doomemacs/modules/lang/cc

lang/cc

• Description
  • Module Flags
  • Plugins
• Prerequisites
  • irony-server
    • MacOS
    • Arch Linux
  • rtags
• Configure
  • Project compile settings

Description

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.

Module Flags

• +irony Enable Irony as a backend for code completion, syntax checking, and eldoc support. This must be disabled to use LSP or another backend.
• +rtags Enable rtags integration. A daemon will be spawned the first time you open a C/C++/ObjC buffer, if one hasn't already.

Plugins

• cmake-mode
• cuda-mode
• demangle-mode
• disaster
• modern-cpp-font-lock
• opencl-mode
• glsl-mode*
• gompany-glsl*
• irony*
• irony-eldoc*
• flycheck-irony*
• company-irony*
• company-irony-c-headers*
• rtags*
• ivy-rtags or helm-rtags*

Prerequisites

This module requires

• irony-server (if +irony is enabled)
• rtags (if +rtags is enabled)

irony-server

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

After installing its dependencies, run M-x irony-install-server in Emacs.

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

pacman -S clang cmake

rtags

Code navigation requires an rtags server (rdm) installed. 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 running). If you prefer to run it yourself:

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

Configure

Project 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 or 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.