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incbin

Include binary and textual files in your C/C++ applications with ease

Example

    #include "incbin.h"

    INCBIN(Icon, "icon.png");

    // Reference in other translation units like this
    INCBIN_EXTERN(Icon);

    // NOTE: Don't forget to use `extern "C"` in case of writing C++ code

    // You may specify an optional type for the included data array as a first
    // additional argument to INCBIN, the macro is overloaded by arity. The
    // default type is `unsigned char`.
    INCBIN(MyType, IconTyped, "icon.png");

    // INCTXT is the same as INCBIN but it uses type `char` by default and 
    // implicitly adds a NUL-terminator byte to the included data, making it
    // safe to use as a string in C.
    INCTXT(Readme, "readme.md");

    // Reference in other translation units like this
    INCTXT_EXTERN(Readme);

    // NOTE: Since INCTXT adds a NUL-terminator byte, it's size is one byte
    // larger than that of INCBIN, so subtract one for string length.

    // The macros produce three global (or external) symbols of the form
    // <type> <prefix><data><name>[]
    // <type> <prefix><end><name>*
    // unsigned int <prefix><size><name>
    //
    // The <type> by default is unsigned char, unless optionally provided.
    // The <prefix> by default is "g", you can override it with INCBIN_PREFIX.
    // The <name> is the identifier you give to INCBIN or INCTXT.
    // The <data>, <end>, and <size> are tokens that depend on INCBIN_STYLE, by
    // default they're "Data", "End", and "Size", but they can be changed to
    // "_data", "_end", and "_size" if INCBIN_STYLE is set to INCBIN_STYLE_SNAKE.

Portability

Known to work on the following compilers

  • GCC
  • Clang
  • PathScale
  • Intel
  • Solaris & Sun Studio
  • Green Hills
  • SNC (ProDG)
  • Diab C++ (WindRiver)
  • XCode
  • ArmCC
  • RealView
  • ImageCraft
  • Stratus VOS C
  • TinyCC
  • cparser & libfirm
  • LCC
  • MSVC See MSVC below

If your compiler is not listed, as long as it supports GCC inline assembler, this should work.

MISRA

INCBIN can be used in MISRA C setting. However it should be independently checked due to its use of inline assembly to achieve what it does. Independent verification of the header has been done several times based on commit: 7e327a28ba5467c4202ec37874beca7084e4b08c

Alignment

The data included by this tool will be aligned on the architectures word boundary unless some variant of SIMD is detected, then it's aligned on a byte boundary that respects SIMD convention just incase your binary data may be used in vectorized code. The table of the alignments for SIMD this header recognizes is as follows:

SIMD Alignment
SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2 16
Neon, AltiVec 16
AVX, AVX2 32
AVX512 64

Prefix

By default, incbin.h emits symbols with a g prefix. This can be adjusted by defining INCBIN_PREFIX before including incbin.h with a desired prefix. For instance

    #define INCBIN_PREFIX g_
    #include "incbin.h"
    INCBIN(test, "test.txt");

    // This translation unit now has three symbols
    // const unsigned char g_<name><data>[];
    // const unsigned char *const g_<name><end>;
    // const unsigned int g_<name><size>;

You can also choose to have no prefix by defining the prefix with nothing, for example:

    #define INCBIN_PREFIX
    #include "incbin.h"
    INCBIN(test, "test.txt");

    // This translation unit now has three symbols
    // const unsigned char <name><data>[];
    // const unsigned char *const <name><end>;
    // const unsigned int <name><size>;

Style

By default, incbin.h emits symbols with CamelCase style. This can be adjusted by defining INCBIN_STYLE before including incbin.h to change the style. There are two possible styles to choose from

  • INCBIN_STYLE_CAMEL (CamelCase)
  • INCBIN_STYLE_SNAKE (snake_case)

For instance:

    #define INCBIN_STYLE INCBIN_STYLE_SNAKE
    #include "incbin.h"
    INCBIN(test, "test.txt");

    // This translation unit now has three symbols
    // const unsigned char <prefix><name>_data[];
    // const unsigned char *const <prefix><name>_end;
    // const unsigned int <prefix><name>_size;

Combining both the style and prefix allows for you to adjust incbin.h to suite your existing style and practices.

Overriding Linker Output section

By default, incbin.h emits into the read-only linker output section used on the detected platform. If you need to override this for whatever reason, you can manually specify the linker output section.

For example, to emit data into program memory for esp8266/Arduino:

#define INCBIN_OUTPUT_SECTION ".irom.text"
#include "incbin.h"
INCBIN(Foo, "foo.txt");
// The three symbols below will all go to ".irom.text"
// <type> <prefix><data><name>[]
// <type> <prefix><end><name>*
// unsigned int <prefix><size><name>

You may also override the output section for data, and size separately, this is useful for Harvard architectures where program memory cannot be directly read from the program without special instructions. With this you can chose to put the size variable in RAM rather than ROM. This can be done with the macros

// <prefix><data><name> and <prefix><end><name> goes into custom data section
#define INCBIN_OUTPUT_DATA_SECTION "..."

// <prefix><size><name> goes into custom size section.
#define INCBIN_OUTPUT_SIZE_SECTION "..."

Explanation

INCBIN is a macro which uses the inline assembler provided by almost all compilers to include binary files. It achieves this by utilizing the .incbin directive of the inline assembler. It then uses the assembler to calculate the size of the included binary and exports two global symbols that can be externally referenced in other translation units which contain the data and size of the included binary data respectively.

MSVC

Supporting MSVC is slightly harder as MSVC lacks an inline assembler which can include data. To support this we ship a tool which can process source files containing INCBIN macro usage and generate an external source file containing the data of all of them combined. This file is named data.c by default. Just include it into your build and use the incbin.h to reference data as needed. It's suggested you integrate this tool as part of your projects's pre-build events so that this can be automated. A more comprehensive list of options for this tool can be viewed by invoking the tool with -help

If you're using a custom prefix, be sure to specify the prefix on the command line with -p <prefix> so that everything matches up; similarly, if you're using a custom style, be sure to specify the style on the command line with -S <style> as well.

NOTE: MSVC currently does not support INCTXT or custom optional type on INCBIN. This will be changed in the future.

Miscellaneous

Documentation for the API is provided by the header using Doxygen notation. For licensing information see UNLICENSE.