OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Add retain attribute to place symbols in SHF_GNU_RETAIN section

Browse Source 
When building Linux kernel, ld in bninutils 2.36 with GCC 11 generates
thousands of

ld: warning: orphan section `.data.event_initcall_finish' from `init/main.o' being placed in section `.data.event_initcall_finish'
ld: warning: orphan section `.data.event_initcall_start' from `init/main.o' being placed in section `.data.event_initcall_start'
ld: warning: orphan section `.data.event_initcall_level' from `init/main.o' being placed in section `.data.event_initcall_level'

Since these sections are marked with SHF_GNU_RETAIN, they are placed in
separate sections.  They become orphan sections since they aren't expected
in the Linux kernel linker script. But orphan sections normally don't work
well with the Linux kernel linker script and the resulting kernel crashed.

Add the "retain" attribute to place symbols in separate SHF_GNU_RETAIN
sections.  Issue a warning if the configured assembler/linker doesn't
support SHF_GNU_RETAIN.

gcc/

	PR target/99113
	* varasm.c (get_section): Replace SUPPORTS_SHF_GNU_RETAIN with
	looking up the retain attribute.
	(resolve_unique_section): Likewise.
	(get_variable_section): Likewise.
	(switch_to_section): Likewise.  Warn when a symbol without the
	retain attribute and a symbol with the retain attribute are
	placed in the section with the same name, instead of the used
	attribute.
	* doc/extend.texi: Document the "retain" attribute.

gcc/c-family/

	PR target/99113
	* c-attribs.c (c_common_attribute_table): Add the "retain"
	attribute.
	(handle_retain_attribute): New function.

gcc/testsuite/

	PR target/99113
	* c-c++-common/attr-retain-1.c: New test.
	* c-c++-common/attr-retain-2.c: Likewise.
	* c-c++-common/attr-retain-3.c: Likewise.
	* c-c++-common/attr-retain-4.c: Likewise.
	* c-c++-common/attr-retain-5.c: Likewise.
	* c-c++-common/attr-retain-6.c: Likewise.
	* c-c++-common/attr-retain-7.c: Likewise.
	* c-c++-common/attr-retain-8.c: Likewise.
	* c-c++-common/attr-retain-9.c: Likewise.
	* c-c++-common/pr99113.c: Likewise.
	* gcc.c-torture/compile/attr-retain-1.c: Likewise.
	* gcc.c-torture/compile/attr-retain-2.c: Likewise.
	* c-c++-common/attr-used.c: Don't expect SHF_GNU_RETAIN section.
	* c-c++-common/attr-used-2.c: Likewise.
	* c-c++-common/attr-used-3.c: Likewise.
	* c-c++-common/attr-used-4.c: Likewise.
	* c-c++-common/attr-used-9.c: Likewise.
	* gcc.c-torture/compile/attr-used-retain-1.c: Likewise.
	* gcc.c-torture/compile/attr-used-retain-2.c: Likewise.
	* c-c++-common/attr-used-5.c: Don't expect warning for the used
	attribute nor SHF_GNU_RETAIN section.
	* c-c++-common/attr-used-6.c: Likewise.
	* c-c++-common/attr-used-7.c: Likewise.
	* c-c++-common/attr-used-8.c: Likewise.
This commit is contained in:
H.J. Lu 2021-02-15 11:31:12 -08:00
parent 1f9db6929d
commit 6347f4a090
26 changed files with 271 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
gcc/c-family/c-attribs.c
View File

@ -163,6 +163,7 @@ static tree handle_objc_root_class_attribute (tree *, tree, tree, int, bool *);
static tree handle_objc_nullability_attribute (tree *, tree, tree, int, bool *);
static tree handle_signed_bool_precision_attribute (tree *, tree, tree, int,
bool *);
static tree handle_retain_attribute (tree *, tree, tree, int, bool *);
/* Helper to define attribute exclusions. */
#define ATTR_EXCL(name, function, type, variable) \
@ -328,6 +329,8 @@ const struct attribute_spec c_common_attribute_table[] =
handle_used_attribute, NULL },
{ "unused", 0, 0, false, false, false, false,
handle_unused_attribute, NULL },
{ "retain", 0, 0, true, false, false, false,
handle_retain_attribute, NULL },
{ "externally_visible", 0, 0, true, false, false, false,
handle_externally_visible_attribute, NULL },
{ "no_reorder", 0, 0, true, false, false, false,
@ -1564,6 +1567,28 @@ handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args),
return NULL_TREE;
}
/* Handle a "retain" attribute; arguments as in
struct attribute_spec.handler. */
static tree
handle_retain_attribute (tree *pnode, tree name, tree ARG_UNUSED (args),
int ARG_UNUSED (flags), bool *no_add_attrs)
{
tree node = *pnode;
if (SUPPORTS_SHF_GNU_RETAIN
&& (TREE_CODE (node) == FUNCTION_DECL
|| (VAR_P (node) && TREE_STATIC (node))))
;
else
{
warning (OPT_Wattributes, "%qE attribute ignored", name);
*no_add_attrs = true;
}
return NULL_TREE;
}
/* Handle a "externally_visible" attribute; arguments as in
struct attribute_spec.handler. */

8
gcc/doc/extend.texi
View File

@ -3913,8 +3913,10 @@ When applied to a member function of a C++ class template, the
attribute also means that the function is instantiated if the
class itself is instantiated.
@item retain
@cindex @code{retain} function attribute
For ELF targets that support the GNU or FreeBSD OSABIs, this attribute
will also save the function from linker garbage collection. To support
will save the function from linker garbage collection. To support
this behavior, functions that have not been placed in specific sections
(e.g. by the @code{section} attribute, or the @code{-ffunction-sections}
option), will be placed in new, unique sections.
@ -7504,8 +7506,10 @@ When applied to a static data member of a C++ class template, the
attribute also means that the member is instantiated if the
class itself is instantiated.
@item retain
@cindex @code{retain} variable attribute
For ELF targets that support the GNU or FreeBSD OSABIs, this attribute
will also save the variable from linker garbage collection. To support
will save the variable from linker garbage collection. To support
this behavior, variables that have not been placed in specific sections
(e.g. by the @code{section} attribute, or the @code{-fdata-sections} option),
will be placed in new, unique sections.

16
gcc/testsuite/c-c++-common/attr-retain-1.c Normal file
View File

@ -0,0 +1,16 @@
/* { dg-do compile { target R_flag_in_section } } */
/* { dg-options "-O3" } */
static void function_declaration_before(void)
__attribute__((__used__, __retain__));
static void function_declaration_before(void) {}
static void function_declaration_after(void) {}
static void function_declaration_after(void)
__attribute__((__used__, __retain__));
/* { dg-final { scan-assembler "function_declaration_before" } } */
/* { dg-final { scan-assembler "function_declaration_after" } } */
/* { dg-final { scan-assembler "\.text.*,\"axR\"" { target R_flag_in_section } } } */

12
gcc/testsuite/c-c++-common/attr-retain-2.c Normal file
View File

@ -0,0 +1,12 @@
/* { dg-do compile { target R_flag_in_section } } */
/* { dg-options "-Wall -O2" } */
static int xyzzy __attribute__((__used__, __retain__)) = 1;
void foo()
{
int x __attribute__((__retain__)); /* { dg-warning "attribute ignored|unused variable" } */
}
/* { dg-final { scan-assembler "xyzzy" } } */
/* { dg-final { scan-assembler "\.data.*,\"awR\"" { target R_flag_in_section } } } */

7
gcc/testsuite/c-c++-common/attr-retain-3.c Normal file
View File

@ -0,0 +1,7 @@
/* { dg-do compile { target R_flag_in_section } } */
/* { dg-options "-Wall -O2 -fcommon" } */
static int xyzzy __attribute__((__used__, __retain__));
/* { dg-final { scan-assembler "xyzzy" } } */
/* { dg-final { scan-assembler ",\"awR\"" { target R_flag_in_section } } } */

7
gcc/testsuite/c-c++-common/attr-retain-4.c Normal file
View File

@ -0,0 +1,7 @@
/* { dg-do compile { target R_flag_in_section } } */
/* { dg-options "-Wall -O2 -fcommon" } */
int xyzzy __attribute__((__used__, __retain__));
/* { dg-final { scan-assembler "xyzzy" } } */
/* { dg-final { scan-assembler ",\"awR\"" { target R_flag_in_section } } } */

28
gcc/testsuite/c-c++-common/attr-retain-5.c Normal file
View File

@ -0,0 +1,28 @@
/* { dg-do compile } */
/* { dg-skip-if "non-ELF target" { *-*-darwin* } } */
/* { dg-options "-Wall -O2" } */
struct dtv_slotinfo_list
{
struct dtv_slotinfo_list *next;
};
extern struct dtv_slotinfo_list *list;
static int __attribute__ ((section ("__libc_freeres_fn")))
free_slotinfo (struct dtv_slotinfo_list **elemp)
/* { dg-warning "'.*' without 'retain' attribute and '.*' with 'retain' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
{
if (!free_slotinfo (&(*elemp)->next))
return 0;
return 1;
}
__attribute__ ((used, retain, section ("__libc_freeres_fn")))
static void free_mem (void)
{
free_slotinfo (&list);
}
/* { dg-final { scan-assembler "__libc_freeres_fn,\"ax\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */

28
gcc/testsuite/c-c++-common/attr-retain-6.c Normal file
View File

@ -0,0 +1,28 @@
/* { dg-do compile } */
/* { dg-skip-if "non-ELF target" { *-*-darwin* } } */
/* { dg-options "-Wall -O2" } */
struct dtv_slotinfo_list
{
struct dtv_slotinfo_list *next;
};
extern struct dtv_slotinfo_list *list;
static int __attribute__ ((used, retain, section ("__libc_freeres_fn")))
free_slotinfo (struct dtv_slotinfo_list **elemp)
{
if (!free_slotinfo (&(*elemp)->next))
return 0;
return 1;
}
__attribute__ ((section ("__libc_freeres_fn")))
void free_mem (void)
/* { dg-warning "'.*' without 'retain' attribute and '.*' with 'retain' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
{
free_slotinfo (&list);
}
/* { dg-final { scan-assembler "__libc_freeres_fn,\"ax\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */

10
gcc/testsuite/c-c++-common/attr-retain-7.c Normal file
View File

@ -0,0 +1,10 @@
/* { dg-do compile } */
/* { dg-skip-if "non-ELF target" { *-*-darwin* } } */
/* { dg-options "-Wall -O2" } */
int __attribute__((used,retain,section(".data.foo"))) foo2 = 2;
int __attribute__((section(".data.foo"))) foo1 = 1;
/* { dg-warning "'.*' without 'retain' attribute and '.*' with 'retain' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
/* { dg-final { scan-assembler ".data.foo,\"aw\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler ".data.foo,\"awR\"" { target R_flag_in_section } } } */

10
gcc/testsuite/c-c++-common/attr-retain-8.c Normal file
View File

@ -0,0 +1,10 @@
/* { dg-do compile } */
/* { dg-skip-if "non-ELF target" { *-*-darwin* } } */
/* { dg-options "-Wall -O2" } */
int __attribute__((section(".data.foo"))) foo1 = 1;
/* { dg-warning "'.*' without 'retain' attribute and '.*' with 'retain' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
int __attribute__((used,retain,section(".data.foo"))) foo2 = 2;
/* { dg-final { scan-assembler ".data.foo,\"aw\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler ".data.foo,\"awR\"" { target R_flag_in_section } } } */

29
gcc/testsuite/c-c++-common/attr-retain-9.c Normal file
View File

@ -0,0 +1,29 @@
/* { dg-do compile } */
/* { dg-skip-if "non-ELF target" { *-*-darwin* } } */
/* { dg-options "-Wall -O2" } */
struct dtv_slotinfo_list
{
struct dtv_slotinfo_list *next;
};
extern struct dtv_slotinfo_list *list;
static int __attribute__ ((used, retain, section ("__libc_freeres_fn")))
free_slotinfo (struct dtv_slotinfo_list **elemp)
{
if (!free_slotinfo (&(*elemp)->next))
return 0;
return 1;
}
__attribute__ ((section ("__libc_freeres_fn")))
static void free_mem (void)
/* { dg-warning "defined but not used" "" { target *-*-* } .-1 } */
{
free_slotinfo (&list);
}
/* { dg-final { scan-assembler-not "__libc_freeres_fn\n" } } */
/* { dg-final { scan-assembler-not "__libc_freeres_fn,\"ax\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */

2
gcc/testsuite/c-c++-common/attr-used-2.c
View File

@ -9,4 +9,4 @@ void foo()
}
/* { dg-final { scan-assembler "xyzzy" } } */
/* { dg-final { scan-assembler "\.data.*,\"awR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not "\.data.*,\"awR\"" { target R_flag_in_section } } } */

2
gcc/testsuite/c-c++-common/attr-used-3.c
View File

@ -4,4 +4,4 @@
static int xyzzy __attribute__((__used__));
/* { dg-final { scan-assembler "xyzzy" } } */
/* { dg-final { scan-assembler ",\"awR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not ",\"awR\"" { target R_flag_in_section } } } */

2
gcc/testsuite/c-c++-common/attr-used-4.c
View File

@ -4,4 +4,4 @@
int xyzzy __attribute__((__used__));
/* { dg-final { scan-assembler "xyzzy" } } */
/* { dg-final { scan-assembler ",\"awR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not ",\"awR\"" { target R_flag_in_section } } } */

3
gcc/testsuite/c-c++-common/attr-used-5.c
View File

@ -11,7 +11,6 @@ extern struct dtv_slotinfo_list *list;
static int __attribute__ ((section ("__libc_freeres_fn")))
free_slotinfo (struct dtv_slotinfo_list **elemp)
/* { dg-warning "'.*' without 'used' attribute and '.*' with 'used' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
{
if (!free_slotinfo (&(*elemp)->next))
return 0;
@ -25,4 +24,4 @@ static void free_mem (void)
}
/* { dg-final { scan-assembler "__libc_freeres_fn,\"ax\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */

3
gcc/testsuite/c-c++-common/attr-used-6.c
View File

@ -19,10 +19,9 @@ free_slotinfo (struct dtv_slotinfo_list **elemp)
__attribute__ ((section ("__libc_freeres_fn")))
void free_mem (void)
/* { dg-warning "'.*' without 'used' attribute and '.*' with 'used' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
{
free_slotinfo (&list);
}
/* { dg-final { scan-assembler "__libc_freeres_fn,\"ax\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */

3
gcc/testsuite/c-c++-common/attr-used-7.c
View File

@ -4,7 +4,6 @@
int __attribute__((used,section(".data.foo"))) foo2 = 2;
int __attribute__((section(".data.foo"))) foo1 = 1;
/* { dg-warning "'.*' without 'used' attribute and '.*' with 'used' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
/* { dg-final { scan-assembler ".data.foo,\"aw\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler ".data.foo,\"awR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not ".data.foo,\"awR\"" { target R_flag_in_section } } } */

3
gcc/testsuite/c-c++-common/attr-used-8.c
View File

@ -3,8 +3,7 @@
/* { dg-options "-Wall -O2" } */
int __attribute__((section(".data.foo"))) foo1 = 1;
/* { dg-warning "'.*' without 'used' attribute and '.*' with 'used' attribute are placed in a section with the same name" "" { target R_flag_in_section } .-1 } */
int __attribute__((used,section(".data.foo"))) foo2 = 2;
/* { dg-final { scan-assembler ".data.foo,\"aw\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler ".data.foo,\"awR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not ".data.foo,\"awR\"" { target R_flag_in_section } } } */

4
gcc/testsuite/c-c++-common/attr-used-9.c
View File

@ -25,5 +25,5 @@ static void free_mem (void)
}
/* { dg-final { scan-assembler-not "__libc_freeres_fn\n" } } */
/* { dg-final { scan-assembler-not "__libc_freeres_fn,\"ax\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler "__libc_freeres_fn,\"ax\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not "__libc_freeres_fn,\"axR\"" { target R_flag_in_section } } } */

2
gcc/testsuite/c-c++-common/attr-used.c
View File

@ -11,4 +11,4 @@ static void function_declaration_after(void) __attribute__((__used__));
/* { dg-final { scan-assembler "function_declaration_before" } } */
/* { dg-final { scan-assembler "function_declaration_after" } } */
/* { dg-final { scan-assembler "\.text.*,\"axR\"" { target R_flag_in_section } } } */
/* { dg-final { scan-assembler-not "\.text.*,\"axR\"" { target R_flag_in_section } } } */

7
gcc/testsuite/c-c++-common/pr99113.c Normal file
View File

@ -0,0 +1,7 @@
/* { dg-do compile } */
/* { dg-options "-Wall -O2" } */
static int xyzzy __attribute__((__used__)) = 1;
/* { dg-final { scan-assembler "xyzzy" } } */
/* { dg-final { scan-assembler-not "\.data.*,\"awR\"" { target R_flag_in_section } } } */

34
gcc/testsuite/gcc.c-torture/compile/attr-retain-1.c Normal file
View File

@ -0,0 +1,34 @@
/* { dg-do compile { target R_flag_in_section } } */
/* { dg-final { scan-assembler ".text.*,\"axR\"" } } */
/* { dg-final { scan-assembler ".bss.*,\"awR\"" } } */
/* { dg-final { scan-assembler ".data.*,\"awR\"" } } */
/* { dg-final { scan-assembler ".rodata.*,\"aR\"" } } */
/* { dg-final { scan-assembler ".data.used_foo_sec,\"awR\"" } } */
void __attribute__((used,retain)) used_fn (void) { }
void unused_fn (void) { }
void __attribute__((hot,used,retain)) used_hot_fn (void) { }
void __attribute__((hot)) unused_hot_fn (void) { }
void __attribute__((cold,used,retain)) used_cold_fn (void) { }
void __attribute__((cold)) unused_cold_fn (void) { }
int __attribute__((used,retain)) used_bss = 0;
int __attribute__((used,retain)) used_data = 1;
const int __attribute__((used,retain)) used_rodata = 2;
int __attribute__((used,retain)) used_comm;
static int __attribute__((used,retain)) used_lcomm;
int unused_bss = 0;
int unused_data = 1;
const int unused_rodata = 2;
int unused_comm;
static int unused_lcomm;
/* Test switching back to the used,retained sections. */
void __attribute__((used,retain)) used_fn2 (void) { }
int __attribute__((used,retain)) used_bss2 = 0;
int __attribute__((used,retain)) used_data2 = 1;
const int __attribute__((used,retain)) used_rodata2 = 2;
int __attribute__((used,retain)) used_comm2;
static int __attribute__((used,retain)) used_lcomm2;
int __attribute__((used,retain,section(".data.used_foo_sec"))) used_foo = 2;

15
gcc/testsuite/gcc.c-torture/compile/attr-retain-2.c Normal file
View File

@ -0,0 +1,15 @@
/* { dg-do compile { target R_flag_in_section } } */
/* { dg-final { scan-assembler ".text.used_fn,\"axR\"" } } */
/* { dg-final { scan-assembler ".text.used_fn2,\"axR\"" } } */
/* { dg-final { scan-assembler ".bss.used_bss,\"awR\"" } } */
/* { dg-final { scan-assembler ".bss.used_bss2,\"awR\"" } } */
/* { dg-final { scan-assembler ".data.used_data,\"awR\"" } } */
/* { dg-final { scan-assembler ".data.used_data2,\"awR\"" } } */
/* { dg-final { scan-assembler ".rodata.used_rodata,\"aR\"" } } */
/* { dg-final { scan-assembler ".rodata.used_rodata2,\"aR\"" } } */
/* { dg-final { scan-assembler ".bss.used_lcomm,\"awR\"" { target arm-*-* } } } */
/* { dg-final { scan-assembler ".bss.used_lcomm2,\"awR\"" { target arm-*-* } } } */
/* { dg-final { scan-assembler ".data.used_foo_sec,\"awR\"" } } */
/* { dg-options "-ffunction-sections -fdata-sections" } */
#include "attr-retain-1.c"

10
gcc/testsuite/gcc.c-torture/compile/attr-used-retain-1.c
View File

@ -1,10 +1,10 @@
/* { dg-do compile } */
/* { dg-require-effective-target R_flag_in_section } */
/* { dg-final { scan-assembler ".text.*,\"axR\"" } } */
/* { dg-final { scan-assembler ".bss.*,\"awR\"" } } */
/* { dg-final { scan-assembler ".data.*,\"awR\"" } } */
/* { dg-final { scan-assembler ".rodata.*,\"aR\"" } } */
/* { dg-final { scan-assembler ".data.used_foo_sec,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".text.*,\"axR\"" } } */
/* { dg-final { scan-assembler-not ".bss.*,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".data.*,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".rodata.*,\"aR\"" } } */
/* { dg-final { scan-assembler-not ".data.used_foo_sec,\"awR\"" } } */
void __attribute__((used)) used_fn (void) { }
void unused_fn (void) { }

22
gcc/testsuite/gcc.c-torture/compile/attr-used-retain-2.c
View File

@ -1,16 +1,16 @@
/* { dg-do compile } */
/* { dg-require-effective-target R_flag_in_section } */
/* { dg-final { scan-assembler ".text.used_fn,\"axR\"" } } */
/* { dg-final { scan-assembler ".text.used_fn2,\"axR\"" } } */
/* { dg-final { scan-assembler ".bss.used_bss,\"awR\"" } } */
/* { dg-final { scan-assembler ".bss.used_bss2,\"awR\"" } } */
/* { dg-final { scan-assembler ".data.used_data,\"awR\"" } } */
/* { dg-final { scan-assembler ".data.used_data2,\"awR\"" } } */
/* { dg-final { scan-assembler ".rodata.used_rodata,\"aR\"" } } */
/* { dg-final { scan-assembler ".rodata.used_rodata2,\"aR\"" } } */
/* { dg-final { scan-assembler ".bss.used_lcomm,\"awR\"" { target arm-*-* } } } */
/* { dg-final { scan-assembler ".bss.used_lcomm2,\"awR\"" { target arm-*-* } } } */
/* { dg-final { scan-assembler ".data.used_foo_sec,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".text.used_fn,\"axR\"" } } */
/* { dg-final { scan-assembler-not ".text.used_fn2,\"axR\"" } } */
/* { dg-final { scan-assembler-not ".bss.used_bss,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".bss.used_bss2,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".data.used_data,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".data.used_data2,\"awR\"" } } */
/* { dg-final { scan-assembler-not ".rodata.used_rodata,\"aR\"" } } */
/* { dg-final { scan-assembler-not ".rodata.used_rodata2,\"aR\"" } } */
/* { dg-final { scan-assembler-not ".bss.used_lcomm,\"awR\"" { target arm-*-* } } } */
/* { dg-final { scan-assembler-not ".bss.used_lcomm2,\"awR\"" { target arm-*-* } } } */
/* { dg-final { scan-assembler-not ".data.used_foo_sec,\"awR\"" } } */
/* { dg-options "-ffunction-sections -fdata-sections" } */
#include "attr-used-retain-1.c"

22
gcc/varasm.c
View File

@ -297,10 +297,9 @@ get_section (const char *name, unsigned int flags, tree decl,
slot = section_htab->find_slot_with_hash (name, htab_hash_string (name),
INSERT);
flags |= SECTION_NAMED;
if (SUPPORTS_SHF_GNU_RETAIN
&& decl != nullptr
if (decl != nullptr
&& DECL_P (decl)
&& DECL_PRESERVE_P (decl))
&& lookup_attribute ("retain", DECL_ATTRIBUTES (decl)))
flags |= SECTION_RETAIN;
if (*slot == NULL)
{
@ -487,7 +486,7 @@ resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
if (DECL_SECTION_NAME (decl) == NULL
&& targetm_common.have_named_sections
&& (flag_function_or_data_sections
|| (SUPPORTS_SHF_GNU_RETAIN && DECL_PRESERVE_P (decl))
|| lookup_attribute ("retain", DECL_ATTRIBUTES (decl))
|| DECL_COMDAT_GROUP (decl)))
{
targetm.asm_out.unique_section (decl, reloc);
@ -1227,7 +1226,7 @@ get_variable_section (tree decl, bool prefer_noswitch_p)
vnode->get_constructor ();
if (DECL_COMMON (decl)
&& !(SUPPORTS_SHF_GNU_RETAIN && DECL_PRESERVE_P (decl)))
&& !lookup_attribute ("retain", DECL_ATTRIBUTES (decl)))
{
/* If the decl has been given an explicit section name, or it resides
in a non-generic address space, then it isn't common, and shouldn't
@ -7761,18 +7760,19 @@ switch_to_section (section *new_section, tree decl)
{
if (in_section == new_section)
{
if (SUPPORTS_SHF_GNU_RETAIN
&& (new_section->common.flags & SECTION_NAMED)
bool retain_p;
if ((new_section->common.flags & SECTION_NAMED)
&& decl != nullptr
&& DECL_P (decl)
&& (!!DECL_PRESERVE_P (decl)
&& ((retain_p = !!lookup_attribute ("retain",
DECL_ATTRIBUTES (decl)))
!= !!(new_section->common.flags & SECTION_RETAIN)))
{
/* If the SECTION_RETAIN bit doesn't match, switch to a new
section. */
tree used_decl, no_used_decl;
if (DECL_PRESERVE_P (decl))
if (retain_p)
{
new_section->common.flags |= SECTION_RETAIN;
used_decl = decl;
@ -7786,8 +7786,8 @@ switch_to_section (section *new_section, tree decl)
no_used_decl = decl;
}
warning (OPT_Wattributes,
"%+qD without %<used%> attribute and %qD with "
"%<used%> attribute are placed in a section with "
"%+qD without %<retain%> attribute and %qD with "
"%<retain%> attribute are placed in a section with "
"the same name", no_used_decl, used_decl);
inform (DECL_SOURCE_LOCATION (used_decl),
"%qD was declared here", used_decl);