[llvm] 8e3b5cb - ThinLTO: Fix inline assembly references to static functions with CFI

[Sami Tolvanen via llvm-commits]

Author: Sami Tolvanen
Date: 2021-07-16T14:33:34-07:00
New Revision: 8e3b5cb39eef462943ed7556469604ce25c07a1d

URL: https://github.com/llvm/llvm-project/commit/8e3b5cb39eef462943ed7556469604ce25c07a1d
DIFF: https://github.com/llvm/llvm-project/commit/8e3b5cb39eef462943ed7556469604ce25c07a1d.diff

LOG: 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

Added: 
    llvm/test/Transforms/ThinLTOBitcodeWriter/cfi-icall-static-inline-asm.ll

Modified: 
    llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
    llvm/test/ThinLTO/X86/devirt2.ll
    llvm/test/Transforms/ThinLTOBitcodeWriter/split-internal2.ll
    llvm/test/Transforms/ThinLTOBitcodeWriter/split-vfunc-internal.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
index 37329b489555e..1644c655d00f6 100644
--- 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 42c15f1c1df50..6501a01a39dfb 100644
--- 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
index 0000000000000..bb3589114c88c
--- /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 98cc80e557f95..ccb8c4c5a9cfa 100644
--- 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 d17cbefb0fb10..3774f16c6a68e 100644
--- 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
 }