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 @@ -179,7 +179,15 @@ return {FunctionImporter::ImportFailureReason::InterposableLinkage, GVSummary}; - auto *Summary = cast(GVSummary->getBaseObject()); + auto *Summary = dyn_cast(GVSummary->getBaseObject()); + + // Ignore any callees that aren't actually functions. This could happen + // in the case of GUID hash collisions. It could also happen in theory + // for SamplePGO profiles collected on old versions of the code after + // renaming, since we synthesize edges to any inlined callees appearing + // in the profile. + if (!Summary) + return {FunctionImporter::ImportFailureReason::GlobalVar, GVSummary}; // If this is a local function, make sure we import the copy // in the caller's module. The only time a local function can diff --git a/llvm/test/Transforms/FunctionImport/Inputs/funcimport_var2.ll b/llvm/test/Transforms/FunctionImport/Inputs/funcimport_var2.ll --- a/llvm/test/Transforms/FunctionImport/Inputs/funcimport_var2.ll +++ b/llvm/test/Transforms/FunctionImport/Inputs/funcimport_var2.ll @@ -3,6 +3,9 @@ @link = internal global i32 0, align 4 +; guid = 12887606300320728018 +@globalvar = global i32 0, align 4 + ; Function Attrs: norecurse nounwind readnone uwtable define nonnull ptr @get_link() local_unnamed_addr { ret ptr @link diff --git a/llvm/test/Transforms/FunctionImport/funcimport_var.ll b/llvm/test/Transforms/FunctionImport/funcimport_var.ll --- a/llvm/test/Transforms/FunctionImport/funcimport_var.ll +++ b/llvm/test/Transforms/FunctionImport/funcimport_var.ll @@ -1,16 +1,20 @@ -; This test makes sure a static var is not selected as a callee target -; (which will crash compilation). +;; This test makes sure a static var is not selected as a callee target (it will +;; have a different GUID). Similarly, ensure that a callee GUID annotated from a +;; sample pgo profile that matches a global variable GUID (either due to code +;; changes or a hash collision), does not get considered for importing. Either +;; of these can crash compilation. ; RUN: opt -module-summary %s -o %t.bc ; RUN: opt -module-summary %p/Inputs/funcimport_var2.ll -o %t2.bc ; RUN: llvm-lto -thinlto -thinlto-action=thinlink -o %t3 %t.bc %t2.bc ; RUN: llvm-lto -thinlto -thinlto-action=import -thinlto-index=%t3 %t.bc %t2.bc ; RUN: llvm-lto -thinlto -thinlto-action=run %t.bc %t2.bc -exported-symbol=_Z4LinkPKcS0_ -; RUN: llvm-nm %t.bc.thinlto.o | FileCheck %s +; RUN: llvm-nm %t.bc.thinlto.o | FileCheck %s --implicit-check-not=globalvar ; RUN: llvm-lto2 run %t.bc %t2.bc -o %t.out \ ; RUN: -r %t.bc,_Z4LinkPKcS0_,plx \ ; RUN: -r %t.bc,link,l \ +; RUN: -r %t2.bc,globalvar,plx \ ; RUN: -r %t2.bc,get_link,plx -; RUN: llvm-nm %t.out.1 | FileCheck %s +; RUN: llvm-nm %t.out.1 | FileCheck %s --implicit-check-not=globalvar ; CHECK: U link ; REQUIRES: x86-registered-target @@ -18,10 +22,13 @@ 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" -define i32 @_Z4LinkPKcS0_(ptr, ptr) local_unnamed_addr { +define i32 @_Z4LinkPKcS0_(ptr, ptr) local_unnamed_addr !prof !1 { %3 = tail call i32 @link(ptr %0, ptr %1) #2 ret i32 %3 } ; Function Attrs: nounwind -declare i32 @link(ptr, ptr) local_unnamed_addr +declare i32 @link(ptr, ptr) local_unnamed_addr + +;; This matches the GUID of global variable @globalvar in the other input. +!1 = !{!"function_entry_count", i64 110, i64 12887606300320728018}