[WebAssemlby] Set IsUsedInRegularObj correctly for undefined data symbols

Differential Revision: https://reviews.llvm.org/D49113

llvm-svn: 337314

3 files changed, 56 insertions, 0 deletions

diff --git a/lld/test/wasm/lto/Inputs/used.ll b/lld/test/wasm/lto/Inputs/used.ll
new file mode 100644
index 00000000000..d0250d518ab
--- /dev/null
+++ b/lld/test/wasm/lto/Inputs/used.ll
@@ -0,0 +1,8 @@
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+@foo = hidden global i32 1
+
+define hidden void @bar() {
+  ret void
+}
diff --git a/lld/test/wasm/lto/used.ll b/lld/test/wasm/lto/used.ll
new file mode 100644
index 00000000000..8bf840366cc
--- /dev/null
+++ b/lld/test/wasm/lto/used.ll
@@ -0,0 +1,45 @@
+; RUN: llc %s -o %t.o -filetype=obj
+; RUN: llvm-as %S/Inputs/used.ll -o %t1.o
+; RUN: wasm-ld %t.o %t1.o -o %t.wasm
+; RUN: obj2yaml %t.wasm | FileCheck %s
+
+; Verify that symbols references from regular objects are preserved by LTO
+
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+declare void @bar()
+
+@foo = external global i32
+
+define void @_start() {
+  %val = load i32, i32* @foo, align 4
+  %tobool = icmp ne i32 %val, 0
+  br i1 %tobool, label %callbar, label %return
+
+callbar:
+  call void @bar()
+  br label %return
+
+return:
+  ret void
+}
+
+; CHECK:        - Type:            DATA
+; CHECK-NEXT:     Segments:
+; CHECK-NEXT:       - SectionOffset:   7
+; CHECK-NEXT:         MemoryIndex:     0
+; CHECK-NEXT:         Offset:
+; CHECK-NEXT:           Opcode:          I32_CONST
+; CHECK-NEXT:           Value:           1024
+; CHECK-NEXT:         Content:         '01000000'
+
+; CHECK:       - Type:            CUSTOM
+; CHECK-NEXT:    Name:            name
+; CHECK-NEXT:    FunctionNames:   
+; CHECK-NEXT:      - Index:           0
+; CHECK-NEXT:        Name:            __wasm_call_ctors
+; CHECK-NEXT:      - Index:           1
+; CHECK-NEXT:        Name:            _start
+; CHECK-NEXT:      - Index:           2
+; CHECK-NEXT:        Name:            bar
diff --git a/lld/wasm/SymbolTable.cpp b/lld/wasm/SymbolTable.cpp
index 6541ddcdb87..e1ba2376973 100644
--- a/lld/wasm/SymbolTable.cpp
+++ b/lld/wasm/SymbolTable.cpp
@@ -307,6 +307,9 @@ Symbol *SymbolTable::addUndefinedData(StringRef Name, uint32_t Flags,
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Name);
 
+  if (!File || File->kind() == InputFile::ObjectKind)
+    S->IsUsedInRegularObj = true;
+
   if (WasInserted)
     replaceSymbol<UndefinedData>(S, Name, Flags, File);
   else if (auto *Lazy = dyn_cast<LazySymbol>(S))