Merge pull request #1921 from rouault/pj_get_relative_share_proj

Use relative directory to locate PROJ resource files.

11 files changed, 136 insertions, 42 deletions

diff --git a/cmake/ProjConfig.cmake b/cmake/ProjConfig.cmake
index 661e6e4f..fa085384 100644
--- a/cmake/ProjConfig.cmake
+++ b/cmake/ProjConfig.cmake
@@ -25,9 +25,11 @@ check_include_files("stdlib.h;stdarg.h;string.h;float.h" STDC_HEADERS)
 
 check_function_exists(localeconv HAVE_LOCALECONV)
 check_function_exists(strerror HAVE_STRERROR)
-
-# check libm need on unix
-check_library_exists(m ceil "" HAVE_LIBM)
+if(NOT WIN32)
+    check_library_exists(dl dladdr "" HAVE_LIBDL)
+    # check libm need on unix
+    check_library_exists(m ceil "" HAVE_LIBM)
+endif()
 
 set(PACKAGE "proj")
 set(PACKAGE_BUGREPORT "https://github.com/OSGeo/PROJ/issues")
diff --git a/cmake/proj_config.cmake.in b/cmake/proj_config.cmake.in
index d8385ce9..ddb24347 100644
--- a/cmake/proj_config.cmake.in
+++ b/cmake/proj_config.cmake.in
@@ -4,6 +4,9 @@
 /* Define to 1 if you have the <inttypes.h> header file. */
 #cmakedefine HAVE_INTTYPES_H 1
 
+/* Define to 1 if you have the `dl' library (-ldl). */
+#cmakedefine HAVE_LIBDL 1
+
 /* Define to 1 if you have the `m' library (-lm). */
 #cmakedefine HAVE_LIBM 1
 
diff --git a/configure.ac b/configure.ac
index fba41302..ea8c7eb4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -199,6 +199,7 @@ AC_SEARCH_LIBS([sqrt], [m])
 
 AC_CHECK_FUNC(localeconv, [AC_DEFINE(HAVE_LOCALECONV,1,[Define to 1 if you have localeconv])])
 AC_CHECK_FUNCS([strerror])
+AC_CHECK_LIB(dl,dladdr,,,)
 
 dnl ---------------------------------------------------------------------------
 dnl Provide a mechanism to disable real mutex support (if lacking win32 or
diff --git a/docs/source/resource_files.rst b/docs/source/resource_files.rst
index 28628d30..48120982 100644
--- a/docs/source/resource_files.rst
+++ b/docs/source/resource_files.rst
@@ -23,8 +23,8 @@ PROJ will attempt to locate its resource files - database, transformation grids
 or init-files - from several directories.
 The following paths are checked in order:
 
-- For transformation grids that have an explict relative or absolute path,
-  the directory specified in the grid filename.
+- For resource files that have an explict relative or absolute path,
+  the directory specified in the filename.
 
 - Path resolved by the callback function set with
   the :c:func:`proj_context_set_file_finder`. If it is set, the next tests
@@ -35,7 +35,9 @@ The following paths are checked in order:
 
 .. _user_writable_directory:
 
-- The PROJ user writable directory, which is :
+- .. versionadded:: 7.0
+
+  The PROJ user writable directory, which is :
 
     * on Windows, ${LOCALAPPDATA}/proj
     * on MacOSX, ${HOME}/Library/Application Support/proj
@@ -45,13 +47,16 @@ The following paths are checked in order:
 - Path(s) set with by the environment variable :envvar:`PROJ_LIB`.
   On Linux/MacOSX/Unix, use ``:`` to separate paths. On Windows, ``;``
 
-- On Windows, the *..\\share\\proj\\* and its contents are found automatically
+- .. versionadded:: 7.0
+
+  The *../share/proj/* and its contents are found automatically
   at run-time if the installation respects the build structure. That is, the
-  binaries and proj.dll are installed under *..\\bin\\*, and resource files
-  are in *..\\share\\proj\\*.
+  binaries and proj.dll/libproj.so are installed under *../bin/* or *../lib/*,
+  and resource files are in *../share/proj/*.
 
 - A path built into PROJ as its resource installation directory (whose value is
-  $(pkgdatadir)), for builds using the Makefile build system. Note, however,
+  $(pkgdatadir) for builds using the Makefile build system or
+  ${CMAKE_INSTALL_PREFIX}/${DATADIR} for CMake builds). Note, however,
   that since this is a hard-wired path setting, it only works if the whole
   PROJ installation is not moved somewhere else.
 
diff --git a/scripts/reference_exported_symbols.txt b/scripts/reference_exported_symbols.txt
index d624a893..01f8204b 100644
--- a/scripts/reference_exported_symbols.txt
+++ b/scripts/reference_exported_symbols.txt
@@ -282,6 +282,7 @@ osgeo::proj::datum::VerticalReferenceFrame::create(osgeo::proj::util::PropertyMa
 osgeo::proj::datum::VerticalReferenceFrame::realizationMethod() const
 osgeo::proj::datum::VerticalReferenceFrame::~VerticalReferenceFrame()
 osgeo::proj::File::~File()
+osgeo::proj::FileManager::exists(projCtx_t*, char const*)
 osgeo::proj::FileManager::open(projCtx_t*, char const*, osgeo::proj::FileAccess)
 osgeo::proj::File::read_line(unsigned long, bool&, bool&)
 osgeo::proj::GenericShiftGrid::~GenericShiftGrid()
@@ -780,6 +781,7 @@ pj_get_default_ctx
 pj_get_default_fileapi
 pj_get_default_searchpaths(projCtx_t*)
 pj_get_errno_ref
+pj_get_relative_share_proj(projCtx_t*)
 pj_get_release
 pj_get_spheroid_defn
 pj_has_inverse
diff --git a/src/apps/projsync.cpp b/src/apps/projsync.cpp
index 40848f51..61681260 100644
--- a/src/apps/projsync.cpp
+++ b/src/apps/projsync.cpp
@@ -137,7 +137,12 @@ int main(int argc, char *argv[]) {
         } else if (arg == "--user-writable-directory") {
             // do nothing
         } else if (arg == "--system-directory") {
-            targetDir = PROJ_LIB;
+            targetDir = pj_get_relative_share_proj(ctx);
+#ifdef PROJ_LIB
+            if (targetDir.empty()) {
+                targetDir = PROJ_LIB;
+            }
+#endif
         } else if (arg == "--target-dir" && i + 1 < argc) {
             i++;
             targetDir = argv[i];
diff --git a/src/filemanager.cpp b/src/filemanager.cpp
index aea9b11d..a90af572 100644
--- a/src/filemanager.cpp
+++ b/src/filemanager.cpp
@@ -46,9 +46,15 @@
 
 #include <sys/stat.h>
 
+#include "proj_config.h"
+
 #ifdef _WIN32
 #include <shlobj.h>
+#include <windows.h>
 #else
+#ifdef HAVE_LIBDL
+#include <dlfcn.h>
+#endif
 #include <sys/types.h>
 #include <unistd.h>
 #endif
@@ -1264,13 +1270,15 @@ static bool is_rel_or_absolute_filename(const char *name) {
 
 // ---------------------------------------------------------------------------
 
+static std::string pj_get_relative_share_proj_internal_no_check() {
+#if defined(_WIN32) || defined(HAVE_LIBDL)
 #ifdef _WIN32
-
-static std::string pj_get_win32_projlib() {
-    /* Check if proj.db lieves in a share/proj dir parallel to bin/proj.dll */
-    /* Based in
-     * https://stackoverflow.com/questions/9112893/how-to-get-path-to-executable-in-c-running-on-windows
-     */
+    HMODULE hm = NULL;
+    if (GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
+                              GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+                          (LPCSTR)&pj_get_relative_share_proj, &hm) == 0) {
+        return std::string();
+    }
 
     DWORD path_size = 1024;
 
@@ -1278,7 +1286,7 @@ static std::string pj_get_win32_projlib() {
     for (;;) {
         wout.clear();
         wout.resize(path_size);
-        DWORD result = GetModuleFileNameW(nullptr, &wout[0], path_size - 1);
+        DWORD result = GetModuleFileNameW(hm, &wout[0], path_size - 1);
         DWORD last_error = GetLastError();
 
         if (result == 0) {
@@ -1292,26 +1300,79 @@ static std::string pj_get_win32_projlib() {
             break;
         }
     }
-    // Now remove the program's name. It was (example)
-    // "C:\programs\gmt6\bin\gdal_translate.exe"
     wout.resize(wcslen(wout.c_str()));
     std::string out = NS_PROJ::WStringToUTF8(wout);
-    size_t k = out.size();
-    while (k > 0 && out[--k] != '\\') {
+    constexpr char dir_sep = '\\';
+#else
+    Dl_info info;
+    if (!dladdr((const void *)pj_get_relative_share_proj, &info)) {
+        return std::string();
     }
-    out.resize(k);
-
-    out += "/../share/proj";
+    std::string out(info.dli_fname);
+    constexpr char dir_sep = '/';
+    // "optimization" for cmake builds where RUNPATH is set to ${prefix}/lib
+    out = replaceAll(out, "/bin/../", "/");
+#ifdef __linux
+    // If we get a filename without any path, this is most likely a static
+    // binary. Resolve the executable name
+    if (out.find(dir_sep) == std::string::npos) {
+        constexpr size_t BUFFER_SIZE = 1024;
+        std::vector<char> path(BUFFER_SIZE + 1);
+        ssize_t nResultLen = readlink("/proc/self/exe", &path[0], BUFFER_SIZE);
+        if (nResultLen >= 0 && static_cast<size_t>(nResultLen) < BUFFER_SIZE) {
+            out.assign(path.data(), static_cast<size_t>(nResultLen));
+        }
+    }
+#endif
+    if (starts_with(out, "./"))
+        out = out.substr(2);
+#endif
+    auto pos = out.find_last_of(dir_sep);
+    if (pos == std::string::npos) {
+        // The initial path was something like libproj.so"
+        out = "../share/proj";
+        return out;
+    }
+    out.resize(pos);
+    pos = out.find_last_of(dir_sep);
+    if (pos == std::string::npos) {
+        // The initial path was something like bin/libproj.so"
+        out = "share/proj";
+        return out;
+    }
+    out.resize(pos);
+    // The initial path was something like foo/bin/libproj.so"
+    out += "/share/proj";
     return out;
+#else
+    return std::string();
+#endif
 }
 
-// ---------------------------------------------------------------------------
+static std::string
+pj_get_relative_share_proj_internal_check_exists(PJ_CONTEXT *ctx) {
+    if (ctx == nullptr) {
+        ctx = pj_get_default_ctx();
+    }
+    std::string path(pj_get_relative_share_proj_internal_no_check());
+    if (!path.empty() && NS_PROJ::FileManager::exists(ctx, path.c_str())) {
+        return path;
+    }
+    return std::string();
+}
 
-static const char *get_path_from_win32_projlib(PJ_CONTEXT *ctx,
-                                               const char *name,
-                                               std::string &out) {
+std::string pj_get_relative_share_proj(PJ_CONTEXT *ctx) {
+    static std::string path(
+        pj_get_relative_share_proj_internal_check_exists(ctx));
+    return path;
+}
 
-    out = pj_get_win32_projlib();
+// ---------------------------------------------------------------------------
+
+static const char *get_path_from_relative_share_proj(PJ_CONTEXT *ctx,
+                                                     const char *name,
+                                                     std::string &out) {
+    out = pj_get_relative_share_proj(ctx);
     if (out.empty()) {
         return nullptr;
     }
@@ -1322,8 +1383,6 @@ static const char *get_path_from_win32_projlib(PJ_CONTEXT *ctx,
                                                           : nullptr;
 }
 
-#endif
-
 /************************************************************************/
 /*                      pj_open_lib_internal()                          */
 /************************************************************************/
@@ -1442,11 +1501,9 @@ pj_open_lib_internal(projCtx ctx, const char *name, const char *mode,
                 if (fid)
                     break;
             }
-#ifdef _WIN32
             /* check if it lives in a ../share/proj dir of the proj dll */
-        } else if ((sysname = get_path_from_win32_projlib(ctx, name, fname)) !=
-                   nullptr) {
-#endif
+        } else if ((sysname = get_path_from_relative_share_proj(
+                        ctx, name, fname)) != nullptr) {
             /* or hardcoded path */
         } else if ((sysname = proj_lib_name) != nullptr) {
             fname = sysname;
@@ -1503,14 +1560,12 @@ std::vector<std::string> pj_get_default_searchpaths(PJ_CONTEXT *ctx) {
     if (!envPROJ_LIB.empty()) {
         ret.push_back(envPROJ_LIB);
     }
-#ifdef _WIN32
     if (envPROJ_LIB.empty()) {
-        const std::string win32Dir = pj_get_win32_projlib();
-        if (!win32Dir.empty()) {
-            ret.push_back(win32Dir);
+        const std::string relativeSharedProj = pj_get_relative_share_proj(ctx);
+        if (!relativeSharedProj.empty()) {
+            ret.push_back(relativeSharedProj);
         }
     }
-#endif
 #ifdef PROJ_LIB
     if (envPROJ_LIB.empty()) {
         ret.push_back(PROJ_LIB);
diff --git a/src/filemanager.hpp b/src/filemanager.hpp
index 9446a0bc..233c657c 100644
--- a/src/filemanager.hpp
+++ b/src/filemanager.hpp
@@ -55,7 +55,7 @@ class FileManager {
     // "Low-level" interface.
     static PROJ_DLL std::unique_ptr<File>
     open(PJ_CONTEXT *ctx, const char *filename, FileAccess access);
-    static bool exists(PJ_CONTEXT *ctx, const char *filename);
+    static PROJ_DLL bool exists(PJ_CONTEXT *ctx, const char *filename);
     static bool mkdir(PJ_CONTEXT *ctx, const char *filename);
     static bool unlink(PJ_CONTEXT *ctx, const char *filename);
     static bool rename(PJ_CONTEXT *ctx, const char *oldPath,
diff --git a/src/lib_proj.cmake b/src/lib_proj.cmake
index 3c42f973..d14a48c6 100644
--- a/src/lib_proj.cmake
+++ b/src/lib_proj.cmake
@@ -415,6 +415,10 @@ if(UNIX)
   if(M_LIB)
     target_link_libraries(${PROJ_CORE_TARGET} -lm)
   endif()
+  find_library(DL_LIB dl)
+  if(M_LIB)
+    target_link_libraries(${PROJ_CORE_TARGET} -ldl)
+  endif()
 endif()
 if(USE_THREAD AND Threads_FOUND AND CMAKE_USE_PTHREADS_INIT)
   target_link_libraries(${PROJ_CORE_TARGET} ${CMAKE_THREAD_LIBS_INIT})
diff --git a/src/proj_internal.h b/src/proj_internal.h
index 557c61cb..0cffb475 100644
--- a/src/proj_internal.h
+++ b/src/proj_internal.h
@@ -874,6 +874,7 @@ std::string PROJ_DLL pj_context_get_grid_cache_filename(PJ_CONTEXT *ctx);
 // For use by projsync
 std::string PROJ_DLL pj_context_get_user_writable_directory(PJ_CONTEXT *ctx, bool create);
 void PROJ_DLL pj_context_set_user_writable_directory(PJ_CONTEXT* ctx, const std::string& path);
+std::string PROJ_DLL pj_get_relative_share_proj(PJ_CONTEXT *ctx);
 
 /* classic public API */
 #include "proj_api.h"
diff --git a/travis/install.sh b/travis/install.sh
index 953a7f0b..b0c16881 100755
--- a/travis/install.sh
+++ b/travis/install.sh
@@ -82,6 +82,14 @@ if [ "$SKIP_BUILDS_WITHOUT_GRID" != "yes" ]; then
 
     cd ..
 
+    if [ $TRAVIS_OS_NAME != "osx" ]; then
+        # Check that we can retrieve the resource directory in a relative way after renaming the installation prefix
+        mkdir /tmp/proj_autoconf_install_from_dist_all_renamed
+        mv /tmp/proj_autoconf_install_from_dist_all /tmp/proj_autoconf_install_from_dist_all_renamed/subdir
+        LD_LIBRARY_PATH=/tmp/proj_autoconf_install_from_dist_all_renamed/subdir/lib /tmp/proj_autoconf_install_from_dist_all_renamed/subdir/bin/projsync --source-id ? --dry-run --system-directory || /bin/true
+        LD_LIBRARY_PATH=/tmp/proj_autoconf_install_from_dist_all_renamed/subdir/lib /tmp/proj_autoconf_install_from_dist_all_renamed/subdir/bin/projsync --source-id ? --dry-run --system-directory 2>/dev/null | grep "Downloading from https://cdn.proj.org into /tmp/proj_autoconf_install_from_dist_all_renamed/subdir/share/proj"
+    fi
+
     # cmake build from generated tarball
     mkdir build_cmake
     cd build_cmake
@@ -92,6 +100,14 @@ if [ "$SKIP_BUILDS_WITHOUT_GRID" != "yes" ]; then
     find /tmp/proj_cmake_install
     cd ..
 
+    if [ $TRAVIS_OS_NAME != "osx" ]; then
+        # Check that we can retrieve the resource directory in a relative way after renaming the installation prefix
+        mkdir /tmp/proj_cmake_install_renamed
+        mv /tmp/proj_cmake_install /tmp/proj_cmake_install_renamed/subdir
+        /tmp/proj_cmake_install_renamed/subdir/bin/projsync --source-id ? --dry-run --system-directory || /bin/true
+        /tmp/proj_cmake_install_renamed/subdir/bin/projsync --source-id ? --dry-run --system-directory 2>/dev/null | grep "Downloading from https://cdn.proj.org into /tmp/proj_cmake_install_renamed/subdir/share/proj"
+    fi
+
     # return to root
     cd ../..
 fi