bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Allow using -C force-unwind-tables=no when panic=unwind

Browse source
This commit is contained in:
hyd-dev 2021-03-25 18:49:35 +08:00
parent 58f32da346
commit 2fd4dd20d7
No known key found for this signature in database
GPG key ID: 74FA7FD5B8DA14B8
7 changed files with 74 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

25
compiler/rustc_session/src/session.rs
View file

@ -807,8 +807,11 @@ impl Session {
// This is used to control the emission of the `uwtable` attribute on
// LLVM functions.
//
// At the very least, unwind tables are needed when compiling with
// `-C panic=unwind`.
// Unwind tables are needed when compiling with `-C panic=unwind`, but
// LLVM won't omit unwind tables unless the function is also marked as
// `nounwind`, so users are allowed to disable `uwtable` emission.
// Historically rustc always emits `uwtable` attributes by default, so
// even they can be disabled, they're still emitted by default.
//
// On some targets (including windows), however, exceptions include
// other events such as illegal instructions, segfaults, etc. This means
@ -821,13 +824,10 @@ impl Session {
// If a target requires unwind tables, then they must be emitted.
// Otherwise, we can defer to the `-C force-unwind-tables=<yes/no>`
// value, if it is provided, or disable them, if not.
if self.panic_strategy() == PanicStrategy::Unwind {
true
} else if self.target.requires_uwtable {
true
} else {
self.opts.cg.force_unwind_tables.unwrap_or(self.target.default_uwtable)
}
self.target.requires_uwtable
|| self.opts.cg.force_unwind_tables.unwrap_or(
self.panic_strategy() == PanicStrategy::Unwind || self.target.default_uwtable,
)
}
/// Returns the symbol name for the registrar function,
@ -1483,13 +1483,6 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
// Unwind tables cannot be disabled if the target requires them.
if let Some(include_uwtables) = sess.opts.cg.force_unwind_tables {
if sess.panic_strategy() == PanicStrategy::Unwind && !include_uwtables {
sess.err(
"panic=unwind requires unwind tables, they cannot be disabled \
with `-C force-unwind-tables=no`.",
);
}
if sess.target.requires_uwtable && !include_uwtables {
sess.err(
"target requires unwind tables, they cannot be disabled with \