nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2025-04-29 11:37:39 +00:00
Code Issues Packages Projects Releases Wiki Activity

Auto merge of #54675 - alexcrichton:defaultlibs, r=varkor

Browse Source 
rust: Add a `-C default-linker-libraries` option

This commit adds a new codegen option for the compiler which disables
rustc's passing of `-nodefaultlibs` by default on relevant platforms.
Sometimes Rust is linked with C code which fails to link with
`-nodefaultlibs` and is unnecessarily onerous to get linking correctly
with `-nodefaultlibs`.

An example of this is that when you compile C code with sanitizers and
then pass `-fsanitize=address` to the linker, it's incompatible with
`-nodefaultlibs` also being passed to the linker.

In these situations it's easiest to turn off Rust's default passing of
`-nodefaultlibs`, which was more ideological to start with than
anything! Preserving the default is somewhat important but having this
be opt-in shouldn't cause any breakage.

Closes #54237
This commit is contained in:
bors 2018-10-01 03:24:02 +00:00
commit f55129d003
2 changed files with 12 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/librustc/session/config.rs
View File

@ -1135,6 +1135,8 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options,
[TRACKED], "panic strategy to compile crate with"), [TRACKED], "panic strategy to compile crate with"),
incremental: Option<String> = (None, parse_opt_string, [UNTRACKED], incremental: Option<String> = (None, parse_opt_string, [UNTRACKED],
"enable incremental compilation"), "enable incremental compilation"),
default_linker_libraries: Option<bool> = (None, parse_opt_bool, [UNTRACKED],
"allow the linker to link its default libraries"),
} }
options! {DebuggingOptions, DebuggingSetter, basic_debugging_options, options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,

16
src/librustc_codegen_llvm/back/link.rs
View File

@ -1138,12 +1138,16 @@ fn link_args(cmd: &mut dyn Linker,
// Pass debuginfo flags down to the linker. // Pass debuginfo flags down to the linker.
cmd.debuginfo(); cmd.debuginfo();
// We want to prevent the compiler from accidentally leaking in any system // We want to, by default, prevent the compiler from accidentally leaking in
// libraries, so we explicitly ask gcc to not link to any libraries by // any system libraries, so we may explicitly ask linkers to not link to any
// default. Note that this does not happen for windows because windows pulls // libraries by default. Note that this does not happen for windows because
// in some large number of libraries and I couldn't quite figure out which // windows pulls in some large number of libraries and I couldn't quite
// subset we wanted. // figure out which subset we wanted.
if t.options.no_default_libraries { //
// This is all naturally configurable via the standard methods as well.
if !sess.opts.cg.default_linker_libraries.unwrap_or(false) &&
t.options.no_default_libraries
{
cmd.no_default_libraries(); cmd.no_default_libraries();
} }