BLAS77Interface

Modern Fortran 90 modules and wrappers for BLAS and LAPACK routines.

The goal is to expose all BLAS/LAPACK interfaces through type-safe Fortran modules, enabling:

• Safer usage of BLAS/LAPACK.
• Optional masking or renaming of BLAS/LAPACK symbols.

Available modules:

• blas77lapack77: combined BLAS and LAPACK interfaces.
• blas77: BLAS-only interfaces.
• lapack77: LAPACK-only interfaces.

Usage

The library currently supports building via the CMake build system or by manual integration.

Fetching the library with CMake:

include(FetchContent)
FetchContent_Declare(BLAS77Interface
    GIT_REPOSITORY https://github.com/foxtran/BLAS77Interface.git
)
FetchContent_MakeAvailable(BLAS77Interface)

Then link it to your Fortran target:

target_link_libraries(<TARGET> PUBLIC BLAS77Interface)

Configuration options (should be set before calling FetchContent_MakeAvailable()):

• BLAS77Interface_ENABLE_LAPACK — enable LAPACK interfaces (default: ON).
• BLAS77Interface_BLA_SIZEOF_INTEGER — BLAS integer size in bytes (4 or 8, default: 4).
• BLAS77Interface_LINKER_TEST — force a link-time error if BLAS/LAPACK symbols are used without the modules (default: OFF).

BLAS77Interface links against chosen BLAS and, when enabled, LAPACK. Examples are available under example/.

Source code generation

The BLAS77Interface generator uses the latest commit of Reference LAPACK to extract routine signatures and generate Fortran modules.

Generation steps:

1. Extract APIs for non-auxiliary BLAS and LAPACK routines.
2. Generate blas77 and lapack77 modules from the APIs.
3. Generate dummy BLAS/LAPACK routines (BLAS77_blas.F90, BLAS77_lapack.F90) used when BLAS77Interface_LINKER_TEST is enabled.
4. Apply patches for special cases.

Known issues

1. LAPACK routines with EXTERNAL procedures are omitted.
2. Only the CMake build is provided.
3. Only a limited set of Fortran compilers is supported.