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       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 {
61       D.Diag(diag::err_drv_clang_unsupported)
62           << (std::string(XRayInstrumentOption) + " on " + Triple.str());
63     }
64     XRayInstrument = true;
65     if (const Arg *A =
66             Args.getLastArg(options::OPT_fxray_instruction_threshold_,
67                             options::OPT_fxray_instruction_threshold_EQ)) {
68       StringRef S = A->getValue();
69       if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
70         D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
71     }
72 
73     // By default, the back-end will not emit the lowering for XRay customevent
74     // calls if the function is not instrumented. In the future we will change
75     // this default to be the reverse, but in the meantime we're going to
76     // introduce the new functionality behind a flag.
77     if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
78                      options::OPT_fnoxray_always_emit_customevents, false))
79       XRayAlwaysEmitCustomEvents = true;
80 
81     if (Args.hasFlag(options::OPT_fxray_always_emit_typedevents,
82                      options::OPT_fnoxray_always_emit_typedevents, false))
83       XRayAlwaysEmitTypedEvents = true;
84 
85     if (!Args.hasFlag(options::OPT_fxray_link_deps,
86                       options::OPT_fnoxray_link_deps, true))
87       XRayRT = false;
88 
89     auto Bundles =
90         Args.getAllArgValues(options::OPT_fxray_instrumentation_bundle);
91     if (Bundles.empty())
92       InstrumentationBundle.Mask = XRayInstrKind::All;
93     else
94       for (const auto &B : Bundles) {
95         llvm::SmallVector<StringRef, 2> BundleParts;
96         llvm::SplitString(B, BundleParts, ",");
97         for (const auto &P : BundleParts) {
98           // TODO: Automate the generation of the string case table.
99           auto Valid = llvm::StringSwitch<bool>(P)
100                            .Cases("none", "all", "function", "custom", true)
101                            .Default(false);
102 
103           if (!Valid) {
104             D.Diag(clang::diag::err_drv_invalid_value)
105                 << "-fxray-instrumentation-bundle=" << P;
106             continue;
107           }
108 
109           auto Mask = parseXRayInstrValue(P);
110           if (Mask == XRayInstrKind::None) {
111             InstrumentationBundle.clear();
112             break;
113           }
114 
115           InstrumentationBundle.Mask |= Mask;
116         }
117       }
118 
119     // Validate the always/never attribute files. We also make sure that they
120     // are treated as actual dependencies.
121     for (const auto &Filename :
122          Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
123       if (llvm::sys::fs::exists(Filename)) {
124         AlwaysInstrumentFiles.push_back(Filename);
125         ExtraDeps.push_back(Filename);
126       } else
127         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
128     }
129 
130     for (const auto &Filename :
131          Args.getAllArgValues(options::OPT_fxray_never_instrument)) {
132       if (llvm::sys::fs::exists(Filename)) {
133         NeverInstrumentFiles.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_attr_list)) {
141       if (llvm::sys::fs::exists(Filename)) {
142         AttrListFiles.push_back(Filename);
143         ExtraDeps.push_back(Filename);
144       } else
145         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
146     }
147 
148     // Get the list of modes we want to support.
149     auto SpecifiedModes = Args.getAllArgValues(options::OPT_fxray_modes);
150     if (SpecifiedModes.empty())
151       llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
152     else
153       for (const auto &Arg : SpecifiedModes) {
154         // Parse CSV values for -fxray-modes=...
155         llvm::SmallVector<StringRef, 2> ModeParts;
156         llvm::SplitString(Arg, ModeParts, ",");
157         for (const auto &M : ModeParts)
158           if (M == "none")
159             Modes.clear();
160           else if (M == "all")
161             llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
162           else
163             Modes.push_back(M);
164       }
165 
166     // Then we want to sort and unique the modes we've collected.
167     llvm::sort(Modes.begin(), Modes.end());
168     Modes.erase(std::unique(Modes.begin(), Modes.end()), Modes.end());
169   }
170 }
171 
172 void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
173                        ArgStringList &CmdArgs, types::ID InputType) const {
174   if (!XRayInstrument)
175     return;
176 
177   CmdArgs.push_back(XRayInstrumentOption);
178 
179   if (XRayAlwaysEmitCustomEvents)
180     CmdArgs.push_back("-fxray-always-emit-customevents");
181 
182   if (XRayAlwaysEmitTypedEvents)
183     CmdArgs.push_back("-fxray-always-emit-typedevents");
184 
185   CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
186                                        Twine(InstructionThreshold)));
187 
188   for (const auto &Always : AlwaysInstrumentFiles) {
189     SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
190     AlwaysInstrumentOpt += Always;
191     CmdArgs.push_back(Args.MakeArgString(AlwaysInstrumentOpt));
192   }
193 
194   for (const auto &Never : NeverInstrumentFiles) {
195     SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
196     NeverInstrumentOpt += Never;
197     CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
198   }
199 
200   for (const auto &AttrFile : AttrListFiles) {
201     SmallString<64> AttrListFileOpt("-fxray-attr-list=");
202     AttrListFileOpt += AttrFile;
203     CmdArgs.push_back(Args.MakeArgString(AttrListFileOpt));
204   }
205 
206   for (const auto &Dep : ExtraDeps) {
207     SmallString<64> ExtraDepOpt("-fdepfile-entry=");
208     ExtraDepOpt += Dep;
209     CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
210   }
211 
212   for (const auto &Mode : Modes) {
213     SmallString<64> ModeOpt("-fxray-modes=");
214     ModeOpt += Mode;
215     CmdArgs.push_back(Args.MakeArgString(ModeOpt));
216   }
217 }
218