Make it possible to build GAP as a dynamic library

GNUmakefile.in

@@ -19,6 +19,9 @@ ABI_CFLAGS = @ABI_CFLAGS@
 HPCGAP = @HPCGAP@
 ADDGUARDS2 = @ADDGUARDS2@
 
+# LibGAP specific
+BUILD_LIBGAP = @BUILD_LIBGAP@
+
 # compatibility mode
 COMPAT_MODE = @COMPAT_MODE@
 GAPARCH = @GAPARCH@

Makefile.rules

@@ -12,7 +12,9 @@
 # Default rule: build gap
 ########################################################################
 all: gap$(EXEEXT) gac
-.PHONY: all
+
+libgap: libgap.la
+.PHONY: libgap
 
 libgap: libgap.la
 .PHONY: libgap
@@ -21,7 +23,6 @@ libgap: libgap.la
 default: all
 .PHONY: default
 
-
 ########################################################################
 # Source files
 #
@@ -118,6 +119,9 @@ ifeq ($(HPCGAP),yes)
   SOURCES += src/hpc/traverse.c
 endif
 
+ifeq ($(BUILD_LIBGAP),yes)
+  SOURCES += src/sage_interface.c
+endif
 
 ########################################################################
 # Preprocessor flags
@@ -1022,3 +1026,13 @@ doc/make_doc: $(srcdir)/doc/make_doc.in config.status
 
 gac: $(srcdir)/cnf/gac.in config.status
 	$(SHELL) ./config.status $@
+
+# TODO: This needs to be done more elegantly
+obj/libgap-test-0001.lo: $(top_srcdir)/tst/testlibgap/0001.c
+	$(QUIET_CC)$(COMPILE) $(DEPFLAGS) $(GAP_CFLAGS) $(CC_EXTRA_FLAGS) $(GAP_CPPFLAGS) -c $< -o $@
+
+test-libgap: libgap.la obj/libgap-test-0001.lo 
+	$(QUIET_LINK)$(LINK) obj/libgap-test-0001.lo libgap.la -o test-libgap
+	./test-libgap -l $(top_srcdir) -m 32m -q -T > 0001.out
+	diff $(top_srcdir)/tst/testlibgap/0001.expect 0001.out
+

configure.ac

@@ -193,6 +193,23 @@ AS_IF([test "x$enable_hpcgap" = xyes],
     AC_DEFINE([MAX_GC_THREADS], [4], [maximum number of GC threads])
     ])
 
+dnl
+dnl User setting: LibGAP mode (off by default)
+dnl
+dnl If on, build an LibGAP instead of standard GAP executable.
+dnl
+dnl TODO: Will there ever be an HPC-GAP libgap?
+dnl
+AC_ARG_ENABLE([libgap],
+[AS_HELP_STRING([--enable-libgap], [enable LibGAP])],
+[AC_DEFINE([LIBGAP], [1], [define if building LibGAP])],
+[enable_libgap=no]
+)
+AC_MSG_CHECKING([whether to enable LibGAP])
+AC_MSG_RESULT([$enable_libgap])
+
+AC_SUBST([BUILD_LIBGAP], [$enable_libgap])
+
 dnl
 dnl User setting: Debug mode (off by default)
 dnl

src/gap.c

@@ -114,6 +114,10 @@
 
 #include <src/gaputils.h>
 
+#if defined(LIBGAP)
+#include <src/sage_interface.h>
+#endif
+
 /****************************************************************************
 **
 *V  Last  . . . . . . . . . . . . . . . . . . . . . . global variable  'last'
@@ -209,6 +213,8 @@ static Int NrImportedFuncs;
 
 static char **sysenviron;
 
+TJumpToCatchFunc JumpToCatchFunc = 0;
+
 /*
 TL: Obj ShellContext = 0;
 TL: Obj BaseShellContext = 0;
@@ -1148,6 +1154,15 @@ Obj FuncJUMP_TO_CATCH( Obj self, Obj payload)
 {
   STATE(ThrownObject) = payload;
   syLongjmp(&(STATE(ReadJmpError)), 1);
+#if defined(LIBGAP)
+  libgap_call_error_handler();
+#endif
+  STATE(ThrownObject) = payload;
+  if(JumpToCatchFunc != 0) {
+      (*JumpToCatchFunc)();
+  }
+  STATE(ThrownObject) = payload;
+  syLongjmp(STATE(ReadJmpError), 1);
   return 0;
 }
 
@@ -3210,7 +3225,7 @@ void InitializeGap (
 
     /* Initialise memory  -- have to do this here to make sure we are at top of C stack */
     InitBags( SyAllocBags, SyStorMin,
-              0, (Bag*)(((UInt)pargc/SyStackAlign)*SyStackAlign), SyStackAlign,
+              0, (Bag*)(((UInt)pargc/SyStackAlign)*SyStackAlign), SyStackAlign, 0,
               SyAbortBags );
 #if !defined(BOEHM_GC)
     InitMsgsFuncBags( SyMsgsBags );
@@ -3230,6 +3245,8 @@ void InitializeGap (
     NrImportedGVars = 0;
     NrImportedFuncs = 0;
 
+    JumpToCatchFunc = 0;
+
     sysenviron = environ;
 
     /* get info structures for the build in modules                        */

src/gap.h

@@ -201,6 +201,11 @@ extern void ErrorReturnVoid (
             Int                 arg2,
             const Char *        msg2 );
 
+typedef void  (* TJumpToCatchFunc)();
+extern TJumpToCatchFunc JumpToCatchFunc;
+static inline void SetJumpToCatchFunc(TJumpToCatchFunc func)
+{ JumpToCatchFunc = func; };
+
 /* TL: extern Obj ErrorLVars;
    TL: extern Obj ErrorLVars0;
  */

src/gasman.c

@@ -967,6 +967,8 @@ TNumAllocFuncBags       AllocFuncBags;
 
 TNumStackFuncBags       StackFuncBags;
 
+TExtraMarkFuncBags      ExtraMarkFuncBags;
+
 Bag *                   StackBottomBags;
 
 UInt                    StackAlignBags;
@@ -979,7 +981,8 @@ void            InitBags (
     TNumStackFuncBags   stack_func,
     Bag *               stack_bottom,
     UInt                stack_align,
-    TNumAbortFuncBags   abort_func )
+    UInt                dirty,
+    TNumAbortFuncBags   abort_func)
 {
     Bag *               p;              /* loop variable                   */
     UInt                i;              /* loop variable                   */
@@ -990,6 +993,7 @@ void            InitBags (
     /* install the allocator and the abort function                        */
     AllocFuncBags   = alloc_func;
     AbortFuncBags   = abort_func;
+    ExtraMarkFuncBags = 0;
 
     /* install the stack marking function and values                       */
     StackFuncBags   = stack_func;
@@ -1687,6 +1691,11 @@ UInt CollectBags (
     for ( i = 0; i < GlobalBags.nr; i++ )
         MarkBag( *GlobalBags.addr[i] );
 
+    /* allow users of libgap to mark their choice of bags */
+    /* TODO: This can probably be solved a lot more cleanly */
+    if ( ExtraMarkFuncBags ) {
+        (*ExtraMarkFuncBags)();
+    }
 
     /* mark from the stack                                                 */
     if ( StackFuncBags ) {

src/gasman.h

@@ -1153,6 +1153,7 @@ typedef Bag *           (* TNumAllocFuncBags) (
                                 UInt            need );
 
 typedef void            (* TNumStackFuncBags) ( void );
+typedef void            (* TExtraMarkFuncBags) (void);
 
 typedef void            (* TNumAbortFuncBags) (
                                 const Char *    msg );
@@ -1163,6 +1164,7 @@ extern  void            InitBags (
             TNumStackFuncBags   stack_func,
             Bag *               stack_bottom,
             UInt                stack_align,
+            UInt                dirty,
             TNumAbortFuncBags   abort_func );
 
 /****************************************************************************
@@ -1190,4 +1192,14 @@ extern void CallbackForAllBags(
 void *AllocateMemoryBlock(UInt size);
 #endif
 
+/*
+ * If not 0 this function will be called in
+ * CollectBags to allow users of libgap to mark bags
+ */
+extern TExtraMarkFuncBags ExtraMarkFuncBags;
+
+static void SetExtraMarkFuncBags(TExtraMarkFuncBags func)
+{ ExtraMarkFuncBags = func; }
+
+
 #endif // GAP_GASMAN_H

src/iostream.c

@@ -683,8 +683,8 @@ static Int InitKernel(StructInitInfo * module)
 
     /* init filters and functions                                          */
     InitHdlrFuncsFromTable(GVarFuncs);
-
-#if !defined(HPCGAP)
+  
+#if !defined(HPCGAP) && !defined(LIBGAP)
     /* Set up the trap to detect future dying children */
     signal(SIGCHLD, ChildStatusChanged);
 #endif