1 //===--- XRayArgs.cpp - Arguments for XRay --------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 #include "clang/Driver/XRayArgs.h"
10 #include "ToolChains/CommonArgs.h"
11 #include "clang/Driver/Driver.h"
12 #include "clang/Driver/DriverDiagnostic.h"
13 #include "clang/Driver/Options.h"
14 #include "clang/Driver/ToolChain.h"
15 #include "llvm/ADT/StringExtras.h"
16 #include "llvm/ADT/StringSwitch.h"
17 #include "llvm/Support/FileSystem.h"
18 #include "llvm/Support/Path.h"
19 #include "llvm/Support/ScopedPrinter.h"
20 #include "llvm/Support/SpecialCaseList.h"
21 
22 using namespace clang;
23 using namespace clang::driver;
24 using namespace llvm::opt;
25 
26 namespace {
27 constexpr char XRayInstrumentOption[] = "-fxray-instrument";
28 constexpr char XRayInstructionThresholdOption[] =
29     "-fxray-instruction-threshold=";
30 constexpr const char *const XRaySupportedModes[] = {"xray-fdr", "xray-basic"};
31 } // namespace
32 
33 XRayArgs::XRayArgs(const ToolChain &TC, const ArgList &Args) {
34   const Driver &D = TC.getDriver();
35   const llvm::Triple &Triple = TC.getTriple();
36   if (Args.hasFlag(options::OPT_fxray_instrument,
37                    options::OPT_fnoxray_instrument, false)) {
38     if (Triple.getOS() == llvm::Triple::Linux) {
39       switch (Triple.getArch()) {
40       case llvm::Triple::x86_64:
41       case llvm::Triple::arm:
42       case llvm::Triple::aarch64:
43       case llvm::Triple::ppc64le:
44       case llvm::Triple::mips:
45       case llvm::Triple::mipsel:
46       case llvm::Triple::mips64:
47       case llvm::Triple::mips64el:
48         break;
49       default:
50         D.Diag(diag::err_drv_clang_unsupported)
51             << (std::string(XRayInstrumentOption) + " on " + Triple.str());
52       }
53     } else if (Triple.getOS() == llvm::Triple::FreeBSD ||
54                Triple.getOS() == llvm::Triple::OpenBSD ||
55                Triple.getOS() == llvm::Triple::NetBSD ||
56                Triple.getOS() == llvm::Triple::Darwin) {
57       if (Triple.getArch() != llvm::Triple::x86_64) {
58         D.Diag(diag::err_drv_clang_unsupported)
59             << (std::string(XRayInstrumentOption) + " on " + Triple.str());
60       }
61     } else if (Triple.getOS() == llvm::Triple::Fuchsia) {
62       switch (Triple.getArch()) {
63       case llvm::Triple::x86_64:
64       case llvm::Triple::aarch64:
65         break;
66       default:
67         D.Diag(diag::err_drv_clang_unsupported)
68             << (std::string(XRayInstrumentOption) + " on " + Triple.str());
69       }
70     } else {
71       D.Diag(diag::err_drv_clang_unsupported)
72           << (std::string(XRayInstrumentOption) + " on " + Triple.str());
73     }
74     XRayInstrument = true;
75     if (const Arg *A =
76             Args.getLastArg(options::OPT_fxray_instruction_threshold_,
77                             options::OPT_fxray_instruction_threshold_EQ)) {
78       StringRef S = A->getValue();
79       if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
80         D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
81     }
82 
83     // By default, the back-end will not emit the lowering for XRay customevent
84     // calls if the function is not instrumented. In the future we will change
85     // this default to be the reverse, but in the meantime we're going to
86     // introduce the new functionality behind a flag.
87     if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
88                      options::OPT_fnoxray_always_emit_customevents, false))
89       XRayAlwaysEmitCustomEvents = true;
90 
91     if (Args.hasFlag(options::OPT_fxray_always_emit_typedevents,
92                      options::OPT_fnoxray_always_emit_typedevents, false))
93       XRayAlwaysEmitTypedEvents = true;
94 
95     if (!Args.hasFlag(options::OPT_fxray_link_deps,
96                       options::OPT_fnoxray_link_deps, true))
97       XRayRT = false;
98 
99     auto Bundles =
100         Args.getAllArgValues(options::OPT_fxray_instrumentation_bundle);
101     if (Bundles.empty())
102       InstrumentationBundle.Mask = XRayInstrKind::All;
103     else
104       for (const auto &B : Bundles) {
105         llvm::SmallVector<StringRef, 2> BundleParts;
106         llvm::SplitString(B, BundleParts, ",");
107         for (const auto &P : BundleParts) {
108           // TODO: Automate the generation of the string case table.
109           auto Valid = llvm::StringSwitch<bool>(P)
110                            .Cases("none", "all", "function", "custom", true)
111                            .Default(false);
112 
113           if (!Valid) {
114             D.Diag(clang::diag::err_drv_invalid_value)
115                 << "-fxray-instrumentation-bundle=" << P;
116             continue;
117           }
118 
119           auto Mask = parseXRayInstrValue(P);
120           if (Mask == XRayInstrKind::None) {
121             InstrumentationBundle.clear();
122             break;
123           }
124 
125           InstrumentationBundle.Mask |= Mask;
126         }
127       }
128 
129     // Validate the always/never attribute files. We also make sure that they
130     // are treated as actual dependencies.
131     for (const auto &Filename :
132          Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
133       if (llvm::sys::fs::exists(Filename)) {
134         AlwaysInstrumentFiles.push_back(Filename);
135         ExtraDeps.push_back(Filename);
136       } else
137         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
138     }
139 
140     for (const auto &Filename :
141          Args.getAllArgValues(options::OPT_fxray_never_instrument)) {
142       if (llvm::sys::fs::exists(Filename)) {
143         NeverInstrumentFiles.push_back(Filename);
144         ExtraDeps.push_back(Filename);
145       } else
146         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
147     }
148 
149     for (const auto &Filename :
150          Args.getAllArgValues(options::OPT_fxray_attr_list)) {
151       if (llvm::sys::fs::exists(Filename)) {
152         AttrListFiles.push_back(Filename);
153         ExtraDeps.push_back(Filename);
154       } else
155         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
156     }
157 
158     // Get the list of modes we want to support.
159     auto SpecifiedModes = Args.getAllArgValues(options::OPT_fxray_modes);
160     if (SpecifiedModes.empty())
161       llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
162     else
163       for (const auto &Arg : SpecifiedModes) {
164         // Parse CSV values for -fxray-modes=...
165         llvm::SmallVector<StringRef, 2> ModeParts;
166         llvm::SplitString(Arg, ModeParts, ",");
167         for (const auto &M : ModeParts)
168           if (M == "none")
169             Modes.clear();
170           else if (M == "all")
171             llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
172           else
173             Modes.push_back(M);
174       }
175 
176     // Then we want to sort and unique the modes we've collected.
177     llvm::sort(Modes);
178     Modes.erase(std::unique(Modes.begin(), Modes.end()), Modes.end());
179   }
180 }
181 
182 void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
183                        ArgStringList &CmdArgs, types::ID InputType) const {
184   if (!XRayInstrument)
185     return;
186 
187   CmdArgs.push_back(XRayInstrumentOption);
188 
189   if (XRayAlwaysEmitCustomEvents)
190     CmdArgs.push_back("-fxray-always-emit-customevents");
191 
192   if (XRayAlwaysEmitTypedEvents)
193     CmdArgs.push_back("-fxray-always-emit-typedevents");
194 
195   CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
196                                        Twine(InstructionThreshold)));
197 
198   for (const auto &Always : AlwaysInstrumentFiles) {
199     SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
200     AlwaysInstrumentOpt += Always;
201     CmdArgs.push_back(Args.MakeArgString(AlwaysInstrumentOpt));
202   }
203 
204   for (const auto &Never : NeverInstrumentFiles) {
205     SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
206     NeverInstrumentOpt += Never;
207     CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
208   }
209 
210   for (const auto &AttrFile : AttrListFiles) {
211     SmallString<64> AttrListFileOpt("-fxray-attr-list=");
212     AttrListFileOpt += AttrFile;
213     CmdArgs.push_back(Args.MakeArgString(AttrListFileOpt));
214   }
215 
216   for (const auto &Dep : ExtraDeps) {
217     SmallString<64> ExtraDepOpt("-fdepfile-entry=");
218     ExtraDepOpt += Dep;
219     CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
220   }
221 
222   for (const auto &Mode : Modes) {
223     SmallString<64> ModeOpt("-fxray-modes=");
224     ModeOpt += Mode;
225     CmdArgs.push_back(Args.MakeArgString(ModeOpt));
226   }
227 
228   SmallString<64> Bundle("-fxray-instrumentation-bundle=");
229   if (InstrumentationBundle.full()) {
230     Bundle += "all";
231   } else if (InstrumentationBundle.empty()) {
232     Bundle += "none";
233   } else {
234     if (InstrumentationBundle.has(XRayInstrKind::Function))
235       Bundle += "function";
236     if (InstrumentationBundle.has(XRayInstrKind::Custom))
237       Bundle += "custom";
238     if (InstrumentationBundle.has(XRayInstrKind::Typed))
239       Bundle += "typed";
240   }
241   CmdArgs.push_back(Args.MakeArgString(Bundle));
242 }
243