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/Path.h"
17 #include "llvm/Support/ScopedPrinter.h"
18 #include "llvm/Support/SpecialCaseList.h"
19 #include "llvm/Support/VirtualFileSystem.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 
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_fno_xray_instrument, false))
37     return;
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::hexagon:
44     case llvm::Triple::ppc64le:
45     case llvm::Triple::mips:
46     case llvm::Triple::mipsel:
47     case llvm::Triple::mips64:
48     case llvm::Triple::mips64el:
49       break;
50     default:
51       D.Diag(diag::err_drv_clang_unsupported)
52           << (std::string(XRayInstrumentOption) + " on " + Triple.str());
53     }
54   } else if (Triple.isOSFreeBSD() || Triple.isOSOpenBSD() ||
55              Triple.isOSNetBSD() || Triple.isMacOSX()) {
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 
74   // Both XRay and -fpatchable-function-entry use
75   // TargetOpcode::PATCHABLE_FUNCTION_ENTER.
76   if (Arg *A = Args.getLastArg(options::OPT_fpatchable_function_entry_EQ))
77     D.Diag(diag::err_drv_argument_not_allowed_with)
78         << "-fxray-instrument" << A->getSpelling();
79 
80   XRayInstrument = true;
81   if (const Arg *A =
82           Args.getLastArg(options::OPT_fxray_instruction_threshold_EQ)) {
83     StringRef S = A->getValue();
84     if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
85       D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
86   }
87 
88   // By default, the back-end will not emit the lowering for XRay customevent
89   // calls if the function is not instrumented. In the future we will change
90   // this default to be the reverse, but in the meantime we're going to
91   // introduce the new functionality behind a flag.
92   if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
93                    options::OPT_fno_xray_always_emit_customevents, false))
94     XRayAlwaysEmitCustomEvents = true;
95 
96   if (Args.hasFlag(options::OPT_fxray_always_emit_typedevents,
97                    options::OPT_fno_xray_always_emit_typedevents, false))
98     XRayAlwaysEmitTypedEvents = true;
99 
100   if (!Args.hasFlag(options::OPT_fxray_link_deps,
101                     options::OPT_fnoxray_link_deps, true))
102     XRayRT = false;
103 
104   if (Args.hasFlag(options::OPT_fxray_ignore_loops,
105                    options::OPT_fno_xray_ignore_loops, false))
106     XRayIgnoreLoops = true;
107 
108   XRayFunctionIndex = Args.hasFlag(options::OPT_fxray_function_index,
109                                    options::OPT_fno_xray_function_index, true);
110 
111   auto Bundles =
112       Args.getAllArgValues(options::OPT_fxray_instrumentation_bundle);
113   if (Bundles.empty())
114     InstrumentationBundle.Mask = XRayInstrKind::All;
115   else
116     for (const auto &B : Bundles) {
117       llvm::SmallVector<StringRef, 2> BundleParts;
118       llvm::SplitString(B, BundleParts, ",");
119       for (const auto &P : BundleParts) {
120         // TODO: Automate the generation of the string case table.
121         auto Valid = llvm::StringSwitch<bool>(P)
122                          .Cases("none", "all", "function", "function-entry",
123                                 "function-exit", "custom", true)
124                          .Default(false);
125 
126         if (!Valid) {
127           D.Diag(clang::diag::err_drv_invalid_value)
128               << "-fxray-instrumentation-bundle=" << P;
129           continue;
130         }
131 
132         auto Mask = parseXRayInstrValue(P);
133         if (Mask == XRayInstrKind::None) {
134           InstrumentationBundle.clear();
135           break;
136         }
137 
138         InstrumentationBundle.Mask |= Mask;
139       }
140     }
141 
142   // Validate the always/never attribute files. We also make sure that they
143   // are treated as actual dependencies.
144   for (const auto &Filename :
145        Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
146     if (D.getVFS().exists(Filename)) {
147       AlwaysInstrumentFiles.push_back(Filename);
148       ExtraDeps.push_back(Filename);
149     } else
150       D.Diag(clang::diag::err_drv_no_such_file) << Filename;
151   }
152 
153   for (const auto &Filename :
154        Args.getAllArgValues(options::OPT_fxray_never_instrument)) {
155     if (D.getVFS().exists(Filename)) {
156       NeverInstrumentFiles.push_back(Filename);
157       ExtraDeps.push_back(Filename);
158     } else
159       D.Diag(clang::diag::err_drv_no_such_file) << Filename;
160   }
161 
162   for (const auto &Filename :
163        Args.getAllArgValues(options::OPT_fxray_attr_list)) {
164     if (D.getVFS().exists(Filename)) {
165       AttrListFiles.push_back(Filename);
166       ExtraDeps.push_back(Filename);
167     } else
168       D.Diag(clang::diag::err_drv_no_such_file) << Filename;
169   }
170 
171   // Get the list of modes we want to support.
172   auto SpecifiedModes = Args.getAllArgValues(options::OPT_fxray_modes);
173   if (SpecifiedModes.empty())
174     llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
175   else
176     for (const auto &Arg : SpecifiedModes) {
177       // Parse CSV values for -fxray-modes=...
178       llvm::SmallVector<StringRef, 2> ModeParts;
179       llvm::SplitString(Arg, ModeParts, ",");
180       for (const auto &M : ModeParts)
181         if (M == "none")
182           Modes.clear();
183         else if (M == "all")
184           llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
185         else
186           Modes.push_back(std::string(M));
187     }
188 
189   if (const Arg *A = Args.getLastArg(options::OPT_fxray_function_groups)) {
190     StringRef S = A->getValue();
191     if (S.getAsInteger(0, XRayFunctionGroups) || XRayFunctionGroups < 1)
192       D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
193   }
194 
195   if (const Arg *A =
196           Args.getLastArg(options::OPT_fxray_selected_function_group)) {
197     StringRef S = A->getValue();
198     if (S.getAsInteger(0, XRaySelectedFunctionGroup) ||
199         XRaySelectedFunctionGroup < 0 ||
200         XRaySelectedFunctionGroup >= XRayFunctionGroups)
201       D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
202   }
203 
204   // Then we want to sort and unique the modes we've collected.
205   llvm::sort(Modes);
206   Modes.erase(std::unique(Modes.begin(), Modes.end()), Modes.end());
207 }
208 
209 void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
210                        ArgStringList &CmdArgs, types::ID InputType) const {
211   if (!XRayInstrument)
212     return;
213 
214   CmdArgs.push_back(XRayInstrumentOption);
215 
216   if (XRayAlwaysEmitCustomEvents)
217     CmdArgs.push_back("-fxray-always-emit-customevents");
218 
219   if (XRayAlwaysEmitTypedEvents)
220     CmdArgs.push_back("-fxray-always-emit-typedevents");
221 
222   if (XRayIgnoreLoops)
223     CmdArgs.push_back("-fxray-ignore-loops");
224 
225   if (!XRayFunctionIndex)
226     CmdArgs.push_back("-fno-xray-function-index");
227 
228   if (XRayFunctionGroups > 1) {
229     CmdArgs.push_back(Args.MakeArgString(Twine("-fxray-function-groups=") +
230                                          Twine(XRayFunctionGroups)));
231   }
232 
233   if (XRaySelectedFunctionGroup != 0) {
234     CmdArgs.push_back(
235         Args.MakeArgString(Twine("-fxray-selected-function-group=") +
236                            Twine(XRaySelectedFunctionGroup)));
237   }
238 
239   CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
240                                        Twine(InstructionThreshold)));
241 
242   for (const auto &Always : AlwaysInstrumentFiles) {
243     SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
244     AlwaysInstrumentOpt += Always;
245     CmdArgs.push_back(Args.MakeArgString(AlwaysInstrumentOpt));
246   }
247 
248   for (const auto &Never : NeverInstrumentFiles) {
249     SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
250     NeverInstrumentOpt += Never;
251     CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
252   }
253 
254   for (const auto &AttrFile : AttrListFiles) {
255     SmallString<64> AttrListFileOpt("-fxray-attr-list=");
256     AttrListFileOpt += AttrFile;
257     CmdArgs.push_back(Args.MakeArgString(AttrListFileOpt));
258   }
259 
260   for (const auto &Dep : ExtraDeps) {
261     SmallString<64> ExtraDepOpt("-fdepfile-entry=");
262     ExtraDepOpt += Dep;
263     CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
264   }
265 
266   for (const auto &Mode : Modes) {
267     SmallString<64> ModeOpt("-fxray-modes=");
268     ModeOpt += Mode;
269     CmdArgs.push_back(Args.MakeArgString(ModeOpt));
270   }
271 
272   SmallString<64> Bundle("-fxray-instrumentation-bundle=");
273   if (InstrumentationBundle.full()) {
274     Bundle += "all";
275   } else if (InstrumentationBundle.empty()) {
276     Bundle += "none";
277   } else {
278     if (InstrumentationBundle.has(XRayInstrKind::FunctionEntry) &&
279         InstrumentationBundle.has(XRayInstrKind::FunctionExit))
280       Bundle += "function";
281     else if (InstrumentationBundle.has(XRayInstrKind::FunctionEntry))
282       Bundle += "function-entry";
283     else if (InstrumentationBundle.has(XRayInstrKind::FunctionExit))
284       Bundle += "function-exit";
285 
286     if (InstrumentationBundle.has(XRayInstrKind::Custom))
287       Bundle += "custom";
288     if (InstrumentationBundle.has(XRayInstrKind::Typed))
289       Bundle += "typed";
290   }
291   CmdArgs.push_back(Args.MakeArgString(Bundle));
292 }
293