1 //===--- XRayArgs.cpp - Arguments for XRay --------------------------------===//
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 #include "clang/Driver/XRayArgs.h"
9 #include "ToolChains/CommonArgs.h"
10 #include "clang/Driver/Driver.h"
11 #include "clang/Driver/DriverDiagnostic.h"
12 #include "clang/Driver/Options.h"
13 #include "clang/Driver/ToolChain.h"
14 #include "llvm/ADT/StringExtras.h"
15 #include "llvm/ADT/StringSwitch.h"
16 #include "llvm/Support/FileSystem.h"
17 #include "llvm/Support/Path.h"
18 #include "llvm/Support/ScopedPrinter.h"
19 #include "llvm/Support/SpecialCaseList.h"
20 
21 using namespace clang;
22 using namespace clang::driver;
23 using namespace llvm::opt;
24 
25 namespace {
26 constexpr char XRayInstrumentOption[] = "-fxray-instrument";
27 constexpr char XRayInstructionThresholdOption[] =
28     "-fxray-instruction-threshold=";
29 constexpr const char *const XRaySupportedModes[] = {"xray-fdr", "xray-basic"};
30 } // namespace
31 
XRayArgs(const ToolChain & TC,const ArgList & Args)32 XRayArgs::XRayArgs(const ToolChain &TC, const ArgList &Args) {
33   const Driver &D = TC.getDriver();
34   const llvm::Triple &Triple = TC.getTriple();
35   if (Args.hasFlag(options::OPT_fxray_instrument,
36                    options::OPT_fnoxray_instrument, false)) {
37     if (Triple.getOS() == llvm::Triple::Linux) {
38       switch (Triple.getArch()) {
39       case llvm::Triple::x86_64:
40       case llvm::Triple::arm:
41       case llvm::Triple::aarch64:
42       case llvm::Triple::ppc64le:
43       case llvm::Triple::mips:
44       case llvm::Triple::mipsel:
45       case llvm::Triple::mips64:
46       case llvm::Triple::mips64el:
47         break;
48       default:
49         D.Diag(diag::err_drv_clang_unsupported)
50             << (std::string(XRayInstrumentOption) + " on " + Triple.str());
51       }
52     } else if (Triple.isOSFreeBSD() ||
53                Triple.isOSOpenBSD() ||
54                Triple.isOSNetBSD() ||
55                Triple.getOS() == llvm::Triple::Darwin) {
56       if (Triple.getArch() != llvm::Triple::x86_64) {
57         D.Diag(diag::err_drv_clang_unsupported)
58             << (std::string(XRayInstrumentOption) + " on " + Triple.str());
59       }
60     } else if (Triple.getOS() == llvm::Triple::Fuchsia) {
61       switch (Triple.getArch()) {
62       case llvm::Triple::x86_64:
63       case llvm::Triple::aarch64:
64         break;
65       default:
66         D.Diag(diag::err_drv_clang_unsupported)
67             << (std::string(XRayInstrumentOption) + " on " + Triple.str());
68       }
69     } else {
70       D.Diag(diag::err_drv_clang_unsupported)
71           << (std::string(XRayInstrumentOption) + " on " + Triple.str());
72     }
73     XRayInstrument = true;
74     if (const Arg *A =
75             Args.getLastArg(options::OPT_fxray_instruction_threshold_,
76                             options::OPT_fxray_instruction_threshold_EQ)) {
77       StringRef S = A->getValue();
78       if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
79         D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
80     }
81 
82     // By default, the back-end will not emit the lowering for XRay customevent
83     // calls if the function is not instrumented. In the future we will change
84     // this default to be the reverse, but in the meantime we're going to
85     // introduce the new functionality behind a flag.
86     if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
87                      options::OPT_fnoxray_always_emit_customevents, false))
88       XRayAlwaysEmitCustomEvents = true;
89 
90     if (Args.hasFlag(options::OPT_fxray_always_emit_typedevents,
91                      options::OPT_fnoxray_always_emit_typedevents, false))
92       XRayAlwaysEmitTypedEvents = true;
93 
94     if (!Args.hasFlag(options::OPT_fxray_link_deps,
95                       options::OPT_fnoxray_link_deps, true))
96       XRayRT = false;
97 
98     auto Bundles =
99         Args.getAllArgValues(options::OPT_fxray_instrumentation_bundle);
100     if (Bundles.empty())
101       InstrumentationBundle.Mask = XRayInstrKind::All;
102     else
103       for (const auto &B : Bundles) {
104         llvm::SmallVector<StringRef, 2> BundleParts;
105         llvm::SplitString(B, BundleParts, ",");
106         for (const auto &P : BundleParts) {
107           // TODO: Automate the generation of the string case table.
108           auto Valid = llvm::StringSwitch<bool>(P)
109                            .Cases("none", "all", "function", "custom", true)
110                            .Default(false);
111 
112           if (!Valid) {
113             D.Diag(clang::diag::err_drv_invalid_value)
114                 << "-fxray-instrumentation-bundle=" << P;
115             continue;
116           }
117 
118           auto Mask = parseXRayInstrValue(P);
119           if (Mask == XRayInstrKind::None) {
120             InstrumentationBundle.clear();
121             break;
122           }
123 
124           InstrumentationBundle.Mask |= Mask;
125         }
126       }
127 
128     // Validate the always/never attribute files. We also make sure that they
129     // are treated as actual dependencies.
130     for (const auto &Filename :
131          Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
132       if (llvm::sys::fs::exists(Filename)) {
133         AlwaysInstrumentFiles.push_back(Filename);
134         ExtraDeps.push_back(Filename);
135       } else
136         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
137     }
138 
139     for (const auto &Filename :
140          Args.getAllArgValues(options::OPT_fxray_never_instrument)) {
141       if (llvm::sys::fs::exists(Filename)) {
142         NeverInstrumentFiles.push_back(Filename);
143         ExtraDeps.push_back(Filename);
144       } else
145         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
146     }
147 
148     for (const auto &Filename :
149          Args.getAllArgValues(options::OPT_fxray_attr_list)) {
150       if (llvm::sys::fs::exists(Filename)) {
151         AttrListFiles.push_back(Filename);
152         ExtraDeps.push_back(Filename);
153       } else
154         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
155     }
156 
157     // Get the list of modes we want to support.
158     auto SpecifiedModes = Args.getAllArgValues(options::OPT_fxray_modes);
159     if (SpecifiedModes.empty())
160       llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
161     else
162       for (const auto &Arg : SpecifiedModes) {
163         // Parse CSV values for -fxray-modes=...
164         llvm::SmallVector<StringRef, 2> ModeParts;
165         llvm::SplitString(Arg, ModeParts, ",");
166         for (const auto &M : ModeParts)
167           if (M == "none")
168             Modes.clear();
169           else if (M == "all")
170             llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
171           else
172             Modes.push_back(M);
173       }
174 
175     // Then we want to sort and unique the modes we've collected.
176     llvm::sort(Modes);
177     Modes.erase(std::unique(Modes.begin(), Modes.end()), Modes.end());
178   }
179 }
180 
addArgs(const ToolChain & TC,const ArgList & Args,ArgStringList & CmdArgs,types::ID InputType) const181 void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
182                        ArgStringList &CmdArgs, types::ID InputType) const {
183   if (!XRayInstrument)
184     return;
185 
186   CmdArgs.push_back(XRayInstrumentOption);
187 
188   if (XRayAlwaysEmitCustomEvents)
189     CmdArgs.push_back("-fxray-always-emit-customevents");
190 
191   if (XRayAlwaysEmitTypedEvents)
192     CmdArgs.push_back("-fxray-always-emit-typedevents");
193 
194   CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
195                                        Twine(InstructionThreshold)));
196 
197   for (const auto &Always : AlwaysInstrumentFiles) {
198     SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
199     AlwaysInstrumentOpt += Always;
200     CmdArgs.push_back(Args.MakeArgString(AlwaysInstrumentOpt));
201   }
202 
203   for (const auto &Never : NeverInstrumentFiles) {
204     SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
205     NeverInstrumentOpt += Never;
206     CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
207   }
208 
209   for (const auto &AttrFile : AttrListFiles) {
210     SmallString<64> AttrListFileOpt("-fxray-attr-list=");
211     AttrListFileOpt += AttrFile;
212     CmdArgs.push_back(Args.MakeArgString(AttrListFileOpt));
213   }
214 
215   for (const auto &Dep : ExtraDeps) {
216     SmallString<64> ExtraDepOpt("-fdepfile-entry=");
217     ExtraDepOpt += Dep;
218     CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
219   }
220 
221   for (const auto &Mode : Modes) {
222     SmallString<64> ModeOpt("-fxray-modes=");
223     ModeOpt += Mode;
224     CmdArgs.push_back(Args.MakeArgString(ModeOpt));
225   }
226 
227   SmallString<64> Bundle("-fxray-instrumentation-bundle=");
228   if (InstrumentationBundle.full()) {
229     Bundle += "all";
230   } else if (InstrumentationBundle.empty()) {
231     Bundle += "none";
232   } else {
233     if (InstrumentationBundle.has(XRayInstrKind::Function))
234       Bundle += "function";
235     if (InstrumentationBundle.has(XRayInstrKind::Custom))
236       Bundle += "custom";
237     if (InstrumentationBundle.has(XRayInstrKind::Typed))
238       Bundle += "typed";
239   }
240   CmdArgs.push_back(Args.MakeArgString(Bundle));
241 }
242