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Re: gas -Werror compilation break [Re: [patch ld bfd gas]: Handle linkonce for cfi generated debug_frame and eh_frame data]
- From: Alan Modra <amodra at gmail dot com>
- To: Dave Korn <dave dot korn dot cygwin at gmail dot com>
- Cc: Binutils <binutils at sourceware dot org>
- Date: Sat, 7 May 2011 12:23:10 +0930
- Subject: Re: gas -Werror compilation break [Re: [patch ld bfd gas]: Handle linkonce for cfi generated debug_frame and eh_frame data]
- References: <BANLkTi=_hynUgqW5UjHDSvtWox2UshG=FQ@mail.gmail.com> <BANLkTinQxcD6pcyna-_AusTeXaTy8J6Knw@mail.gmail.com> <BANLkTi=SOrur_bPOMM5GKPtozYT0pw8vEw@mail.gmail.com> <BANLkTim3DpFxpY+yjuGExYWPZXRE3xwvag@mail.gmail.com> <4DB6E500.5030807@redhat.com> <20110427203457.GA12977@host1.jankratochvil.net> <4DC1EF60.5050308@gmail.com> <20110505084454.GH7018@bubble.grove.modra.org> <20110505132113.GI7018@bubble.grove.modra.org> <4DC43687.5030900@gmail.com>
On Fri, May 06, 2011 at 06:57:27PM +0100, Dave Korn wrote:
> Hmm, still getting this:
>
> > /n/10/davek/binutils/src.clean/gas/dw2gencfi.c: In function 'cfi_finish':
> > /n/10/davek/binutils/src.clean/gas/dw2gencfi.c:1903:17: error: variable 'ccseg' set but not used [-Werror=unused-but-set-variable]
> > cc1: all warnings being treated as errors
Caught out by my habit of compiling with -fno-inline. These warnings
are a bit of a pain when you want to reduce struct size as I did with
#if SUPPORT_FRAME_LINKONCE.
Let's clean up some of the conditional compilation. Shame on me for
not doing this properly in the first place. SET_CUR_SEG in the
!SUPPORT_FRAME_LINKONCE case is a little tricky since you need to
reference the rhs to ensure no warnings about is_now_linkonce_segment
being unused, but don't want gcc to actually call (or emit) the
function.
* dw2gencfi.c (CUR_SEG, SET_CUR_SEG, HANDLED, SET_HANDLED): Define.
Use throughout in place of #if SUPPORT_FRAME_LINKONCE.
(struct fde_entry): Rename cseg to cur_seg.
(cfi_change_reg_numbers): Remove ATTRIBUTE_UNUSED.
(get_cfi_seg): Likewise. Use if (SUPPORT_FRAME_LINKONCE) rather
that #if SUPPORT_FRAME_LINKONCE.
(cfi_finish): Likewise.
Index: gas/dw2gencfi.c
===================================================================
RCS file: /cvs/src/src/gas/dw2gencfi.c,v
retrieving revision 1.53
diff -u -p -r1.53 dw2gencfi.c
--- gas/dw2gencfi.c 5 May 2011 13:11:36 -0000 1.53
+++ gas/dw2gencfi.c 7 May 2011 02:30:31 -0000
@@ -83,6 +83,17 @@
#endif
#if SUPPORT_FRAME_LINKONCE
+#define CUR_SEG(structp) structp->cur_seg
+#define SET_CUR_SEG(structp, seg) structp->cur_seg = seg
+#define HANDLED(structp) structp->handled
+#define SET_HANDLED(structp, val) structp->handled = val
+#else
+#define CUR_SEG(structp) NULL
+#define SET_CUR_SEG(structp, seg) (void) (0 && seg)
+#define HANDLED(structp) 0
+#define SET_HANDLED(structp, val) (void) (0 && val)
+#endif
+
/* Private segment collection list. */
struct dwcfi_seg_list
{
@@ -232,7 +243,6 @@ dwcfi_hash_find_or_make (segT cseg, cons
return item;
}
-#endif
/* ??? Share this with dwarf2cfg.c. */
#ifndef TC_DWARF2_EMIT_OFFSET
@@ -302,7 +312,7 @@ struct fde_entry
{
struct fde_entry *next;
#if SUPPORT_FRAME_LINKONCE
- segT cseg;
+ segT cur_seg;
#endif
symbolS *start_address;
symbolS *end_address;
@@ -371,10 +381,8 @@ alloc_fde_entry (void)
frchain_now->frch_cfi_data->cur_fde_data = fde;
*last_fde_data = fde;
last_fde_data = &fde->next;
-#if SUPPORT_FRAME_LINKONCE
- fde->cseg = is_now_linkonce_segment ();
- fde->handled = 0;
-#endif
+ SET_CUR_SEG (fde, is_now_linkonce_segment ());
+ SET_HANDLED (fde, 0);
fde->last = &fde->data;
fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN;
fde->per_encoding = DW_EH_PE_omit;
@@ -398,9 +406,7 @@ alloc_cfi_insn_data (void)
*cur_fde_data->last = insn;
cur_fde_data->last = &insn->next;
-#if SUPPORT_FRAME_LINKONCE
- insn->cur_seg = is_now_linkonce_segment ();
-#endif
+ SET_CUR_SEG (insn, is_now_linkonce_segment ());
return insn;
}
@@ -1569,10 +1575,8 @@ output_cie (struct cie_entry *cie, bfd_b
{
for (i = cie->first; i != cie->last; i = i->next)
{
-#if SUPPORT_FRAME_LINKONCE
- if (i->cur_seg != cie->cur_seg)
+ if (CUR_SEG (i) != CUR_SEG (cie))
continue;
-#endif
output_cfi_insn (i);
}
}
@@ -1682,9 +1686,7 @@ output_fde (struct fde_entry *fde, struc
}
for (; first; first = first->next)
-#if SUPPORT_FRAME_LINKONCE
- if (first->cur_seg == fde->cseg)
-#endif
+ if (CUR_SEG (first) == CUR_SEG (fde))
output_cfi_insn (first);
frag_align (align, DW_CFA_nop, 0);
@@ -1700,10 +1702,8 @@ select_cie_for_fde (struct fde_entry *fd
for (cie = cie_root; cie; cie = cie->next)
{
-#if SUPPORT_FRAME_LINKONCE
- if (cie->cur_seg != fde->cseg)
+ if (CUR_SEG (cie) != CUR_SEG (fde))
continue;
-#endif
if (cie->return_column != fde->return_column
|| cie->signal_frame != fde->signal_frame
|| cie->per_encoding != fde->per_encoding
@@ -1802,9 +1802,7 @@ select_cie_for_fde (struct fde_entry *fd
cie = (struct cie_entry *) xmalloc (sizeof (struct cie_entry));
cie->next = cie_root;
cie_root = cie;
-#if SUPPORT_FRAME_LINKONCE
- cie->cur_seg = fde->cseg;
-#endif
+ SET_CUR_SEG (cie, CUR_SEG (fde));
cie->return_column = fde->return_column;
cie->signal_frame = fde->signal_frame;
cie->per_encoding = fde->per_encoding;
@@ -1829,14 +1827,12 @@ select_cie_for_fde (struct fde_entry *fd
#ifdef md_reg_eh_frame_to_debug_frame
static void
-cfi_change_reg_numbers (struct cfi_insn_data *insn, segT ccseg ATTRIBUTE_UNUSED)
+cfi_change_reg_numbers (struct cfi_insn_data *insn, segT ccseg)
{
for (; insn; insn = insn->next)
{
-#if SUPPORT_FRAME_LINKONCE
- if (insn->cur_seg != ccseg)
+ if (CUR_SEG (insn) != ccseg)
continue;
-#endif
switch (insn->insn)
{
case DW_CFA_advance_loc:
@@ -1878,20 +1874,22 @@ cfi_change_reg_numbers (struct cfi_insn_
#endif
static segT
-get_cfi_seg (segT cseg ATTRIBUTE_UNUSED,
- const char *base, flagword flags, int align)
+get_cfi_seg (segT cseg, const char *base, flagword flags, int align)
{
-#if SUPPORT_FRAME_LINKONCE
- struct dwcfi_seg_list *l;
+ if (SUPPORT_FRAME_LINKONCE)
+ {
+ struct dwcfi_seg_list *l;
- l = dwcfi_hash_find_or_make (cseg, base, flags);
+ l = dwcfi_hash_find_or_make (cseg, base, flags);
- cseg = l->seg;
- subseg_set (cseg, l->subseg);
-#else
- cseg = subseg_new (base, 0);
- bfd_set_section_flags (stdoutput, cseg, flags);
-#endif
+ cseg = l->seg;
+ subseg_set (cseg, l->subseg);
+ }
+ else
+ {
+ cseg = subseg_new (base, 0);
+ bfd_set_section_flags (stdoutput, cseg, flags);
+ }
record_alignment (cseg, align);
return cseg;
}
@@ -1914,18 +1912,19 @@ cfi_finish (void)
save_flag_traditional_format = flag_traditional_format;
flag_traditional_format = 1;
-#if !SUPPORT_FRAME_LINKONCE
- /* Open .eh_frame section. */
- cfi_seg = get_cfi_seg (NULL, ".eh_frame",
- SEC_ALLOC | SEC_LOAD | SEC_DATA
- | DWARF2_EH_FRAME_READ_ONLY,
- EH_FRAME_ALIGNMENT);
+ if (!SUPPORT_FRAME_LINKONCE)
+ {
+ /* Open .eh_frame section. */
+ cfi_seg = get_cfi_seg (NULL, ".eh_frame",
+ (SEC_ALLOC | SEC_LOAD | SEC_DATA
+ | DWARF2_EH_FRAME_READ_ONLY),
+ EH_FRAME_ALIGNMENT);
#ifdef md_fix_up_eh_frame
- md_fix_up_eh_frame (cfi_seg);
+ md_fix_up_eh_frame (cfi_seg);
#else
- (void) cfi_seg;
-#endif
+ (void) cfi_seg;
#endif
+ }
do
{
@@ -1941,31 +1940,32 @@ cfi_finish (void)
for (fde = all_fde_data; fde ; fde = fde->next)
{
-#if SUPPORT_FRAME_LINKONCE
- if (fde->handled != 0)
- continue;
- if (seek_next_seg && fde->cseg != ccseg)
- {
- seek_next_seg = 2;
- continue;
- }
- if (!seek_next_seg)
- {
- ccseg = fde->cseg;
- /* Open .eh_frame section. */
- cfi_seg = get_cfi_seg (ccseg, ".eh_frame",
- SEC_ALLOC | SEC_LOAD | SEC_DATA
- | DWARF2_EH_FRAME_READ_ONLY,
- EH_FRAME_ALIGNMENT);
+ if (SUPPORT_FRAME_LINKONCE)
+ {
+ if (HANDLED (fde))
+ continue;
+ if (seek_next_seg && CUR_SEG (fde) != ccseg)
+ {
+ seek_next_seg = 2;
+ continue;
+ }
+ if (!seek_next_seg)
+ {
+ ccseg = CUR_SEG (fde);
+ /* Open .eh_frame section. */
+ cfi_seg = get_cfi_seg (ccseg, ".eh_frame",
+ (SEC_ALLOC | SEC_LOAD | SEC_DATA
+ | DWARF2_EH_FRAME_READ_ONLY),
+ EH_FRAME_ALIGNMENT);
#ifdef md_fix_up_eh_frame
- md_fix_up_eh_frame (cfi_seg);
+ md_fix_up_eh_frame (cfi_seg);
#else
- (void) cfi_seg;
+ (void) cfi_seg;
#endif
- seek_next_seg = 1;
+ seek_next_seg = 1;
+ }
+ SET_HANDLED (fde, 1);
}
- fde->handled = 1;
-#endif
if (fde->end_address == NULL)
{
@@ -1980,10 +1980,9 @@ cfi_finish (void)
}
while (SUPPORT_FRAME_LINKONCE && seek_next_seg == 2);
-#if SUPPORT_FRAME_LINKONCE
- for (fde = all_fde_data; fde ; fde = fde->next)
- fde->handled = 0;
-#endif
+ if (SUPPORT_FRAME_LINKONCE)
+ for (fde = all_fde_data; fde ; fde = fde->next)
+ SET_HANDLED (fde, 0);
flag_traditional_format = save_flag_traditional_format;
}
@@ -1992,11 +1991,11 @@ cfi_finish (void)
{
int alignment = ffs (DWARF2_ADDR_SIZE (stdoutput)) - 1;
-#if !SUPPORT_FRAME_LINKONCE
- get_cfi_seg (NULL, ".debug_frame",
- SEC_READONLY | SEC_DEBUGGING,
- alignment);
-#endif
+ if (!SUPPORT_FRAME_LINKONCE)
+ get_cfi_seg (NULL, ".debug_frame",
+ SEC_READONLY | SEC_DEBUGGING,
+ alignment);
+
do
{
ccseg = NULL;
@@ -2011,25 +2010,26 @@ cfi_finish (void)
for (fde = all_fde_data; fde ; fde = fde->next)
{
-#if SUPPORT_FRAME_LINKONCE
- if (fde->handled != 0)
- continue;
- if (seek_next_seg && fde->cseg != ccseg)
- {
- seek_next_seg = 2;
- continue;
- }
- if (!seek_next_seg)
- {
- ccseg = fde->cseg;
- /* Open .debug_frame section. */
- get_cfi_seg (ccseg, ".debug_frame",
- SEC_READONLY | SEC_DEBUGGING,
- alignment);
- seek_next_seg = 1;
+ if (SUPPORT_FRAME_LINKONCE)
+ {
+ if (HANDLED (fde))
+ continue;
+ if (seek_next_seg && CUR_SEG (fde) != ccseg)
+ {
+ seek_next_seg = 2;
+ continue;
+ }
+ if (!seek_next_seg)
+ {
+ ccseg = CUR_SEG (fde);
+ /* Open .debug_frame section. */
+ get_cfi_seg (ccseg, ".debug_frame",
+ SEC_READONLY | SEC_DEBUGGING,
+ alignment);
+ seek_next_seg = 1;
+ }
+ SET_HANDLED (fde, 1);
}
- fde->handled = 1;
-#endif
if (fde->end_address == NULL)
{
as_bad (_("open CFI at the end of file; missing .cfi_endproc directive"));
@@ -2045,10 +2045,9 @@ cfi_finish (void)
}
while (SUPPORT_FRAME_LINKONCE && seek_next_seg == 2);
-#if SUPPORT_FRAME_LINKONCE
- for (fde = all_fde_data; fde ; fde = fde->next)
- fde->handled = 0;
-#endif
+ if (SUPPORT_FRAME_LINKONCE)
+ for (fde = all_fde_data; fde ; fde = fde->next)
+ SET_HANDLED (fde, 0);
}
}
--
Alan Modra
Australia Development Lab, IBM