Supported Subset of Fortran Language

Program Units

• PROGRAM program-name

and END[PROGRAM [program-name]]

(R1101 -- 1103)

• MODULE module-name

and END[MODULE [module-name]]

(R1104 -- 1106)

• BLOCK DATA [block-data-name]

and END [BLOCK DATA [block-data-name]]

• SUBROUTINE
• FUNCTION
• Labels

Types

• REAL DOUBLE PRECISION
• INTEGER
• CHARACTER
• LOGICAL
• IMPLICIT NONE (TODO: Implement the check, when it is used.)

Expressions

(array sections)

Statements

• USE module-name [, rename-list]

or USE module-name , ONLY : [ only-list ]

(R1107 -- 1109)

• CALL

• DO (struct) END DO
• DO WHILE
• EXIT
• CONTINUE
• IF (struct) THEN ELSE
• GOTO & computed GOTO

Fortran Transformations

Here are all transformations converting Fortran program behaviors to CIVL-C ones.

1 Program Unit

1.1 Program Entry

• PROGRAM indicates the entry of the whole program.

A 'PROGRAM' chunk is transformed to be the main function in CIVL-C.

1.2 Subroutines & Call Statements

• SUBROUTINE is a set of program instructions that process given arguments.

A 'SUBROUTINE' chunk is transformed as a CIVL-C function with void type; All parameters with scalar types will be transformed as passed-by-reference.

• 'SUBROUTINE' chunks are triggered by CALL keyword.

A CALL-statement is transformed as a normal function call without a return-value. Argument variables with scalar types are transformed as an address-of expression.

(Same procedures should be applied on any other non-array type arguments, like structs.)

(If non-array argument variables are declared as passed-by-value, there should be no change.)

(An array argument variable will be handled by 'array-lambda', an array-type argument declared as value)

([ONLT TRUE FOR NON MULTI-THREAD PROGRAMS] Analysis to determine whether parameters could be modified in the coerce of the call; If a parameter is proved to be never modified then it can be transformed as it self.)

1.3 Functions & Function Returned Values

2 Statements

2.1 Control Statements

• IF-ELSE IF-ELSE structure keeps unchanged.

• DO loops are transformed as for loops in CIVL-C.

(TODO: Fix the bound issue on the loop variable, which goes beyond the bound in C but stops on the bound in Fortran.)

• Computed GOTO structures are transformed as switch-case structure in CIVL.

2.2 Common Block Statements

2.3 Inclusion

3 Expressions

4 Variables & Types

4.1 Scalar Types

4.2 Array Types & Array Sections