15.3 Missing Features

This section lists features we know are missing from g77, and which we want to add someday. (There is no priority implied in the ordering below.)

GNU Fortran language:

• Better Source Model
• Fortran 90 Support
• Intrinsics in PARAMETER Statements
• Arbitrary Concatenation
• SELECT CASE on CHARACTER Type
• RECURSIVE Keyword
• Popular Non-standard Types
• Full Support for Compiler Types
• Array Bounds Expressions
• POINTER Statements
• Sensible Non-standard Constructs
• READONLY Keyword
• FLUSH Statement
• Expressions in FORMAT Statements
• Explicit Assembler Code
• Q Edit Descriptor

GNU Fortran dialects:

• Old-style PARAMETER Statements
• TYPE and ACCEPT I/O Statements
• STRUCTURE UNION RECORD MAP
• OPEN CLOSE and INQUIRE Keywords
• ENCODE and DECODE
• AUTOMATIC Statement
• Suppressing Space Padding
• Fortran Preprocessor
• Bit Operations on Floating-point Data
• Really Ugly Character Assignments

New facilities:

• POSIX Standard
• Floating-point Exception Handling
• Nonportable Conversions
• Large Automatic Arrays
• Support for Threads
• Increasing Precision/Range
• Enabling Debug Lines

Better diagnostics:

• Better Warnings
• Gracefully Handle Sensible Bad Code
• Non-standard Conversions
• Non-standard Intrinsics
• Modifying DO Variable
• Better Pedantic Compilation
• Warn About Implicit Conversions
• Invalid Use of Hollerith Constant
• Dummy Array Without Dimensioning Dummy
• Invalid FORMAT Specifiers
• Ambiguous Dialects
• Unused Labels
• Informational Messages

Run-time facilities:

• Uninitialized Variables at Run Time
• Portable Unformatted Files
• Better List-directed I/O
• Default to Console I/O

Debugging:

• Labels Visible to Debugger