[ELF] Add -Bsymbolic-non-weak
This adds a new -Bsymbolic option that directly binds all non-weak
symbols. There's a couple of reasons motivating this:
* The new flag will match the default behavior on Mach-O, so you can get
consistent behavior across platforms.
* We have use cases for which making weak data preemptible is useful,
but we don't want to pessimize access to non-weak data. (For a large
internal app, we measured 2000+ data symbols whose accesses would be
unnecessarily pessimized by `-Bsymbolic-functions`.)
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D158322
diff --git a/lld/ELF/Symbols.cpp b/lld/ELF/Symbols.cpp
index 840385a..07061d3 100644
--- a/lld/ELF/Symbols.cpp
+++ b/lld/ELF/Symbols.cpp
@@ -365,6 +365,8 @@
// in the dynamic list. -Bsymbolic-non-weak-functions is a non-weak subset of
// -Bsymbolic-functions.
if (config->symbolic ||
+ (config->bsymbolic == BsymbolicKind::NonWeak &&
+ sym.binding != STB_WEAK) ||
(config->bsymbolic == BsymbolicKind::Functions && sym.isFunc()) ||
(config->bsymbolic == BsymbolicKind::NonWeakFunctions && sym.isFunc() &&
sym.binding != STB_WEAK))
