Module rustc_codegen_ssa::back::metadata

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Reading of the rustc metadata for rlibs and dylibs





  • Xcoff - On AIX, custom sections are merged into predefined sections, so custom .rustc section is not preserved during linking. For this reason, we store metadata in predefined .info section, and define a symbol to reference the metadata. To preserve metadata during linking on AIX, we have toCreate an empty .text section, a empty .data section.Define an empty symbol named symbol_name inside .data section.Define an symbol named AIX_METADATA_SYMBOL_NAME referencing data inside .info section. From XCOFF’s view, (2) creates a csect entry in the symbol table, the symbol created by (3) is a info symbol for the preceding csect. Thus two symbols are preserved during linking and we can use the second symbol to reference the metadata.
  • Creates a simple WebAssembly object file, which is itself a wasm module, that contains a custom section of the name section_name with contents data.
  • For rlibs we “pack” rustc metadata into a dummy object file.
  • Is Apple’s CPU subtype arm64es
  • Since Xcode 15 Apple’s LD requires object files to contain information about what they were built for (LC_BUILD_VERSION): the platform (macOS/watchOS etc), minimum OS version, and SDK version. This returns a MachOBuildVersion for the target.