1 //===- CommonLinkerContext.cpp --------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lld/Common/CommonLinkerContext.h"
10 #include "lld/Common/Driver.h"
11 #include "lld/Common/ErrorHandler.h"
12 #include "lld/Common/Memory.h"
13 
14 using namespace llvm;
15 using namespace lld;
16 
17 // Reference to the current LLD instance. This is a temporary situation, until
18 // we pass this context everywhere by reference, or we make it a thread_local,
19 // as in https://reviews.llvm.org/D108850?id=370678 where each thread can be
20 // associated with a LLD instance. Only then will LLD be free of global
21 // state.
22 static CommonLinkerContext *lctx;
23 
24 CommonLinkerContext::CommonLinkerContext() { lctx = this; }
25 
26 CommonLinkerContext::~CommonLinkerContext() {
27   assert(lctx);
28   // Explicitly call the destructors since we created the objects with placement
29   // new in SpecificAlloc::create().
30   for (auto &it : instances)
31     it.second->~SpecificAllocBase();
32   lctx = nullptr;
33 }
34 
35 CommonLinkerContext &lld::commonContext() {
36   assert(lctx);
37   return *lctx;
38 }
39 
40 bool lld::hasContext() { return lctx != nullptr; }
41 
42 void CommonLinkerContext::destroy() {
43   if (lctx == nullptr)
44     return;
45   delete lctx;
46 }
47 
48 // Temporary API that forces global state cleanup between explicit calls to
49 // drivers. See discussion in https://reviews.llvm.org/D119049.
50 void lld::cleanup() {
51   // Delete the global context and clear the global context pointer, so that it
52   // cannot be accessed anymore.
53   CommonLinkerContext::destroy();
54 }
55