for-beginners.md

Enable full rust-analyzer support of cg_gcc for your editor

Steps to Follow

1. (Already done in by project.) Add the following lines to Cargo.toml

[package.metadata.rust-analyzer]
rustc_private = true

2. Install rust-src with rustup: rustup component add rust-src. NOTE: Make sure you've switched to the corresponding toolchain as is used by cg_gcc
3. Set the lsp option rust-analyzer.rustc.source = "discover" (you can also set it to an explicit path), depending on your editor.
   1. Neovim(nvim-lspconfig):

   require('lspconfig').rust_analyzer.setup{
     settings = {
       ['rust-analyzer'] = {
         -- add this section
         rustc = {
           source = "discover",
         },
       },
     },
   }
   

   2. Emacs: customize Lsp Rust Analyzer Rustc Source to the Path discover

FAQ

Why is this needed?

Without these steps, rust-analyzer will NOT import rustc related packages to its scope and all rustc related clauses will fail to be analyzed in lsp, and the analyzer will notify you of the missing rustc_* packages.

Why is this NOT needed for rustc_codegen_llvm in your rust-src?

In the Cargo.toml of the rustc_codegen_llvm, you may notice the following lines:

rustc_ast = { path = "../rustc_ast" }
rustc_attr = { path = "../rustc_attr" }
rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
rustc_data_structures = { path = "../rustc_data_structures" }
rustc_errors = { path = "../rustc_errors" }
rustc_fluent_macro = { path = "../rustc_fluent_macro" }
rustc_fs_util = { path = "../rustc_fs_util" }
rustc_hir = { path = "../rustc_hir" }
rustc_index = { path = "../rustc_index" }
rustc_llvm = { path = "../rustc_llvm" }
rustc_macros = { path = "../rustc_macros" }
rustc_metadata = { path = "../rustc_metadata" }
rustc_middle = { path = "../rustc_middle" }
rustc_query_system = { path = "../rustc_query_system" }
rustc_session = { path = "../rustc_session" }
rustc_span = { path = "../rustc_span" }
rustc_symbol_mangling = { path = "../rustc_symbol_mangling" }

They set the paths to the rustc-related packages, solving the problem of rustc_private packages.

In theory, it is possible that you use the same workaround as in rustc_codegen_llvm.

While the rustc_codegen_cranelift uses the same approach as rustc_codegen_gcc.

[package.metadata.rust-analyzer]
rustc_private = true

Compiling External Project with rustc_codegen_gcc

1. Run the program with (in the root dir of rustc_codegen_gcc )(where --manifest-path is the path to the Cargo.toml of the project to run cargo against):

    ./y.sh cargo --manifest-path="..."

or you may as well add this alias in your .bash_aliases:

    alias cargcc="/path/to/rustc_codegen_gcc/y.sh cargo"

2. If std or libcore is needed, then the sysroot should be built first(see build_system/src/test.rs for hint.)