Using the Compilation Tool

The compilation tool hiasn1cli is stored in /usr/local/ksl/bin. You can use it to parse ASN.1 scripts and convert ASN.1 scripts into C intermediate files (containing multiple source files and header files).

This section describes how to use hiasn1cli to convert an .asn file into a C source file.

Getting Help

Run the following command to obtain help information:

1	./hiasn1cli --help

The following information is displayed:

ASN.1 Compiler, hiasn1cli 2.3.1
Copyright (c) 2023-2026 Huawei Technologies Co., Ltd.

USAGE:
    hiasn1cli [OPTIONS] [SUBCOMMANDS] ...

OPTIONS:
    -v, --version
        Display version information.
    -h, --help
        Display this help information.
    -i, --input <files>
        Select ASN.1 files, such as -i a.asn b.asn, or use wildcards, such as -i *.asn
    --merge <directory name>
        Merge and compile all input ASN.1 files to generate target files.
        Multi-level directories is supported, for example, a/b/c, the final output directory is exports/a/b/c.
        Each ASN.1 file is compiled and exported independently without merging.
    -m, --method <aper|uper|ber|der|xer>
        Specifies the codec method.

SUBCOMMANDS:
    cc  Compiling ASN.1 files into C code.

Subcommands

The tool has many subcommands. For example, you can run the following command to view the help information about the cc subcommand:

1	./hiasn1cli cc --help

The following information is displayed:

Compiling ASN.1 files into C code.

USAGE:
    hiasn1cli [OPTIONS] cc [FLAGS]

FLAGS:
    -h, --help      Display this subcommand help information.
    --values        Generate definitions for all values.
    --static-array  Define arrays using static array. Dynamic array are used by default.
    --prefix        Add prefix to files and types.
    --sample-code   Generate a code framework that traverses all data structures.
    --ignore-version-brackets  Ignore the version brackets of SEQUENCE.

cc subcommand options:

--values: Generates two files, codec_values.c and codec_values.h, to define and declare the values in the script.
--static-array: Statically defines arrays. By default, arrays are defined dynamically.
--prefix: Adds a prefix to the generated file names and type names. The prefix generation rule complies with the sub-directory naming convention of the exports directory described above.
--sample-code: Generates five files, which are complete executable examples of encoding, decoding, and data structure traversal.
- sample_code.c and sample_code.h: code skeleton for traversing data structures.
- sample_value.c and sample_value.h: used to assign values to structure fields.
- sample_main.c: main function for the encoding and decoding workflow of the first type in the ASN.1 script.
--ignore-version-brackets: ignores the version brackets of SEQUENCE. This option is provided to maintain compatibility with the open-source software asn1c for this feature.

Example

Convert an ASN.1 script test.asn into a C code file in BER format.

Create a test directory test_demo and go to the directory.
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mkdir test_demo cd test_demo
Create a test.asn file in test_demo.
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vim test.asn

Press i to enter the insert mode and add the following content to the file:

MyModule DEFINITIONS AUTOMATIC TAGS ::= BEGIN

OctStrType ::= OCTET STRING(SIZE(0..3))

MyType ::= SEQUENCE { 
    boolType BOOLEAN, 
    intType INTEGER(0..128), 
    enumType ENUMERATED { a, b }, 
    bitStrType BIT STRING(SIZE(24)), 
    seqOfType SEQUENCE OF OctStrType, 
    choiceType CHOICE { 
        a INTEGER(0..3), 
        b BOOLEAN 
    }, 
    oidType OBJECT IDENTIFIER
}

END

Press Esc, type :wq!, and press Enter to save the file and exit.
Run the hiasn1cli command to perform the conversion.
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/usr/local/ksl/bin/hiasn1cli -i test.asn -m aper cc
The generated code file is stored in the test_demo/exports directory.
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exports └── test ├── codec_index.h ├── codec_interfaces.h └── codec_tables.c
- codec_index.h: defines the unique identifier of each data unit, which will be used in encoding and decoding interfaces.
- codec_interfaces.h: provides C program interfaces for data description in abstract syntax.
- codec_tables.c: defines static variables for describing each data type.

Parent topic: Usage Description