src/ld/Snapshot.h

   1 //
   2 //  Snapshot.h
   3 //  ld64
   4 //
   5 //  Created by Josh Behnke on 8/25/11.
   6 //  Copyright (c) 2011 Apple Inc. All rights reserved.
   7 //
   8
   9 #ifndef ld64_Snapshot_h
  10 #define ld64_Snapshot_h
  11 #include <stdint.h>
  12 #include <string.h>
  13 #include <map>
  14 #include <vector>
  15
  16 #include "ld.hpp"
  17
  18 class Options;
  19 class SnapshotLogItem;
  20
  21 class Snapshot {
  22
  23 public:
  24     static Snapshot *globalSnapshot;
  25
  26     typedef enum {
  27         SNAPSHOT_DISABLED, // nothing is recorded
  28         SNAPSHOT_DEBUG, // records: .o, .dylib, .framework, .a, and other data files
  29     } SnapshotMode;
  30
  31     Snapshot();
  32     ~Snapshot();
  33
  34     // Control the data captured in the snapshot
  35     void setSnapshotMode(SnapshotMode mode);
  36
  37     // Use the basename of path to construct the snapshot name.
  38     // Must be called prior to createSnapshot().
  39     void setSnapshotName(const char *path);
  40
  41     // Set the directory in which the snapshot will be created.
  42     // Must be called prior to createSnapshot().
  43     void setSnapshotPath(const char *path);
  44
  45     // Stores the linker command line in the snapshot
  46     void recordRawArgs(int argc, const char *argv[]);
  47
  48     // Adds one or more args to the snapshot link command.
  49     // argIndex is the index in the original raw args vector to start adding args
  50     // argCount is the count of args to copy from the raw args vector
  51     // fileArg is the index relative to argIndex of a file arg. The file is copied into the
  52     // snapshot and the path is fixed up in the snapshot link command. (skipped if fileArg==-1)
  53     // recordRawArgs() must be called prior to the first call to addSnapshotLinkArg()
  54     void addSnapshotLinkArg(int argIndex, int argCount=1, int fileArg=-1);
  55
  56     // record the -arch string
  57     void recordArch(const char *arch);
  58
  59     // Stores an object file in the snapshot, using a unique name in an "objects" subdir.
  60     void recordObjectFile(const char *path);
  61
  62     // Records symbol names used in dylibs. Does not store anything in the snapshot.
  63     void recordDylibSymbol(ld::dylib::File* dylibFile, const char *name);
  64
  65     // Stores an archive (.a) file in the snapshot.
  66     void recordArchive(const char *archiveFile);
  67
  68     // Copies the framework binary into the snapshot frameworks directory.
  69     void recordSubUmbrella(const char *frameworkPath);
  70
  71     // Copies the library binary into the snapshot dylibs directory.
  72     void recordSubLibrary(const char *dylibPath);
  73
  74     // Records arbitrary text messages into a log file in the snapshot.
  75     // Used by the assertion failure machienery.
  76     void recordAssertionMessage(const char *fmt, ...);
  77
  78     // Create the snapshot.
  79     // Until this is called the snapshot operates lazily, storing minimal data in memory.
  80     // When this is called the snapshot is created and any previously recorded data is
  81     // immediately copied. Any subsequent additions to the snapshot are copied immediately.
  82     void createSnapshot();
  83
  84     // Returns the snapshot root directory.
  85     const char *rootDir() { return fRootDir; }
  86
  87 private:
  88
  89     friend class SnapshotArchiveFileLog;
  90
  91     typedef std::vector<void(^)(void)> SnapshotLog;
  92
  93     struct strcompclass {
  94         bool operator() (const char *a, const char *b) const { return ::strcmp(a, b) < 0; }
  95     };
  96     typedef std::vector<const char *> StringVector;
  97     typedef std::map<const char *, int, strcompclass > DylibMap;
  98     typedef std::map<const char *, const char *, strcompclass> PathMap;
  99
 100
 101     // Write the current contents of the args vector to a file in the snapshot.
 102     // If filename is NULL then "link_command" is used.
 103     // This is used to write both the original and the "cooked" versions of the link command
 104     void writeCommandLine(StringVector &args, const char *filename=NULL, bool includeCWD=false);
 105
 106     // Construct a path in the snapshot.
 107     // buf is a sring buffer in which the path is constructed
 108     // subdir is an optional subdirectory, and file is a file name
 109     // Constructs the path <snapshot_root>/<subdir>/<file> in buf
 110     void buildPath(char *buf, const char *subdir, const char *file);
 111
 112     // Similar to buildPath(), except this ensures the returned path
 113     // does not reference an existing file in the snapshot.
 114     // Performs uniquing by appending a count suffex to the path (ie .../file-XX)
 115     void buildUniquePath(char *buf, const char *subdir, const char *file);
 116
 117     // Copies an arbitrary file to the snapshot. Subdir specifies an optional subdirectory name.
 118     // Uses buildUniquePath to construct a unique path. If the result path is needed by the caller
 119     // then a path buffer can be supplied in buf. Otherwise an internal buffer is used.
 120     void copyFileToSnapshot(const char *sourcePath, const char *subdir, char *buf=NULL);
 121
 122     // Convert a full path to snapshot relative by constructing an interior pointer at the right offset.
 123     const char *snapshotRelativePath(const char *path) { return path+strlen(fRootDir)+1; }
 124
 125     // returns true if the snapshot has not been created (by createSnapshot()) yet
 126     bool isLazy() { return fRootDir == NULL; }
 127
 128     void addFrameworkArg(const char *framework);
 129     void addDylibArg(const char *dylib);
 130
 131     SnapshotLog fLog;           // log of events that recorded data in a snapshot prior to createSnapshot()
 132     bool fRecordArgs;           // record command line
 133     bool fRecordObjects;        // record .o files
 134     bool fRecordDylibSymbols;   // record referenced dylib/framework symbols
 135     bool fRecordArchiveFiles;   // record .a files
 136     bool fRecordUmbrellaFiles;  // record re-exported sub frameworks/dylibs
 137     bool fRecordDataFiles;      // record other data files
 138     bool fFrameworkArgAdded;
 139
 140     const char *fSnapshotLocation; // parent directory of frootDir
 141     const char *fSnapshotName;    // a string to use in constructing the snapshot name
 142     char *fRootDir;             // root directory of the snapshot
 143     int fFilelistFile;          // file descriptor to the open text file used for the -filelist
 144
 145     StringVector fRawArgs;      // stores the raw command line args
 146     StringVector fArgs;         // stores the "cooked" command line args
 147     PathMap fPathMap;           // mapping of original paths->snapshot paths for copied files
 148
 149     DylibMap fDylibSymbols;    // map of dylib names to string vector containing referenced symbol names
 150     StringVector *fCopiedArchives;  // vector of .a files that have been copied to the snapshot
 151 };
 152
 153 #endif