diff options
| -rw-r--r-- | lib/Transforms/NaCl/GlobalCleanup.cpp | 11 | ||||
| -rw-r--r-- | test/Transforms/NaCl/globalcleanup.ll | 14 |
2 files changed, 23 insertions, 2 deletions
diff --git a/lib/Transforms/NaCl/GlobalCleanup.cpp b/lib/Transforms/NaCl/GlobalCleanup.cpp index 55886f8f7d..d3c58b400a 100644 --- a/lib/Transforms/NaCl/GlobalCleanup.cpp +++ b/lib/Transforms/NaCl/GlobalCleanup.cpp @@ -44,7 +44,9 @@ namespace { char GlobalCleanup::ID = 0; INITIALIZE_PASS(GlobalCleanup, "nacl-global-cleanup", - "GlobalValue cleanup for PNaCl", false, false) + "GlobalValue cleanup for PNaCl " + "(assumes all of the binary is linked statically)", + false, false) static bool CleanUpLinkage(GlobalValue *GV) { // TODO(dschuff): handle the rest of the linkage types as necessary without @@ -82,7 +84,12 @@ bool GlobalCleanup::runOnModule(Module &M) { for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ) { GlobalVariable *GV = I++; - Modified |= CleanUpLinkage(GV); + if (GV->use_empty()) { + GV->eraseFromParent(); + Modified = true; + } else { + Modified |= CleanUpLinkage(GV); + } } for (Module::iterator I = M.begin(), E = M.end(); I != E; ) { diff --git a/test/Transforms/NaCl/globalcleanup.ll b/test/Transforms/NaCl/globalcleanup.ll index 44e5b45e16..7e1fa3d8a5 100644 --- a/test/Transforms/NaCl/globalcleanup.ll +++ b/test/Transforms/NaCl/globalcleanup.ll @@ -16,6 +16,14 @@ ; CHECK: @weak_gv = internal global @weak_gv = weak global i32 0 +; Libc++'s declarations of iostream values are purely ``extern`` and +; unused otherwise which led to a bug when used as ``(void)std::clog``: +; the global would survive as ``external global`` post-link but without +; a proper definition. Global cleanup should take care of it. +; GV-NOT: ostream +%"class.fake_ostream" = type { i32 } +@ostream = external global %"class.fake_ostream" + ; CHECK: define void @_start define void @_start() { ret void @@ -35,6 +43,12 @@ define i32* @ewc() { ret i32* @extern_weak_gv } +; Make sure @weak_gv is actually used. +define i32* @wgv() { +; CHECK: ret i32* @weak_gv + ret i32* @weak_gv +} + ; GV-NOT: @extern_weak_func declare extern_weak i32 @extern_weak_func() ; CHECK: @ewf |