gdbhooks.py: dump-fn, dot-fn: cast ret values of fopen/fclose

Work around the following

    (gdb) Python Exception <class 'gdb.error'> 'fclose@@GLIBC_2.2.5' has
    unknown return type; cast the call to its declared return type:
    (gdb) Error occurred in Python: 'fclose@@GLIBC_2.2.5' has unknown
    return type; cast the call to its declared return type

This is due to GDB not being able to pick up and use the return types from
debug info for external declarations.

2019-07-14  Vladislav Ivanishin <vlad@ispras.ru>

        * gdbhooks.py (DumpFn.invoke): Add explicit casts of return values of
        fopen and fclose to their respective types.
        (DotFn.invoke): Ditto.

From-SVN: r273480

gcc/ChangeLog

+2019-07-14  Vladislav Ivanishin <vlad@ispras.ru>
+
+	* gdbhooks.py (DumpFn.invoke): Add explicit casts of return values of
+	fopen and fclose to their respective types.
+	(DotFn.invoke): Ditto.
+
 2019-07-14  Jan Hubicka  <hubicka@ucw.cz>
 
 	* ipa-fnsummary.c (ipa_dump_hints): Do not dump array_index.

gcc/gdbhooks.py

@@ -740,18 +740,17 @@ class DumpFn(gdb.Command):
             f.close()
 
         # Open file
-        fp = gdb.parse_and_eval("fopen (\"%s\", \"w\")" % filename)
+        fp = gdb.parse_and_eval("(FILE *) fopen (\"%s\", \"w\")" % filename)
         if fp == 0:
             print ("Could not open file: %s" % filename)
             return
-        fp = "(FILE *)%u" % fp
 
         # Dump function to file
         _ = gdb.parse_and_eval("dump_function_to_file (%s, %s, %u)" %
                                (func, fp, flags))
 
         # Close file
-        ret = gdb.parse_and_eval("fclose (%s)" % fp)
+        ret = gdb.parse_and_eval("(int) fclose (%s)" % fp)
         if ret != 0:
             print ("Could not close file: %s" % filename)
             return
@@ -810,11 +809,10 @@ class DotFn(gdb.Command):
 
         # Close and reopen temp file to get C FILE*
         f.close()
-        fp = gdb.parse_and_eval("fopen (\"%s\", \"w\")" % filename)
+        fp = gdb.parse_and_eval("(FILE *) fopen (\"%s\", \"w\")" % filename)
         if fp == 0:
             print("Cannot open temp file")
             return
-        fp = "(FILE *)%u" % fp
 
         # Write graph to temp file
         _ = gdb.parse_and_eval("start_graph_dump (%s, \"<debug>\")" % fp)
@@ -823,7 +821,7 @@ class DotFn(gdb.Command):
         _ = gdb.parse_and_eval("end_graph_dump (%s)" % fp)
 
         # Close temp file
-        ret = gdb.parse_and_eval("fclose (%s)" % fp)
+        ret = gdb.parse_and_eval("(int) fclose (%s)" % fp)
         if ret != 0:
             print("Could not close temp file: %s" % filename)
             return