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Commit eac188c5 by Georg-Johann Lay Committed by Georg-Johann Lay
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re PR target/53256 ([avr] Attribute 'interrupt' shall override attribute 'signal') 

	PR target/53256
	* config/avr/elf.h (ASM_DECLARE_FUNCTION_NAME): Remove.
	* config/avr/avr-protos.h (avr_asm_declare_function_name): Remove.
	* config/avr/avr.h (struct machine_function): Add attributes_checked_p.
	* config/avr/avr.c (avr_asm_declare_function_name): Remove.
	(expand_prologue): Move initialization of cfun->machine->is_naked,
	is_interrupt, is_signal, is_OS_task, is_OS_main from here to...
	(avr_set_current_function): ...this new static function.
	(TARGET_SET_CURRENT_FUNCTION): New define.
	(avr_function_ok_for_sibcall): Use cfun->machine->is_* instead of
	checking attributes of current_function_decl.
	(avr_regs_to_save): Ditto.
	(signal_function_p): Rename to avr_signal_function_p.
	(interrupt_function_p): Rename to avr_interrupt_function_p.
	* doc/extend.texi (Function Attributes): Better explanation of
	'interrupt' and 'signal' for AVR. Move 'ifunc' down to establish
	alphabetical order.

From-SVN: r187342
parent 5b0d38e4
Showing with 181 additions and 114 deletions
gcc/ChangeLog
2012-05-09 Georg-Johann Lay <avr@gjlay.de>
PR target/53256
* config/avr/elf.h (ASM_DECLARE_FUNCTION_NAME): Remove.
* config/avr/avr-protos.h (avr_asm_declare_function_name): Remove.
* config/avr/avr.h (struct machine_function): Add attributes_checked_p.
* config/avr/avr.c (avr_asm_declare_function_name): Remove.
(expand_prologue): Move initialization of cfun->machine->is_naked,
is_interrupt, is_signal, is_OS_task, is_OS_main from here to...
(avr_set_current_function): ...this new static function.
(TARGET_SET_CURRENT_FUNCTION): New define.
(avr_function_ok_for_sibcall): Use cfun->machine->is_* instead of
checking attributes of current_function_decl.
(avr_regs_to_save): Ditto.
(signal_function_p): Rename to avr_signal_function_p.
(interrupt_function_p): Rename to avr_interrupt_function_p.
* doc/extend.texi (Function Attributes): Better explanation of
'interrupt' and 'signal' for AVR. Move 'ifunc' down to establish
alphabetical order.
2012-05-09 Michael Matz <matz@suse.de>
PR tree-optimization/53185
......
gcc/config/avr/avr-protos.h
......@@ -26,7 +26,6 @@ extern int function_arg_regno_p (int r);
extern void avr_cpu_cpp_builtins (struct cpp_reader * pfile);
extern enum reg_class avr_regno_reg_class (int r);
extern void asm_globalize_label (FILE *file, const char *name);
extern void avr_asm_declare_function_name (FILE *, const char *, tree);
extern void order_regs_for_local_alloc (void);
extern int avr_initial_elimination_offset (int from, int to);
extern int avr_simple_epilogue (void);
......
gcc/config/avr/avr.c
......@@ -138,12 +138,6 @@ static const char* out_movqi_mr_r (rtx, rtx[], int*);
static const char* out_movhi_mr_r (rtx, rtx[], int*);
static const char* out_movsi_mr_r (rtx, rtx[], int*);
static int avr_naked_function_p (tree);
static int interrupt_function_p (tree);
static int signal_function_p (tree);
static int avr_OS_task_function_p (tree);
static int avr_OS_main_function_p (tree);
static int avr_regs_to_save (HARD_REG_SET *);
static int get_sequence_length (rtx insns);
static int sequent_regs_live (void);
static const char *ptrreg_to_str (int);
......@@ -491,7 +485,7 @@ avr_naked_function_p (tree func)
by the "interrupt" attribute. */
static int
interrupt_function_p (tree func)
avr_interrupt_function_p (tree func)
{
return avr_lookup_function_attribute1 (func, "interrupt");
}
......@@ -500,7 +494,7 @@ interrupt_function_p (tree func)
by the "signal" attribute. */
static int
signal_function_p (tree func)
avr_signal_function_p (tree func)
{
return avr_lookup_function_attribute1 (func, "signal");
}
......@@ -522,6 +516,80 @@ avr_OS_main_function_p (tree func)
}
/* Implement `TARGET_SET_CURRENT_FUNCTION'. */
/* Sanity cheching for above function attributes. */
static void
avr_set_current_function (tree decl)
{
location_t loc;
const char *isr;
if (decl == NULL_TREE
|| current_function_decl == NULL_TREE
|| current_function_decl == error_mark_node
|| cfun->machine->attributes_checked_p)
return;
loc = DECL_SOURCE_LOCATION (decl);
cfun->machine->is_naked = avr_naked_function_p (decl);
cfun->machine->is_signal = avr_signal_function_p (decl);
cfun->machine->is_interrupt = avr_interrupt_function_p (decl);
cfun->machine->is_OS_task = avr_OS_task_function_p (decl);
cfun->machine->is_OS_main = avr_OS_main_function_p (decl);
isr = cfun->machine->is_interrupt ? "interrupt" : "signal";
/* Too much attributes make no sense as they request conflicting features. */
if (cfun->machine->is_OS_task + cfun->machine->is_OS_main
+ (cfun->machine->is_signal || cfun->machine->is_interrupt) > 1)
error_at (loc, "function attributes %qs, %qs and %qs are mutually"
" exclusive", "OS_task", "OS_main", isr);
/* 'naked' will hide effects of 'OS_task' and 'OS_main'. */
if (cfun->machine->is_naked
&& (cfun->machine->is_OS_task || cfun->machine->is_OS_main))
warning_at (loc, OPT_Wattributes, "function attributes %qs and %qs have"
" no effect on %qs function", "OS_task", "OS_main", "naked");
if (cfun->machine->is_interrupt || cfun->machine->is_signal)
{
tree args = TYPE_ARG_TYPES (TREE_TYPE (decl));
tree ret = TREE_TYPE (TREE_TYPE (decl));
const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
/* Silently ignore 'signal' if 'interrupt' is present. AVR-LibC startet
using this when it switched from SIGNAL and INTERRUPT to ISR. */
if (cfun->machine->is_interrupt)
cfun->machine->is_signal = 0;
/* Interrupt handlers must be void __vector (void) functions. */
if (args && TREE_CODE (TREE_VALUE (args)) != VOID_TYPE)
error_at (loc, "%qs function cannot have arguments", isr);
if (TREE_CODE (ret) != VOID_TYPE)
error_at (loc, "%qs function cannot return a value", isr);
/* If the function has the 'signal' or 'interrupt' attribute, ensure
that the name of the function is "__vector_NN" so as to catch
when the user misspells the vector name. */
if (!STR_PREFIX_P (name, "__vector"))
warning_at (loc, 0, "%qs appears to be a misspelled %s handler",
name, isr);
}
/* Avoid the above diagnosis to be printed more than once. */
cfun->machine->attributes_checked_p = 1;
}
/* Implement `ACCUMULATE_OUTGOING_ARGS'. */
int
......@@ -570,8 +638,7 @@ static int
avr_regs_to_save (HARD_REG_SET *set)
{
int reg, count;
int int_or_sig_p = (interrupt_function_p (current_function_decl)
|| signal_function_p (current_function_decl));
int int_or_sig_p = cfun->machine->is_interrupt || cfun->machine->is_signal;
if (set)
CLEAR_HARD_REG_SET (*set);
......@@ -683,9 +750,9 @@ avr_simple_epilogue (void)
&& get_frame_size () == 0
&& avr_outgoing_args_size() == 0
&& avr_regs_to_save (NULL) == 0
&& ! interrupt_function_p (current_function_decl)
&& ! signal_function_p (current_function_decl)
&& ! avr_naked_function_p (current_function_decl)
&& ! cfun->machine->is_interrupt
&& ! cfun->machine->is_signal
&& ! cfun->machine->is_naked
&& ! TREE_THIS_VOLATILE (current_function_decl));
}
......@@ -1096,12 +1163,6 @@ expand_prologue (void)
size = get_frame_size() + avr_outgoing_args_size();
/* Init cfun->machine. */
cfun->machine->is_naked = avr_naked_function_p (current_function_decl);
cfun->machine->is_interrupt = interrupt_function_p (current_function_decl);
cfun->machine->is_signal = signal_function_p (current_function_decl);
cfun->machine->is_OS_task = avr_OS_task_function_p (current_function_decl);
cfun->machine->is_OS_main = avr_OS_main_function_p (current_function_decl);
cfun->machine->stack_usage = 0;
/* Prologue: naked. */
......@@ -2458,17 +2519,17 @@ avr_function_ok_for_sibcall (tree decl_callee, tree exp_callee)
/* Ensure that caller and callee have compatible epilogues */
if (interrupt_function_p (current_function_decl)
|| signal_function_p (current_function_decl)
if (cfun->machine->is_interrupt
|| cfun->machine->is_signal
|| cfun->machine->is_naked
|| avr_naked_function_p (decl_callee)
|| avr_naked_function_p (current_function_decl)
/* FIXME: For OS_task and OS_main, we are over-conservative.
This is due to missing documentation of these attributes
and what they actually should do and should not do. */
|| (avr_OS_task_function_p (decl_callee)
!= avr_OS_task_function_p (current_function_decl))
!= cfun->machine->is_OS_task)
|| (avr_OS_main_function_p (decl_callee)
!= avr_OS_main_function_p (current_function_decl)))
!= cfun->machine->is_OS_main))
{
return false;
}
......@@ -6656,40 +6717,6 @@ avr_assemble_integer (rtx x, unsigned int size, int aligned_p)
}
/* Worker function for ASM_DECLARE_FUNCTION_NAME. */
void
avr_asm_declare_function_name (FILE *file, const char *name, tree decl)
{
/* If the function has the 'signal' or 'interrupt' attribute, test to
make sure that the name of the function is "__vector_NN" so as to
catch when the user misspells the interrupt vector name. */
if (cfun->machine->is_interrupt)
{
if (!STR_PREFIX_P (name, "__vector"))
{
warning_at (DECL_SOURCE_LOCATION (decl), 0,
"%qs appears to be a misspelled interrupt handler",
name);
}
}
else if (cfun->machine->is_signal)
{
if (!STR_PREFIX_P (name, "__vector"))
{
warning_at (DECL_SOURCE_LOCATION (decl), 0,
"%qs appears to be a misspelled signal handler",
name);
}
}
ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function");
ASM_OUTPUT_LABEL (file, name);
}
/* Return value is nonzero if pseudos that have been
assigned to registers of class CLASS would likely be spilled
because registers of CLASS are needed for spill registers. */
......@@ -10865,6 +10892,9 @@ avr_fold_builtin (tree fndecl, int n_args ATTRIBUTE_UNUSED, tree *arg,
#undef TARGET_FUNCTION_ARG_ADVANCE
#define TARGET_FUNCTION_ARG_ADVANCE avr_function_arg_advance
#undef TARGET_SET_CURRENT_FUNCTION
#define TARGET_SET_CURRENT_FUNCTION avr_set_current_function
#undef TARGET_RETURN_IN_MEMORY
#define TARGET_RETURN_IN_MEMORY avr_return_in_memory
......
gcc/config/avr/avr.h
......@@ -707,6 +707,10 @@ struct GTY(()) machine_function
/* 'true' if a callee might be tail called */
int sibcall_fails;
/* 'true' if the above is_foo predicates are sanity-checked to avoid
multiple diagnose for the same function. */
int attributes_checked_p;
};
/* AVR does not round pushes, but the existance of this macro is
......
gcc/config/avr/elf.h
......@@ -32,11 +32,6 @@
#undef STRING_LIMIT
#define STRING_LIMIT ((unsigned) 64)
/* Take care of `signal' and `interrupt' attributes. */
#undef ASM_DECLARE_FUNCTION_NAME
#define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
avr_asm_declare_function_name ((FILE), (NAME), (DECL))
/* Output alignment 2**1 for jump tables. */
#undef ASM_OUTPUT_BEFORE_CASE_LABEL
#define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \
......
gcc/doc/extend.texi
......@@ -2714,6 +2714,51 @@ then be sure to write this declaration in both files.
This attribute is ignored for R8C target.
@item ifunc ("@var{resolver}")
@cindex @code{ifunc} attribute
The @code{ifunc} attribute is used to mark a function as an indirect
function using the STT_GNU_IFUNC symbol type extension to the ELF
standard. This allows the resolution of the symbol value to be
determined dynamically at load time, and an optimized version of the
routine can be selected for the particular processor or other system
characteristics determined then. To use this attribute, first define
the implementation functions available, and a resolver function that
returns a pointer to the selected implementation function. The
implementation functions' declarations must match the API of the
function being implemented, the resolver's declaration is be a
function returning pointer to void function returning void:
@smallexample
void *my_memcpy (void *dst, const void *src, size_t len)
@{
@dots{}
@}
static void (*resolve_memcpy (void)) (void)
@{
return my_memcpy; // we'll just always select this routine
@}
@end smallexample
The exported header file declaring the function the user calls would
contain:
@smallexample
extern void *memcpy (void *, const void *, size_t);
@end smallexample
allowing the user to call this as a regular function, unaware of the
implementation. Finally, the indirect function needs to be defined in
the same translation unit as the resolver function:
@smallexample
void *memcpy (void *, const void *, size_t)
__attribute__ ((ifunc ("resolve_memcpy")));
@end smallexample
Indirect functions cannot be weak, and require a recent binutils (at
least version 2.20.1), and GNU C library (at least version 2.11.1).
@item interrupt
@cindex interrupt handler functions
Use this attribute on the ARM, AVR, CR16, Epiphany, M32C, M32R/D, m68k, MeP, MIPS,
......@@ -2726,7 +2771,13 @@ code to initialize the interrupt vector table.
Note, interrupt handlers for the Blackfin, H8/300, H8/300H, H8S, MicroBlaze,
and SH processors can be specified via the @code{interrupt_handler} attribute.
Note, on the AVR, interrupts will be enabled inside the function.
Note, on the AVR, the hardware globally disables interrupts when an
interrupt is executed. The first instruction of an interrupt handler
declared with this attribute will be a @code{SEI} instruction to
re-enable interrupts. See also the @code{signal} function attribute
that does not insert a @code{SEI} instuction. If both @code{signal} and
@code{interrupt} are specified for the same function, @code{signal}
will be silently ignored.
Note, for the ARM, you can specify the kind of interrupt to be handled by
adding an optional parameter to the interrupt attribute like this:
......@@ -2822,51 +2873,6 @@ On RL78, use @code{brk_interrupt} instead of @code{interrupt} for
handlers intended to be used with the @code{BRK} opcode (i.e. those
that must end with @code{RETB} instead of @code{RETI}).
@item ifunc ("@var{resolver}")
@cindex @code{ifunc} attribute
The @code{ifunc} attribute is used to mark a function as an indirect
function using the STT_GNU_IFUNC symbol type extension to the ELF
standard. This allows the resolution of the symbol value to be
determined dynamically at load time, and an optimized version of the
routine can be selected for the particular processor or other system
characteristics determined then. To use this attribute, first define
the implementation functions available, and a resolver function that
returns a pointer to the selected implementation function. The
implementation functions' declarations must match the API of the
function being implemented, the resolver's declaration is be a
function returning pointer to void function returning void:
@smallexample
void *my_memcpy (void *dst, const void *src, size_t len)
@{
@dots{}
@}
static void (*resolve_memcpy (void)) (void)
@{
return my_memcpy; // we'll just always select this routine
@}
@end smallexample
The exported header file declaring the function the user calls would
contain:
@smallexample
extern void *memcpy (void *, const void *, size_t);
@end smallexample
allowing the user to call this as a regular function, unaware of the
implementation. Finally, the indirect function needs to be defined in
the same translation unit as the resolver function:
@smallexample
void *memcpy (void *, const void *, size_t)
__attribute__ ((ifunc ("resolve_memcpy")));
@end smallexample
Indirect functions cannot be weak, and require a recent binutils (at
least version 2.20.1), and GNU C library (at least version 2.11.1).
@item interrupt_handler
@cindex interrupt handler functions on the Blackfin, m68k, H8/300 and SH processors
Use this attribute on the Blackfin, m68k, H8/300, H8/300H, H8S, and SH to
......@@ -3471,11 +3477,23 @@ See long_call/short_call.
See longcall/shortcall.
@item signal
@cindex signal handler functions on the AVR processors
@cindex interrupt handler functions on the AVR processors
Use this attribute on the AVR to indicate that the specified
function is a signal handler. The compiler will generate function
entry and exit sequences suitable for use in a signal handler when this
attribute is present. Interrupts will be disabled inside the function.
function is an interrupt handler. The compiler will generate function
entry and exit sequences suitable for use in an interrupt handler when this
attribute is present.
See also the @code{interrupt} function attribute.
The AVR hardware globally disables interrupts when an interrupt is executed.
Interrupt handler functions defined with the @code{signal} attribute
do not re-enable interrupts. It is save to enable interrupts in a
@code{signal} handler. This ``save'' only applies to the code
generated by the compiler and not to the IRQ-layout of the
application which is responsibility of the application.
If both @code{signal} and @code{interrupt} are specified for the same
function, @code{signal} will be silently ignored.
@item sp_switch
Use this attribute on the SH to indicate an @code{interrupt_handler}
......
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