From 71a3a48ee52a5cbc3fa3e3e8d322ebeb97ed109f Mon Sep 17 00:00:00 2001 From: Onur Özkan Date: Fri, 28 Oct 2022 10:20:51 +0300 Subject: improve `filesearch::get_or_default_sysroot` r=ozkanonur MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Onur Özkan --- compiler/rustc_session/Cargo.toml | 7 ++ compiler/rustc_session/src/config.rs | 2 +- compiler/rustc_session/src/filesearch.rs | 136 +++++++++++++++++++++++++++---- compiler/rustc_session/src/session.rs | 2 +- 4 files changed, 129 insertions(+), 18 deletions(-) (limited to 'compiler/rustc_session') diff --git a/compiler/rustc_session/Cargo.toml b/compiler/rustc_session/Cargo.toml index 6b1eaa4d399..a052f293341 100644 --- a/compiler/rustc_session/Cargo.toml +++ b/compiler/rustc_session/Cargo.toml @@ -17,3 +17,10 @@ rustc_span = { path = "../rustc_span" } rustc_fs_util = { path = "../rustc_fs_util" } rustc_ast = { path = "../rustc_ast" } rustc_lint_defs = { path = "../rustc_lint_defs" } +smallvec = "1.8.1" + +[target.'cfg(unix)'.dependencies] +libc = "0.2" + +[target.'cfg(windows)'.dependencies] +winapi = { version = "0.3", features = ["libloaderapi"] } diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs index f2ee52262ad..5dfd9f00ad1 100644 --- a/compiler/rustc_session/src/config.rs +++ b/compiler/rustc_session/src/config.rs @@ -2431,7 +2431,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options { let sysroot = match &sysroot_opt { Some(s) => s, None => { - tmp_buf = crate::filesearch::get_or_default_sysroot(); + tmp_buf = crate::filesearch::get_or_default_sysroot().expect("Failed finding sysroot"); &tmp_buf } }; diff --git a/compiler/rustc_session/src/filesearch.rs b/compiler/rustc_session/src/filesearch.rs index e8edb38f503..1b66773be6f 100644 --- a/compiler/rustc_session/src/filesearch.rs +++ b/compiler/rustc_session/src/filesearch.rs @@ -1,5 +1,6 @@ //! A module for searching for libraries +use smallvec::{smallvec, SmallVec}; use std::env; use std::fs; use std::iter::FromIterator; @@ -62,9 +63,99 @@ pub fn make_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf { PathBuf::from_iter([sysroot, Path::new(&rustlib_path), Path::new("lib")]) } +#[cfg(unix)] +fn current_dll_path() -> Result { + use std::ffi::{CStr, OsStr}; + use std::os::unix::prelude::*; + + unsafe { + let addr = current_dll_path as usize as *mut _; + let mut info = std::mem::zeroed(); + if libc::dladdr(addr, &mut info) == 0 { + return Err("dladdr failed".into()); + } + if info.dli_fname.is_null() { + return Err("dladdr returned null pointer".into()); + } + let bytes = CStr::from_ptr(info.dli_fname).to_bytes(); + let os = OsStr::from_bytes(bytes); + Ok(PathBuf::from(os)) + } +} + +#[cfg(windows)] +fn current_dll_path() -> Result { + use std::ffi::OsString; + use std::io; + use std::os::windows::prelude::*; + use std::ptr; + + use winapi::um::libloaderapi::{ + GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, + }; + + unsafe { + let mut module = ptr::null_mut(); + let r = GetModuleHandleExW( + GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, + current_dll_path as usize as *mut _, + &mut module, + ); + if r == 0 { + return Err(format!("GetModuleHandleExW failed: {}", io::Error::last_os_error())); + } + let mut space = Vec::with_capacity(1024); + let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32); + if r == 0 { + return Err(format!("GetModuleFileNameW failed: {}", io::Error::last_os_error())); + } + let r = r as usize; + if r >= space.capacity() { + return Err(format!("our buffer was too small? {}", io::Error::last_os_error())); + } + space.set_len(r); + let os = OsString::from_wide(&space); + Ok(PathBuf::from(os)) + } +} + +pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> { + let target = crate::config::host_triple(); + let mut sysroot_candidates: SmallVec<[PathBuf; 2]> = + smallvec![get_or_default_sysroot().expect("Failed finding sysroot")]; + let path = current_dll_path().and_then(|s| Ok(s.canonicalize().map_err(|e| e.to_string())?)); + if let Ok(dll) = path { + // use `parent` twice to chop off the file name and then also the + // directory containing the dll which should be either `lib` or `bin`. + if let Some(path) = dll.parent().and_then(|p| p.parent()) { + // The original `path` pointed at the `rustc_driver` crate's dll. + // Now that dll should only be in one of two locations. The first is + // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The + // other is the target's libdir, for example + // `$sysroot/lib/rustlib/$target/lib/*.dll`. + // + // We don't know which, so let's assume that if our `path` above + // ends in `$target` we *could* be in the target libdir, and always + // assume that we may be in the main libdir. + sysroot_candidates.push(path.to_owned()); + + if path.ends_with(target) { + sysroot_candidates.extend( + path.parent() // chop off `$target` + .and_then(|p| p.parent()) // chop off `rustlib` + .and_then(|p| p.parent()) // chop off `lib` + .map(|s| s.to_owned()), + ); + } + } + } + + return sysroot_candidates; +} + /// This function checks if sysroot is found using env::args().next(), and if it -/// is not found, uses env::current_exe() to imply sysroot. -pub fn get_or_default_sysroot() -> PathBuf { +/// is not found, finds sysroot from current rustc_driver dll. +pub fn get_or_default_sysroot() -> Result { // Follow symlinks. If the resolved path is relative, make it absolute. fn canonicalize(path: PathBuf) -> PathBuf { let path = fs::canonicalize(&path).unwrap_or(path); @@ -74,17 +165,32 @@ pub fn get_or_default_sysroot() -> PathBuf { fix_windows_verbatim_for_gcc(&path) } - // Use env::current_exe() to get the path of the executable following - // symlinks/canonicalizing components. - fn from_current_exe() -> PathBuf { - match env::current_exe() { - Ok(exe) => { - let mut p = canonicalize(exe); - p.pop(); - p.pop(); - p - } - Err(e) => panic!("failed to get current_exe: {e}"), + fn default_from_rustc_driver_dll() -> Result { + let dll = current_dll_path().and_then(|s| Ok(canonicalize(s)))?; + + // `dll` will be in one of the following two: + // - compiler's libdir: $sysroot/lib/*.dll + // - target's libdir: $sysroot/lib/rustlib/$target/lib/*.dll + // + // use `parent` twice to chop off the file name and then also the + // directory containing the dll + let dir = dll.parent().and_then(|p| p.parent()).ok_or(format!( + "Could not move 2 levels upper using `parent()` on {}", + dll.display() + ))?; + + // if `dir` points target's dir, move up to the sysroot + if dir.ends_with(crate::config::host_triple()) { + dir.parent() // chop off `$target` + .and_then(|p| p.parent()) // chop off `rustlib` + .and_then(|p| p.parent()) // chop off `lib` + .map(|s| s.to_owned()) + .ok_or(format!( + "Could not move 3 levels upper using `parent()` on {}", + dir.display() + )) + } else { + Ok(dir.to_owned()) } } @@ -118,7 +224,5 @@ pub fn get_or_default_sysroot() -> PathBuf { } } - // Check if sysroot is found using env::args().next(), and if is not found, - // use env::current_exe() to imply sysroot. - from_env_args_next().unwrap_or_else(from_current_exe) + Ok(from_env_args_next().unwrap_or(default_from_rustc_driver_dll()?)) } diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs index 100c66f6364..5086117f921 100644 --- a/compiler/rustc_session/src/session.rs +++ b/compiler/rustc_session/src/session.rs @@ -1280,7 +1280,7 @@ pub fn build_session( let sysroot = match &sopts.maybe_sysroot { Some(sysroot) => sysroot.clone(), - None => filesearch::get_or_default_sysroot(), + None => filesearch::get_or_default_sysroot().expect("Failed finding sysroot"), }; let target_cfg = config::build_target_config(&sopts, target_override, &sysroot); -- cgit 1.4.1-3-g733a5