asn1c(1) ASN.1 Compiler


asn1c [-E [-F] | -P | -R]
      [-Sdir] [-X]
      [-Wdebug-...] [-foption] [-gen-option] [-pdu={all|auto|Type}]


asn1c compiles ASN.1 specifications into a set of target language (C/C++) encoders and decoders for BER, DER, PER, XER and other encoding rules.


Overall Options
-E -F -P -R -S directory -X
Warning Options

-Werror -Wdebug-lexer -Wdebug-fixer -Wdebug-compiler
Language Options

-fbless-SIZE -fcompound-names -findirect-choice -fknown-extern-type=<name> -fnative-types -fno-constraints -fno-include-deps -funnamed-unions -fskeletons-copy
Codecs Generation Options

-gen-PER -pdu={all|auto|Type}
Output Options

-print-constraints -print-lines


Stop after the parsing stage and print the reconstructed ASN.1 specification code to the standard output.
Used together with -E, instructs the compiler to stop after the ASN.1 syntax tree fixing stage and dump the reconstructed ASN.1 specification to the standard output.
Dump the compiled output to the standard output instead of creating the target language files on disk.
Restrict the compiler to generate only the ASN.1 tables, omitting the usual support code.
-S directory
Use the specified directory with ASN.1 skeleton files.
Generate an XML DTD schema for the specified ASN.1 files.


Treat warnings as errors; abort if any warning is produced.
Enable lexer debugging during the ASN.1 parsing stage.
Enable ASN.1 syntax tree fixer debugging during the fixing stage.
Enable debugging during the actual compile time.


Allow SIZE() constraint for INTEGER, ENUMERATED, and other types for which this constraint is normally prohibited by the standard. This is a violation of ASN.1 standard, and the compiler may fail to produce a meaningful code.
Using this option prevents name collisions in the target source code by using complex names for target language structures. (Name collisions may occur if the ASN.1 module reuses the same identifiers in multiple contexts).
When generating code for a CHOICE type, compile the CHOICE members as indirect pointers instead of declaring them inline. Consider using this option together with -fno-include-deps to prevent circular references.
Pretend the specified type is known. The compiler will assume the target language source files for the given type have been provided manually.
Use the native machine's data types (int, double) whenever possible, instead of the compound INTEGER_t, ENUMERATED_t and REAL_t types.
Do not generate ASN.1 subtype constraint checking code. This may make a shorter executable.
Do not generate courtesy #include lines for non-critical type dependencies. Helps prevent namespace collisions.
Enable unnamed unions in the definitions of target language's structures.
Copy support files (skeletons) rather than symlink them.


Generate Packed Encoding Rules (PER) support code.
Create a PDU table for specified types, or discover Protocol Data Units automatically. In case of -pdu=all, all ASN.1 types defined in all modules will form a PDU table. In case of -pdu=auto, all types not referenced by any other type will form a PDU table. If Type is an ASN.1 type identifier, it is added to a PDU table. The last form may be specified multiple times to add any number of PDUs.


When -EF are also specified, this option forces the compiler to explain its internal understanding of subtype constraints.
Generate "-- #line" comments in -E output.


Lev Walkin <[email protected]>