Re: [patch, fortran] Patch for PR fortran/39352, using -fexceptions.

[Tobias Burnus <burnus at net-b dot de>]

Tobias Burnus wrote:
>>> This patch for PR fortran/39352 initializes eh_personality_libfunc
>>>       
This is an updated patch. The only difference to the previous version is
that the newly added headers are moved up to avoid the #define/undefine
trickery - and a completely unrelated patch to misc.c which avoids a
similar define trickery for gfc_free by using "(free)" instead of
"free". (Both suggested by Jakub. Thanks!)

The patch does the same as C does (c-decl.c's c_maybe_initialize_eh). It
only adds the eh_personality_libfunc if -fexception is set (which is the
default for C++ but not for C and Fortran) and then it only adds it when
OpenMP directives (other than atomic) are used. This is also in line
with C, cf. c-parser.c's c_parser_omp_construct.

The modified patch has been tested and bootstrapped on x86-64-linux. The
original patch has been bootstrapped successfully by Steve Ellcey on
IA64 Linux and HP-UX.

Ian today looked at the patch an concluded: the patch looks reasonable
though I don't understand all the details here. I think Jakub also
agreed with the patch (he gave some advices when I initially created
patch and suggested to get rid of the define trickery).

Unless there are objections, I plan to commit the patch tomorrow.


Tobias

2009-05-15  Tobias Burnus  <burnus@net-b.de>

        PR fortran/39352
        * f95-lang.c: Add gfc_maybe_initialize_eh.
        * gfortran.h: Add gfc_maybe_initialize_eh prototype.
        * Make-lang.in: Add new .h dendencies for f95-lang.c
        * openmp.c (resolve_omp_do): Call gfc_maybe_initialize_eh.
	* misc.c (gfc_free): Avoid #define trickery for free.

Index: gcc/fortran/openmp.c
===================================================================
--- gcc/fortran/openmp.c	(Revision 147534)
+++ gcc/fortran/openmp.c	(Arbeitskopie)
@@ -1503,6 +1503,9 @@
 void
 gfc_resolve_omp_directive (gfc_code *code, gfc_namespace *ns ATTRIBUTE_UNUSED)
 {
+  if (code->op != EXEC_OMP_ATOMIC)
+    gfc_maybe_initialize_eh ();
+
   switch (code->op)
     {
     case EXEC_OMP_DO:
Index: gcc/fortran/Make-lang.in
===================================================================
--- gcc/fortran/Make-lang.in	(Revision 147534)
+++ gcc/fortran/Make-lang.in	(Arbeitskopie)
@@ -313,7 +313,8 @@
 
 fortran/f95-lang.o: $(GFORTRAN_TRANS_DEPS) fortran/mathbuiltins.def \
   gt-fortran-f95-lang.h gtype-fortran.h $(CGRAPH_H) $(TARGET_H) fortran/cpp.h \
-  $(BUILTINS_DEF) fortran/types.def
+  $(BUILTINS_DEF) fortran/types.def \
+  libfuncs.h expr.h except.h
 fortran/scanner.o: toplev.h fortran/cpp.h
 fortran/convert.o: $(GFORTRAN_TRANS_DEPS)
 fortran/trans.o: $(GFORTRAN_TRANS_DEPS) tree-iterator.h
Index: gcc/fortran/gfortran.h
===================================================================
--- gcc/fortran/gfortran.h	(Revision 147534)
+++ gcc/fortran/gfortran.h	(Arbeitskopie)
@@ -2198,6 +2198,9 @@
 int gfc_handle_option (size_t, const char *, int);
 bool gfc_post_options (const char **);
 
+/* f95-lang.c */
+void gfc_maybe_initialize_eh (void);
+
 /* iresolve.c */
 const char * gfc_get_string (const char *, ...) ATTRIBUTE_PRINTF_1;
 bool gfc_find_sym_in_expr (gfc_symbol *, gfc_expr *);
Index: gcc/fortran/f95-lang.c
===================================================================
--- gcc/fortran/f95-lang.c	(Revision 147534)
+++ gcc/fortran/f95-lang.c	(Arbeitskopie)
@@ -43,6 +43,10 @@
 #include "diagnostic.h"
 #include "tree-dump.h"
 #include "cgraph.h"
+/* For gfc_maybe_initialize_eh.  */
+#include "libfuncs.h"
+#include "expr.h"
+#include "except.h"
 
 #include "gfortran.h"
 #include "cpp.h"
@@ -165,6 +169,10 @@
    It is indexed by a RID_... value.  */
 tree *ridpointers = NULL;
 
+/* True means we've initialized exception handling.  */
+bool gfc_eh_initialized_p;
+
+
 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
    or validate its data type for an `if' or `while' statement or ?..: exp.
 
@@ -1223,5 +1231,21 @@
   tree_contains_struct[NAMESPACE_DECL][TS_DECL_MINIMAL] = 1;
 }
 
+void
+gfc_maybe_initialize_eh (void)
+{
+  if (!flag_exceptions || gfc_eh_initialized_p)
+    return;
+
+  gfc_eh_initialized_p = true;
+  eh_personality_libfunc
+    = init_one_libfunc (USING_SJLJ_EXCEPTIONS
+                       ? "__gcc_personality_sj0"
+                       : "__gcc_personality_v0");
+  default_init_unwind_resume_libfunc ();
+  using_eh_for_cleanups ();
+}
+
+
 #include "gt-fortran-f95-lang.h"
 #include "gtype-fortran.h"
Index: gcc/fortran/misc.c
===================================================================
--- gcc/fortran/misc.c	(Revision 147534)
+++ gcc/fortran/misc.c	(Arbeitskopie)
@@ -42,23 +42,16 @@
 }
 
 
-/* gfortran.h defines free to something that triggers a syntax error,
-   but we need free() here.  */
-
-#define temp free
-#undef free
-
 void
 gfc_free (void *p)
 {
+  /* The parentheses around free are needed in order to call not
+     the redefined free of gfortran.h.  */
   if (p != NULL)
-    free (p);
+    (free) (p);
 }
 
-#define free temp
-#undef temp
 
-
 /* Get terminal width.  */
 
 int