[llvm] 7956576 - Reland "[llvm] Support forward-referenced globals with dso_local_equivalent"
Leonard Chan via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 23 11:32:31 PDT 2022
Author: Leonard Chan
Date: 2022-09-23T18:32:07Z
New Revision: 79565766be94f7944278671a9f473d79ac18f7e1
URL: https://github.com/llvm/llvm-project/commit/79565766be94f7944278671a9f473d79ac18f7e1
DIFF: https://github.com/llvm/llvm-project/commit/79565766be94f7944278671a9f473d79ac18f7e1.diff
LOG: Reland "[llvm] Support forward-referenced globals with dso_local_equivalent"
This reverts commit eef5db2c744e4799dc40ada54fdde7dbbd552807.
See https://github.com/llvm/llvm-project/issues/57815.
dso_local_equivalent would fail with an assertion on forward-referenced
globals. This is an issue that only comes up in textual IR, which is why
we've never seen this assertion with clang.
Differential Revision: https://reviews.llvm.org/D134234
Added:
llvm/test/Assembler/dso_local_equivalent.ll
llvm/test/CodeGen/X86/dso_local_equivalent_errors.ll
Modified:
llvm/include/llvm/AsmParser/LLParser.h
llvm/lib/AsmParser/LLParser.cpp
llvm/test/CodeGen/X86/dso_local_equivalent.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/AsmParser/LLParser.h b/llvm/include/llvm/AsmParser/LLParser.h
index f63f0eda95501..b40b8695223d8 100644
--- a/llvm/include/llvm/AsmParser/LLParser.h
+++ b/llvm/include/llvm/AsmParser/LLParser.h
@@ -132,6 +132,14 @@ namespace llvm {
/// function.
PerFunctionState *BlockAddressPFS;
+ // References to dso_local_equivalent. The key is the global's ValID, the
+ // value is a placeholder value that will be replaced. Note there are two
+ // maps for tracking ValIDs that are GlobalNames and ValIDs that are
+ // GlobalIDs. These are needed because "operator<" doesn't discriminate
+ // between the two.
+ std::map<ValID, GlobalValue *> ForwardRefDSOLocalEquivalentNames;
+ std::map<ValID, GlobalValue *> ForwardRefDSOLocalEquivalentIDs;
+
// Attribute builder reference information.
std::map<Value*, std::vector<unsigned> > ForwardRefAttrGroups;
std::map<unsigned, AttrBuilder> NumberedAttrBuilders;
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 7475868f1e019..23445f4a71b9d 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -215,6 +215,44 @@ bool LLParser::validateEndOfModule(bool UpgradeDebugInfo) {
return error(ForwardRefBlockAddresses.begin()->first.Loc,
"expected function name in blockaddress");
+ auto ResolveForwardRefDSOLocalEquivalents = [&](const ValID &GVRef,
+ GlobalValue *FwdRef) {
+ GlobalValue *GV = nullptr;
+ if (GVRef.Kind == ValID::t_GlobalName) {
+ GV = M->getNamedValue(GVRef.StrVal);
+ } else if (GVRef.UIntVal < NumberedVals.size()) {
+ GV = dyn_cast<GlobalValue>(NumberedVals[GVRef.UIntVal]);
+ }
+
+ if (!GV)
+ return error(GVRef.Loc, "unknown function '" + GVRef.StrVal +
+ "' referenced by dso_local_equivalent");
+
+ if (!GV->getValueType()->isFunctionTy())
+ return error(GVRef.Loc,
+ "expected a function, alias to function, or ifunc "
+ "in dso_local_equivalent");
+
+ auto *Equiv = DSOLocalEquivalent::get(GV);
+ FwdRef->replaceAllUsesWith(Equiv);
+ FwdRef->eraseFromParent();
+ return false;
+ };
+
+ // If there are entries in ForwardRefDSOLocalEquivalentIDs/Names at this
+ // point, they are references after the function was defined. Resolve those
+ // now.
+ for (auto &Iter : ForwardRefDSOLocalEquivalentIDs) {
+ if (ResolveForwardRefDSOLocalEquivalents(Iter.first, Iter.second))
+ return true;
+ }
+ for (auto &Iter : ForwardRefDSOLocalEquivalentNames) {
+ if (ResolveForwardRefDSOLocalEquivalents(Iter.first, Iter.second))
+ return true;
+ }
+ ForwardRefDSOLocalEquivalentNames.clear();
+ ForwardRefDSOLocalEquivalentNames.clear();
+
for (const auto &NT : NumberedTypes)
if (NT.second.second.isValid())
return error(NT.second.second,
@@ -3428,7 +3466,22 @@ bool LLParser::parseValID(ValID &ID, PerFunctionState *PFS, Type *ExpectedTy) {
GV = M->getNamedValue(Fn.StrVal);
}
- assert(GV && "Could not find a corresponding global variable");
+ if (!GV) {
+ // Make a placeholder global variable as a placeholder for this reference.
+ auto &FwdRefMap = (Fn.Kind == ValID::t_GlobalID)
+ ? ForwardRefDSOLocalEquivalentIDs
+ : ForwardRefDSOLocalEquivalentNames;
+ GlobalValue *&FwdRef = FwdRefMap.try_emplace(Fn, nullptr).first->second;
+ if (!FwdRef) {
+ FwdRef = new GlobalVariable(*M, Type::getInt8Ty(Context), false,
+ GlobalValue::InternalLinkage, nullptr, "",
+ nullptr, GlobalValue::NotThreadLocal);
+ }
+
+ ID.ConstantVal = FwdRef;
+ ID.Kind = ValID::t_Constant;
+ return false;
+ }
if (!GV->getValueType()->isFunctionTy())
return error(Fn.Loc, "expected a function, alias to function, or ifunc "
diff --git a/llvm/test/Assembler/dso_local_equivalent.ll b/llvm/test/Assembler/dso_local_equivalent.ll
new file mode 100644
index 0000000000000..f78539ff44f7a
--- /dev/null
+++ b/llvm/test/Assembler/dso_local_equivalent.ll
@@ -0,0 +1,95 @@
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
+; RUN: verify-uselistorder %s
+
+declare void @extern_func()
+
+; CHECK: @call_extern_func
+; CHECK: call void dso_local_equivalent @extern_func()
+define void @call_extern_func() {
+ call void dso_local_equivalent @extern_func()
+ ret void
+}
+
+declare hidden void @hidden_func()
+declare protected void @protected_func()
+declare dso_local void @dso_local_func()
+define internal void @internal_func() {
+entry:
+ ret void
+}
+define private void @private_func() {
+entry:
+ ret void
+}
+
+; CHECK: @call_hidden_func
+; CHECK: call void dso_local_equivalent @hidden_func()
+define void @call_hidden_func() {
+ call void dso_local_equivalent @hidden_func()
+ ret void
+}
+
+; CHECK: @call_protected_func
+; CHECK: call void dso_local_equivalent @protected_func()
+define void @call_protected_func() {
+ call void dso_local_equivalent @protected_func()
+ ret void
+}
+
+; CHECK: @call_dso_local_func
+; CHECK: call void dso_local_equivalent @dso_local_func()
+define void @call_dso_local_func() {
+ call void dso_local_equivalent @dso_local_func()
+ ret void
+}
+
+; CHECK: @call_internal_func
+; CHECK: call void dso_local_equivalent @internal_func()
+define void @call_internal_func() {
+ call void dso_local_equivalent @internal_func()
+ ret void
+}
+
+define void @aliasee_func() {
+entry:
+ ret void
+}
+
+ at alias_func = alias void (), ptr @aliasee_func
+ at dso_local_alias_func = dso_local alias void (), ptr @aliasee_func
+
+; CHECK: @call_alias_func
+; CHECK: call void dso_local_equivalent @alias_func()
+define void @call_alias_func() {
+ call void dso_local_equivalent @alias_func()
+ ret void
+}
+
+; CHECK: @call_dso_local_alias_func
+; CHECK: call void dso_local_equivalent @dso_local_alias_func()
+define void @call_dso_local_alias_func() {
+ call void dso_local_equivalent @dso_local_alias_func()
+ ret void
+}
+
+ at ifunc_func = ifunc void (), ptr @resolver
+ at dso_local_ifunc_func = dso_local ifunc void (), ptr @resolver
+
+define internal ptr @resolver() {
+entry:
+ ret ptr null
+}
+
+; CHECK: @call_ifunc_func
+; CHECK: call void dso_local_equivalent @ifunc_func()
+define void @call_ifunc_func() {
+ call void dso_local_equivalent @ifunc_func()
+ ret void
+}
+
+; CHECK: @call_dso_local_ifunc_func
+; CHECK: call void dso_local_equivalent @dso_local_ifunc_func()
+define void @call_dso_local_ifunc_func() {
+ call void dso_local_equivalent @dso_local_ifunc_func()
+ ret void
+}
diff --git a/llvm/test/CodeGen/X86/dso_local_equivalent.ll b/llvm/test/CodeGen/X86/dso_local_equivalent.ll
index e5a61f8547a00..ed31f62d5a750 100644
--- a/llvm/test/CodeGen/X86/dso_local_equivalent.ll
+++ b/llvm/test/CodeGen/X86/dso_local_equivalent.ll
@@ -97,3 +97,121 @@ define void @call_dso_local_ifunc_func() {
call void dso_local_equivalent @dso_local_ifunc_func()
ret void
}
+
+;; PR57815
+;; Ensure dso_local_equivalent works the exact same way as the previous
+;; examples but with forward-referenced symbols.
+
+; CHECK: call_forward_func:
+; CHECK: callq forward_extern_func at PLT
+define void @call_forward_func() {
+ call void dso_local_equivalent @forward_extern_func()
+ ret void
+}
+
+; CHECK: call_forward_hidden_func:
+; CHECK: callq forward_hidden_func{{$}}
+define void @call_forward_hidden_func() {
+ call void dso_local_equivalent @forward_hidden_func()
+ ret void
+}
+
+; CHECK: call_forward_protected_func:
+; CHECK: callq forward_protected_func{{$}}
+define void @call_forward_protected_func() {
+ call void dso_local_equivalent @forward_protected_func()
+ ret void
+}
+
+; CHECK: call_forward_dso_local_func:
+; CHECK: callq forward_dso_local_func{{$}}
+define void @call_forward_dso_local_func() {
+ call void dso_local_equivalent @forward_dso_local_func()
+ ret void
+}
+
+; CHECK: call_forward_internal_func:
+; CHECK: callq forward_internal_func{{$}}
+define void @call_forward_internal_func() {
+ call void dso_local_equivalent @forward_internal_func()
+ ret void
+}
+
+declare hidden void @forward_hidden_func()
+declare protected void @forward_protected_func()
+declare dso_local void @forward_dso_local_func()
+define internal void @forward_internal_func() {
+entry:
+ ret void
+}
+define private void @forward_private_func() {
+entry:
+ ret void
+}
+
+; CHECK: call_forward_alias_func:
+; CHECK: callq forward_alias_func at PLT
+define void @call_forward_alias_func() {
+ call void dso_local_equivalent @forward_alias_func()
+ ret void
+}
+
+; CHECK: call_forward_dso_local_alias_func:
+; CHECK: callq .Lforward_dso_local_alias_func$local{{$}}
+define void @call_forward_dso_local_alias_func() {
+ call void dso_local_equivalent @forward_dso_local_alias_func()
+ ret void
+}
+
+define void @forward_aliasee_func() {
+entry:
+ ret void
+}
+
+ at forward_alias_func = alias void (), ptr @forward_aliasee_func
+ at forward_dso_local_alias_func = dso_local alias void (), ptr @forward_aliasee_func
+
+; If an ifunc is not dso_local already, then we should still emit a stub for it
+; to ensure it will be dso_local.
+; CHECK: call_forward_ifunc_func:
+; CHECK: callq forward_ifunc_func at PLT
+define void @call_forward_ifunc_func() {
+ call void dso_local_equivalent @forward_ifunc_func()
+ ret void
+}
+
+; CHECK: call_forward_dso_local_ifunc_func:
+; CHECK: callq forward_dso_local_ifunc_func{{$}}
+define void @call_forward_dso_local_ifunc_func() {
+ call void dso_local_equivalent @forward_dso_local_ifunc_func()
+ ret void
+}
+
+ at forward_ifunc_func = ifunc void (), ptr @resolver
+ at forward_dso_local_ifunc_func = dso_local ifunc void (), ptr @resolver
+
+;; Test "no-named" variables
+; CHECK: call_no_name_hidden:
+; CHECK: callq __unnamed_{{[0-9]+}}{{$}}
+define void @call_no_name_hidden() {
+ call void dso_local_equivalent @0()
+ ret void
+}
+
+; CHECK: call_no_name_extern:
+; CHECK: callq __unnamed_{{[0-9]+}}@PLT
+define void @call_no_name_extern() {
+ call void dso_local_equivalent @1()
+ ret void
+}
+
+declare hidden void @0()
+declare void @1()
+
+;; Note that we keep this at the very end because llc emits this after all the
+;; functions.
+; CHECK: const:
+; CHECK: .long forward_extern_func at PLT
+ at const = constant i32 trunc (i64 ptrtoint (ptr dso_local_equivalent @forward_extern_func to i64) to i32)
+
+declare void @forward_extern_func()
diff --git a/llvm/test/CodeGen/X86/dso_local_equivalent_errors.ll b/llvm/test/CodeGen/X86/dso_local_equivalent_errors.ll
new file mode 100644
index 0000000000000..c2b7602e248cd
--- /dev/null
+++ b/llvm/test/CodeGen/X86/dso_local_equivalent_errors.ll
@@ -0,0 +1,19 @@
+; RUN: split-file %s %t
+; RUN: not llc -mtriple=x86_64-linux-gnu -o - %t/undefined_func.ll 2>&1 | FileCheck %s -check-prefix=UNDEFINED
+; RUN: not llc -mtriple=x86_64-linux-gnu -o - %t/invalid_arg.ll 2>&1 | FileCheck %s -check-prefix=INVALID
+
+;--- undefined_func.ll
+; UNDEFINED: error: unknown function 'undefined_func' referenced by dso_local_equivalent
+define void @call_undefined() {
+ call void dso_local_equivalent @undefined_func()
+ ret void
+}
+
+;--- invalid_arg.ll
+; INVALID: error: expected a function, alias to function, or ifunc in dso_local_equivalent
+define void @call_global_var() {
+ call void dso_local_equivalent @glob()
+ ret void
+}
+
+ at glob = constant i32 1
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