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