Table of Contents

Previous: AN EXAMPLE

 

INTERPRETING THE OUTPUT

The messages given by ftnchek include not only syntax errors but also warnings and informational messages about things that are legal Fortran but that may indicate errors or carelessness. Most of these messages can be turned off by command-line options. Which option controls each message depends on the nature of the condition being warned about. See the descriptions of the command-line flags in the previous sections, and of individual messages below. Each message is prefixed with a word or phrase indicating the nature of the condition and its severity.

``Error'' means a syntax error. The simplest kind of syntax errors are typographical errors, for example unbalanced parentheses or misspelling of a keyword. This type of error is caught by the parser and appears with the description ``parse error'' or ``syntax error'' (depending on whether the parser was built using GNU bison or UNIX yacc respectively). This type of error message cannot be suppressed. Be aware that this type of error often means that ftnchek has not properly interpreted the statement where the error occurs, so that its subsequent checking operations will be compromised. You should eliminate all syntax errors before proceeding to interpret the other messages ftnchek gives.

``Warning: Nonstandard syntax'' indicates an extension to Fortran that ftnchek supports but that is not according to the Fortran 77 Standard. The extensions that ftnchek accepts are described in the section on Extensions below. One example is the DO ... ENDDO construction. If a program uses these extensions, warnings will be given according to specifications under the -f77 setting. The default behavior is to give no warnings.

``Warning'' in other cases means a condition that is suspicious but that may or may not be a programming error. Frequently these conditions are legal under the standard. Some are illegal but do not fall under the heading of syntax errors. Usage errors are one example. These refer to the possibility that a variable may be used before it has been assigned a value (generally an error), or that a variable is declared but never used (harmless but may indicate carelessness). The amount of checking for usage errors is controlled by the -usage flag, which specifies the maximum amount of checking by default.

Truncation warnings cover situations in which accuracy may be lost unintentionally, for example when a double precision COUNT -> exact number of input values 31 C AVG -> average returned by COMPAV 32 C I -> loop counter 33 C 34 35 PARAMETER(MAXNOS=5) 36 INTEGER I, COUNT 37 REAL NUMS(MAXNOS), AVG 38 COUNT = 0 39 DO 80 I = 1,MAXNOS 40 READ (5,*,END=100) NUMS(I) 41 COUNT = COUNT + 1 42 80 CONTINUE 43 100 AVG = COMPAV(NUMS, COUNT) 44 END Module AVENUM: prog External subprograms referenced: COMPAV: real* Variables: Name Type Dims Name Type Dims Name Type Dims Name Type Dims AVG real COUNT intg I intg MAXNOS intg* NUMS real 1 * Variable not declared. Type has been implicitly defined. Warning in module AVENUM: Variables set but never used: AVG set at line 43 Statement labels defined: Label Line StmtType Label Line StmtType <80> 42 exec <100> 43 exec 0 syntax errors detected in file average.f 6 warnings issued in file average.f Warning: Subprogram COMPAV argument data type mismatch at position 1: Dummy arg SCORE in module COMPAV line 10 file average.f is type intg Actual arg NUMS in module AVENUM line 43 file average.f is type real

According to ftnchek, the program contains variables which may be used before they are assigned an initial value, and variables which are not needed. ftnchek also warns the user that an integer quotient has been converted to a real. This may assist the user in catching an unintended roundoff error. Since the -symtab flag was given, ftnchek prints out a table containing identifiers from the local module and their corresponding datatype and number of dimensions. Finally, ftnchek warns that the function COMPAV is not used with the proper type of arguments.

With ftnchek's help, we can debug the program. We can see that there were the following errors:

1.
SUM and COUNT should have been converted to real before doing the division.
2.
SUM should have been initialized to 0 before entering the loop.
3.
AVG was never printed out after being calculated.
4.
NUMS should have been declared INTEGER instead of REAL.

We also see that I, not J, should have been declared INTEGER in function COMPAV. Also, MAXNOS was not declared as INTEGER, nor COMPAV as REAL, in program AVENUM. These are not errors, but they may indicate carelessness. As it happened, the default type of these variables coincided with the intended type.

Here is the corrected program, and its output when run: 


C       AUTHORS: MIKE MYERS AND LUCIA SPAGNUOLO
C       DATE:    MAY 8, 1989
C
C       Variables:
C               SCORE -> an array of test scores
C               SUM ->   sum of the test scores
C               COUNT -> counter of scores read in
C               I ->     loop counter
C
       REAL FUNCTION COMPAV(SCORE,COUNT)
            INTEGER SUM,COUNT,I,SCORE(5)
C
            SUM = 0
            DO 30 I = 1,COUNT
                SUM = SUM + SCORE(I)
30          CONTINUE
            COMPAV = FLOAT(SUM)/FLOAT(COUNT)
        END
C
C
        PROGRAM AVENUM
C
C                       MAIN PROGRAM
C
C       AUTHOR:   LOIS BIGBIE
C       DATE:     MAY 15, 1990
C
C       Variables:
C               MAXNOS -> maximum number of input values
C               NUMS    -> an array of numbers
C               COUNT   -> exact number of input values
C               AVG     -> average returned by COMPAV
C               I       -> loop counter
C
C
            INTEGER MAXNOS
            PARAMETER(MAXNOS=5)
            INTEGER I, NUMS(MAXNOS), COUNT
            REAL AVG,COMPAV
            COUNT = 0
            DO 80 I = 1,MAXNOS
                READ (5,*,END=100) NUMS(I)
                COUNT = COUNT + 1
80          CONTINUE
100         AVG = COMPAV(NUMS, COUNT)
            WRITE(6,*) 'AVERAGE =',AVG
        END
$ run average
70
90
85
<EOF>
AVERAGE =   81.66666
$

With ftnchek's help, our program is a success!

Next: INTERPRETING THE OUTPUT ./usr/share/doc/ftnchek/html/lbAJ.html0100644000000000000000000006705507375770222016506 0ustar rootroot INTERPRETING THE OUTPUT Table of Contents

Previous: AN EXAMPLE

 

INTERPRETING THE OUTPUT

The messages given by ftnchek include not only syntax errors but also warnings and informational messages about things that are legal Fortran but that may indicate errors or carelessness. Most of these messages can be turned off by command-line options. Which option controls each message depends on the nature of the condition being warned about. See the descriptions of the command-line flags in the previous sections, and of individual messages below. Each message is prefixed with a word or phrase indicating the nature of the condition and its severity.

``Error'' means a syntax error. The simplest kind of syntax errors are typographical errors, for example unbalanced parentheses or misspelling of a keyword. This type of error is caught by the parser and appears with the description ``parse error'' or ``syntax error'' (depending on whether the parser was built using GNU bison or UNIX yacc respectively). This type of error message cannot be suppressed. Be aware that this type of error often means that ftnchek has not properly interpreted the statement where the error occurs, so that its subsequent checking operations will be compromised. You should eliminate all syntax errors before proceeding to interpret the other messages ftnchek gives.

``Warning: Nonstandard syntax'' indicates an extension to Fortran that ftnchek supports but that is not according to the Fortran 77 Standard. The extensions that ftnchek accepts are described in the section on Extensions below. One example is the DO ... ENDDO construction. If a program uses these extensions, warnings will be given according to specifications under the -f77 setting. The default behavior is to give no warnings.

``Warning'' in other cases means a condition that is suspicious but that may or may not be a programming error. Frequently these conditions are legal under the standard. Some are illegal but do not fall under the heading of syntax errors. Usage errors are one example. These refer to the possibility that a variable may be used before it has been assigned a value (generally an error), or that a variable is declared but never used (harmless but may indicate carelessness). The amount of checking for usage errors is controlled by the -usage flag, which specifies the maximum amount of checking by default.

Truncation warnings cover situations in which accuracy may be lost unintentionally, for example when a double precision COUNT -> exact number of input values 31 C AVG -> average returned by COMPAV 32 C I -> loop counter 33 C 34 35 PARAMETER(MAXNOS=5) 36 INTEGER I, COUNT 37 REAL NUMS(MAXNOS), AVG 38 COUNT = 0 39 DO 80 I = 1,MAXNOS 40 READ (5,*,END=100) NUMS(I) 41 COUNT = COUNT + 1 42 80 CONTINUE 43 100 AVG = COMPAV(NUMS, COUNT) 44 END Module AVENUM: prog External subprograms referenced: COMPAV: real* Variables: Name Type Dims Name Type Dims Name Type Dims Name Type Dims AVG real COUNT intg I intg MAXNOS intg* NUMS real 1 * Variable not declared. Type has been implicitly defined. Warning in module AVENUM: Variables set but never used: AVG set at line 43 Statement labels defined: Label Line StmtType Label Line StmtType <80> 42 exec <100> 43 exec 0 syntax errors detected in file average.f 6 warnings issued in file average.f Warning: Subprogram COMPAV argument data type mismatch at position 1: Dummy arg SCORE in module COMPAV line 10 file average.f is type intg Actual arg NUMS in module AVENUM line 43 file average.f is type real

According to ftnchek, the program contains variables which may be used before they are assigned an initial value, and variables which are not needed. ftnchek also warns the user that an integer quotient has been converted to a real. This may assist the user in catching an unintended roundoff error. Since the -symtab flag was given, ftnchek prints out a table containing identifiers from the local module and their corresponding datatype and number of dimensions. Finally, ftnchek warns that the function COMPAV is not used with the proper type of arguments.

With ftnchek's help, we can debug the program. We can see that there were the following errors:

1.
SUM and COUNT should have been converted to real before doing the division.
2.
SUM should have been initialized to 0 before entering the loop.
3.
AVG was never printed out after being calculated.
4.
NUMS should have been declared INTEGER instead of REAL.

We also see that I, not J, should have been declared INTEGER in function COMPAV. Also, MAXNOS was not declared as INTEGER, nor COMPAV as REAL, in program AVENUM. These are not errors, but they may indicate carelessness. As it happened, the default type of these variables coincided with the intended type.

Here is the corrected program, and its output when run: 


C       AUTHORS: MIKE MYERS AND LUCIA SPAGNUOLO
C       DATE:    MAY 8, 1989
C
C       Variables:
C               SCORE -> an array of test scores
C               SUM ->   sum of the test scores
C               COUNT -> counter of scores read in
C               I ->     loop counter
C
       REAL FUNCTION COMPAV(SCORE,COUNT)
            INTEGER SUM,COUNT,I,SCORE(5)
C
            SUM = 0
            DO 30 I = 1,COUNT
                SUM = SUM + SCORE(I)
30          CONTINUE
            COMPAV = FLOAT(SUM)/FLOAT(COUNT)
        END
C
C
        PROGRAM AVENUM
C
C                       MAIN PROGRAM
C
C       AUTHOR:   LOIS BIGBIE
C       DATE:     MAY 15, 1990
C
C       Variables:
C               MAXNOS -> maximum number of input values
C               NUMS    -> an array of numbers
C               COUNT   -> exact number of input values
C               AVG     -> average returned by COMPAV
C               I       -> loop counter
C
C
            INTEGER MAXNOS
            PARAMETER(MAXNOS=5)
            INTEGER I, NUMS(MAXNOS), COUNT
            REAL AVG,COMPAV
            COUNT = 0
            DO 80 I = 1,MAXNOS
                READ (5,*,END=100) NUMS(I)
                COUNT = COUNT + 1
80          CONTINUE
100         AVG = COMPAV(NUMS, COUNT)
            WRITE(6,*) 'AVERAGE =',AVG
        END
$ run average
70
90
85
<EOF>
AVERAGE =   81.66666
$

With ftnchek's help, our program is a success!

Next: INTERPRETING THE OUTPUT ./usr/share/doc/ftnchek/html/lbAJ.html0100644000000000000000000006705507375770222016506 0ustar rootroot INTERPRETING THE OUTPUT Table of Contents

Previous: AN EXAMPLE

 

INTERPRETING THE OUTPUT

The messages given by ftnchek include not only syntax errors but also warnings and informational messages about things that are legal Fortran but that may indicate errors or carelessness. Most of these messages can be turned off by command-line options. Which option controls each message depends on the nature of the condition being warned about. See the descriptions of the command-line flags in the previous sections, and of individual messages below. Each message is prefixed with a word or phrase indicating the nature of the condition and its severity.

``Error'' means a syntax error. The simplest kind of syntax errors are typographical errors, for example unbalanced parentheses or misspelling of a keyword. This type of error is caught by the parser and appears with the description ``parse error'' or ``syntax error'' (depending on whether the parser was built using GNU bison or UNIX yacc respectively). This type of error message cannot be suppressed. Be aware that this type of error often means that ftnchek has not properly interpreted the statement where the error occurs, so that its subsequent checking operations will be compromised. You should eliminate all syntax errors before proceeding to interpret the other messages ftnchek gives.

``Warning: Nonstandard syntax'' indicates an extension to Fortran that ftnchek supports but that is not according to the Fortran 77 Standard. The extensions that ftnchek accepts are described in the section on Extensions below. One example is the DO ... ENDDO construction. If a program uses these extensions, warnings will be given according to specifications under the -f77 setting. The default behavior is to give no warnings.

``Warning'' in other cases means a condition that is suspicious but that may or may not be a programming error. Frequently these conditions are legal under the standard. Some are illegal but do not fall under the heading of syntax errors. Usage errors are one example. These refer to the possibility that a variable may be used before it has been assigned a value (generally an error), or that a variable is declared but never used (harmless but may indicate carelessness). The amount of checking for usage errors is controlled by the -usage flag, which specifies the maximum amount of checking by default.

Truncation warnings cover situations in which accuracy may be lost unintentionally, for example when a double precision COUNT -> exact number of input values 31 C AVG -> average returned by COMPAV 32 C I -> loop counter 33 C 34 35 PARAMETER(MAXNOS=5) 36 INTEGER I, COUNT 37 REAL NUMS(MAXNOS), AVG 38 COUNT = 0 39 DO 80 I = 1,MAXNOS 40 READ (5,*,END=100) NUMS(I) 41 COUNT = COUNT + 1 42 80 CONTINUE 43 100 AVG = COMPAV(NUMS, COUNT) 44 END Module AVENUM: prog External subprograms referenced: COMPAV: real* Variables: Name Type Dims Name Type Dims Name Type Dims Name Type Dims AVG real COUNT intg I intg MAXNOS intg* NUMS real 1 * Variable not declared. Type has been implicitly defined. Warning in module AVENUM: Variables set but never used: AVG set at line 43 Statement labels defined: Label Line StmtType Label Line StmtType <80> 42 exec <100> 43 exec 0 syntax errors detected in file average.f 6 warnings issued in file average.f Warning: Subprogram COMPAV argument data type mismatch at position 1: Dummy arg SCORE in module COMPAV line 10 file average.f is type intg Actual arg NUMS in module AVENUM line 43 file average.f is type real

According to ftnchek, the program contains variables which may be used before they are assigned an initial value, and variables which are not needed. ftnchek also warns the user that an integer quotient has been converted to a real. This may assist the user in catching an unintended roundoff error. Since the -symtab flag was given, ftnchek prints out a table containing identifiers from the local module and their corresponding datatype and number of dimensions. Finally, ftnchek warns that the function COMPAV is not used with the proper type of arguments.

With ftnchek's help, we can debug the program. We can see that there were the following errors:

1.
SUM and COUNT should have been converted to real before doing the division.
2.
SUM should have been initialized to 0 before entering the loop.
3.
AVG was never printed out after being calculated.
4.
NUMS should have been declared INTEGER instead of REAL.

We also see that I, not J, should have been declared INTEGER in function COMPAV. Also, MAXNOS was not declared as INTEGER, nor COMPAV as REAL, in program AVENUM. These are not errors, but they may indicate carelessness. As it happened, the default type of these variables coincided with the intended type.

Here is the corrected program, and its output when run: 


C       AUTHORS: MIKE MYERS AND LUCIA SPAGNUOLO
C       DATE:    MAY 8, 1989
C
C       Variables:
C               SCORE -> an array of test scores
C               SUM ->   sum of the test scores
C               COUNT -> counter of scores read in
C               I ->     loop counter
C
       REAL FUNCTION COMPAV(SCORE,COUNT)
            INTEGER SUM,COUNT,I,SCORE(5)
C
            SUM = 0
            DO 30 I = 1,COUNT
                SUM = SUM + SCORE(I)
30          CONTINUE
            COMPAV = FLOAT(SUM)/FLOAT(COUNT)
        END
C
C
        PROGRAM AVENUM
C
C                       MAIN PROGRAM
C
C       AUTHOR:   LOIS BIGBIE
C       DATE:     MAY 15, 1990
C
C       Variables:
C               MAXNOS -> maximum number of input values
C               NUMS    -> an array of numbers
C               COUNT   -> exact number of input values
C               AVG     -> average returned by COMPAV
C               I       -> loop counter
C
C
            INTEGER MAXNOS
            PARAMETER(MAXNOS=5)
            INTEGER I, NUMS(MAXNOS), COUNT
            REAL AVG,COMPAV
            COUNT = 0
            DO 80 I = 1,MAXNOS
                READ (5,*,END=100) NUMS(I)
                COUNT = COUNT + 1
80          CONTINUE
100         AVG = COMPAV(NUMS, COUNT)
            WRITE(6,*) 'AVERAGE =',AVG
        END
$ run average
70
90
85
<EOF>
AVERAGE =   81.66666
$

With ftnchek's help, our program is a success!

Next: INTERPRETING THE OUTPUT ./usr/share/doc/ftnchek/html/lbAJ.html0100644000000000000000000006705507375770222016506 0ustar rootroot INTERPRETING THE OUTPUT Table of Contents

Previous: AN EXAMPLE

 

INTERPRETING THE OUTPUT

The messages given by ftnchek include not only syntax errors but also warnings and informational messages about things that are legal Fortran but that may indicate errors or carelessness. Most of these messages can be turned off by command-line options. Which option controls each message depends on the nature of the condition being warned about. See the descriptions of the command-line flags in the previous sections, and of individual messages below. Each message is prefixed with a word or phrase indicating the nature of the condition and its severity.

``Error'' means a syntax error. The simplest kind of syntax errors are typographical errors, for example unbalanced parentheses or misspelling of a keyword. This type of error is caught by the parser and appears with the description ``parse error'' or ``syntax error'' (depending on whether the parser was built using GNU bison or UNIX yacc respectively). This type of error message cannot be suppressed. Be aware that this type of error often means that ftnchek has not properly interpreted the statement where the error occurs, so that its subsequent checking operations will be compromised. You should eliminate all syntax errors before proceeding to interpret the other messages ftnchek gives.

``Warning: Nonstandard syntax'' indicates an extension to Fortran that ftnchek supports but that is not according to the Fortran 77 Standard. The extensions that ftnchek accepts are described in the section on Extensions below. One example is the DO ... ENDDO construction. If a program uses these extensions, warnings will be given according to specifications under the -f77 setting. The default behavior is to give no warnings.

``Warning'' in other cases means a condition that is suspicious but that may or may not be a programming error. Frequently these conditions are legal under the standard. Some are illegal but do not fall under the heading of syntax errors. Usage errors are one example. These refer to the possibility that a variable may be used before it has been assigned a value (generally an error), or that a variable is declared but never used (harmless but may indicate carelessness). The amount of checking for usage errors is controlled by the -usage flag, which specifies the maximum amount of checking by default.

Truncation warnings cover situations in which accuracy may be lost unintentionally, for example when a double precision COUNT -> exact number of input values 31 C AVG -> average returned by COMPAV 32 C I -> loop counter 33 C 34 35 PARAMETER(MAXNOS=5) 36 INTEGER I, COUNT 37 REAL NUMS(MAXNOS), AVG 38 COUNT = 0 39 DO 80 I = 1,MAXNOS 40 READ (5,*,END=100) NUMS(I) 41 COUNT = COUNT + 1 42 80 CONTINUE 43 100 AVG = COMPAV(NUMS, COUNT) 44 END Module AVENUM: prog External subprograms referenced: COMPAV: real* Variables: Name Type Dims Name Type Dims Name Type Dims Name Type Dims AVG real COUNT intg I intg MAXNOS intg*