[llvm] 38ef568 - Teach RuntimeDyld about COFF weak references and to consider comdat symbols weak.
Vassil Vassilev via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 24 10:26:06 PST 2023
Author: Vassil Vassilev
Date: 2023-01-24T18:25:49Z
New Revision: 38ef56880a99e6382f4a1f9113646295953c0b16
URL: https://github.com/llvm/llvm-project/commit/38ef56880a99e6382f4a1f9113646295953c0b16
DIFF: https://github.com/llvm/llvm-project/commit/38ef56880a99e6382f4a1f9113646295953c0b16.diff
LOG: Teach RuntimeDyld about COFF weak references and to consider comdat symbols weak.
Patch by Lang Hames and Sunho Kim!
Differential revision: https://reviews.llvm.org/D138264
Added:
llvm/test/ExecutionEngine/OrcLazy/Inputs/comdat-functions.ll
llvm/test/ExecutionEngine/OrcLazy/comdat-functions.ll
Modified:
llvm/lib/ExecutionEngine/Orc/Layer.cpp
llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp
Removed:
################################################################################
diff --git a/llvm/lib/ExecutionEngine/Orc/Layer.cpp b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
index b0acab0137bc5..95380d912392e 100644
--- a/llvm/lib/ExecutionEngine/Orc/Layer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
@@ -77,6 +77,9 @@ IRMaterializationUnit::IRMaterializationUnit(
// Otherwise we just need a normal linker mangling.
auto MangledName = Mangle(G.getName());
SymbolFlags[MangledName] = JITSymbolFlags::fromGlobalValue(G);
+ if (G.getComdat() &&
+ G.getComdat()->getSelectionKind() != Comdat::NoDeduplicate)
+ SymbolFlags[MangledName] |= JITSymbolFlags::Weak;
SymbolToDefinition[MangledName] = &G;
}
diff --git a/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp b/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp
index 9e781e9cbac9f..07b19b2e54f19 100644
--- a/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.cpp
@@ -259,6 +259,46 @@ Error RTDyldObjectLinkingLayer::onObjLoad(
if (COFFSec.Characteristics & COFF::IMAGE_SCN_LNK_COMDAT)
I->second.setFlags(I->second.getFlags() | JITSymbolFlags::Weak);
}
+
+ // Handle any aliases.
+ for (auto &Sym : COFFObj->symbols()) {
+ uint32_t SymFlags = cantFail(Sym.getFlags());
+ if (SymFlags & object::BasicSymbolRef::SF_Undefined)
+ continue;
+ auto Name = Sym.getName();
+ if (!Name)
+ return Name.takeError();
+ auto I = Resolved.find(*Name);
+
+ // Skip already-resolved symbols, and symbols that we're not responsible
+ // for.
+ if (I != Resolved.end() || !R.getSymbols().count(ES.intern(*Name)))
+ continue;
+
+ // Skip anything other than weak externals.
+ auto COFFSym = COFFObj->getCOFFSymbol(Sym);
+ if (!COFFSym.isWeakExternal())
+ continue;
+ auto *WeakExternal = COFFSym.getAux<object::coff_aux_weak_external>();
+ if (WeakExternal->Characteristics != COFF::IMAGE_WEAK_EXTERN_SEARCH_ALIAS)
+ continue;
+
+ // We found an alias. Reuse the resolution of the alias target for the
+ // alias itself.
+ Expected<object::COFFSymbolRef> TargetSymbol =
+ COFFObj->getSymbol(WeakExternal->TagIndex);
+ if (!TargetSymbol)
+ return TargetSymbol.takeError();
+ Expected<StringRef> TargetName = COFFObj->getSymbolName(*TargetSymbol);
+ if (!TargetName)
+ return TargetName.takeError();
+ auto J = Resolved.find(*TargetName);
+ if (J == Resolved.end())
+ return make_error<StringError>("Could alias target " + *TargetName +
+ " not resolved",
+ inconvertibleErrorCode());
+ Resolved[*Name] = J->second;
+ }
}
for (auto &KV : Resolved) {
diff --git a/llvm/test/ExecutionEngine/OrcLazy/Inputs/comdat-functions.ll b/llvm/test/ExecutionEngine/OrcLazy/Inputs/comdat-functions.ll
new file mode 100644
index 0000000000000..9c873a1a22163
--- /dev/null
+++ b/llvm/test/ExecutionEngine/OrcLazy/Inputs/comdat-functions.ll
@@ -0,0 +1,6 @@
+$baz = comdat any
+
+define i32 @baz() comdat {
+entry:
+ ret i32 0
+}
diff --git a/llvm/test/ExecutionEngine/OrcLazy/comdat-functions.ll b/llvm/test/ExecutionEngine/OrcLazy/comdat-functions.ll
new file mode 100644
index 0000000000000..895410da98a11
--- /dev/null
+++ b/llvm/test/ExecutionEngine/OrcLazy/comdat-functions.ll
@@ -0,0 +1,16 @@
+; REQUIRES: system-windows
+; RUN: lli -jit-kind=orc-lazy -extra-module %p/Inputs/comdat-functions.ll %s
+; Check if crashing comdat any functions are not causing duplicate symbol error.
+
+$baz = comdat any
+
+define i32 @baz() comdat {
+entry:
+ ret i32 0
+}
+
+define i32 @main(i32 %argc, i8** %argv) {
+entry:
+ %call = tail call i32 @baz()
+ ret i32 %call
+}
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