doomemacs/modules/lang/cc

:lang cc

• Table of Contents
• Install
  • irony-server
    • MacOS
    • Arch Linux
  • rtags
• Configure
  • Compile settings

This module adds support for the C-family of languages: C, C++, and Objective-C.

• Code completion (company-irony)
• eldoc support (irony-eldoc)
• Syntax-checking (flycheck-irony)
• Code navigation (rtags)
• File Templates (c-mode, c++-mode)
• Snippets (cc-mode, c-mode, c++-mode)
• Several improvements to C++11 indentation and syntax highlighting.

C contends with Haskell and Ruby for my favorite language. That said, it's more accurate to say I write C, but a C++ feature or three.

The module provides nominal support for Objective-C, which I really only use to inspect generated glue code for iOS mobile apps. Otherwise, I prefer Swift.

Table of Contents   TOC

• Install

  • irony-server
  • rtags

• Configure

  • Compile settings

Install

This module requires:

• irony-server
• rtags

irony-server

Irony powers the code completion, eldoc and syntax checking systems.

MacOS

Due to linking issues, MacOS users must compile irony-server manually:

brew install cmake
brew install llvm  # 1gb+ installation! May take a while!

git clone https://github.com/Sarcasm/irony-mode irony-mode
mkdir irony-mode/server/build
pushd irony-mode/server/build

DEST="$HOME/.emacs.d/.local/$(hostname)/etc/irony-server/"
cmake -DCMAKE_INSTALL_RPATH_USE_LINK_PATH=ON \
      -DCMAKE_INSTALL_PREFIX="$DEST" ../
cmake --build . --use-stderr --config Release --target install

install_name_tool -change @rpath/libclang.dylib \
    /usr/local/opt/llvm/lib/libclang.dylib \
    "$DEST/bin/irony-server"

# cleanup
popd
rm -rf irony-mode

Arch Linux

sudo pacman --needed --noconfirm -S clang cmake

Then run M-x irony-install-server in Emacs.

rtags

Code navigation requires an rtags server (rdm) installed and running. This should be available through your OS's package manager.

This module will auto-start rdm when you open C/C++ buffers (so long as one isn't already). If you prefer to run it yourself, outside of Emacs:

rdm &
rc -J $PROJECT_ROOT  # loads PROJECT_ROOT's compile_commands.json

Configure

Compile settings

By default, a set of default compile settings are defined in +cc-default-compiler-options for C, C++ and Objective C. Irony, rtags and flycheck will fall back to these.

To make these tools aware of project specific build settings, you need a JSON compilation database present (i.e. a compile_commands.json file).

There are many ways to generate one. I use CMake and bear:

# For CMake projects
cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON .

# For non-CMake projects
make clean
bear make

Use M-x +cc/reload-compile-db to reload your compile db in an already-open C/C++/ObjC buffer.