4 files changed, 104 insertions, 1 deletions
diff --git a/lld/ELF/LTO.cpp b/lld/ELF/LTO.cpp
index 3dac26454bc..24a8ff65b91 100644
--- a/lld/ELF/LTO.cpp
+++ b/lld/ELF/LTO.cpp
@@ -10,6 +10,7 @@
 #include "LTO.h"
 #include "Config.h"
 #include "Error.h"
+#include "LinkerScript.h"
 #include "InputFiles.h"
 #include "SymbolTable.h"
 #include "Symbols.h"
@@ -128,6 +129,11 @@ void BitcodeCompiler::add(BitcodeFile &F) {
   std::vector<SymbolBody *> Syms = F.getSymbols();
   std::vector<lto::SymbolResolution> Resols(Syms.size());
 
+  DenseSet<StringRef> ScriptSymbols;
+  for (BaseCommand *Base : Script->Opt.Commands)
+    if (auto *Cmd = dyn_cast<SymbolAssignment>(Base))
+      ScriptSymbols.insert(Cmd->Name);
+
   // Provide a resolution to the LTO API for each symbol.
   for (const lto::InputFile::Symbol &ObjSym : Obj.symbols()) {
     SymbolBody *B = Syms[SymNum];
@@ -153,7 +159,13 @@ void BitcodeCompiler::add(BitcodeFile &F) {
                             UsedStartStop.count(ObjSym.getSectionName());
     if (R.Prevailing)
       undefine(Sym);
-    R.LinkerRedefined = !Sym->CanInline;
+
+    // We tell LTO to not apply interprocedural optimization for following
+    // symbols because otherwise LTO would inline them while their values are
+    // still not final:
+    // 1) Aliased (with --defsym) or wrapped (with --wrap) symbols.
+    // 2) Symbols redefined in linker script.
+    R.LinkerRedefined = !Sym->CanInline || ScriptSymbols.count(B->getName());
   }
   checkError(LTOObj->add(std::move(F.Obj), Resols));
 }
diff --git a/lld/test/ELF/lto/Inputs/linker-script-symbols-ipo.ll b/lld/test/ELF/lto/Inputs/linker-script-symbols-ipo.ll
new file mode 100644
index 00000000000..c872f9e1dd5
--- /dev/null
+++ b/lld/test/ELF/lto/Inputs/linker-script-symbols-ipo.ll
@@ -0,0 +1,9 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare i32 @bar()
+
+define i32 @_start() {
+  %1 = tail call i32 @bar()
+  ret i32 %1
+}
diff --git a/lld/test/ELF/lto/linker-script-symbols-assign.ll b/lld/test/ELF/lto/linker-script-symbols-assign.ll
new file mode 100644
index 00000000000..c69911d295a
--- /dev/null
+++ b/lld/test/ELF/lto/linker-script-symbols-assign.ll
@@ -0,0 +1,50 @@
+; REQUIRES: x86
+; RUN: llvm-as %s -o %t.o
+
+; RUN: echo "foo = 1;" > %t.script
+; RUN: ld.lld -m elf_x86_64 %t.o -o %t2 --script %t.script -save-temps
+; RUN: llvm-readobj -symbols %t2.lto.o | FileCheck %s
+
+; CHECK-NOT: bar
+; CHECK:     Symbol {
+; CHECK:         Name: foo
+; CHECK-NEXT:    Value: 0x0
+; CHECK-NEXT:    Size: 4
+; FIXME: Binding should be Global here. Symbols redefined in script does not
+;        receive correct binding and visibility, this is a known bug.
+; CHECK-NEXT:    Binding: Weak
+; CHECK-NEXT:    Type: Object
+; CHECK-NEXT:    Other: 0
+; CHECK-NEXT:    Section: .bss.foo
+; CHECK-NEXT:  }
+; CHECK-NEXT:]
+
+; RUN: llvm-readobj -symbols %t2 | FileCheck %s --check-prefix=VAL
+; VAL:       Symbol {
+; VAL:        Name: foo
+; VAL-NEXT:   Value: 0x1
+; VAL-NEXT:   Size:
+; VAL-NEXT:   Binding: Global
+; VAL-NEXT:   Type: None
+; VAL-NEXT:   Other:
+; VAL-NEXT:   Section: Absolute
+; VAL-NEXT: }
+
+; RUN: echo "zed = 1;" > %t2.script
+; RUN: ld.lld -m elf_x86_64 %t.o -o %t3 --script %t2.script
+; RUN: llvm-readobj -symbols %t3 | FileCheck %s --check-prefix=ABS
+; ABS:      Symbol {
+; ABS:        Name: zed
+; ABS-NEXT:   Value: 0x1
+; ABS-NEXT:   Size: 0
+; ABS-NEXT:   Binding: Global
+; ABS-NEXT:   Type: None
+; ABS-NEXT:   Other: 0
+; ABS-NEXT:   Section: Absolute
+; ABS-NEXT: }
+
+target triple = "x86_64-unknown-linux-gnu"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+@foo = global i32 0
+@bar = global i32 0
diff --git a/lld/test/ELF/lto/linker-script-symbols-ipo.ll b/lld/test/ELF/lto/linker-script-symbols-ipo.ll
new file mode 100644
index 00000000000..6ac1a83e1ec
--- /dev/null
+++ b/lld/test/ELF/lto/linker-script-symbols-ipo.ll
@@ -0,0 +1,32 @@
+; REQUIRES: x86
+; RUN: llvm-as %s -o %t1.o
+; RUN: llvm-as %S/Inputs/linker-script-symbols-ipo.ll -o %t2.o
+; RUN: echo "bar = foo;" > %t.script
+
+;; Check that without linkerscript bar is inlined.
+; RUN: ld.lld  -m elf_x86_64 %t1.o %t2.o -o %t3 -save-temps
+; RUN: llvm-objdump -d %t3 | FileCheck %s --check-prefix=IPO
+; IPO:      Disassembly of section .text:
+; IPO:      _start:
+; IPO-NEXT:   201000: {{.*}} movl $1, %eax
+; IPO-NEXT:   201005: {{.*}} retq
+
+;; Check that LTO does not do IPO for symbols assigned by script.
+; RUN: ld.lld  -m elf_x86_64 %t1.o %t2.o -o %t4 --script %t.script -save-temps
+; RUN: llvm-objdump -d %t4 | FileCheck %s --check-prefix=NOIPO
+; NOIPO:      Disassembly of section .text:
+; NOIPO:      foo:
+; NOIPO-NEXT:   201010: {{.*}} movl $2, %eax
+; NOIPO:      _start:
+; NOIPO-NEXT:   201020: {{.*}} jmp -21 <foo>
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @bar() {
+  ret i32 1
+}
+
+define i32 @foo() {
+  ret i32 2
+}