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 if (Triple.getOS() == llvm::Triple::FreeBSD) {
53         if (Triple.getArch() != llvm::Triple::x86_64) {
54           D.Diag(diag::err_drv_clang_unsupported)
55               << (std::string(XRayInstrumentOption) + " on " + Triple.str());
56         }
57     } else {
58       D.Diag(diag::err_drv_clang_unsupported)
59           << (std::string(XRayInstrumentOption) + " on non-supported target OS");
60     }
61     XRayInstrument = true;
62     if (const Arg *A =
63             Args.getLastArg(options::OPT_fxray_instruction_threshold_,
64                             options::OPT_fxray_instruction_threshold_EQ)) {
65       StringRef S = A->getValue();
66       if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
67         D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
68     }
69 
70     // By default, the back-end will not emit the lowering for XRay customevent
71     // calls if the function is not instrumented. In the future we will change
72     // this default to be the reverse, but in the meantime we're going to
73     // introduce the new functionality behind a flag.
74     if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
75                      options::OPT_fnoxray_always_emit_customevents, false))
76       XRayAlwaysEmitCustomEvents = true;
77 
78     // Validate the always/never attribute files. We also make sure that they
79     // are treated as actual dependencies.
80     for (const auto &Filename :
81          Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
82       if (llvm::sys::fs::exists(Filename)) {
83         AlwaysInstrumentFiles.push_back(Filename);
84         ExtraDeps.push_back(Filename);
85       } else
86         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
87     }
88 
89     for (const auto &Filename :
90          Args.getAllArgValues(options::OPT_fxray_never_instrument)) {
91       if (llvm::sys::fs::exists(Filename)) {
92         NeverInstrumentFiles.push_back(Filename);
93         ExtraDeps.push_back(Filename);
94       } else
95         D.Diag(clang::diag::err_drv_no_such_file) << Filename;
96     }
97   }
98 }
99 
100 void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
101                        ArgStringList &CmdArgs, types::ID InputType) const {
102   if (!XRayInstrument)
103     return;
104 
105   CmdArgs.push_back(XRayInstrumentOption);
106 
107   if (XRayAlwaysEmitCustomEvents)
108     CmdArgs.push_back("-fxray-always-emit-customevents");
109 
110   CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
111                                        Twine(InstructionThreshold)));
112 
113   for (const auto &Always : AlwaysInstrumentFiles) {
114     SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
115     AlwaysInstrumentOpt += Always;
116     CmdArgs.push_back(Args.MakeArgString(AlwaysInstrumentOpt));
117   }
118 
119   for (const auto &Never : NeverInstrumentFiles) {
120     SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
121     NeverInstrumentOpt += Never;
122     CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
123   }
124 
125   for (const auto &Dep : ExtraDeps) {
126     SmallString<64> ExtraDepOpt("-fdepfile-entry=");
127     ExtraDepOpt += Dep;
128     CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
129   }
130 }
131