1 //===-- Statistic.cpp - Easy way to expose stats information --------------===//
2 //
3 // This file implements the 'Statistic' class, which is designed to be an easy
4 // way to expose various success metrics from passes.  These statistics are
5 // printed at the end of a run, when the -stats command line option is enabled
6 // on the command line.
7 //
8 // This is useful for reporting information like the number of instructions
9 // simplified, optimized or removed by various transformations, like this:
10 //
11 // static Statistic<> NumInstEliminated("GCSE - Number of instructions killed");
12 //
13 // Later, in the code: ++NumInstEliminated;
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #include "Support/Statistic.h"
18 #include "Support/CommandLine.h"
19 #include <iostream>
20 #include <sstream>
21 #include <algorithm>
22 
23 // GetLibSupportInfoOutputFile - Return a file stream to print our output on...
24 std::ostream *GetLibSupportInfoOutputFile();
25 
26 bool DebugFlag;  // DebugFlag - Exported boolean set by the -debug option
27 
28 unsigned StatisticBase::NumStats = 0;
29 
30 // -stats - Command line option to cause transformations to emit stats about
31 // what they did.
32 //
33 static cl::opt<bool>
34 Enabled("stats", cl::desc("Enable statistics output from program"));
35 
36 #ifndef NDEBUG
37 // -debug - Command line option to enable the DEBUG statements in the passes.
38 // This flag may only be enabled in debug builds.
39 static cl::opt<bool, true>
40 Debug("debug", cl::desc("Enable debug output"), cl::Hidden,
41       cl::location(DebugFlag));
42 #endif
43 
44 struct StatRecord {
45   std::string Value;
46   const char *Name, *Desc;
47 
48   StatRecord(const std::string V, const char *N, const char *D)
49     : Value(V), Name(N), Desc(D) {}
50 
51   bool operator<(const StatRecord &SR) const {
52     return std::strcmp(Name, SR.Name) < 0;
53   }
54 
55   void print(unsigned ValFieldSize, unsigned NameFieldSize,
56              std::ostream &OS) {
57     OS << std::string(ValFieldSize-Value.length(), ' ')
58        << Value << " " << Name
59        << std::string(NameFieldSize-std::strlen(Name), ' ')
60        << " - " << Desc << "\n";
61   }
62 };
63 
64 static std::vector<StatRecord> *AccumStats = 0;
65 
66 // Print information when destroyed, iff command line option is specified
67 void StatisticBase::destroy() const {
68   if (Enabled && hasSomeData()) {
69     if (AccumStats == 0)
70       AccumStats = new std::vector<StatRecord>();
71 
72     std::ostringstream Out;
73     printValue(Out);
74     AccumStats->push_back(StatRecord(Out.str(), Name, Desc));
75   }
76 
77   if (--NumStats == 0 && AccumStats) {
78     std::ostream *OutStream = GetLibSupportInfoOutputFile();
79 
80     // Figure out how long the biggest Value and Name fields are...
81     unsigned MaxNameLen = 0, MaxValLen = 0;
82     for (unsigned i = 0, e = AccumStats->size(); i != e; ++i) {
83       MaxValLen = std::max(MaxValLen,
84                            (unsigned)(*AccumStats)[i].Value.length());
85       MaxNameLen = std::max(MaxNameLen,
86                             (unsigned)std::strlen((*AccumStats)[i].Name));
87     }
88 
89     // Sort the fields...
90     std::stable_sort(AccumStats->begin(), AccumStats->end());
91 
92     // Print out the statistics header...
93     *OutStream << "===" << std::string(73, '-') << "===\n"
94                << "                          ... Statistics Collected ...\n"
95                << "===" << std::string(73, '-') << "===\n\n";
96 
97     // Print all of the statistics accumulated...
98     for (unsigned i = 0, e = AccumStats->size(); i != e; ++i)
99       (*AccumStats)[i].print(MaxValLen, MaxNameLen, *OutStream);
100 
101     *OutStream << std::endl;  // Flush the output stream...
102 
103     // Free all accumulated statistics...
104     delete AccumStats;
105     AccumStats = 0;
106     if (OutStream != &std::cerr && OutStream != &std::cout)
107       delete OutStream;   // Close the file...
108   }
109 }
110