1 //===- DXILFinalizeLinkage.cpp - Finalize linkage of functions ------------===//
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 "DXILFinalizeLinkage.h"
10 #include "DirectX.h"
11 #include "llvm/IR/Function.h"
12 #include "llvm/IR/GlobalValue.h"
13 #include "llvm/IR/Metadata.h"
14 #include "llvm/IR/Module.h"
15
16 #define DEBUG_TYPE "dxil-finalize-linkage"
17
18 using namespace llvm;
19
finalizeLinkage(Module & M)20 static bool finalizeLinkage(Module &M) {
21 bool MadeChange = false;
22
23 // Convert private global variables to internal linkage.
24 for (GlobalVariable &GV : M.globals()) {
25 if (GV.hasPrivateLinkage()) {
26 GV.setLinkage(GlobalValue::InternalLinkage);
27 MadeChange = true;
28 }
29 }
30
31 SmallVector<Function *> Funcs;
32
33 // Collect non-entry and non-exported functions to set to internal linkage.
34 for (Function &EF : M.functions()) {
35 if (EF.isIntrinsic())
36 continue;
37 if (EF.hasExternalLinkage() && EF.hasDefaultVisibility())
38 continue;
39 if (EF.hasFnAttribute("hlsl.shader"))
40 continue;
41 Funcs.push_back(&EF);
42 }
43
44 for (Function *F : Funcs) {
45 if (F->getLinkage() == GlobalValue::ExternalLinkage) {
46 F->setLinkage(GlobalValue::InternalLinkage);
47 MadeChange = true;
48 }
49 if (F->isDefTriviallyDead()) {
50 M.getFunctionList().erase(F);
51 MadeChange = true;
52 }
53 }
54
55 return MadeChange;
56 }
57
run(Module & M,ModuleAnalysisManager & AM)58 PreservedAnalyses DXILFinalizeLinkage::run(Module &M,
59 ModuleAnalysisManager &AM) {
60 if (finalizeLinkage(M))
61 return PreservedAnalyses::none();
62 return PreservedAnalyses::all();
63 }
64
runOnModule(Module & M)65 bool DXILFinalizeLinkageLegacy::runOnModule(Module &M) {
66 return finalizeLinkage(M);
67 }
68
69 char DXILFinalizeLinkageLegacy::ID = 0;
70
71 INITIALIZE_PASS_BEGIN(DXILFinalizeLinkageLegacy, DEBUG_TYPE,
72 "DXIL Finalize Linkage", false, false)
73 INITIALIZE_PASS_END(DXILFinalizeLinkageLegacy, DEBUG_TYPE,
74 "DXIL Finalize Linkage", false, false)
75
createDXILFinalizeLinkageLegacyPass()76 ModulePass *llvm::createDXILFinalizeLinkageLegacyPass() {
77 return new DXILFinalizeLinkageLegacy();
78 }
79