implement the fix for hybrid LTO, and update test cases

Author: mingmingl-llvm

llvm/lib/LTO/LTO.cpp

@@ -1314,7 +1314,8 @@ Error LTO::runRegularLTO(AddStreamFn AddStream) {
   // expected to be handled separately.
   auto IsVisibleToRegularObj = [&](StringRef name) {
     auto It = GlobalResolutions->find(name);
-    return (It == GlobalResolutions->end() || It->second.VisibleOutsideSummary);
+    return (It == GlobalResolutions->end() ||
+            It->second.VisibleOutsideSummary || It->second.ExportDynamic);
   };
 
   // If allowed, upgrade public vcall visibility metadata to linkage unit

llvm/test/ThinLTO/X86/nodevirt_exort_dynamic.ll renamed to llvm/test/ThinLTO/X86/nodevirt_export_dynamic.ll

@@ -1,12 +1,12 @@
 ; RUN: rm -rf %t && mkdir %t && cd %t
 
+; Tests that devirtualization is suppressed on a class when its compatible
+; class could be referenced from dynamic linker that is not visible to the
+; linker.
+
 ; Generate unsplit module with summary for ThinLTO index-based WPD.
 ; RUN: opt -thinlto-bc -o summary.o %s
 
-; RUN: llvm-dis -o - summary.o
-
-;; TODO: Implement the fix for WPD in regular or hybrid LTO, and add test coverage.
-
 ; Index based WPD
 ; For `_ZTI7Derived`, the 'llvm-lto2' resolution arguments specifies  `VisibleOutsideSummary` as false
 ; and `ExportDynamic` as false. The callsite inside @_ZN4Base8dispatchEv
@@ -21,15 +21,12 @@
 ; RUN:   -r=summary.o,_ZN4Base8dispatchEv,px \
 ; RUN:   -r=summary.o,_ZN7DerivedC2Ev, \
 ; RUN:   -r=summary.o,_ZN8DerivedN5printEv,px \
-; RUN:   -r=summary.o,_ZTS4Base, \
 ; RUN:   -r=summary.o,_ZTV8DerivedN,p \
 ; RUN:   -r=summary.o,_ZTI8DerivedN,p \
-; RUN:   -r=summary.o,_ZTI4Base, \
 ; RUN:   -r=summary.o,_ZTS8DerivedN,p \
 ; RUN:   -r=summary.o,_ZTI7Derived, \
-; RUN:   -r=summary.o,_ZTV4Base 2>&1 | FileCheck --allow-empty %s --check-prefix=REMARK
+; RUN:   2>&1 | FileCheck --allow-empty %s --check-prefix=REMARK
 
-; REMARK: single-impl: devirtualized a call to _ZN8DerivedN5printEv 
 
 ; Index based WPD
 ; For `_ZTI7Derived`, the 'llvm-lto2' resolution arguments specifies  `VisibleOutsideSummary` as false
@@ -45,24 +42,70 @@
 ; RUN:   -r=summary.o,_ZN4Base8dispatchEv,px \
 ; RUN:   -r=summary.o,_ZN7DerivedC2Ev, \
 ; RUN:   -r=summary.o,_ZN8DerivedN5printEv,px \
-; RUN:   -r=summary.o,_ZTS4Base, \
 ; RUN:   -r=summary.o,_ZTV8DerivedN,p \
 ; RUN:   -r=summary.o,_ZTI8DerivedN,p \
-; RUN:   -r=summary.o,_ZTI4Base, \
 ; RUN:   -r=summary.o,_ZTS8DerivedN,p \
 ; RUN:   -r=summary.o,_ZTI7Derived,d \
-; RUN:   -r=summary.o,_ZTV4Base 2>&1 | FileCheck %s --allow-empty --implicit-check-not='single-impl: devirtualized a call to'
+; RUN:   2>&1 | FileCheck %s --allow-empty --implicit-check-not='single-impl: devirtualized a call to'
+
+
+; Hybrid LTO WPD
+; RUN: opt  --thinlto-bc --thinlto-split-lto-unit -o hybrid.o %s
+; RUN: llvm-lto2 run hybrid.o -save-temps -pass-remarks=. \
+; RUN:   -o hybrid \
+; RUN:   --whole-program-visibility-enabled-in-lto=true \
+; RUN:   --validate-all-vtables-have-type-infos=true \
+; RUN:   --all-vtables-have-type-infos=true \
+; RUN:   -r=hybrid.o,__cxa_pure_virtual, \
+; RUN:   -r=hybrid.o,_ZN8DerivedNC2Ev,x \
+; RUN:   -r=hybrid.o,_ZN4Base8dispatchEv,px \
+; RUN:   -r=hybrid.o,_ZN7DerivedC2Ev, \
+; RUN:   -r=hybrid.o,_ZN8DerivedN5printEv,px \
+; RUN:   -r=hybrid.o,_ZTV8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTI8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTS8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTI7Derived, \
+; RUN:   -r=hybrid.o,_ZN8DerivedN5printEv,px \
+; RUN:   -r=hybrid.o,_ZTV8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTI8DerivedN,p \
+; RUN:   2>&1 | FileCheck --allow-empty %s --check-prefix=REMARK
+
+; Hybrid LTO WPD
+; RUN: llvm-lto2 run hybrid.o -save-temps -pass-remarks=. \
+; RUN:   -o hybrid \
+; RUN:   --whole-program-visibility-enabled-in-lto=true \
+; RUN:   --validate-all-vtables-have-type-infos=true \
+; RUN:   --all-vtables-have-type-infos=true \
+; RUN:   -r=hybrid.o,__cxa_pure_virtual, \
+; RUN:   -r=hybrid.o,_ZN8DerivedNC2Ev,x \
+; RUN:   -r=hybrid.o,_ZN4Base8dispatchEv,px \
+; RUN:   -r=hybrid.o,_ZN7DerivedC2Ev, \
+; RUN:   -r=hybrid.o,_ZN8DerivedN5printEv,px \
+; RUN:   -r=hybrid.o,_ZTV8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTI8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTS8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTI7Derived,d \
+; RUN:   -r=hybrid.o,_ZN8DerivedN5printEv,px \
+; RUN:   -r=hybrid.o,_ZTV8DerivedN,p \
+; RUN:   -r=hybrid.o,_ZTI8DerivedN,p \
+; RUN:   2>&1 | FileCheck --allow-empty %s --implicit-check-not='single-impl: devirtualized a call to'
+
+
+; In regular LTO, global resolutions (as expected) show symbols are visible
+; outside summary (when they come from regular LTO module without summaries).
+; In the setting of this test case (equivalent of `-Wl,--lto-whole-program-visibility -Wl,--lto-validate-all-vtables-have-type-infos` in lld),
+; devirtualization will be suppressed even if the compatible class is not
+; referenced from shared libraries. So regular LTO test coverage is not meaningful.
+
+; REMARK: single-impl: devirtualized a call to _ZN8DerivedN5printEv
 
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
-@_ZTV8DerivedN = linkonce_odr hidden constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr @_ZTI8DerivedN, ptr @_ZN8DerivedN5printEv] }, !type !0, !type !1, !type !2, !type !3, !type !4, !type !5, !vcall_visibility !6
+@_ZTV8DerivedN = linkonce_odr hidden constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr @_ZTI8DerivedN, ptr @_ZN8DerivedN5printEv] }, !type !0, !type !1, !type !2, !type !3, !vcall_visibility !6
 @_ZTI8DerivedN = linkonce_odr hidden constant { ptr, ptr, ptr } { ptr null, ptr @_ZTS8DerivedN, ptr @_ZTI7Derived }
 @_ZTS8DerivedN = linkonce_odr hidden constant [10 x i8] c"8DerivedN\00", align 1
 @_ZTI7Derived = external constant ptr
-@_ZTV4Base = linkonce_odr hidden constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr @_ZTI4Base, ptr @__cxa_pure_virtual] }, !type !0, !type !1, !vcall_visibility !6
-@_ZTI4Base = linkonce_odr hidden constant { ptr, ptr } { ptr null, ptr @_ZTS4Base }
-@_ZTS4Base = linkonce_odr hidden constant [6 x i8] c"4Base\00", align 1
 
 @llvm.used = appending global [1 x ptr] [ptr @_ZN8DerivedNC2Ev], section "llvm.metadata"
 
@@ -102,10 +145,10 @@ declare i1 @llvm.type.test(ptr, metadata)
 declare void @llvm.assume(i1)
 declare void @_ZN7DerivedC2Ev(ptr)
 
-!0 = !{i64 16, !"_ZTS4Base"}
-!1 = !{i64 16, !"_ZTSM4BaseFvvE.virtual"}
-!2 = !{i64 16, !"_ZTS7Derived"}
-!3 = !{i64 16, !"_ZTSM7DerivedFvvE.virtual"}
-!4 = !{i64 16, !"_ZTS8DerivedN"}
-!5 = !{i64 16, !"_ZTSM8DerivedNFvvE.virtual"}
+!0 = !{i64 16, !"_ZTS7Derived"}
+!1 = !{i64 16, !"_ZTSM7DerivedFvvE.virtual"}
+!2 = !{i64 16, !"_ZTS8DerivedN"}
+!3 = !{i64 16, !"_ZTSM8DerivedNFvvE.virtual"}
+;!4 = !{i64 16, !"_ZTS8DerivedN"}
+;!5 = !{i64 16, !"_ZTSM8DerivedNFvvE.virtual"}
 !6 = !{i64 0}