diff --git a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp --- a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp +++ b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp @@ -646,15 +646,20 @@ Index.addGlobalValueSummary(V, std::move(GVarSummary)); } -static void -computeAliasSummary(ModuleSummaryIndex &Index, const GlobalAlias &A, - DenseSet &CantBePromoted) { +static void computeAliasSummary(ModuleSummaryIndex &Index, const GlobalAlias &A, + DenseSet &CantBePromoted) { + auto *Aliasee = A.getAliaseeObject(); + + // Skip summary for indirect function aliases as summary for aliasee will not + // be emitted. + if (isa(Aliasee)) + return; + bool NonRenamableLocal = isNonRenamableLocal(A); GlobalValueSummary::GVFlags Flags( A.getLinkage(), A.getVisibility(), NonRenamableLocal, /* Live = */ false, A.isDSOLocal(), A.canBeOmittedFromSymbolTable()); auto AS = std::make_unique(Flags); - auto *Aliasee = A.getAliaseeObject(); auto AliaseeVI = Index.getValueInfo(Aliasee->getGUID()); assert(AliaseeVI && "Alias expects aliasee summary to be available"); assert(AliaseeVI.getSummaryList().size() == 1 && diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp --- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp +++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp @@ -4103,8 +4103,9 @@ for (const GlobalAlias &A : M.aliases()) { auto *Aliasee = A.getAliaseeObject(); - if (!Aliasee->hasName()) - // Nameless function don't have an entry in the summary, skip it. + // IFunc function and Nameless function don't have an entry in the + // summary, skip it. + if (!Aliasee->hasName() || isa(Aliasee)) continue; auto AliasId = VE.getValueID(&A); auto AliaseeId = VE.getValueID(Aliasee); diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp --- a/llvm/lib/Transforms/IPO/FunctionImport.cpp +++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp @@ -1147,6 +1147,12 @@ // Declare a callback for the internalize pass that will ask for every // candidate GlobalValue if it can be internalized or not. auto MustPreserveGV = [&](const GlobalValue &GV) -> bool { + // It maybe the case that the symbol is aliasing an ifunc where + // the summary is not available. + if (isa(&GV) && + isa(dyn_cast(&GV)->getAliasee())) + return true; + // Lookup the linkage recorded in the summaries during global analysis. auto GS = DefinedGlobals.find(GV.getGUID()); if (GS == DefinedGlobals.end()) { diff --git a/llvm/test/LTO/Resolution/X86/alias-indirect-function-lto.ll b/llvm/test/LTO/Resolution/X86/alias-indirect-function-lto.ll new file mode 100644 --- /dev/null +++ b/llvm/test/LTO/Resolution/X86/alias-indirect-function-lto.ll @@ -0,0 +1,22 @@ +; RUN: opt -module-summary -o %t.bc %s +; RUN: llvm-lto2 run %t.bc -r %t.bc,foo,pl -r %t.bc,bar,pl -r %t.bc,baz,pl -o %t2 +; RUN: llvm-nm %t2.1 | FileCheck %s +; CHECK: i bar +; CHECK: i baz +; CHECK: i foo +; CHECK: t foo_resolver + +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +@foo = ifunc i32 (i32), i32 (i32)* ()* @foo_resolver + +define internal i32 (i32)* @foo_resolver() { +entry: + ret i32 (i32)* null +} + +@bar = alias i32 (i32), i32 (i32)* @foo + +@baz = weak alias i32 (i32), i32 (i32)* @foo +; no crash