feat(util/exe_location): add function for finding the location of the executable

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/util/CMakeLists.txt

@@ -8,6 +8,6 @@ add_library(util trace.cpp debug.cpp name.cpp name_set.cpp
   exception.cpp interrupt.cpp hash.cpp escaped.cpp bit_tricks.cpp
   safe_arith.cpp ascii.cpp memory.cpp shared_mutex.cpp realpath.cpp
   script_state.cpp script_exception.cpp splay_map.cpp lua.cpp
-  luaref.cpp stackinfo.cpp ${THREAD_CPP})
+  luaref.cpp stackinfo.cpp exe_location.cpp ${THREAD_CPP})
 
 target_link_libraries(util ${LEAN_LIBS})

src/util/exe_location.cpp

@@ -0,0 +1,58 @@
+/*
+Copyright (c) 2013 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#include <string>
+#include "util/exception.h"
+
+namespace lean {
+static std::string g_exe_location;
+#if defined(LEAN_WINDOWS)
+// Windows version
+#include <windows.h>
+static void init_exe_location() {
+    HMODULE hModule = GetModuleHandleW(NULL);
+    WCHAR path[MAX_PATH];
+    GetModuleFileNameW(hModule, path, MAX_PATH);
+    g_exe_location = path;
+}
+#elif defined(__APPLE__)
+// OSX version
+#include <mach-o/dyld.h>
+#include <limits.h>
+static void init_exe_location() {
+    char buf[PATH_MAX];
+    uint32_t bufsize = PATH_MAX;
+    if (_NSGetExecutablePath(buf, &bufsize) != 0)
+        throw exception("failed to locate Lean executable location");
+    g_exe_location = buf;
+}
+#else
+// Linux version
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <limits.h> // NOLINT
+#include <stdio.h>
+static void init_exe_location() {
+    char path[PATH_MAX];
+    char dest[PATH_MAX];
+    pid_t pid = getpid();
+    snprintf(path, PATH_MAX, "/proc/%d/exe", pid);
+    if (readlink(path, dest, PATH_MAX) == -1) {
+        throw exception("failed to locate Lean executable location");
+    } else {
+        g_exe_location = dest;
+    }
+}
+#endif
+struct init_exe_location_proc {
+    init_exe_location_proc() { init_exe_location(); }
+};
+static init_exe_location_proc g_init_exe_location_proc;
+char const * get_exe_location() {
+    return g_exe_location.c_str();
+}
+}

src/util/exe_location.h

@@ -0,0 +1,10 @@
+/*
+Copyright (c) 2013 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#pragma once
+namespace lean {
+char const * get_exe_location();
+}