1 //===-- RenderScriptExpressionOpts.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 <string>
10
11 #include "llvm/ADT/None.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/IR/Instruction.h"
14 #include "llvm/IR/Instructions.h"
15 #include "llvm/IR/LegacyPassManager.h"
16 #include "llvm/IR/Module.h"
17 #include "llvm/Support/TargetRegistry.h"
18 #include "llvm/Target/TargetMachine.h"
19 #include "llvm/Target/TargetOptions.h"
20
21 #include "clang/Basic/TargetOptions.h"
22
23 #include "lldb/Target/Process.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Utility/Log.h"
26
27 #include "RenderScriptExpressionOpts.h"
28 #include "RenderScriptRuntime.h"
29 #include "RenderScriptx86ABIFixups.h"
30
31 using namespace lldb_private;
32 using namespace lldb_renderscript;
33
34 // [``slang``](https://android.googlesource.com/platform/frameworks/compile/slang),
35 // the compiler frontend for RenderScript embeds an ARM specific triple in IR
36 // that is shipped in the app, after generating IR that has some assumptions
37 // that an ARM device is the target. As the IR is then compiled on a device of
38 // unknown (at time the IR was generated at least) architecture, when calling
39 // RenderScript API function as part of debugger expressions, we have to
40 // perform a fixup pass that removes those assumptions right before the module
41 // is sent to be generated by the llvm backend.
42
43 namespace {
registerRSDefaultTargetOpts(clang::TargetOptions & proto,const llvm::Triple::ArchType & arch)44 bool registerRSDefaultTargetOpts(clang::TargetOptions &proto,
45 const llvm::Triple::ArchType &arch) {
46 switch (arch) {
47 case llvm::Triple::ArchType::x86:
48 proto.Triple = "i686--linux-android";
49 proto.CPU = "atom";
50 proto.Features.push_back("+long64");
51 // Fallthrough for common x86 family features
52 LLVM_FALLTHROUGH;
53 case llvm::Triple::ArchType::x86_64:
54 proto.Features.push_back("+mmx");
55 proto.Features.push_back("+sse");
56 proto.Features.push_back("+sse2");
57 proto.Features.push_back("+sse3");
58 proto.Features.push_back("+ssse3");
59 proto.Features.push_back("+sse4.1");
60 proto.Features.push_back("+sse4.2");
61 break;
62 case llvm::Triple::ArchType::mipsel:
63 // pretend this is `arm' for the front-end
64 proto.Triple = "armv7-none-linux-android";
65 proto.CPU = "";
66 proto.Features.push_back("+long64");
67 break;
68 case llvm::Triple::ArchType::mips64el:
69 // pretend this is `aarch64' for the front-end
70 proto.Triple = "aarch64-none-linux-android";
71 proto.CPU = "";
72 break;
73 default:
74 return false;
75 }
76 return true;
77 }
78 } // end anonymous namespace
79
runOnModule(llvm::Module & module)80 bool RenderScriptRuntimeModulePass::runOnModule(llvm::Module &module) {
81 bool changed_module = false;
82 Log *log(
83 GetLogIfAllCategoriesSet(LIBLLDB_LOG_LANGUAGE | LIBLLDB_LOG_EXPRESSIONS));
84
85 std::string err;
86 llvm::StringRef real_triple =
87 m_process_ptr->GetTarget().GetArchitecture().GetTriple().getTriple();
88 const llvm::Target *target_info =
89 llvm::TargetRegistry::lookupTarget(std::string(real_triple), err);
90 if (!target_info) {
91 if (log)
92 log->Warning("couldn't determine real target architecture: '%s'",
93 err.c_str());
94 return false;
95 }
96
97 llvm::Optional<llvm::Reloc::Model> reloc_model = llvm::None;
98 assert(m_process_ptr && "no available lldb process");
99 switch (m_process_ptr->GetTarget().GetArchitecture().GetMachine()) {
100 case llvm::Triple::ArchType::x86:
101 changed_module |= fixupX86FunctionCalls(module);
102 // For some reason this triple gets totally missed by the backend, and must
103 // be set manually. There a reference in bcc/Main.cpp about auto feature-
104 // detection being removed from LLVM3.5, but I can't see that discussion
105 // anywhere public.
106 real_triple = "i686--linux-android";
107 break;
108 case llvm::Triple::ArchType::x86_64:
109 changed_module |= fixupX86_64FunctionCalls(module);
110 break;
111 case llvm::Triple::ArchType::mipsel:
112 case llvm::Triple::ArchType::mips64el:
113 // No actual IR fixup pass is needed on MIPS, but the datalayout and
114 // targetmachine do need to be explicitly set.
115
116 // bcc explicitly compiles MIPS code to use the static relocation model due
117 // to an issue with relocations in mclinker. see
118 // libbcc/support/CompilerConfig.cpp for details
119 reloc_model = llvm::Reloc::Static;
120 changed_module = true;
121 break;
122 case llvm::Triple::ArchType::arm:
123 case llvm::Triple::ArchType::aarch64:
124 // ARM subtargets need no fixup passes as they are the initial target as
125 // generated by the
126 // slang compiler frontend.
127 break;
128 default:
129 if (log)
130 log->Warning("Ignoring unknown renderscript target");
131 return false;
132 }
133
134 if (changed_module) {
135 llvm::TargetOptions options;
136 llvm::TargetMachine *target_machine = target_info->createTargetMachine(
137 real_triple, "", "", options, reloc_model);
138 assert(target_machine &&
139 "failed to identify RenderScriptRuntime target machine");
140 // We've been using a triple and datalayout of some ARM variant all along,
141 // so we need to let the backend know that this is no longer the case.
142 if (log) {
143 LLDB_LOGF(log, "%s - Changing RS target triple to '%s'", __FUNCTION__,
144 real_triple.str().c_str());
145 LLDB_LOGF(
146 log, "%s - Changing RS datalayout to '%s'", __FUNCTION__,
147 target_machine->createDataLayout().getStringRepresentation().c_str());
148 }
149 module.setTargetTriple(real_triple);
150 module.setDataLayout(target_machine->createDataLayout());
151 }
152 return changed_module;
153 }
154
155 char RenderScriptRuntimeModulePass::ID = 0;
156
157 namespace lldb_private {
158
GetOverrideExprOptions(clang::TargetOptions & proto)159 bool RenderScriptRuntime::GetOverrideExprOptions(clang::TargetOptions &proto) {
160 auto *process = GetProcess();
161 assert(process);
162 return registerRSDefaultTargetOpts(
163 proto, process->GetTarget().GetArchitecture().GetMachine());
164 }
165
GetIRPasses(LLVMUserExpression::IRPasses & passes)166 bool RenderScriptRuntime::GetIRPasses(LLVMUserExpression::IRPasses &passes) {
167 if (!m_ir_passes)
168 m_ir_passes = new RSIRPasses(GetProcess());
169 assert(m_ir_passes);
170
171 passes.EarlyPasses = m_ir_passes->EarlyPasses;
172 passes.LatePasses = m_ir_passes->LatePasses;
173
174 return true;
175 }
176
177 namespace lldb_renderscript {
178
RSIRPasses(Process * process)179 RSIRPasses::RSIRPasses(Process *process) {
180 IRPasses();
181 assert(process);
182
183 EarlyPasses = std::make_shared<llvm::legacy::PassManager>();
184 assert(EarlyPasses);
185 EarlyPasses->add(new RenderScriptRuntimeModulePass(process));
186 }
187
~RSIRPasses()188 RSIRPasses::~RSIRPasses() {}
189
190 } // namespace lldb_renderscript
191 } // namespace lldb_private
192