diff options
author | Dean Michael Berris <dberris@google.com> | 2017-01-03 04:35:24 +0000 |
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committer | Dean Michael Berris <dberris@google.com> | 2017-01-03 04:35:24 +0000 |
commit | 55278303a867879391300d56e1a390b7db57e689 (patch) | |
tree | 1bdf91d720f19e5ac4c43ab42708b4930de50e61 /lib/xray/xray_inmemory_log.cc | |
parent | b92697bddf3ec2631db9e850b6a885636748c08f (diff) |
[XRay] [compiler-rt] Include argv[0] in the log file name.
Summary:
If you decide to recompile parts of your Linux distro with XRay, it may
be useful to know which trace belongs to which binary. While there, get
rid of the incorrect strncat() usage; it always returns a pointer to the
start which makes that if() always true. Replace with snprintf which is
bounded so that enough from both strings fits nicely.
Reviewers: dberris
Subscribers: danalbert, srhines, kubabrecka, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D27912
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@290861 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/xray/xray_inmemory_log.cc')
-rw-r--r-- | lib/xray/xray_inmemory_log.cc | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/lib/xray/xray_inmemory_log.cc b/lib/xray/xray_inmemory_log.cc index 7ec56f486..adcb21671 100644 --- a/lib/xray/xray_inmemory_log.cc +++ b/lib/xray/xray_inmemory_log.cc @@ -112,14 +112,23 @@ static int __xray_OpenLogFile() XRAY_NEVER_INSTRUMENT { // Open a temporary file once for the log. static char TmpFilename[256] = {}; static char TmpWildcardPattern[] = "XXXXXX"; - auto E = internal_strncat(TmpFilename, flags()->xray_logfile_base, - sizeof(TmpFilename) - 10); - if (static_cast<size_t>((E + 6) - TmpFilename) > (sizeof(TmpFilename) - 1)) { - Report("XRay log file base too long: %s\n", flags()->xray_logfile_base); + auto Argv = GetArgv(); + const char *Progname = Argv[0] == nullptr ? "(unknown)" : Argv[0]; + const char *LastSlash = internal_strrchr(Progname, '/'); + + if (LastSlash != nullptr) + Progname = LastSlash + 1; + + const int HalfLength = sizeof(TmpFilename) / 2 - sizeof(TmpWildcardPattern); + int NeededLength = internal_snprintf(TmpFilename, sizeof(TmpFilename), + "%.*s%.*s.%s", + HalfLength, flags()->xray_logfile_base, + HalfLength, Progname, + TmpWildcardPattern); + if (NeededLength > int(sizeof(TmpFilename))) { + Report("XRay log file name too long (%d): %s\n", NeededLength, TmpFilename); return -1; } - internal_strncat(TmpFilename, TmpWildcardPattern, - sizeof(TmpWildcardPattern) - 1); int Fd = mkstemp(TmpFilename); if (Fd == -1) { Report("XRay: Failed opening temporary file '%s'; not logging events.\n", |