[llvm] r308642 - LowerTypeTests: Drop function type metadata only if we're going to replace it.
Peter Collingbourne via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 20 11:02:05 PDT 2017
Author: pcc
Date: Thu Jul 20 11:02:05 2017
New Revision: 308642
URL: http://llvm.org/viewvc/llvm-project?rev=308642&view=rev
Log:
LowerTypeTests: Drop function type metadata only if we're going to replace it.
Previously we were (mis)handling jump table members with a prevailing
definition in a full LTO module and a non-prevailing definition in a
ThinLTO module by dropping type metadata on those functions entirely,
which would cause type tests involving such functions to fail.
This patch causes us to drop metadata only if we are about to replace
it with metadata from cfi.functions.
We also want to replace metadata for available_externally functions,
which can arise in the opposite scenario (prevailing ThinLTO
definition, non-prevailing full LTO definition). The simplest way
to handle that is to remove the definition; there's little value in
keeping it around at this point (i.e. after most optimization passes
have already run) and later code will try to use the function's linkage
to create an alias, which would result in invalid IR if the function
is available_externally.
Fixes PR33832.
Differential Revision: https://reviews.llvm.org/D35604
Modified:
llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp
llvm/trunk/test/Transforms/LowerTypeTests/export-icall.ll
Modified: llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp?rev=308642&r1=308641&r2=308642&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp Thu Jul 20 11:02:05 2017
@@ -1512,14 +1512,27 @@ bool LowerTypeTestsModule::lower() {
FunctionType::get(Type::getVoidTy(M.getContext()), false),
GlobalVariable::ExternalLinkage, FunctionName, &M);
- if (Linkage == CFL_Definition)
- F->eraseMetadata(LLVMContext::MD_type);
+ // If the function is available_externally, remove its definition so
+ // that it is handled the same way as a declaration. Later we will try
+ // to create an alias using this function's linkage, which will fail if
+ // the linkage is available_externally. This will also result in us
+ // following the code path below to replace the type metadata.
+ if (F->hasAvailableExternallyLinkage()) {
+ F->setLinkage(GlobalValue::ExternalLinkage);
+ F->deleteBody();
+ F->setComdat(nullptr);
+ F->clearMetadata();
+ }
+ // If the function in the full LTO module is a declaration, replace its
+ // type metadata with the type metadata we found in cfi.functions. That
+ // metadata is presumed to be more accurate than the metadata attached
+ // to the declaration.
if (F->isDeclaration()) {
if (Linkage == CFL_WeakDeclaration)
F->setLinkage(GlobalValue::ExternalWeakLinkage);
- SmallVector<MDNode *, 2> Types;
+ F->eraseMetadata(LLVMContext::MD_type);
for (unsigned I = 2; I < FuncMD->getNumOperands(); ++I)
F->addMetadata(LLVMContext::MD_type,
*cast<MDNode>(FuncMD->getOperand(I).get()));
Modified: llvm/trunk/test/Transforms/LowerTypeTests/export-icall.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LowerTypeTests/export-icall.ll?rev=308642&r1=308641&r2=308642&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LowerTypeTests/export-icall.ll (original)
+++ llvm/trunk/test/Transforms/LowerTypeTests/export-icall.ll Thu Jul 20 11:02:05 2017
@@ -9,8 +9,14 @@ define void @h(i8 %x) !type !2 {
}
declare !type !8 void @f(i32 %x)
+define available_externally void @f2(i32 %x) !type !8 {
+ ret void
+}
+define void @f3(i32 %x) !type !8 {
+ ret void
+}
-!cfi.functions = !{!0, !1, !3, !4, !5, !6}
+!cfi.functions = !{!0, !1, !3, !9, !10, !4, !5, !6}
; declaration of @h with a different type is ignored
!0 = !{!"h", i8 1, !7}
@@ -19,8 +25,10 @@ declare !type !8 void @f(i32 %x)
!1 = !{!"h", i8 2, !8}
!2 = !{i64 0, !"typeid1"}
-; definition of @f replaces types on the IR declaration above
+; definitions of @f and @f2 replace types on the IR declarations above
!3 = !{!"f", i8 0, !2}
+!9 = !{!"f2", i8 0, !2}
+!10 = !{!"f3", i8 0, !2}
!4 = !{!"external", i8 1, !2}
!5 = !{!"external_weak", i8 2, !2}
!6 = !{!"g", i8 0, !7}
@@ -30,10 +38,11 @@ declare !type !8 void @f(i32 %x)
; CHECK-DAG: @__typeid_typeid1_global_addr = hidden alias i8, bitcast (void ()* [[JT1:.*]] to i8*)
; CHECK-DAG: @__typeid_typeid1_align = hidden alias i8, inttoptr (i8 3 to i8*)
-; CHECK-DAG: @__typeid_typeid1_size_m1 = hidden alias i8, inttoptr (i64 3 to i8*)
+; CHECK-DAG: @__typeid_typeid1_size_m1 = hidden alias i8, inttoptr (i64 4 to i8*)
; CHECK-DAG: @h = alias void (i8), bitcast (void ()* [[JT1]] to void (i8)*)
; CHECK-DAG: @f = alias void (i32), {{.*}}getelementptr {{.*}}void ()* [[JT1]]
+; CHECK-DAG: @f2 = alias void (i32), {{.*}}getelementptr {{.*}}void ()* [[JT1]]
; CHECK-DAG: @external.cfi_jt = hidden alias void (), {{.*}}getelementptr {{.*}}void ()* [[JT1]]
; CHECK-DAG: @external_weak.cfi_jt = hidden alias void (), {{.*}}getelementptr {{.*}}void ()* [[JT1]]
@@ -45,6 +54,9 @@ declare !type !8 void @f(i32 %x)
; CHECK-DAG: declare !type !{{.*}} void @external()
; CHECK-DAG: declare !type !{{.*}} void @external_weak()
; CHECK-DAG: declare !type !{{.*}} void @f.cfi(i32)
+; CHECK-DAG: declare !type !{{.*}} void @f2.cfi(i32)
+; CHECK-DAG: define void @f3(i32 {{.*}}) !type !3
+; CHECK-DAG: !3 = !{i64 0, !"typeid3"}
; CHECK-DAG: declare !type !{{.*}} void @g.cfi()
@@ -62,6 +74,7 @@ declare !type !8 void @f(i32 %x)
; SUMMARY: CfiFunctionDefs:
; SUMMARY-NEXT: - f
+; SUMMARY-NEXT: - f2
; SUMMARY-NEXT: - g
; SUMMARY-NEXT: - h
; SUMMARY-NEXT: CfiFunctionDecls:
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