Add init flags and make init less intrusive by default (fixes #64)

cmake/geogram.cmake

@@ -46,7 +46,7 @@ if(NOT DEFINED GEOGRAM_WITH_EXPLORAGRAM)
    else()
       set(GEOGRAM_WITH_EXPLORAGRAM OFF)
    endif()
-endif()   
+endif()
 
 if (GEOGRAM_WITH_GEOGRAMPLUS)
    message(STATUS "addon: geogramplus")

src/lib/geogram/CMakeLists.txt

@@ -47,6 +47,8 @@ include_directories(${PROJECT_BINARY_DIR}/src/lib)
 
 add_library(geogram ${SOURCES} $<TARGET_OBJECTS:geogram_third_party>)
 
+target_compile_features(geogram PUBLIC cxx_std_17)
+
 target_include_directories(geogram PRIVATE
     ${PROJECT_SOURCE_DIR}/src/lib/geogram/third_party/amgcl
 )

src/lib/geogram/basic/common.cpp

@@ -59,28 +59,34 @@
 
 #include <sstream>
 #include <iomanip>
+#include <optional>
 
 #ifdef GEO_OS_EMSCRIPTEN
 #include <emscripten.h>
 #endif
 
 namespace GEO {
 
-    void initialize(int flags) {
-    static bool initialized = false;
+namespace {
 
-    if(initialized) {
-        return;
-    }
+struct MySingleton {
+        static std::optional<MySingleton>& instance(int flags) {
+                static std::optional<MySingleton> instance(flags);
+                return instance;
+        }
 
+        MySingleton(int flags) {
+
         // When locale is set to non-us countries,
         // this may cause some problems when reading
         // floating-point numbers (some locale expect
         // a decimal ',' instead of a '.').
         // This restores the default behavior for
         // reading floating-point numbers.
 #ifdef GEO_OS_UNIX
-        setenv("LC_NUMERIC","POSIX",1);
+        if (flags & GEOGRAM_INSTALL_LOCALE) {
+                setenv("LC_NUMERIC","POSIX",1);
+        }
 #endif
 
 #ifndef GEOGRAM_PSM
@@ -99,16 +105,19 @@ namespace GEO {
         Delaunay::initialize();
 
 #ifndef GEOGRAM_PSM
-    Biblio::initialize();
+        if (flags & GEOGRAM_INSTALL_BIBLIO) {
+                Biblio::initialize();
+        }
 #endif
-        atexit(GEO::terminate);
 
 #ifndef GEOGRAM_PSM
         mesh_io_initialize();
 #endif
 
         // Clear last system error
-        errno = 0;
+        if (flags & GEOGRAM_INSTALL_ERRNO) {
+                errno = 0;
+        }
 
 #ifndef GEOGRAM_PSM
         // Register attribute types that can be saved into files.
@@ -154,11 +163,10 @@ namespace GEO {
         geo_declare_image_serializer<ImageSerializer_xpm>("xpm") ;
         geo_declare_image_serializer<ImageSerializer_pgm>("pgm") ;
 #endif
+        }
 
-    initialized = true;
-    }
-
-    void terminate() {
+        ~MySingleton() {
+
         if(
             CmdLine::arg_is_declared("sys:stats") &&
             CmdLine::get_arg_bool("sys:stats")
@@ -181,6 +189,18 @@ namespace GEO {
         Logger::terminate();
     FileSystem::terminate();
         Environment::terminate();
+
+        }
+};
+
+}
+
+    void initialize(int flags) {
+        MySingleton::instance(flags);
+    }
+
+    void terminate() {
+        MySingleton::instance(GEOGRAM_INSTAL_NONE).reset();
     }
 }
 

src/lib/geogram/basic/common.h

@@ -64,9 +64,25 @@ namespace GEO {
      * \brief Symbolic constants for GEO::initialize()
      */
     enum {
-    GEOGRAM_NO_HANDLER = 0,
-    GEOGRAM_INSTALL_HANDLERS = 1
-    };
+        /// Do not install error handlers
+        GEOGRAM_INSTAL_NONE = 0,
+        /// Install Geogram's signal handlers
+        GEOGRAM_INSTALL_HANDLERS = 1,
+        /// Sets the locale to POSIX
+        GEOGRAM_INSTALL_LOCALE = 2,
+        /// Reset errno to 0
+        GEOGRAM_INSTALL_ERRNO = 4,
+        /// Enable or disable FPE during initialization
+        GEOGRAM_INSTALL_FPE = 8,
+        /// Enable global citation database
+        GEOGRAM_INSTALL_BIBLIO = 16,
+        /// Install everything
+        GEOGRAM_INSTALL_ALL = GEOGRAM_INSTALL_HANDLERS
+                            | GEOGRAM_INSTALL_LOCALE
+                            | GEOGRAM_INSTALL_ERRNO
+                            | GEOGRAM_INSTALL_FPE
+                            | GEOGRAM_INSTALL_BIBLIO
+     };
 
     /**
      * \brief Initialize Geogram
@@ -76,13 +92,17 @@ namespace GEO {
      *  test suite. Else continuous integration tests hang because of the dialog
      *  box. Normal users may want to keep the default Windows behavior, since
      *  geogram error handlers may make debugging more difficult under Windows.
+     * - GEOGRAM_INSTALL_LOCALE to set the locale to POSIX.
+     * - GEOGRAM_INSTALL_ERRNO to clear the last system error.
+     * - GEOGRAM_INSTALL_FPE to enable/disable floating point exceptions.
+     * - GEOGRAM_INSTALL_BIBLIO to enable global citation database.
      * \details This function must be called once at the very beginning of a
      * program to initialize the Vorpaline library. It also installs a exit()
      * handler that calls function terminate() when the program exists
      * normally. If it is called multiple times, then the supplemental calls
      * have no effect.
      */
-    void GEOGRAM_API initialize(int flags = GEOGRAM_INSTALL_HANDLERS);
+    void GEOGRAM_API initialize(int flags = GEOGRAM_INSTAL_NONE);
 
     /**
      * \brief Cleans up Geogram

src/lib/geogram/basic/process.cpp

@@ -381,7 +381,9 @@ namespace GEO {
             // Initialize Process default values
             enable_multithreading(multithreading_enabled_);
             set_max_threads(number_of_cores());
-            enable_FPE(fpe_enabled_);
+            if (flags & GEOGRAM_INSTALL_FPE) {
+                enable_FPE(fpe_enabled_);
+            }
             enable_cancel(cancel_enabled_);
 
             start_time_ = Stopwatch::now();