Swift Package Manager无法找到头文件问题求助

项目结构 #

.
├── Package.swift
├── Sources
│   └── Argon
│       ├── include
│       │   └── Argon.h
│       └── some_source.c
└── deps
    └── olive.c
        └── olive.c # Header file

Package.swift 代码 #

// swift-tools-version: 5.7
import PackageDescription

let package = Package(
  name: "MyPackage",
  targets: [
    .target(
      name: "Argon",
      cSettings: [
        .headerSearchPath("deps/olive.c"),
      ]
    )
  ]
)

Argon.h 中的引入语句 #

#include <olive.c>

编译报错信息 #

In file included from /Users/jonaseveraert/Documents/projects/photobooth/Sources/Argon/some_source.c:3:
/Users/jonaseveraert/Documents/projects/photobooth/Sources/Argon/src/../include/argon.h:41:10: fatal error: 'olive.c' file not found
#include <olive.c>
^~~~~~~~~
1 error generated.

已尝试但无效的操作：

• 使用.unsafeFlags(["-Idep/olive.c"])
• 将olive.c重命名为olive.h

需要解决：headerSearchPath未生效的原因，以及如何正确找到这个以.c为扩展名的头文件。

核心问题 #

Swift Package Manager中，.headerSearchPath的路径是相对于目标源码目录（Sources/Argon/），而非项目根目录。你之前写的deps/olive.c会被解析为Sources/Argon/deps/olive.c，显然不存在这个路径。

方法一：修正相对路径 #

直接调整headerSearchPath的路径，从Sources/Argon/回到项目根目录，再指向依赖目录：

// swift-tools-version: 5.7
import PackageDescription

let package = Package(
  name: "MyPackage",
  targets: [
    .target(
      name: "Argon",
      cSettings: [
        .headerSearchPath("../../deps/olive.c"),
      ]
    )
  ]
)

方法二：声明为头文件依赖目标（更规范） #

将olive.c目录声明为独立的头文件目标，让SPM自动处理路径：

// swift-tools-version: 5.7
import PackageDescription

let package = Package(
  name: "MyPackage",
  targets: [
    .target(
      name: "Olive",
      path: "deps/olive.c",
      publicHeadersPath: ".",
      type: .headerOnly
    ),
    .target(
      name: "Argon",
      dependencies: ["Olive"]
    )
  ]
)

这种方式不需要手动设置搜索路径，保留#include <olive.c>即可正常编译，且更符合SPM的依赖管理规范。

内容的提问来源于stack exchange，提问作者Jomy