intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 199 insertions, 0 deletions

diff --git a/util/system/execpath.cpp b/util/system/execpath.cpp
new file mode 100644
index 0000000000..33198af58b
--- /dev/null
+++ b/util/system/execpath.cpp
@@ -0,0 +1,199 @@
+#include "platform.h"
+
+#include <stdlib.h>
+
+#if defined(_solaris_)
+    #include <stdlib.h>
+#elif defined(_darwin_)
+    #include <mach-o/dyld.h>
+#elif defined(_win_)
+    #include "winint.h"
+    #include <io.h>
+#elif defined(_linux_)
+    #include <unistd.h>
+#elif defined(_freebsd_)
+    #include <string.h>
+    #include <sys/types.h> // for u_int not defined in sysctl.h
+    #include <sys/sysctl.h>
+    #include <unistd.h>
+#endif
+
+#include <util/folder/dirut.h>
+#include <util/generic/singleton.h>
+#include <util/generic/function.h>
+#include <util/generic/yexception.h>
+#include <util/memory/tempbuf.h>
+#include <util/stream/file.h>
+#include <util/stream/pipe.h>
+#include <util/string/cast.h>
+
+#include "filemap.h"
+#include "execpath.h"
+#include "fs.h"
+
+#if defined(_freebsd_)
+static inline bool GoodPath(const TString& path) {
+    return path.find('/') != TString::npos;
+}
+
+static inline int FreeBSDSysCtl(int* mib, size_t mibSize, TTempBuf& res) {
+    for (size_t i = 0; i < 2; ++i) {
+        size_t cb = res.Size();
+        if (sysctl(mib, mibSize, res.Data(), &cb, nullptr, 0) == 0) {
+            res.Proceed(cb);
+            return 0;
+        } else if (errno == ENOMEM) {
+            res = TTempBuf(cb);
+        } else {
+            return errno;
+        }
+    }
+    return errno;
+}
+
+static inline TString FreeBSDGetExecPath() {
+    int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+    TTempBuf buf;
+    int r = FreeBSDSysCtl(mib, Y_ARRAY_SIZE(mib), buf);
+    if (r == 0) {
+        return TString(buf.Data(), buf.Filled() - 1);
+    } else if (r == ENOTSUP) { // older FreeBSD version
+        /*
+         * BSD analogue for /proc/self is /proc/curproc.
+         * See:
+         * https://www.freebsd.org/cgi/man.cgi?query=procfs&sektion=5&format=html
+         */
+        TString path("/proc/curproc/file");
+        return NFs::ReadLink(path);
+    } else {
+        return TString();
+    }
+}
+
+static inline TString FreeBSDGetArgv0() {
+    int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_ARGS, getpid()};
+    TTempBuf buf;
+    int r = FreeBSDSysCtl(mib, Y_ARRAY_SIZE(mib), buf);
+    if (r == 0) {
+        return TString(buf.Data());
+    } else if (r == ENOTSUP) {
+        return TString();
+    } else {
+        ythrow yexception() << "FreeBSDGetArgv0() failed: " << LastSystemErrorText();
+    }
+}
+
+static inline bool FreeBSDGuessExecPath(const TString& guessPath, TString& execPath) {
+    if (NFs::Exists(guessPath)) {
+        // now it should work for real
+        execPath = FreeBSDGetExecPath();
+        if (RealPath(execPath) == RealPath(guessPath)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static inline bool FreeBSDGuessExecBasePath(const TString& guessBasePath, TString& execPath) {
+    return FreeBSDGuessExecPath(TString(guessBasePath) + "/" + getprogname(), execPath);
+}
+
+#endif
+
+static TString GetExecPathImpl() {
+#if defined(_solaris_)
+    return execname();
+#elif defined(_darwin_)
+    TTempBuf execNameBuf;
+    for (size_t i = 0; i < 2; ++i) {
+        std::remove_pointer_t<TFunctionArg<decltype(_NSGetExecutablePath), 1>> bufsize = execNameBuf.Size();
+        int r = _NSGetExecutablePath(execNameBuf.Data(), &bufsize);
+        if (r == 0) {
+            return execNameBuf.Data();
+        } else if (r == -1) {
+            execNameBuf = TTempBuf(bufsize);
+        }
+    }
+    ythrow yexception() << "GetExecPathImpl() failed";
+#elif defined(_win_)
+    TTempBuf execNameBuf;
+    for (;;) {
+        DWORD r = GetModuleFileName(nullptr, execNameBuf.Data(), execNameBuf.Size());
+        if (r == execNameBuf.Size()) {
+            execNameBuf = TTempBuf(execNameBuf.Size() * 2);
+        } else if (r == 0) {
+            ythrow yexception() << "GetExecPathImpl() failed: " << LastSystemErrorText();
+        } else {
+            return execNameBuf.Data();
+        }
+    }
+#elif defined(_linux_) || defined(_cygwin_)
+    TString path("/proc/self/exe");
+    return NFs::ReadLink(path);
+// TODO(yoda): check if the filename ends with " (deleted)"
+#elif defined(_freebsd_)
+    TString execPath = FreeBSDGetExecPath();
+    if (GoodPath(execPath)) {
+        return execPath;
+    }
+    if (FreeBSDGuessExecPath(FreeBSDGetArgv0(), execPath)) {
+        return execPath;
+    }
+    if (FreeBSDGuessExecPath(getenv("_"), execPath)) {
+        return execPath;
+    }
+    if (FreeBSDGuessExecBasePath(getenv("PWD"), execPath)) {
+        return execPath;
+    }
+    if (FreeBSDGuessExecBasePath(NFs::CurrentWorkingDirectory(), execPath)) {
+        return execPath;
+    }
+
+    ythrow yexception() << "can not resolve exec path";
+#else
+    #error dont know how to implement GetExecPath on this platform
+#endif
+}
+
+static bool GetPersistentExecPathImpl(TString& to) {
+#if defined(_solaris_)
+    to = TString("/proc/self/object/a.out");
+    return true;
+#elif defined(_linux_) || defined(_cygwin_)
+    to = TString("/proc/self/exe");
+    return true;
+#elif defined(_freebsd_)
+    to = TString("/proc/curproc/file");
+    return true;
+#else // defined(_win_) || defined(_darwin_)  or unknown
+    Y_UNUSED(to);
+    return false;
+#endif
+}
+
+namespace {
+    struct TExecPathsHolder {
+        inline TExecPathsHolder() {
+            ExecPath = GetExecPathImpl();
+
+            if (!GetPersistentExecPathImpl(PersistentExecPath)) {
+                PersistentExecPath = ExecPath;
+            }
+        }
+
+        static inline auto Instance() {
+            return SingletonWithPriority<TExecPathsHolder, 1>();
+        }
+
+        TString ExecPath;
+        TString PersistentExecPath;
+    };
+}
+
+const TString& GetExecPath() {
+    return TExecPathsHolder::Instance()->ExecPath;
+}
+
+const TString& GetPersistentExecPath() {
+    return TExecPathsHolder::Instance()->PersistentExecPath;
+}