From 8a87f94f09c98f2c503da541239b819d2fe0178c Mon Sep 17 00:00:00 2001
From: Fabio Valentini <decathorpe@gmail.com>
Date: Mon, 12 Dec 2022 23:28:52 +0100
Subject: [PATCH] build: unconditionally link against system liblzma

---
 build.rs | 107 ++-----------------------------------------------------
 1 file changed, 2 insertions(+), 105 deletions(-)

diff --git a/build.rs b/build.rs
index 6bec545..22ab405 100644
--- a/build.rs
+++ b/build.rs
@@ -1,108 +1,5 @@
-use std::env;
-use std::fs;
-use std::path::PathBuf;
-
-const SKIP_FILENAMES: &[&str] = &["crc32_small", "crc64_small"];
-
 fn main() {
-    let target = env::var("TARGET").unwrap();
-
     println!("cargo:rerun-if-changed=build.rs");
-    println!("cargo:rerun-if-env-changed=LZMA_API_STATIC");
-    let want_static = cfg!(feature = "static") || env::var("LZMA_API_STATIC").is_ok();
-    let msvc = target.contains("msvc");
-
-    // If a static link is desired, we compile from source.
-    // If we're compiling for MSVC, pkg-config runs a risk of picking up MinGW
-    // libraries by accident, so disable it.
-    //
-    // Otherwise check the system to see if it has an lzma library already
-    // installed that we can use.
-    if !want_static && !msvc && pkg_config::probe_library("liblzma").is_ok() {
-        return;
-    }
-
-    let out_dir = env::var("OUT_DIR").unwrap();
-    println!("cargo:root={}", out_dir);
-    let include_dir = env::current_dir().unwrap().join("xz-5.2/src/liblzma/api");
-    println!("cargo:include={}", include_dir.display());
-
-    let mut src_files = [
-        "xz-5.2/src/liblzma/common",
-        "xz-5.2/src/liblzma/lzma",
-        "xz-5.2/src/liblzma/lz",
-        "xz-5.2/src/liblzma/check",
-        "xz-5.2/src/liblzma/delta",
-        "xz-5.2/src/liblzma/rangecoder",
-        "xz-5.2/src/liblzma/simple",
-    ]
-    .iter()
-    .flat_map(|dir| read_dir_files(dir))
-    .chain(vec![
-        "xz-5.2/src/common/tuklib_cpucores.c".into(),
-        "xz-5.2/src/common/tuklib_physmem.c".into(),
-    ])
-    .collect::<Vec<_>>();
-
-    // sort to make build reproducible.
-    src_files.sort();
-
-    let mut build = cc::Build::new();
-
-    build
-        .files(src_files)
-        // all C preproc defines are in `./config.h`
-        .define("HAVE_CONFIG_H", "1")
-        .include("xz-5.2/src/liblzma/api")
-        .include("xz-5.2/src/liblzma/lzma")
-        .include("xz-5.2/src/liblzma/lz")
-        .include("xz-5.2/src/liblzma/check")
-        .include("xz-5.2/src/liblzma/simple")
-        .include("xz-5.2/src/liblzma/delta")
-        .include("xz-5.2/src/liblzma/common")
-        .include("xz-5.2/src/liblzma/rangecoder")
-        .include("xz-5.2/src/common")
-        .include(env::current_dir().unwrap());
-
-    if !target.ends_with("msvc") {
-        build.flag("-std=c99").flag("-pthread");
-    }
-
-    if let Ok(s) = env::var("CARGO_CFG_TARGET_ENDIAN") {
-        if s == "big" {
-            build.define("WORDS_BIGENDIAN", None);
-        }
-    }
-
-    build.compile("liblzma.a");
-}
-
-fn read_dir_files(dir: &str) -> impl Iterator<Item = PathBuf> {
-    fs::read_dir(dir)
-        .expect(&format!("failed to read dir {}", dir))
-        .filter_map(|ent| {
-            let ent = ent.expect("failed to read entry");
-
-            if ent.file_type().unwrap().is_dir() {
-                return None;
-            }
-
-            let path = ent.path();
-
-            if path.extension().unwrap() != "c" {
-                return None;
-            }
-
-            {
-                let file_stem = path.file_stem().unwrap().to_str().unwrap();
-                if SKIP_FILENAMES.contains(&file_stem) {
-                    return None;
-                }
-                if file_stem.ends_with("tablegen") {
-                    return None;
-                }
-            }
-
-            Some(path)
-        })
+    pkg_config::probe_library("liblzma").unwrap();
+    return;
 }
-- 
2.38.1