compile: Use -Wall, not -w

For a reason unknown to me GDB was using -w instead of -Wall for 'compile code'.
The problem is later patch for 'compile printf' really needs some warnings to
be able to catch for example missing format string parameters:
	(gdb) compile printf "%d\n"
GCC does not seem to be able to cancel -w (there is nothing like -no-w).

Besides that I think even 'compile code' can benefit from -Wall.

That #ifndef change in print_one_macro() is needed otherwise we get
macro-redefinition warnings for the GCC built-in macros (as -w is no
longer in effect).  For example, without the #ifndef/#endif one gets:

	compile -r -- void _gdb_expr(){int i = 5;}^M
	/tmp/gdbobj-xpU1yB/out4.c:4:0: warning: "__FILE__" redefined [-Wbuiltin-macro-redefined]^M
	/tmp/gdbobj-xpU1yB/out4.c:5:0: warning: "__LINE__" redefined^M
	...

It makes more sense to pick the inferior's version of the macros, hence
#ifndef instead of #undef.

That new testsuite XFAIL is there as if one changes the struct definition to be
compliant with cv-qualifiers (to prevent the warnings):
struct struct_type {
-  struct struct_type *selffield;
+  volatile struct struct_type *selffield;
only then GCC/GDB will hit the crash, described in that GDB PR 18202.


gdb/ChangeLog
2015-05-16  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* compile/compile-c-support.c (print_one_macro): Use #ifndef.
	(generate_register_struct): Use __gdb_uintptr for TYPE_CODE_PTR.
	(c_compute_program): Call generate_register_struct after typedefs.
	* compile/compile-loc2c.c (push, pushf_register_address)
	(pushf_register): Cast to GCC_UINTPTR.
	(do_compile_dwarf_expr_to_c): Use unused attribute.  Add space after
	type.  Use GCC_UINTPTR instead of void *.  Remove excessive cast.
	(compile_dwarf_expr_to_c): Use GCC_UINTPTR instead of void *.
	* compile/compile.c (_initialize_compile): Enable warnings for
	COMPILE_ARGS.

gdb/testsuite/ChangeLog
2015-05-16  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.compile/compile-ops.exp: Cast param to void.
	* gdb.compile/compile.exp: Complete type for _gdb_expr.
	(compile code struct_object.selffield = &struct_object): Add xfail.

gdb/testsuite/gdb.compile/compile-ops.exp

@@ -416,7 +416,7 @@ if {[skip_compile_feature_tests]} {
 }
 
 # If we have a bug, this will hang.
-gdb_test_no_output "compile code param"
+gdb_test_no_output "compile code (void) param"
 
 # We can't access optimized-out variables, but their presence should
 # not affect compilations that don't refer to them.

gdb/testsuite/gdb.compile/compile.exp

@@ -71,13 +71,13 @@ gdb_test_no_output "compile -- f = 10" \
 gdb_test "compile f = 10;" ".*= 10;: No such file.*" \
     "Test abbreviations and code collision"
 
-gdb_test_no_output "compile -r -- _gdb_expr(){int i = 5;}" \
+gdb_test_no_output "compile -r -- void _gdb_expr(){int i = 5;}" \
     "Test delimiter with -r"
 
-gdb_test_no_output "compile -raw -- _gdb_expr(){int i = 5;}" \
+gdb_test_no_output "compile -raw -- void _gdb_expr(){int i = 5;}" \
     "Test delimiter with -raw"
 
-gdb_test "compile -- -r  _gdb_expr(){int i = 5;}" \
+gdb_test "compile -- -r  void _gdb_expr(){int i = 5;}" \
     ".* error: 'r' undeclared \\(first use in this function\\).*" \
     "Test delimiter with -r after it"
 
@@ -189,7 +189,15 @@ gdb_test "p localvar" " = 1"
 # Test setting fields and also many different types.
 #
 
-gdb_test_no_output "compile code struct_object.selffield = &struct_object"
+set test "compile code struct_object.selffield = &struct_object"
+gdb_test_multiple $test $test {
+    -re "^$test\r\n$gdb_prompt $" {
+	pass "$test"
+    }
+    -re "gdb command line:1:25: warning: assignment discards 'volatile' qualifier from pointer target type \\\[-Wdiscarded-qualifiers\\\]\r\n$gdb_prompt $" {
+	xfail "$test (PR compile/18202)"
+    }
+}
 gdb_test "print struct_object.selffield == &struct_object" " = 1"
 
 gdb_test_no_output "compile code struct_object.charfield = 1"
@@ -261,7 +269,7 @@ gdb_test "print 'compile.c'::globalshadow" " = 77000" \
 
 # Test GOT vs. resolving jit function pointers.
 
-gdb_test_no_output "compile -raw -- int func(){return 21;} _gdb_expr(){int (*funcp)()=func; if (funcp()!=21) abort();}" \
+gdb_test_no_output "compile -raw -- int func(){return 21;} void _gdb_expr(){ void abort (void); int (*funcp)()=func; if (funcp()!=21) abort(); }" \
     "pointer to jit function"
 
 #