Build libarchive with cmake if it can't be found

.travis.yml

@@ -8,7 +8,7 @@ jobs:
         apt:
           packages:
             - ninja-build
-            - libarchive-dev
+            - cmake
       install:
         - source ~/virtualenv/python3.6/bin/activate
         - pip install meson
@@ -32,7 +32,7 @@ jobs:
           packages:
             - ninja
             - llvm
-            - libarchive
+            - cmake
           update: true
       script:
         - xcodebuild -project iSH.xcodeproj -scheme iSH -sdk iphoneos CODE_SIGNING_ALLOWED=NO

README.md

@@ -31,7 +31,7 @@ You'll need these things to build the project:
  - Meson (`pip install meson`)
  - Clang and LLD (on mac, `brew install llvm`, on linux, `sudo apt install clang lld` or `sudo pacman -S clang lld` or whatever)
  - sqlite3 (this is so common it may already be installed on linux and is definitely already installed on mac. if not, do something like `sudo apt install libsqlite3-dev`)
- - libarchive (`brew install libarchive`, `sudo port install libarchive`, `sudo apt install libarchive-dev`) TODO: bundle this dependency
+ - Either libarchive (from your package manager) or cmake (to build a bundled libarchive)
 
 ## Build for iOS
 
@@ -41,7 +41,7 @@ Open the project in Xcode, open iSH.xcconfig, and change `ROOT_BUNDLE_IDENTIFIER
 
 To set up your environment, cd to the project and run `meson build` to create a build directory in `build`. Then cd to the build directory and run `ninja`.
 
-To set up a self-contained Alpine linux filesystem, download the Alpine minirootfs tarball for i386 from the [Alpine website](https://alpinelinux.org/downloads/) and run `./tools/fakefsify`, with the minirootfs tarball as the first argument and the name of the output directory as the second argument. Then you can run things inside the Alpine filesystem with `./ish -f alpine /bin/login -f root`, assuming the output directory is called `alpine`. If `tools/fakefsify` doesn't exist for you in your build directory, that might be because it couldn't find libarchive on your system (see above for ways to install it.)
+To set up a self-contained Alpine linux filesystem, download the Alpine minirootfs tarball for i386 from the [Alpine website](https://alpinelinux.org/downloads/) and run `./tools/fakefsify`, with the minirootfs tarball as the first argument and the name of the output directory as the second argument. Then you can run things inside the Alpine filesystem with `./ish -f alpine /bin/login -f root`, assuming the output directory is called `alpine`. If `tools/fakefsify` doesn't exist for you in your build directory, you probably need to install libarchive or cmake (see above)
 
 You can replace `ish` with `tools/ptraceomatic` to run the program in a real process and single step and compare the registers at each step. I use it for debugging. Requires 64-bit Linux 4.11 or later.
 

deps/script/meson.build

@@ -0,0 +1,14 @@
+libarchive = dependency('libarchive', method: 'pkg-config', required: false)
+if not libarchive.found()
+    # try homebrew
+    libarchive_lib = cc.find_library('libarchive', dirs: ['/usr/local/opt/libarchive/lib'], required: false)
+    if libarchive_lib.found()
+        libarchive = declare_dependency(dependencies: [libarchive_lib], include_directories: include_directories(['/usr/local/opt/libarchive/include']))
+    endif
+endif
+if not libarchive.found()
+    warning('no system libarchive found, building with cmake')
+    cmake = import('cmake')
+    libarchive = cmake.subproject('libarchive').dependency('archive_static')
+endif
+

meson.build

@@ -1,5 +1,6 @@
 project('ish', 'c',
-    default_options: ['default_library=static', 'c_std=gnu11', 'warning_level=2'])
+    default_options: ['default_library=static', 'c_std=gnu11', 'warning_level=2'],
+    subproject_dir: 'deps')
 cc = meson.get_compiler('c')
 
 if cc.get_id() == 'clang'
@@ -34,6 +35,7 @@ threads = dependency('threads')
 librt = cc.find_library('rt', required: false)
 libm = cc.find_library('m', required: false)
 sqlite3 = cc.find_library('sqlite3')
+subdir('deps/script')
 
 dependencies = [librt, libm, threads, sqlite3]
 

tools/meson.build

@@ -19,19 +19,8 @@ if unicorn.found()
     configure_file(input: 'ptraceomatic-gdb.gdb', output: 'unicornomatic-gdb.gdb', copy: true)
 endif
 
-libarchive = dependency('libarchive', required: false)
-if not libarchive.found()
-    # homebrew
-    libarchive_lib = cc.find_library('libarchive', dirs: ['/usr/local/opt/libarchive/lib'], required: false)
-    if libarchive_lib.found()
-        libarchive = declare_dependency(dependencies: [libarchive_lib], include_directories: include_directories(['/usr/local/opt/libarchive/include']))
-    endif
-endif
-
-if libarchive.found()
-    fakefsify = executable('fakefsify', ['fakefsify.c', 'fakefs.c'], dependencies: [ish, libarchive])
-    custom_target('unfakefsify',
-        build_by_default: true,
-        command: ['ln', '-sf', 'fakefsify', '@OUTPUT@'],
-        output: 'unfakefsify')
-endif
+fakefsify = executable('fakefsify', ['fakefsify.c', 'fakefs.c'], dependencies: [ish, libarchive])
+custom_target('unfakefsify',
+    build_by_default: true,
+    command: ['ln', '-sf', 'fakefsify', '@OUTPUT@'],
+    output: 'unfakefsify')