[lld] b3b4cda - [lld][WebAssembly] Don't GC library objects under `--whole-archive`

[Sam Clegg via llvm-commits]

Author: Sam Clegg
Date: 2020-10-12T21:19:19-07:00
New Revision: b3b4cda104068e92b77f18c4e3fc0e0b8f3650e0

URL: https://github.com/llvm/llvm-project/commit/b3b4cda104068e92b77f18c4e3fc0e0b8f3650e0
DIFF: https://github.com/llvm/llvm-project/commit/b3b4cda104068e92b77f18c4e3fc0e0b8f3650e0.diff

LOG: [lld][WebAssembly] Don't GC library objects under `--whole-archive`

Followup on https://reviews.llvm.org/D85062 which ignores
entire library objects when no symbols are used within them.
This is shouldn't apply with `--whole-archive` since this
is specified to treat them like direct object inputs.

Differential Revision: https://reviews.llvm.org/D89290

Added: 
    

Modified: 
    lld/test/wasm/ctor-gc.test
    lld/wasm/Driver.cpp
    lld/wasm/InputFiles.cpp

Removed: 
    


################################################################################
diff  --git a/lld/test/wasm/ctor-gc.test b/lld/test/wasm/ctor-gc.test
index 18deab54b4e3..a0dcd375229d 100644
--- a/lld/test/wasm/ctor-gc.test
+++ b/lld/test/wasm/ctor-gc.test
@@ -7,6 +7,10 @@
 ; RUN: rm -f %t.lib.a
 ; RUN: llvm-ar rcs %t.lib.a %t.lib.o %t.ctor.o
 ; RUN: wasm-ld %t.start.o %t.lib.a -o %t.wasm
+; RUN: wasm-ld %t.start.o --whole-archive %t.lib.a -o %t2.wasm
 ; RUN: obj2yaml %t.wasm | FileCheck %s
+; RUN: obj2yaml %t2.wasm | FileCheck %s -check-prefix=WHOLEARCHIVE
 
 ; CHECK-NOT: __wasm_call_ctors
+
+; WHOLEARCHIVE: __wasm_call_ctors

diff  --git a/lld/wasm/Driver.cpp b/lld/wasm/Driver.cpp
index c00c7eb7522e..fb003558d1c9 100644
--- a/lld/wasm/Driver.cpp
+++ b/lld/wasm/Driver.cpp
@@ -252,8 +252,15 @@ void LinkerDriver::addFile(StringRef path) {
 
     // Handle -whole-archive.
     if (inWholeArchive) {
-      for (MemoryBufferRef &m : getArchiveMembers(mbref))
-        files.push_back(createObjectFile(m, path));
+      for (MemoryBufferRef &m : getArchiveMembers(mbref)) {
+        auto *object = createObjectFile(m, path);
+        // Mark object as live; object members are normally not
+        // live by default but -whole-archive is designed to treat
+        // them as such.
+        object->markLive();
+        files.push_back(object);
+      }
+
       return;
     }
 

diff  --git a/lld/wasm/InputFiles.cpp b/lld/wasm/InputFiles.cpp
index fbe6888355ea..d6848211c983 100644
--- a/lld/wasm/InputFiles.cpp
+++ b/lld/wasm/InputFiles.cpp
@@ -59,8 +59,7 @@ Optional<MemoryBufferRef> readFile(StringRef path) {
   return mbref;
 }
 
-InputFile *createObjectFile(MemoryBufferRef mb,
-                                       StringRef archiveName) {
+InputFile *createObjectFile(MemoryBufferRef mb, StringRef archiveName) {
   file_magic magic = identify_magic(mb.getBuffer());
   if (magic == file_magic::wasm_object) {
     std::unique_ptr<Binary> bin =