ThinLTO: Fix inline assembly references to static functions with CFI

Create an internal alias with the original name for static functions
that are renamed in promoteInternals to avoid breaking inline
assembly references to them. This version uses module inline assembly
to avoid issues with LowerTypeTestsModule.

Link: https://github.com/ClangBuiltLinux/linux/issues/1354
Reviewed By: nickdesaulniers, pcc

Differential Revision: https://reviews.llvm.org/D104058

diff --git a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
index 37329b4..1644c65 100644 (file)
--- a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
+++ b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
@@ -55,6 +55,7 @@ void promoteInternals(Module &ExportM, Module &ImportM, StringRef ModuleId,
       }
     }
 
+    std::string OldName = Name.str();
     std::string NewName = (Name + ModuleId).str();
 
     if (const auto *C = ExportGV.getComdat())
@@ -69,6 +70,13 @@ void promoteInternals(Module &ExportM, Module &ImportM, StringRef ModuleId,
       ImportGV->setName(NewName);
       ImportGV->setVisibility(GlobalValue::HiddenVisibility);
     }
+
+    if (Function *F = dyn_cast<Function>(&ExportGV)) {
+      // Create a local alias with the original name to avoid breaking
+      // references from inline assembly.
+      std::string Alias = ".set " + OldName + "," + NewName + "\n";
+      ExportM.appendModuleInlineAsm(Alias);
+    }
   }
 
   if (!RenamedComdats.empty())

diff --git a/llvm/test/ThinLTO/X86/devirt2.ll b/llvm/test/ThinLTO/X86/devirt2.ll
index 42c15f1..6501a01 100644 (file)
--- a/llvm/test/ThinLTO/X86/devirt2.ll
+++ b/llvm/test/ThinLTO/X86/devirt2.ll
@@ -131,10 +131,12 @@
 ; RUN:   -r=%t1.o,_ZN1D1mEi, \
 ; RUN:   -r=%t1.o,test2, \
 ; RUN:   -r=%t2.o,_ZN1A1nEi,p \
+; RUN:   -r=%t2.o,_ZN1A1nEi, \
 ; RUN:   -r=%t2.o,_ZN1B1fEi,p \
 ; RUN:   -r=%t2.o,_ZN1C1fEi,p \
 ; RUN:   -r=%t2.o,_ZN1D1mEi,p \
 ; RUN:   -r=%t2.o,_ZN1E1mEi,p \
+; RUN:   -r=%t2.o,_ZN1E1mEi, \
 ; RUN:   -r=%t2.o,_ZTV1B, \
 ; RUN:   -r=%t2.o,_ZTV1C, \
 ; RUN:   -r=%t2.o,_ZTV1D, \
@@ -167,10 +169,12 @@
 ; RUN:   -r=%t1.o,_ZN1D1mEi, \
 ; RUN:   -r=%t1.o,test2, \
 ; RUN:   -r=%t2.o,_ZN1A1nEi,p \
+; RUN:   -r=%t2.o,_ZN1A1nEi, \
 ; RUN:   -r=%t2.o,_ZN1B1fEi,p \
 ; RUN:   -r=%t2.o,_ZN1C1fEi,p \
 ; RUN:   -r=%t2.o,_ZN1D1mEi,p \
 ; RUN:   -r=%t2.o,_ZN1E1mEi,p \
+; RUN:   -r=%t2.o,_ZN1E1mEi, \
 ; RUN:   -r=%t2.o,_ZTV1B, \
 ; RUN:   -r=%t2.o,_ZTV1C, \
 ; RUN:   -r=%t2.o,_ZTV1D, \

diff --git a/llvm/test/Transforms/ThinLTOBitcodeWriter/cfi-icall-static-inline-asm.ll b/llvm/test/Transforms/ThinLTOBitcodeWriter/cfi-icall-static-inline-asm.ll
new file mode 100644 (file)
index 0000000..bb35891
--- /dev/null
+++ b/llvm/test/Transforms/ThinLTOBitcodeWriter/cfi-icall-static-inline-asm.ll
@@ -0,0 +1,21 @@
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o - %s | llvm-modextract -b -n 0 -o - | llvm-dis | FileCheck %s
+
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK: module asm ".set a,a.[[HASH:[0-9a-f]+]]"
+
+define void @b() {
+  %f = alloca void ()*, align 8
+  ; CHECK: store{{.*}} @a.[[HASH]],{{.*}} %f
+  store void ()* @a, void ()** %f, align 8
+  ; CHECK: %1 = call void ()* asm sideeffect "leaq a(%rip)
+  %1 = call void ()* asm sideeffect "leaq a(%rip), $0\0A\09", "=r,~{dirflag},~{fpsr},~{flags}"()
+  ret void
+}
+
+; CHECK: define{{.*}} @a.[[HASH]](){{.*}} !type
+define internal void @a() !type !0 {
+  ret void
+}
+
+!0 = !{i64 0, !"typeid1"}

diff --git a/llvm/test/Transforms/ThinLTOBitcodeWriter/split-internal2.ll b/llvm/test/Transforms/ThinLTOBitcodeWriter/split-internal2.ll
index 98cc80e..ccb8c4c 100644 (file)
--- a/llvm/test/Transforms/ThinLTOBitcodeWriter/split-internal2.ll
+++ b/llvm/test/Transforms/ThinLTOBitcodeWriter/split-internal2.ll
@@ -7,6 +7,8 @@
 ; RUN: llvm-bcanalyzer -dump %t0 | FileCheck --check-prefix=BCA0 %s
 ; RUN: llvm-bcanalyzer -dump %t1 | FileCheck --check-prefix=BCA1 %s
 
+target triple = "x86_64-unknown-linux-gnu"
+
 ; ERROR: llvm-modextract: error: module index out of range; bitcode file contains 2 module(s)
 
 ; BCA0: <GLOBALVAL_SUMMARY_BLOCK

diff --git a/llvm/test/Transforms/ThinLTOBitcodeWriter/split-vfunc-internal.ll b/llvm/test/Transforms/ThinLTOBitcodeWriter/split-vfunc-internal.ll
index d17cbef..3774f16 100644 (file)
--- a/llvm/test/Transforms/ThinLTOBitcodeWriter/split-vfunc-internal.ll
+++ b/llvm/test/Transforms/ThinLTOBitcodeWriter/split-vfunc-internal.ll
@@ -2,6 +2,8 @@
 ; RUN: llvm-modextract -b -n 0 -o - %t | llvm-dis | FileCheck --check-prefix=M0 %s
 ; RUN: llvm-modextract -b -n 1 -o - %t | llvm-dis | FileCheck --check-prefix=M1 %s
 
+target triple = "x86_64-unknown-linux-gnu"
+
 define [1 x i8*]* @source() {
   ret [1 x i8*]* @g
 }