After being reminded of the tm.h issues brought up last november (here:
https://gcc.gnu.org/ml/gcc-patches/2013-11/msg01731.html ), I started
looking back into it.
The general summary is the any header file which has a conditional on a
target macro could be affected by include file reordering... ie, if a
header file has
#ifdef BLAH
<whatever>
and we move the header files around a bit, it wouldn't be immediately
obvious if the order where changes and BLAH was define later in the
include structure. The results for this header files would be different
because <whatever> would no longer be in the preprocess source, and it
may take a long time to discover the difference.
Josephs solution was to identify these and instead put a default
definition in default.h ... then change all the uses to #if instead.. ie,
#if BLAH
This way we can ensure that the definition has been seen and it will be
a compile error if not.
I looked at all the target macros listed by Joseph, and decide to start
with the ones which are used *only* in an "if defined" situation in a .h
files of some sort.
ie
#ifdef
#ifndef
or #if define()
If this happens in a .c file, then changing the order of .h's shouldn't
matter. (Unless the .c file is doing something really screwy. So for
the moment, ignoring that.)
So looking at only .h files, I found a number of default definitions in
rtl.h, which this patch moves to defaults.h. I was going to #error if
defaults.h wasn't included, but found that to be unnecessary since it
uses some of those macros and would cause a compile failure anyway if it
wasn't included. All the other uses of these particular macros use the
#if model, so no further adjustment is required for them.
This patch bootstraps on x86_64-unknown-linux-gnu, and regressions are
running. Assuming no issues show up, OK for mainline?
The remaining macros I will have a closer look at and most will likely
need the full treatment moving from #ifdef to the #if model. I plan to
do these next. The macros which fit this category for potential header
trouble (along with their usage count) are:
2 USE_COLLECT2
3 TARGET_TERMINATE_DW2_EH_FRAME_INFO
3 TARGET_HAVE_CTORS_DTORS
3 REGMODE_NATURAL_SIZE
4 CC_STATUS_MDEP_INIT
4 CC_STATUS_MDEP_INIT
4 MODE_BASE_REG_REG_CLASS
4 REGNO_MODE_OK_FOR_REG_BASE_P
5 MODE_BASE_REG_CLASS
5 XCOFF_DEBUGGING_INFO
6 VMS_DEBUGGING_INFO
6 TARGET_ASM_OUTPUT_ANCHOR
6 EH_FRAME_SECTION_NAME
8 MODE_CODE_BASE_REG_CLASS
9 HARD_REGNO_CALLER_SAVE_MODE
9 HARD_REGNO_CALL_PART_CLOBBERED
9 SDB_DEBUGGING_INFO
9 CC_STATUS_MDEP
9 REGNO_MODE_CODE_OK_FOR_BASE_P
10 SECONDARY_RELOAD_CLASS
10 TARGET_VXWORKS_RTP
14 NO_DOT_IN_LABEL
14 REGNO_MODE_OK_FOR_BASE_P
17 STACK_REGS
19 TARGET_ASM_DESTRUCTOR
20 OBJECT_FORMAT_ELF
20 TARGET_ASM_CONSTRUCTOR
24 NO_DOLLAR_IN_LABEL
26 DBX_DEBUGGING_INFO
30 CPLUSPLUS_CPP_SPEC
42 ASM_OUTPUT_DEF
* defaults.h (HAVE_PRE_INCREMENT, HAVE_PRE_DECREMENT,
HAVE_POST_INCREMENT, HAVE_POST_DECREMENT, HAVE_POST_MODIFY_DISP,
HAVE_POST_MODIFY_REG, HAVE_PRE_MODIFY_DISP, HAVE_PRE_MODIFY_REG,
USE_LOAD_POST_INCREMENT, USE_LOAD_POST_DECREMENT,
USE_LOAD_PRE_INCREMENT, USE_LOAD_PRE_DECREMENT,
USE_STORE_POST_INCREMENT, USE_STORE_POST_DECREMENT,
USE_STORE_PRE_INCREMENT, USE_STORE_PRE_DECREMENT,
HARD_FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_IS_FRAME_POINTER,
HARD_FRAME_POINTER_IS_ARG_POINTER): Relocate from rtl.h.
* rtl.h: Move default definitions to defaults.h.
(AUTO_INC_DEC): Adjust defintion check to assumed defaults exist.
Index: defaults.h
===================================================================
*** defaults.h (revision 215355)
--- defaults.h (working copy)
*************** see the files COPYING3 and COPYING.RUNTI
*** 1168,1173 ****
--- 1168,1264 ----
#define DEFAULT_PCC_STRUCT_RETURN 1
#endif
+ #ifndef HAVE_PRE_INCREMENT
+ #define HAVE_PRE_INCREMENT 0
+ #endif
+
+ #ifndef HAVE_PRE_DECREMENT
+ #define HAVE_PRE_DECREMENT 0
+ #endif
+
+ #ifndef HAVE_POST_INCREMENT
+ #define HAVE_POST_INCREMENT 0
+ #endif
+
+ #ifndef HAVE_POST_DECREMENT
+ #define HAVE_POST_DECREMENT 0
+ #endif
+
+ #ifndef HAVE_POST_MODIFY_DISP
+ #define HAVE_POST_MODIFY_DISP 0
+ #endif
+
+ #ifndef HAVE_POST_MODIFY_REG
+ #define HAVE_POST_MODIFY_REG 0
+ #endif
+
+ #ifndef HAVE_PRE_MODIFY_DISP
+ #define HAVE_PRE_MODIFY_DISP 0
+ #endif
+
+ #ifndef HAVE_PRE_MODIFY_REG
+ #define HAVE_PRE_MODIFY_REG 0
+ #endif
+
+ /* Some architectures do not have complete pre/post increment/decrement
+ instruction sets, or only move some modes efficiently. These macros
+ allow us to tune autoincrement generation. */
+
+ #ifndef USE_LOAD_POST_INCREMENT
+ #define USE_LOAD_POST_INCREMENT(MODE) HAVE_POST_INCREMENT
+ #endif
+
+ #ifndef USE_LOAD_POST_DECREMENT
+ #define USE_LOAD_POST_DECREMENT(MODE) HAVE_POST_DECREMENT
+ #endif
+
+ #ifndef USE_LOAD_PRE_INCREMENT
+ #define USE_LOAD_PRE_INCREMENT(MODE) HAVE_PRE_INCREMENT
+ #endif
+
+ #ifndef USE_LOAD_PRE_DECREMENT
+ #define USE_LOAD_PRE_DECREMENT(MODE) HAVE_PRE_DECREMENT
+ #endif
+
+ #ifndef USE_STORE_POST_INCREMENT
+ #define USE_STORE_POST_INCREMENT(MODE) HAVE_POST_INCREMENT
+ #endif
+
+ #ifndef USE_STORE_POST_DECREMENT
+ #define USE_STORE_POST_DECREMENT(MODE) HAVE_POST_DECREMENT
+ #endif
+
+ #ifndef USE_STORE_PRE_INCREMENT
+ #define USE_STORE_PRE_INCREMENT(MODE) HAVE_PRE_INCREMENT
+ #endif
+
+ #ifndef USE_STORE_PRE_DECREMENT
+ #define USE_STORE_PRE_DECREMENT(MODE) HAVE_PRE_DECREMENT
+ #endif
+
+ /* If HARD_FRAME_POINTER_REGNUM is defined, then a special dummy reg
+ is used to represent the frame pointer. This is because the
+ hard frame pointer and the automatic variables are separated by an amount
+ that cannot be determined until after register allocation. We can assume
+ that in this case ELIMINABLE_REGS will be defined, one action of which
+ will be to eliminate FRAME_POINTER_REGNUM into HARD_FRAME_POINTER_REGNUM. */
+ #ifndef HARD_FRAME_POINTER_REGNUM
+ #define HARD_FRAME_POINTER_REGNUM FRAME_POINTER_REGNUM
+ #endif
+
+ #ifndef HARD_FRAME_POINTER_IS_FRAME_POINTER
+ #define HARD_FRAME_POINTER_IS_FRAME_POINTER \
+ (HARD_FRAME_POINTER_REGNUM == FRAME_POINTER_REGNUM)
+ #endif
+
+ #ifndef HARD_FRAME_POINTER_IS_ARG_POINTER
+ #define HARD_FRAME_POINTER_IS_ARG_POINTER \
+ (HARD_FRAME_POINTER_REGNUM == ARG_POINTER_REGNUM)
+ #endif
+
+
+
+
#ifdef GCC_INSN_FLAGS_H
/* Dependent default target macro definitions
Index: rtl.h
===================================================================
*** rtl.h (revision 215355)
--- rtl.h (working copy)
*************** do { \
*** 2390,2399 ****
/* Indicate whether the machine has any sort of auto increment addressing.
If not, we can avoid checking for REG_INC notes. */
! #if (defined (HAVE_PRE_INCREMENT) || defined (HAVE_PRE_DECREMENT) \
! || defined (HAVE_POST_INCREMENT) || defined (HAVE_POST_DECREMENT) \
! || defined (HAVE_PRE_MODIFY_DISP) || defined (HAVE_POST_MODIFY_DISP) \
! || defined (HAVE_PRE_MODIFY_REG) || defined (HAVE_POST_MODIFY_REG))
#define AUTO_INC_DEC
#endif
--- 2390,2399 ----
/* Indicate whether the machine has any sort of auto increment addressing.
If not, we can avoid checking for REG_INC notes. */
! #if (HAVE_PRE_INCREMENT || HAVE_PRE_DECREMENT \
! || HAVE_POST_INCREMENT || HAVE_POST_DECREMENT \
! || HAVE_PRE_MODIFY_DISP || HAVE_POST_MODIFY_DISP \
! || HAVE_PRE_MODIFY_REG || HAVE_POST_MODIFY_REG)
#define AUTO_INC_DEC
#endif
*************** do { \
*** 2408,2482 ****
#else
#define FIND_REG_INC_NOTE(INSN, REG) 0
#endif
-
- #ifndef HAVE_PRE_INCREMENT
- #define HAVE_PRE_INCREMENT 0
- #endif
-
- #ifndef HAVE_PRE_DECREMENT
- #define HAVE_PRE_DECREMENT 0
- #endif
-
- #ifndef HAVE_POST_INCREMENT
- #define HAVE_POST_INCREMENT 0
- #endif
-
- #ifndef HAVE_POST_DECREMENT
- #define HAVE_POST_DECREMENT 0
- #endif
-
- #ifndef HAVE_POST_MODIFY_DISP
- #define HAVE_POST_MODIFY_DISP 0
- #endif
-
- #ifndef HAVE_POST_MODIFY_REG
- #define HAVE_POST_MODIFY_REG 0
- #endif
-
- #ifndef HAVE_PRE_MODIFY_DISP
- #define HAVE_PRE_MODIFY_DISP 0
- #endif
-
- #ifndef HAVE_PRE_MODIFY_REG
- #define HAVE_PRE_MODIFY_REG 0
- #endif
-
-
- /* Some architectures do not have complete pre/post increment/decrement
- instruction sets, or only move some modes efficiently. These macros
- allow us to tune autoincrement generation. */
-
- #ifndef USE_LOAD_POST_INCREMENT
- #define USE_LOAD_POST_INCREMENT(MODE) HAVE_POST_INCREMENT
- #endif
-
- #ifndef USE_LOAD_POST_DECREMENT
- #define USE_LOAD_POST_DECREMENT(MODE) HAVE_POST_DECREMENT
- #endif
-
- #ifndef USE_LOAD_PRE_INCREMENT
- #define USE_LOAD_PRE_INCREMENT(MODE) HAVE_PRE_INCREMENT
- #endif
-
- #ifndef USE_LOAD_PRE_DECREMENT
- #define USE_LOAD_PRE_DECREMENT(MODE) HAVE_PRE_DECREMENT
- #endif
-
- #ifndef USE_STORE_POST_INCREMENT
- #define USE_STORE_POST_INCREMENT(MODE) HAVE_POST_INCREMENT
- #endif
-
- #ifndef USE_STORE_POST_DECREMENT
- #define USE_STORE_POST_DECREMENT(MODE) HAVE_POST_DECREMENT
- #endif
-
- #ifndef USE_STORE_PRE_INCREMENT
- #define USE_STORE_PRE_INCREMENT(MODE) HAVE_PRE_INCREMENT
- #endif
-
- #ifndef USE_STORE_PRE_DECREMENT
- #define USE_STORE_PRE_DECREMENT(MODE) HAVE_PRE_DECREMENT
- #endif
/* Nonzero when we are generating CONCATs. */
extern int generating_concat_p;
--- 2408,2413 ----
*************** extern GTY(()) rtx cc0_rtx;
*** 2954,2979 ****
extern GTY(()) rtx ret_rtx;
extern GTY(()) rtx simple_return_rtx;
- /* If HARD_FRAME_POINTER_REGNUM is defined, then a special dummy reg
- is used to represent the frame pointer. This is because the
- hard frame pointer and the automatic variables are separated by an amount
- that cannot be determined until after register allocation. We can assume
- that in this case ELIMINABLE_REGS will be defined, one action of which
- will be to eliminate FRAME_POINTER_REGNUM into HARD_FRAME_POINTER_REGNUM. */
- #ifndef HARD_FRAME_POINTER_REGNUM
- #define HARD_FRAME_POINTER_REGNUM FRAME_POINTER_REGNUM
- #endif
-
- #ifndef HARD_FRAME_POINTER_IS_FRAME_POINTER
- #define HARD_FRAME_POINTER_IS_FRAME_POINTER \
- (HARD_FRAME_POINTER_REGNUM == FRAME_POINTER_REGNUM)
- #endif
-
- #ifndef HARD_FRAME_POINTER_IS_ARG_POINTER
- #define HARD_FRAME_POINTER_IS_ARG_POINTER \
- (HARD_FRAME_POINTER_REGNUM == ARG_POINTER_REGNUM)
- #endif
-
/* Index labels for global_rtl. */
enum global_rtl_index
{
--- 2885,2890 ----
