项目Makefile放置位置选择：根目录、src/及其他场景分析

Let’s break down the best spots to put your Makefile based on your project’s structure and needs—there’s no universal answer, but here’s how to make the right call:

1. Root Directory (The Most Common & Logically Sound Choice) #

This is the standard pick for most projects, and it’s easy to see why:

• Intuitive for everyone: Anyone cloning or exploring your project can just run make right from the root without digging through subfolders. It’s a no-brainer for new contributors or users who want to build the project quickly.
• Full project control: A root Makefile can handle all your project tasks—not just compiling code. You can set up targets to build binaries into bin/, generate documentation in doc/, install libraries to lib/, run tests, clean up all artifacts across directories, and more.
• Follows community norms: Most open-source projects use this pattern, so it aligns with what developers expect. If your project has multiple parts (like a library in lib/ and a CLI tool in src/), a root Makefile ties everything together smoothly.

Best for:

• Standard apps, libraries, or multi-component projects where you need to manage more than just source code compilation.
• Projects that need to be easy to use for external contributors or end-users.

2. src/ Subdirectory #

Putting the Makefile inside src/ only makes sense in specific, narrow scenarios:

• Small, single-component projects: If your project is just a single binary or library with all core code in src/, and you don’t need to handle cross-directory tasks (like building docs or managing external libraries separately), keeping the Makefile right next to the source can feel cleaner.
• Isolated build logic: If the src/ folder is self-contained (e.g., it has its own dependencies and build rules that don’t interact with other project directories), having the Makefile here keeps build logic localized to the code it affects.

Caveats to consider:

• Users will have to cd src/ before running make, which adds an extra step and can confuse folks used to root-level Makefiles.
• You’ll either need a separate root Makefile to call the src/ one (which defeats the purpose of keeping it in src/) or give up managing non-src tasks (like docs or installation) via Makefile.

Best for:

• Tiny, simple projects where all build-related work is tied directly to the code in src/, and you don’t need broader project automation.

3. Other Directories (e.g., Component-Specific Subfolders or build/) #

In more complex projects, you might split Makefiles across multiple directories or use a dedicated build/ folder:

• Multi-component monorepos: If your project has independent subprojects (like src/cli/ and src/lib/, each with their own build rules), you can have a root Makefile that calls Makefiles in each subdirectory. Alternatively, each subcomponent can have its own Makefile, with the root one acting as a coordinator.
• Separated build configuration: A build/ directory might hold the main Makefile if your project uses generated build files (like from CMake or autotools), though this is less common for hand-written Makefiles.

Best for:

• Large monorepos with distinct, independently buildable components.
• Projects where build configuration needs to be kept separate from source code and other assets.

Content of the question comes from Stack Exchange, asked by Tim