diff --git a/gdb/compile/compile-c-support.c b/gdb/compile/compile-c-support.c
index 1711cda..48a17e2 100644
--- a/gdb/compile/compile-c-support.c
+++ b/gdb/compile/compile-c-support.c
@@ -131,7 +131,9 @@ print_one_macro (const char *name, const struct macro_definition *macro,
   if (line == 0)
     return;
 
-  fprintf_filtered (file, "#define %s", name);
+  /* None of -Wno-builtin-macro-redefined, #undef first
+     or plain #define of the same value would avoid a warning.  */
+  fprintf_filtered (file, "#ifndef %s\n# define %s", name, name);
 
   if (macro->kind == macro_function_like)
     {
@@ -147,7 +149,7 @@ print_one_macro (const char *name, const struct macro_definition *macro,
       fputs_filtered (")", file);
     }
 
-  fprintf_filtered (file, " %s\n", macro->replacement);
+  fprintf_filtered (file, " %s\n#endif\n", macro->replacement);
 }
 
 /* Write macro definitions at PC to FILE.  */
@@ -252,7 +254,7 @@ generate_register_struct (struct ui_file *stream, struct gdbarch *gdbarch,
 	    switch (TYPE_CODE (regtype))
 	      {
 	      case TYPE_CODE_PTR:
-		fprintf_filtered (stream, "void *%s", regname);
+		fprintf_filtered (stream, "__gdb_uintptr %s", regname);
 		break;
 
 	      case TYPE_CODE_INT:
@@ -340,8 +342,6 @@ c_compute_program (struct compile_instance *inst,
 							  expr_block, expr_pc);
       make_cleanup (xfree, registers_used);
 
-      generate_register_struct (buf, gdbarch, registers_used);
-
       fputs_unfiltered ("typedef unsigned int"
 			" __attribute__ ((__mode__(__pointer__)))"
 			" __gdb_uintptr;\n",
@@ -363,6 +363,8 @@ c_compute_program (struct compile_instance *inst,
 			      " __gdb_int_%s;\n",
 			      mode, mode);
 	}
+
+      generate_register_struct (buf, gdbarch, registers_used);
     }
 
   add_code_header (inst->scope, buf);
diff --git a/gdb/compile/compile-loc2c.c b/gdb/compile/compile-loc2c.c
index 6a3615d..6f53814 100644
--- a/gdb/compile/compile-loc2c.c
+++ b/gdb/compile/compile-loc2c.c
@@ -436,7 +436,8 @@ compute_stack_depth (enum bfd_endian byte_order, unsigned int addr_size,
 static void
 push (int indent, struct ui_file *stream, ULONGEST l)
 {
-  fprintfi_filtered (indent, stream, "__gdb_stack[++__gdb_tos] = %s;\n",
+  fprintfi_filtered (indent, stream,
+		     "__gdb_stack[++__gdb_tos] = (" GCC_UINTPTR ") %s;\n",
 		     hex_string (l));
 }
 
@@ -520,7 +521,8 @@ pushf_register_address (int indent, struct ui_file *stream,
   struct cleanup *cleanups = make_cleanup (xfree, regname);
 
   registers_used[regnum] = 1;
-  pushf (indent, stream, "&" COMPILE_I_SIMPLE_REGISTER_ARG_NAME	 "->%s",
+  pushf (indent, stream,
+	 "(" GCC_UINTPTR ") &" COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s",
 	 regname);
 
   do_cleanups (cleanups);
@@ -544,7 +546,8 @@ pushf_register (int indent, struct ui_file *stream,
     pushf (indent, stream, COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s",
 	   regname);
   else
-    pushf (indent, stream, COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s + %s",
+    pushf (indent, stream,
+	   COMPILE_I_SIMPLE_REGISTER_ARG_NAME "->%s + (" GCC_UINTPTR ") %s",
 	   regname, hex_string (offset));
 
   do_cleanups (cleanups);
@@ -605,7 +608,8 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 
   ++scope;
 
-  fprintfi_filtered (indent, stream, "%s%s;\n", type_name, result_name);
+  fprintfi_filtered (indent, stream, "__attribute__ ((unused)) %s %s;\n",
+		     type_name, result_name);
   fprintfi_filtered (indent, stream, "{\n");
   indent += 2;
 
@@ -899,7 +903,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 		       (long) (op_ptr - base));
 
 	    do_compile_dwarf_expr_to_c (indent, stream,
-					"void *", fb_name,
+					GCC_UINTPTR, fb_name,
 					sym, pc,
 					arch, registers_used, addr_size,
 					datastart, datastart + datalen,
@@ -1080,7 +1084,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 			   "__cfa_%ld", (long) (op_ptr - base));
 
 		do_compile_dwarf_expr_to_c (indent, stream,
-					    "void *", cfa_name,
+					    GCC_UINTPTR, cfa_name,
 					    sym, pc, arch, registers_used,
 					    addr_size,
 					    cfa_start, cfa_end,
@@ -1117,8 +1121,8 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 	}
     }
 
-  fprintfi_filtered (indent, stream, "%s = (%s) __gdb_stack[__gdb_tos];\n",
-		     result_name, type_name);
+  fprintfi_filtered (indent, stream, "%s = __gdb_stack[__gdb_tos];\n",
+		     result_name);
   fprintfi_filtered (indent - 2, stream, "}\n");
 
   do_cleanups (cleanup);
@@ -1134,7 +1138,7 @@ compile_dwarf_expr_to_c (struct ui_file *stream, const char *result_name,
 			 const gdb_byte *op_ptr, const gdb_byte *op_end,
 			 struct dwarf2_per_cu_data *per_cu)
 {
-  do_compile_dwarf_expr_to_c (2, stream, "void *", result_name, sym, pc,
+  do_compile_dwarf_expr_to_c (2, stream, GCC_UINTPTR, result_name, sym, pc,
 			      arch, registers_used, addr_size, op_ptr, op_end,
 			      NULL, per_cu);
 }
diff --git a/gdb/compile/compile.c b/gdb/compile/compile.c
index 621de66..ab19a5d 100644
--- a/gdb/compile/compile.c
+++ b/gdb/compile/compile.c
@@ -680,8 +680,11 @@ String quoting is parsed like in shell, for example:\n\
      absolute target address.
      -fPIC is not used at is would require from GDB to generate .got.  */
 			 " -fPIE"
-  /* We don't want warnings.  */
-			 " -w"
+  /* We want warnings, except for some commonly happening for GDB commands.  */
+			 " -Wall "
+			 " -Wno-implicit-function-declaration"
+			 " -Wno-unused-but-set-variable"
+			 " -Wno-unused-variable"
   /* Override CU's possible -fstack-protector-strong.  */
 			 " -fno-stack-protector"
   );
diff --git a/gdb/testsuite/gdb.compile/compile-ops.exp b/gdb/testsuite/gdb.compile/compile-ops.exp
index 26882bd..0ef3c8d 100644
--- a/gdb/testsuite/gdb.compile/compile-ops.exp
+++ b/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.
diff --git a/gdb/testsuite/gdb.compile/compile.exp b/gdb/testsuite/gdb.compile/compile.exp
index dc09770..07276bd 100644
--- a/gdb/testsuite/gdb.compile/compile.exp
+++ b/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"
 
 #
