C`COMMON\*(C'\fR block is not declared with -consistent data types everywhere, this padding can cause trouble, and -\&\fB\-fno\-align\-commons\fR can be used to disable automatic alignment. The -same form of this option should be used for all files that share a \f(CW\*(C`COMMON\*(C'\fR block. -To avoid potential alignment issues in \f(CW\*(C`COMMON\*(C'\fR blocks, it is recommended to order -objects from largest to smallest. -.IP "\fB\-fno\-protect\-parens\fR" 4 -.IX Item "-fno-protect-parens" -By default the parentheses in expression are honored for all optimization -levels such that the compiler does not do any re-association. Using -\&\fB\-fno\-protect\-parens\fR allows the compiler to reorder \f(CW\*(C`REAL\*(C'\fR and -\&\f(CW\*(C`COMPLEX\*(C'\fR expressions to produce faster code. Note that for the re-association -optimization \fB\-fno\-signed\-zeros\fR and \fB\-fno\-trapping\-math\fR -need to be in effect. The parentheses protection is enabled by default, unless -\&\fB\-Ofast\fR is given. -.IP "\fB\-frealloc\-lhs\fR" 4 -.IX Item "-frealloc-lhs" -An allocatable left-hand side of an intrinsic assignment is automatically -(re)allocated if it is either unallocated or has a different shape. The -option is enabled by default except when \fB\-std=f95\fR is given. See -also \fB\-Wrealloc\-lhs\fR. -.IP "\fB\-faggressive\-function\-elimination\fR" 4 -.IX Item "-faggressive-function-elimination" -Functions with identical argument lists are eliminated within -statements, regardless of whether these functions are marked -\&\f(CW\*(C`PURE\*(C'\fR or not. For example, in -.Sp -.Vb 1 -\& a = f(b,c) + f(b,c) -.Ve -.Sp -there will only be a single call to \f(CW\*(C`f\*(C'\fR. This option only works -if \fB\-ffrontend\-optimize\fR is in effect. -.IP "\fB\-ffrontend\-optimize\fR" 4 -.IX Item "-ffrontend-optimize" -This option performs front-end optimization, based on manipulating -parts the Fortran parse tree. Enabled by default by any \fB\-O\fR -option. Optimizations enabled by this option include elimination of -identical function calls within expressions, removing unnecessary -calls to \f(CW\*(C`TRIM\*(C'\fR in comparisons and assignments and replacing -\&\f(CWTRIM(a)\fR with \f(CW\*(C`a(1:LEN_TRIM(a))\*(C'\fR. -It can be deselected by specifying \fB\-fno\-frontend\-optimize\fR. -.SH "ENVIRONMENT" -.IX Header "ENVIRONMENT" -The \fBgfortran\fR compiler currently does not make use of any environment -variables to control its operation above and beyond those -that affect the operation of \fBgcc\fR. -.SH "BUGS" -.IX Header "BUGS" -For instructions on reporting bugs, see -<\fBhttp://gcc.gnu.org/bugs.html\fR>. -.SH "SEE ALSO" -.IX Header "SEE ALSO" -\&\fIgpl\fR\|(7), \fIgfdl\fR\|(7), \fIfsf\-funding\fR\|(7), -\&\fIcpp\fR\|(1), \fIgcov\fR\|(1), \fIgcc\fR\|(1), \fIas\fR\|(1), \fIld\fR\|(1), \fIgdb\fR\|(1), \fIadb\fR\|(1), \fIdbx\fR\|(1), \fIsdb\fR\|(1) -and the Info entries for \fIgcc\fR, \fIcpp\fR, \fIgfortran\fR, \fIas\fR, -\&\fIld\fR, \fIbinutils\fR and \fIgdb\fR. -.SH "AUTHOR" -.IX Header "AUTHOR" -See the Info entry for \fBgfortran\fR for contributors to \s-1GCC\s0 and -\&\s-1GNU\s0 Fortran. -.SH "COPYRIGHT" -.IX Header "COPYRIGHT" -Copyright (c) 2004\-2014 Free Software Foundation, Inc. -.PP -Permission is granted to copy, distribute and/or modify this document -under the terms of the \s-1GNU\s0 Free Documentation License, Version 1.3 or -any later version published by the Free Software Foundation; with the -Invariant Sections being \*(L"Funding Free Software\*(R", the Front-Cover -Texts being (a) (see below), and with the Back-Cover Texts being (b) -(see below). A copy of the license is included in the \fIgfdl\fR\|(7) man page. -.PP -(a) The \s-1FSF\s0's Front-Cover Text is: -.PP -.Vb 1 -\& A GNU Manual -.Ve -.PP -(b) The \s-1FSF\s0's Back-Cover Text is: -.PP -.Vb 3 -\& You have freedom to copy and modify this GNU Manual, like GNU -\& software. Copies published by the Free Software Foundation raise -\& funds for GNU development. -.Ve |