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 } // 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_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
53       D.Diag(diag::err_drv_clang_unsupported)
54           << (std::string(XRayInstrumentOption) + " on non-Linux target OS");
55     XRayInstrument = true;
56     if (const Arg *A =
57             Args.getLastArg(options::OPT_fxray_instruction_threshold_,
58                             options::OPT_fxray_instruction_threshold_EQ)) {
59       StringRef S = A->getValue();
60       if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
61         D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
62     }
63 
64     // By default, the back-end will not emit the lowering for XRay customevent
65     // calls if the function is not instrumented. In the future we will change
66     // this default to be the reverse, but in the meantime we're going to
67     // introduce the new functionality behind a flag.
68     if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
69                      options::OPT_fnoxray_always_emit_customevents, false))
70       XRayAlwaysEmitCustomEvents = true;
71 
72     // Validate the always/never attribute files. We also make sure that they
73     // are treated as actual dependencies.
74     for (const auto &Filename :
75          Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
76       if (llvm::sys::fs::exists(Filename)) {
77         AlwaysInstrumentFiles.push_back(Filename);
78         ExtraDeps.push_back(Filename);
79       } else
80         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
81     }
82 
83     for (const auto &Filename :
84          Args.getAllArgValues(options::OPT_fxray_never_instrument)) {
85       if (llvm::sys::fs::exists(Filename)) {
86         NeverInstrumentFiles.push_back(Filename);
87         ExtraDeps.push_back(Filename);
88       } else
89         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
90     }
91   }
92 }
93 
94 void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
95                        ArgStringList &CmdArgs, types::ID InputType) const {
96   if (!XRayInstrument)
97     return;
98 
99   CmdArgs.push_back(XRayInstrumentOption);
100 
101   if (XRayAlwaysEmitCustomEvents)
102     CmdArgs.push_back("-fxray-always-emit-customevents");
103 
104   CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
105                                        Twine(InstructionThreshold)));
106 
107   for (const auto &Always : AlwaysInstrumentFiles) {
108     SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
109     AlwaysInstrumentOpt += Always;
110     CmdArgs.push_back(Args.MakeArgString(AlwaysInstrumentOpt));
111   }
112 
113   for (const auto &Never : NeverInstrumentFiles) {
114     SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
115     NeverInstrumentOpt += Never;
116     CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
117   }
118 
119   for (const auto &Dep : ExtraDeps) {
120     SmallString<64> ExtraDepOpt("-fdepfile-entry=");
121     ExtraDepOpt += Dep;
122     CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
123   }
124 }
125