Merge commit '39683d8eb7a32a74bea96ecbf1e87675d3338506' into sync_cg_gcc-2022-03-26

[rust.git] / compiler / rustc_codegen_gcc / Readme.md

diff --git a/compiler/rustc_codegen_gcc/Readme.md b/compiler/rustc_codegen_gcc/Readme.md
index 1fcfb5f6e20a108661fce85ecbc8fa36ab5d7820..27b30e0fd1b336a11de9f2bf6c184d0354ec60fb 100644 (file)
--- a/compiler/rustc_codegen_gcc/Readme.md
+++ b/compiler/rustc_codegen_gcc/Readme.md
@@ -21,6 +21,8 @@ You can also use my [fork of gcc](https://github.com/antoyo/gcc) which already i
 ```bash
 $ git clone https://github.com/rust-lang/rustc_codegen_gcc.git
 $ cd rustc_codegen_gcc
+$ git clone https://github.com/llvm/llvm-project llvm --depth 1 --single-branch
+$ export RUST_COMPILER_RT_ROOT="$PWD/llvm/compiler-rt"
 $ ./prepare_build.sh # download and patch sysroot src
 $ ./build.sh --release
 ```
@@ -109,6 +111,13 @@ Or add a breakpoint to `add_error` in gdb and print the line number using:
 
 ```
 p loc->m_line
+p loc->m_filename->m_buffer
+```
+
+To print a debug representation of a tree:
+
+```c
+debug_tree(expr);
 ```
 
 To get the `rustc` command to run in `gdb`, add the `--verbose` flag to `cargo build`.
@@ -134,4 +143,5 @@ To get the `rustc` command to run in `gdb`, add the `--verbose` flag to `cargo b
  * Set `linker='-Clinker=m68k-linux-gcc'`.
  * Set the path to the cross-compiling libgccjit in `gcc_path`.
  * Disable the 128-bit integer types if the target doesn't support them by using `let i128_type = context.new_type::<i64>();` in `context.rs` (same for u128_type).
+ * Comment the line: `context.add_command_line_option("-masm=intel");` in src/base.rs.
  * (might not be necessary) Disable the compilation of libstd.so (and possibly libcore.so?).