TL;DR
The source summarizes three common techniques for embedding external files into C/C++ programs: converting files with external tools, wrapping ASCII data via the preprocessor, and inserting binary data through inline assembly. Each approach has trade-offs in portability, build dependencies and ease of automation.
What happened
The 2013 write-up outlines multiple strategies developers use to include resource files inside C or C++ executables. One approach uses external conversion utilities to transform assets into C headers or data arrays; the post cites general-purpose converters and image tools as examples. A second method leverages the preprocessor by defining a STRINGIFY-style macro and including a plain ASCII file inside a string literal; this is noted as useful for text resources such as shader source and is relatively simple to script. The third technique embeds raw bytes into the read-only data section via inline assembly: a macro emits .rodata labels, an .incbin directive for the file contents, and symbols marking start and end so code can compute size and access bytes. The assembly route is flagged as platform-specific, while external-tool methods add build-time dependencies.
Why it matters
- Embedding resources can simplify distribution by keeping assets inside a single binary.
- Different techniques trade off portability, build complexity, and runtime convenience.
- Knowing multiple methods helps engineers choose the best fit for text assets versus arbitrary binaries.
- Build-time dependencies or platform constraints may affect cross-compilation and CI workflows.
Key facts
- External conversion tools (examples in the source include image conversion utilities and xxd) can produce C headers from files but introduce build dependencies.
- The preprocessor technique wraps an ASCII file in a STRINGIFY macro so the included file becomes a C string literal; this is presented as suitable for plain text resources like shaders.
- The assembly approach defines start and end symbols and uses an .incbin-like directive to place the file in the .rodata section; code can then compute size by pointer difference.
- A sample assembly macro in the source creates global symbols named incbin_<name>_start and incbin_<name>_end and aligns the data.
- Example runtime code prints the start and end addresses, calculates the size, and inspects the first byte of the embedded data.
- The post warns that the assembly-based method is platform specific and may not work everywhere.
- Embedding via external tools is described as valid but may complicate the build with additional tool dependencies.
- The preprocessor inclusion still requires editing the external file to add the macro wrapper, but that step is called rudimentary and typically scriptable.
What to watch next
- Platform compatibility and linker behavior when using assembly-based embedding; the source notes this method is platform specific.
- Management of additional build-time dependencies introduced by external conversion tools in CI and cross-compilation setups.
- not confirmed in the source
Quick glossary
- Preprocessor macro: A compile-time text substitution mechanism that runs before actual C/C++ compilation, often used to define constants or transform included code.
- .rodata: A read-only data section in a compiled binary where constant data, such as string literals or embedded resources, is typically placed.
- incbin / .incbin: An assembler directive (commonly supported in GNU as) that inserts the raw contents of a file directly into the assembled output.
- Header (.h) conversion: The process of transforming a file into C source or header form (for example, an array or string literal) so it can be compiled into a program.
Reader FAQ
Can I embed binary files using the preprocessor STRINGIFY method?
The source recommends the STRINGIFY approach for plain ASCII files (such as shaders); whether it works for arbitrary binary data is not confirmed in the source.
Are the assembly-based embedding techniques portable?
No — the source explicitly describes the assembly solution as platform specific and notes it may not work on all platforms.
Do external conversion tools add complexity to the build?
Yes. The post says using external converters is valid but adds extra dependencies to the build process.
Is automating the preprocessor wrapping step feasible?
The source describes the wrapper-editing operation as rudimentary and usually relatively simple to automate.
C/C++ EMBEDDED FILES PUBLISHED: 27 JANUARY 2013 A summary of different approaches for embedding files within c / c++ code TABLE OF CONTENTS Using external tools Using the preprocessor Using…
Sources
- C/C++ Embedded Files (2013)
- c++ – How to embed a file into an executable?
- Implementing #embed for C and C++ | The Pasture – ThePhD
- How to implement C23 #embed in GCC 15
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