make separate compilation respect #[inline] attributes

Adjust the handling of `#[inline]` items so that they get translated into every
compilation unit that uses them.  This is necessary to preserve the semantics
of `#[inline(always)]`.

Crate-local `#[inline]` functions and statics are blindly translated into every
compilation unit.  Cross-crate inlined items and monomorphizations of
`#[inline]` functions are translated the first time a reference is seen in each
compilation unit.  When using multiple compilation units, inlined items are
given `available_externally` linkage whenever possible to avoid duplicating
object code.

1 files changed, 9 insertions, 1 deletions

diff --git a/src/libsyntax/attr.rs b/src/libsyntax/attr.rs
index c234bea0a33..dd422d02149 100644
--- a/src/libsyntax/attr.rs
+++ b/src/libsyntax/attr.rs
@@ -280,7 +280,7 @@ pub enum InlineAttr {
     InlineNever,
 }
 
-/// True if something like #[inline] is found in the list of attrs.
+/// Determine what `#[inline]` attribute is present in `attrs`, if any.
 pub fn find_inline_attr(attrs: &[Attribute]) -> InlineAttr {
     // FIXME (#2809)---validate the usage of #[inline] and #[inline]
     attrs.iter().fold(InlineNone, |ia,attr| {
@@ -304,6 +304,14 @@ pub fn find_inline_attr(attrs: &[Attribute]) -> InlineAttr {
     })
 }
 
+/// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
+pub fn requests_inline(attrs: &[Attribute]) -> bool {
+    match find_inline_attr(attrs) {
+        InlineHint | InlineAlways => true,
+        InlineNone | InlineNever => false,
+    }
+}
+
 /// Tests if any `cfg(...)` meta items in `metas` match `cfg`. e.g.
 ///
 /// test_cfg(`[foo="a", bar]`, `[cfg(foo), cfg(bar)]`) == true