[PATCH] D65584: [ELF] resolveUndefined: make STB_WEAK logic consistent for Undefined and SharedFile
Fangrui Song via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 1 08:56:44 PDT 2019
MaskRay updated this revision to Diff 212829.
MaskRay edited the summary of this revision.
MaskRay added a comment.
Mention --allow-shlib-undefined
Repository:
rLLD LLVM Linker
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D65584/new/
https://reviews.llvm.org/D65584
Files:
ELF/InputFiles.cpp
ELF/Symbols.cpp
ELF/Symbols.h
test/ELF/weak-undef-shared.s
Index: test/ELF/weak-undef-shared.s
===================================================================
--- test/ELF/weak-undef-shared.s
+++ test/ELF/weak-undef-shared.s
@@ -30,6 +30,9 @@
# RUN: ld.lld %t1.o %t2.so -o %t
# RUN: llvm-readelf --dyn-syms %t | FileCheck --check-prefix=WEAK %s
+# RUN: ld.lld %t2.so %t1.o -o %t
+# RUN: llvm-readelf --dyn-syms %t | FileCheck --check-prefix=WEAK %s
+
# WEAK: NOTYPE WEAK DEFAULT UND foo
# GLOBAL: NOTYPE GLOBAL DEFAULT UND foo
Index: ELF/Symbols.h
===================================================================
--- ELF/Symbols.h
+++ ELF/Symbols.h
@@ -127,6 +127,11 @@
// doesn't know the final contents of the symbol.
unsigned canInline : 1;
+ // Used by Undefind and SharedSymbol to track if there has been at least one
+ // undefined reference to the symbol. The binding may change to STB_WEAK if
+ // the first undefined reference from a non-shared object is weak.
+ unsigned referenced : 1;
+
// True if this symbol is specified by --trace-symbol option.
unsigned traced : 1;
@@ -367,11 +372,6 @@
uint64_t value; // st_value
uint64_t size; // st_size
uint32_t alignment;
-
- // This is true if there has been at least one undefined reference to the
- // symbol. The binding may change to STB_WEAK if the first undefined reference
- // is weak.
- bool referenced = false;
};
// LazyArchive and LazyObject represent a symbols that is not yet in the link,
@@ -535,6 +535,7 @@
isUsedInRegularObj = old.isUsedInRegularObj;
exportDynamic = old.exportDynamic;
canInline = old.canInline;
+ referenced = old.referenced;
traced = old.traced;
isPreemptible = old.isPreemptible;
scriptDefined = old.scriptDefined;
Index: ELF/Symbols.cpp
===================================================================
--- ELF/Symbols.cpp
+++ ELF/Symbols.cpp
@@ -492,17 +492,13 @@
if (dyn_cast_or_null<SharedFile>(other.file))
return;
- if (isUndefined()) {
- // The binding may "upgrade" from weak to non-weak.
- if (other.binding != STB_WEAK)
+ if (isUndefined() || isShared()) {
+ // The binding will be weak if there is at least one reference and all are
+ // weak. The binding has one opportunity to change to weak: if the first
+ // reference is weak.
+ if (other.binding != STB_WEAK || !referenced)
binding = other.binding;
- } else if (auto *s = dyn_cast<SharedSymbol>(this)) {
- // The binding of a SharedSymbol will be weak if there is at least one
- // reference and all are weak. The binding has one opportunity to change to
- // weak: if the first reference is weak.
- if (other.binding != STB_WEAK || !s->referenced)
- binding = other.binding;
- s->referenced = true;
+ referenced = true;
}
}
@@ -658,6 +654,6 @@
uint8_t bind = binding;
replace(other);
binding = bind;
- cast<SharedSymbol>(this)->referenced = true;
+ referenced = true;
}
}
Index: ELF/InputFiles.cpp
===================================================================
--- ELF/InputFiles.cpp
+++ ELF/InputFiles.cpp
@@ -1098,6 +1098,7 @@
// Handle global undefined symbols.
if (eSym.st_shndx == SHN_UNDEF) {
this->symbols[i]->resolve(Undefined{this, name, binding, stOther, type});
+ this->symbols[i]->referenced = true;
continue;
}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D65584.212829.patch
Type: text/x-patch
Size: 3337 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190801/a9024fd1/attachment.bin>
More information about the llvm-commits
mailing list