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
21using namespace clang;
22using namespace clang::driver;
23using namespace llvm::opt;
24
25namespace {
26constexpr char XRayInstrumentOption[] = "-fxray-instrument";
27constexpr char XRayInstructionThresholdOption[] =
28    "-fxray-instruction-threshold=";
29constexpr const char *const XRaySupportedModes[] = {"xray-fdr", "xray-basic"};
30} // namespace
31
32XRayArgs::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.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_,
83                            options::OPT_fxray_instruction_threshold_EQ)) {
84      StringRef S = A->getValue();
85      if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
86        D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
87    }
88
89    // By default, the back-end will not emit the lowering for XRay customevent
90    // calls if the function is not instrumented. In the future we will change
91    // this default to be the reverse, but in the meantime we're going to
92    // introduce the new functionality behind a flag.
93    if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
94                     options::OPT_fnoxray_always_emit_customevents, false))
95      XRayAlwaysEmitCustomEvents = true;
96
97    if (Args.hasFlag(options::OPT_fxray_always_emit_typedevents,
98                     options::OPT_fnoxray_always_emit_typedevents, false))
99      XRayAlwaysEmitTypedEvents = true;
100
101    if (!Args.hasFlag(options::OPT_fxray_link_deps,
102                      options::OPT_fnoxray_link_deps, true))
103      XRayRT = false;
104
105    auto Bundles =
106        Args.getAllArgValues(options::OPT_fxray_instrumentation_bundle);
107    if (Bundles.empty())
108      InstrumentationBundle.Mask = XRayInstrKind::All;
109    else
110      for (const auto &B : Bundles) {
111        llvm::SmallVector<StringRef, 2> BundleParts;
112        llvm::SplitString(B, BundleParts, ",");
113        for (const auto &P : BundleParts) {
114          // TODO: Automate the generation of the string case table.
115          auto Valid = llvm::StringSwitch<bool>(P)
116                           .Cases("none", "all", "function", "custom", true)
117                           .Default(false);
118
119          if (!Valid) {
120            D.Diag(clang::diag::err_drv_invalid_value)
121                << "-fxray-instrumentation-bundle=" << P;
122            continue;
123          }
124
125          auto Mask = parseXRayInstrValue(P);
126          if (Mask == XRayInstrKind::None) {
127            InstrumentationBundle.clear();
128            break;
129          }
130
131          InstrumentationBundle.Mask |= Mask;
132        }
133      }
134
135    // Validate the always/never attribute files. We also make sure that they
136    // are treated as actual dependencies.
137    for (const auto &Filename :
138         Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
139      if (D.getVFS().exists(Filename)) {
140        AlwaysInstrumentFiles.push_back(Filename);
141        ExtraDeps.push_back(Filename);
142      } else
143        D.Diag(clang::diag::err_drv_no_such_file) << Filename;
144    }
145
146    for (const auto &Filename :
147         Args.getAllArgValues(options::OPT_fxray_never_instrument)) {
148      if (D.getVFS().exists(Filename)) {
149        NeverInstrumentFiles.push_back(Filename);
150        ExtraDeps.push_back(Filename);
151      } else
152        D.Diag(clang::diag::err_drv_no_such_file) << Filename;
153    }
154
155    for (const auto &Filename :
156         Args.getAllArgValues(options::OPT_fxray_attr_list)) {
157      if (D.getVFS().exists(Filename)) {
158        AttrListFiles.push_back(Filename);
159        ExtraDeps.push_back(Filename);
160      } else
161        D.Diag(clang::diag::err_drv_no_such_file) << Filename;
162    }
163
164    // Get the list of modes we want to support.
165    auto SpecifiedModes = Args.getAllArgValues(options::OPT_fxray_modes);
166    if (SpecifiedModes.empty())
167      llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
168    else
169      for (const auto &Arg : SpecifiedModes) {
170        // Parse CSV values for -fxray-modes=...
171        llvm::SmallVector<StringRef, 2> ModeParts;
172        llvm::SplitString(Arg, ModeParts, ",");
173        for (const auto &M : ModeParts)
174          if (M == "none")
175            Modes.clear();
176          else if (M == "all")
177            llvm::copy(XRaySupportedModes, std::back_inserter(Modes));
178          else
179            Modes.push_back(M);
180      }
181
182    // Then we want to sort and unique the modes we've collected.
183    llvm::sort(Modes);
184    Modes.erase(std::unique(Modes.begin(), Modes.end()), Modes.end());
185  }
186}
187
188void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
189                       ArgStringList &CmdArgs, types::ID InputType) const {
190  if (!XRayInstrument)
191    return;
192
193  CmdArgs.push_back(XRayInstrumentOption);
194
195  if (XRayAlwaysEmitCustomEvents)
196    CmdArgs.push_back("-fxray-always-emit-customevents");
197
198  if (XRayAlwaysEmitTypedEvents)
199    CmdArgs.push_back("-fxray-always-emit-typedevents");
200
201  CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
202                                       Twine(InstructionThreshold)));
203
204  for (const auto &Always : AlwaysInstrumentFiles) {
205    SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
206    AlwaysInstrumentOpt += Always;
207    CmdArgs.push_back(Args.MakeArgString(AlwaysInstrumentOpt));
208  }
209
210  for (const auto &Never : NeverInstrumentFiles) {
211    SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
212    NeverInstrumentOpt += Never;
213    CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
214  }
215
216  for (const auto &AttrFile : AttrListFiles) {
217    SmallString<64> AttrListFileOpt("-fxray-attr-list=");
218    AttrListFileOpt += AttrFile;
219    CmdArgs.push_back(Args.MakeArgString(AttrListFileOpt));
220  }
221
222  for (const auto &Dep : ExtraDeps) {
223    SmallString<64> ExtraDepOpt("-fdepfile-entry=");
224    ExtraDepOpt += Dep;
225    CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
226  }
227
228  for (const auto &Mode : Modes) {
229    SmallString<64> ModeOpt("-fxray-modes=");
230    ModeOpt += Mode;
231    CmdArgs.push_back(Args.MakeArgString(ModeOpt));
232  }
233
234  SmallString<64> Bundle("-fxray-instrumentation-bundle=");
235  if (InstrumentationBundle.full()) {
236    Bundle += "all";
237  } else if (InstrumentationBundle.empty()) {
238    Bundle += "none";
239  } else {
240    if (InstrumentationBundle.has(XRayInstrKind::Function))
241      Bundle += "function";
242    if (InstrumentationBundle.has(XRayInstrKind::Custom))
243      Bundle += "custom";
244    if (InstrumentationBundle.has(XRayInstrKind::Typed))
245      Bundle += "typed";
246  }
247  CmdArgs.push_back(Args.MakeArgString(Bundle));
248}
249