1 //===- lib/Support/CodeGenCoverage.cpp -------------------------------------==//
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 /// \file
10 /// This file implements the CodeGenCoverage class.
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/Support/CodeGenCoverage.h"
14
15 #include "llvm/Config/llvm-config.h"
16 #include "llvm/Support/Endian.h"
17 #include "llvm/Support/FileSystem.h"
18 #include "llvm/Support/MemoryBuffer.h"
19 #include "llvm/Support/Mutex.h"
20 #include "llvm/Support/ScopedPrinter.h"
21 #include "llvm/Support/ToolOutputFile.h"
22
23 #if LLVM_ON_UNIX
24 #include <unistd.h>
25 #elif _WIN32
26 #include <windows.h>
27 #endif
28
29 using namespace llvm;
30
31 static sys::SmartMutex<true> OutputMutex;
32
CodeGenCoverage()33 CodeGenCoverage::CodeGenCoverage() {}
34
setCovered(uint64_t RuleID)35 void CodeGenCoverage::setCovered(uint64_t RuleID) {
36 if (RuleCoverage.size() <= RuleID)
37 RuleCoverage.resize(RuleID + 1, 0);
38 RuleCoverage[RuleID] = true;
39 }
40
isCovered(uint64_t RuleID) const41 bool CodeGenCoverage::isCovered(uint64_t RuleID) const {
42 if (RuleCoverage.size() <= RuleID)
43 return false;
44 return RuleCoverage[RuleID];
45 }
46
47 iterator_range<CodeGenCoverage::const_covered_iterator>
covered() const48 CodeGenCoverage::covered() const {
49 return RuleCoverage.set_bits();
50 }
51
parse(MemoryBuffer & Buffer,StringRef BackendName)52 bool CodeGenCoverage::parse(MemoryBuffer &Buffer, StringRef BackendName) {
53 const char *CurPtr = Buffer.getBufferStart();
54
55 while (CurPtr != Buffer.getBufferEnd()) {
56 // Read the backend name from the input.
57 const char *LexedBackendName = CurPtr;
58 while (*CurPtr++ != 0)
59 ;
60 if (CurPtr == Buffer.getBufferEnd())
61 return false; // Data is invalid, expected rule id's to follow.
62
63 bool IsForThisBackend = BackendName.equals(LexedBackendName);
64 while (CurPtr != Buffer.getBufferEnd()) {
65 if (std::distance(CurPtr, Buffer.getBufferEnd()) < 8)
66 return false; // Data is invalid. Not enough bytes for another rule id.
67
68 uint64_t RuleID = support::endian::read64(CurPtr, support::native);
69 CurPtr += 8;
70
71 // ~0ull terminates the rule id list.
72 if (RuleID == ~0ull)
73 break;
74
75 // Anything else, is recorded or ignored depending on whether it's
76 // intended for the backend we're interested in.
77 if (IsForThisBackend)
78 setCovered(RuleID);
79 }
80 }
81
82 return true;
83 }
84
emit(StringRef CoveragePrefix,StringRef BackendName) const85 bool CodeGenCoverage::emit(StringRef CoveragePrefix,
86 StringRef BackendName) const {
87 if (!CoveragePrefix.empty() && !RuleCoverage.empty()) {
88 sys::SmartScopedLock<true> Lock(OutputMutex);
89
90 // We can handle locking within a process easily enough but we don't want to
91 // manage it between multiple processes. Use the process ID to ensure no
92 // more than one process is ever writing to the same file at the same time.
93 std::string Pid =
94 #if LLVM_ON_UNIX
95 llvm::to_string(::getpid());
96 #elif _WIN32
97 llvm::to_string(::GetCurrentProcessId());
98 #else
99 "";
100 #endif
101
102 std::string CoverageFilename = (CoveragePrefix + Pid).str();
103
104 std::error_code EC;
105 sys::fs::OpenFlags OpenFlags = sys::fs::F_Append;
106 std::unique_ptr<ToolOutputFile> CoverageFile =
107 llvm::make_unique<ToolOutputFile>(CoverageFilename, EC, OpenFlags);
108 if (EC)
109 return false;
110
111 uint64_t Zero = 0;
112 uint64_t InvZero = ~0ull;
113 CoverageFile->os() << BackendName;
114 CoverageFile->os().write((const char *)&Zero, sizeof(unsigned char));
115 for (uint64_t I : RuleCoverage.set_bits())
116 CoverageFile->os().write((const char *)&I, sizeof(uint64_t));
117 CoverageFile->os().write((const char *)&InvZero, sizeof(uint64_t));
118
119 CoverageFile->keep();
120 }
121
122 return true;
123 }
124
reset()125 void CodeGenCoverage::reset() { RuleCoverage.resize(0); }
126