feat(util/lean_path): add support for LEAN_PATH

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

src/shell/CMakeLists.txt

@@ -13,6 +13,8 @@ add_test(lean_version1 ${CMAKE_CURRENT_BINARY_DIR}/lean --version)
 add_test(lean_version2 ${CMAKE_CURRENT_BINARY_DIR}/lean --v)
 add_test(lean_ghash1 ${CMAKE_CURRENT_BINARY_DIR}/lean -g)
 add_test(lean_ghash2 ${CMAKE_CURRENT_BINARY_DIR}/lean --githash)
+add_test(lean_path1 ${CMAKE_CURRENT_BINARY_DIR}/lean -p)
+add_test(lean_path2 ${CMAKE_CURRENT_BINARY_DIR}/lean --path)
 add_test(lean_luahook1 ${CMAKE_CURRENT_BINARY_DIR}/lean --luahook=100 "${LEAN_SOURCE_DIR}/../tests/lua/big.lua")
 add_test(lean_luahook2 ${CMAKE_CURRENT_BINARY_DIR}/lean -c 100 "${LEAN_SOURCE_DIR}/../tests/lua/big.lua")
 add_test(lean_lua1 ${LEAN_SOURCE_DIR}/cmake/redirect.sh "${CMAKE_CURRENT_BINARY_DIR}/lean" "--lua" "${LEAN_SOURCE_DIR}/../tests/lua/single.lua")

src/shell/lean.cpp

@@ -15,6 +15,7 @@ Author: Leonardo de Moura
 #include "util/interrupt.h"
 #include "util/script_state.h"
 #include "util/thread.h"
+#include "util/lean_path.h"
 #include "kernel/printer.h"
 #include "kernel/environment.h"
 #include "library/io_state.h"
@@ -55,6 +56,7 @@ static void display_help(std::ostream & out) {
     std::cout << "  --help -h         display this message\n";
     std::cout << "  --version -v      display version number\n";
     std::cout << "  --githash         display the git commit hash number used to build this binary\n";
+    std::cout << "  --path            display the path used for finding Lean libraries and extensions\n";
     std::cout << "  --luahook=num -c  how often the Lua interpreter checks the interrupted flag,\n";
     std::cout << "                    it is useful for interrupting non-terminating user scripts,\n";
     std::cout << "                    0 means 'do not check'.\n";
@@ -82,6 +84,7 @@ static struct option g_long_options[] = {
     {"help",       no_argument,       0, 'h'},
     {"lean",       no_argument,       0, 'l'},
     {"lua",        no_argument,       0, 'u'},
+    {"path",       no_argument,       0, 'p'},
     {"luahook",    required_argument, 0, 'c'},
     {"githash",    no_argument,       0, 'g'},
 #if defined(LEAN_USE_BOOST)
@@ -95,7 +98,7 @@ int main(int argc, char ** argv) {
     lean::register_modules();
     input_kind default_k = input_kind::Lean; // default
     while (true) {
-        int c = getopt_long(argc, argv, "lugvhc:012s:012", g_long_options, NULL);
+        int c = getopt_long(argc, argv, "lupgvhc:012s:012", g_long_options, NULL);
         if (c == -1)
             break; // end of command line
         switch (c) {
@@ -117,6 +120,9 @@ int main(int argc, char ** argv) {
         case 'c':
             script_state::set_check_interrupt_freq(atoi(optarg));
             break;
+        case 'p':
+            std::cout << lean::get_lean_path() << "\n";
+            return 0;
         case 's':
             lean::set_thread_stack_size(atoi(optarg)*1024);
             break;

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 exe_location.cpp ${THREAD_CPP})
+  luaref.cpp stackinfo.cpp lean_path.cpp ${THREAD_CPP})
 
 target_link_libraries(util ${LEAN_LIBS})

src/util/lean_path.cpp

@@ -5,29 +5,29 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 */
 #include <string>
+#include <cstdlib>
 #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() {
+static std::string get_exe_location() {
     HMODULE hModule = GetModuleHandleW(NULL);
     WCHAR path[MAX_PATH];
     GetModuleFileNameW(hModule, path, MAX_PATH);
-    g_exe_location = path;
+    return std::string(path);
 }
 #elif defined(__APPLE__)
 // OSX version
 #include <mach-o/dyld.h>
 #include <limits.h>
-static void init_exe_location() {
+static std::string get_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;
+    return std::string(buf);
 }
 #else
 // Linux version
@@ -36,7 +36,7 @@ static void init_exe_location() {
 #include <sys/stat.h>
 #include <limits.h> // NOLINT
 #include <stdio.h>
-static void init_exe_location() {
+static std::string get_exe_location() {
     char path[PATH_MAX];
     char dest[PATH_MAX];
     pid_t pid = getpid();
@@ -44,15 +44,22 @@ static void init_exe_location() {
     if (readlink(path, dest, PATH_MAX) == -1) {
         throw exception("failed to locate Lean executable location");
     } else {
-        g_exe_location = dest;
+        return std::string(dest);
     }
 }
 #endif
-struct init_exe_location_proc {
+static std::string g_lean_path;
-    init_exe_location_proc() { init_exe_location(); }
+struct init_lean_path {
+    init_lean_path() {
+        char * r = getenv("LEAN_PATH");
+        if (r == nullptr)
+            g_lean_path = get_exe_location();
+        else
+            g_lean_path = r;
+    }
 };
-static init_exe_location_proc g_init_exe_location_proc;
+static init_lean_path g_init_lean_path;
-char const * get_exe_location() {
+char const * get_lean_path() {
-    return g_exe_location.c_str();
+    return g_lean_path.c_str();
 }
 }

src/util/lean_path.h

@@ -6,5 +6,5 @@ Author: Leonardo de Moura
 */
 #pragma once
 namespace lean {
-char const * get_exe_location();
+char const * get_lean_path();
 }