WIP LoadKernelExtension, IsKernelExtensionAvailable

lib/files.gd

@@ -605,6 +605,60 @@ BIND_GLOBAL( "LoadStaticModule", function( filename )
 end );
 
 
+#############################################################################
+##
+#F  IsKernelExtensionAvailable( <pkgname> [, <modname> ] )
+##
+BIND_GLOBAL( "IsKernelExtensionAvailable", function( pkgname, modname... )
+    local fname;
+
+    if Length(modname) = 0 then
+        modname := pkgname;
+    elif Length(modname) = 1 then
+        modname := modname[1];
+    else
+        Error( "usage: IsKernelExtensionAvailable( <pkgname> [, <modname> ] )" );
+    fi;
+
+    if modname in SHOW_STAT() then
+        return true;
+    fi;
+    fname := Filename(DirectoriesPackagePrograms(pkgname), Concatenation(modname, ".so"));
+    if fname <> fail then
+        return IS_LOADABLE_DYN(fname);
+    fi;
+    return false;
+end );
+
+
+#############################################################################
+##
+#F  LoadKernelExtension( <pkgname> [, <modname> ] )
+##
+BIND_GLOBAL( "LoadKernelExtension", function( pkgname, modname... )
+    local fname;
+
+    if Length(modname) = 0 then
+        modname := pkgname;
+    elif Length(modname) = 1 then
+        modname := modname[1];
+    else
+        Error( "usage: LoadKernelExtension( <pkgname> [, <modname> ] )" );
+    fi;
+
+    if modname in SHOW_STAT() then
+        LoadStaticModule(modname);
+        return true;
+    fi;
+    fname := Filename(DirectoriesPackagePrograms(pkgname), Concatenation(modname, ".so"));
+    if fname <> fail then
+        LoadDynamicModule(fname);
+        return true;
+    fi;
+    return false;
+end );
+
+
 #############################################################################
 ##
 #F  Edit( <filename> )  . . . . . . . . . . . . . . . . .  edit and read file

lib/package.gi

@@ -1234,6 +1234,18 @@ InstallGlobalFunction( DirectoriesPackagePrograms, function( name )
       # This package is not known.
       return [];
     fi;
+# FIXME: inject another secondary path??? to allow "out of tree builds"
+# for packages, and/or allow GAP itself to store binaries for the package
+# so that the precise combination of GAP and package are matched...
+# That is, take the precise GAP version (possibly including the git commit
+# it was compiled from), plus the package version (and possibly also the locations of both?)
+# and combine them into a unique ID (e.g. via a hash), then use that to
+# store .so binaries
+
+
+# also add a new mechanism to integrate kernel extensions into a package:
+# let the package declare in its PackageInfo.g that it has a kernel extension;
+# how to build it; what's its name; then GAP can take care of that dynamically
     return [ Directory( Concatenation( installationpath, "/bin/",
                             GAPInfo.Architecture, "/" ) ) ];
 end );

src/modules.c

@@ -203,32 +203,66 @@ StructInitInfo * LookupStaticModule(const char * name)
 **  This function attempts to load a compiled module <name>.
 **  If successful, it returns 0, and sets <func> to a pointer to the init
 **  function of the module. In case of an error, <func> is set to 0, and the
-**  return value indicates which error occurred.
+**  return value is a pointer to a string with more information.
 */
 #ifdef HAVE_DLOPEN
-static Int SyLoadModule(const Char * name, InitInfoFunc * func)
+static const char * SyLoadModule(const Char * name, InitInfoFunc * func)
 {
-    void *          init;
-    void *          handle;
-
-    *func = 0;
-
-    handle = dlopen( name, RTLD_LAZY | RTLD_LOCAL);
-    if ( handle == 0 ) {
-      Pr("#W dlopen() error: %s\n", (long) dlerror(), 0);
-      return 1;
+    void * handle = dlopen(name, RTLD_LAZY | RTLD_LOCAL);
+    if (handle == 0) {
+        *func = 0;
+        return dlerror();
     }
 
-    init = dlsym( handle, "Init__Dynamic" );
-    if ( init == 0 )
-      return 3;
+    *func = (InitInfoFunc)dlsym(handle, "Init__Dynamic");
+    if (*func == 0)
+        return "symbol 'Init__Dynamic' not found";
 
-    *func = (InitInfoFunc) init;
     return 0;
 }
 #endif
 
 
+/****************************************************************************
+**
+*F  FuncIS_LOADABLE_DYN( <self>, <name> ) . test if a dyn. module is loadable
+*/
+static Obj FuncIS_LOADABLE_DYN(Obj self, Obj filename)
+{
+    RequireStringRep(SELF_NAME, filename);
+
+#if !defined(HAVE_DLOPEN)
+    return False;
+#else
+
+    InitInfoFunc init;
+
+    // try to load the module
+    SyLoadModule(CONST_CSTR_STRING(filename), &init);
+    if (init == 0)
+        return False;
+
+    // get the description structure
+    StructInitInfo * info = (*init)();
+    if (info == 0)
+        return False;
+
+    // info->type should not be larger than kernel version
+    if (info->type / 10 > GAP_KERNEL_API_VERSION)
+        return False;
+
+    // info->type should not have an older major version
+    if (info->type / 10000 < GAP_KERNEL_MAJOR_VERSION)
+        return False;
+
+    // info->type % 10 should be 0, 1 or 2, for the 3 types of module
+    if (info->type % 10 > 2)
+        return False;
+
+    return True;
+#endif
+}
+
 
 /****************************************************************************
 **
@@ -248,14 +282,12 @@ static Obj FuncLOAD_DYN(Obj self, Obj filename)
 
     InitInfoFunc init;
 
-    /* try to read the module                                              */
-    Int res = SyLoadModule(CONST_CSTR_STRING(filename), &init);
-    if (res == 1)
-        ErrorQuit("module '%g' not found", (Int)filename, 0);
-    else if (res == 3)
-        ErrorQuit("symbol 'Init_Dynamic' not found", 0, 0);
+    // try to read the module
+    const char * res = SyLoadModule(CONST_CSTR_STRING(filename), &init);
+    if (res)
+        ErrorQuit("failed to load dynamic module %g, %s", (Int)filename, (Int)res);
 
-    /* get the description structure                                       */
+    // get the description structure
     StructInitInfo * info = (*init)();
     if (info == 0)
         ErrorQuit("call to init function failed", 0, 0);
@@ -855,17 +887,13 @@ void LoadModules(void)
                 InitInfoFunc init;
 
 #ifdef HAVE_DLOPEN
-                int res = SyLoadModule(buf, &init);
-                if (res != 0) {
-                    Panic("Failed to load needed dynamic module %s, error "
-                          "code %d\n",
-                          buf, res);
+                const char * res = SyLoadModule(buf, &init);
+                if (init == 0) {
+                    Panic("failed to load dynamic module %s, %s\n", buf, res);
                 }
                 info = (*init)();
                 if (info == 0) {
-                    Panic("Failed to init needed dynamic module %s, error "
-                          "code %d\n",
-                          buf, res);
+                    Panic("failed to init dynamic module %s\n", buf);
                 }
 #else
                 Panic("workspace require dynamic module %s, but dynamic "
@@ -1051,6 +1079,7 @@ void ModulesPostRestore(void)
 */
 static StructGVarFunc GVarFuncs[] = {
     GVAR_FUNC_1ARGS(GAP_CRC, filename),
+    GVAR_FUNC_1ARGS(IS_LOADABLE_DYN, filename),
     GVAR_FUNC_1ARGS(LOAD_DYN, filename),
     GVAR_FUNC_1ARGS(LOAD_STAT, filename),
     GVAR_FUNC_0ARGS(SHOW_STAT),

tst/testinstall/kernel/gap.tst

@@ -130,19 +130,6 @@ Error, GAP_CRC: <filename> must be a string (not the value 'fail')
 gap> GAP_CRC("foobar");
 0
 
-#
-gap> LOAD_DYN(fail);
-Error, LOAD_DYN: <filename> must be a string (not the value 'fail')
-
-#
-gap> LOAD_STAT(fail);
-Error, LOAD_STAT: <filename> must be a string (not the value 'fail')
-gap> LOAD_STAT("foobar");
-false
-
-#
-gap> LoadedModules();;
-
 #
 gap> GASMAN();
 Error, usage: GASMAN( "display"|"displayshort"|"clear"|"collect"|"message"|"pa\
@@ -186,7 +173,7 @@ gap> Sleep(0);
 gap> Sleep(1);
 
 #
-gap>    MicroSleep(fail);
+gap> MicroSleep(fail);
 Error, MicroSleep: <msecs> must be a small integer (not the value 'fail')
 gap> MicroSleep(0);
 gap> MicroSleep(1);

tst/testinstall/kernel/modules.tst

@@ -0,0 +1,24 @@
+#
+# Tests for functions defined in src/modules.c
+#
+gap> START_TEST("kernel/modules.tst");
+
+#
+gap> IS_LOADABLE_DYN(fail);
+Error, IS_LOADABLE_DYN: <filename> must be a string (not the value 'fail')
+
+#
+gap> LOAD_DYN(fail);
+Error, LOAD_DYN: <filename> must be a string (not the value 'fail')
+
+#
+gap> LOAD_STAT(fail);
+Error, LOAD_STAT: <filename> must be a string (not the value 'fail')
+gap> LOAD_STAT("foobar");
+false
+
+#
+gap> LoadedModules();;
+
+#
+gap> STOP_TEST("kernel/modules.tst", 1);