Currently patchable area is at the wrong place. It is placed immediately
after function label and before .cfi_startproc. A backend should be able
to add a pseudo patchable area instruction durectly into RTL. This patch
adds patch_area_size and patch_area_entry to cfun so that the patchable
area info is available in RTL passes.
It also limits patch_area_size and patch_area_entry to 65535, which is
a reasonable maximum size for patchable area.
gcc/
PR target/93492
* function.c (expand_function_start): Set cfun->patch_area_size
and cfun->patch_area_entry.
* function.h (function): Add patch_area_size and patch_area_entry.
* opts.c (common_handle_option): Limit
function_entry_patch_area_size and function_entry_patch_area_start
to USHRT_MAX. Fix a typo in error message.
* varasm.c (assemble_start_function): Use cfun->patch_area_size
and cfun->patch_area_entry.
* doc/invoke.texi: Document the maximum value for
-fpatchable-function-entry.
gcc/testsuite/
PR target/93492
* c-c++-common/patchable_function_entry-error-1.c: New test.
* c-c++-common/patchable_function_entry-error-2.c: Likewise.
* c-c++-common/patchable_function_entry-error-3.c: Likewise.
---
gcc/doc/invoke.texi | 1 +
gcc/function.c | 35 +++++++++++++++++++
gcc/function.h | 6 ++++
gcc/opts.c | 4 ++-
.../patchable_function_entry-error-1.c | 9 +++++
.../patchable_function_entry-error-2.c | 9 +++++
.../patchable_function_entry-error-3.c | 20 +++++++++++
gcc/varasm.c | 30 ++--------------
8 files changed, 85 insertions(+), 29 deletions(-)
create mode 100644
gcc/testsuite/c-c++-common/patchable_function_entry-error-1.c
create mode 100644
gcc/testsuite/c-c++-common/patchable_function_entry-error-2.c
create mode 100644
gcc/testsuite/c-c++-common/patchable_function_entry-error-3.c
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 35b341e759f..dd4835199b0 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -13966,6 +13966,7 @@ If @code{N=0}, no pad location is recorded.
The NOP instructions are inserted at---and maybe before, depending on
@var{M}---the function entry address, even before the prologue.
+The maximum value of @var{N} and @var{M} is 65535.
@end table
diff --git a/gcc/function.c b/gcc/function.c
index d8008f60422..badbf538eec 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -5202,6 +5202,41 @@ expand_function_start (tree subr)
/* If we are doing generic stack checking, the probe should go here. */
if (flag_stack_check == GENERIC_STACK_CHECK)
stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
+
+ unsigned HOST_WIDE_INT patch_area_size = function_entry_patch_area_size;
+ unsigned HOST_WIDE_INT patch_area_entry = function_entry_patch_area_start;
+
+ tree patchable_function_entry_attr
+ = lookup_attribute ("patchable_function_entry",
+ DECL_ATTRIBUTES (cfun->decl));
+ if (patchable_function_entry_attr)
+ {
+ tree pp_val = TREE_VALUE (patchable_function_entry_attr);
+ tree patchable_function_entry_value1 = TREE_VALUE (pp_val);
+
+ patch_area_size = tree_to_uhwi (patchable_function_entry_value1);
+ patch_area_entry = 0;
+ if (TREE_CHAIN (pp_val) != NULL_TREE)
+ {
+ tree patchable_function_entry_value2
+ = TREE_VALUE (TREE_CHAIN (pp_val));
+ patch_area_entry = tree_to_uhwi (patchable_function_entry_value2);
+ }
+ if (patch_area_size > USHRT_MAX || patch_area_size > USHRT_MAX)
+ error ("invalid values for %<patchable_function_entry%> attribute");
+ }
+
+ if (patch_area_entry > patch_area_size)
+ {
+ if (patch_area_size > 0)
+ warning (OPT_Wattributes,
+ "patchable function entry %wu exceeds size %wu",
+ patch_area_entry, patch_area_size);
+ patch_area_entry = 0;
+ }
+
+ cfun->patch_area_size = patch_area_size;
+ cfun->patch_area_entry = patch_area_entry;
}
void
diff --git a/gcc/function.h b/gcc/function.h
index 1ee8ed3de53..1ed7c400f23 100644
--- a/gcc/function.h
+++ b/gcc/function.h
@@ -332,6 +332,12 @@ struct GTY(()) function {
/* Last assigned dependence info clique. */
unsigned short last_clique;
+ /* How many NOP insns to place at each function entry by default. */
+ unsigned short patch_area_size;
+
+ /* How far the real asm entry point is into this area. */
+ unsigned short patch_area_entry;
+
/* Collected bit flags. */
/* Number of units of general registers that need saving in stdarg
diff --git a/gcc/opts.c b/gcc/opts.c
index 7affeb41a96..c6011f1f9b7 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2598,10 +2598,12 @@ common_handle_option (struct gcc_options *opts,
function_entry_patch_area_start = 0;
}
if (function_entry_patch_area_size < 0
+ || function_entry_patch_area_size > USHRT_MAX
|| function_entry_patch_area_start < 0
+ || function_entry_patch_area_start > USHRT_MAX
|| function_entry_patch_area_size
< function_entry_patch_area_start)
- error ("invalid arguments for %<-fpatchable_function_entry%>");
+ error ("invalid arguments for %<-fpatchable-function-entry%>");
free (patch_area_arg);
}
break;
diff --git a/gcc/testsuite/c-c++-common/patchable_function_entry-error-1.c
b/gcc/testsuite/c-c++-common/patchable_function_entry-error-1.c
new file mode 100644
index 00000000000..f60bf46cfe3
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/patchable_function_entry-error-1.c
@@ -0,0 +1,9 @@
+/* { dg-do compile { target { ! { nvptx*-*-* visium-*-* } } } } */
+/* { dg-options "-O2 -fpatchable-function-entry=65536,1" } */
+/* { dg-additional-options "-fno-pie" { target sparc*-*-* } } */
+/* { dg-error "invalid arguments for '-fpatchable-function-entry'" "" { target
*-*-* } 0 } */
+
+void
+foo (void)
+{
+}
diff --git a/gcc/testsuite/c-c++-common/patchable_function_entry-error-2.c
b/gcc/testsuite/c-c++-common/patchable_function_entry-error-2.c
new file mode 100644
index 00000000000..90f88c78be7
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/patchable_function_entry-error-2.c
@@ -0,0 +1,9 @@
+/* { dg-do compile { target { ! { nvptx*-*-* visium-*-* } } } } */
+/* { dg-options "-O2 -fpatchable-function-entry=1,65536" } */
+/* { dg-additional-options "-fno-pie" { target sparc*-*-* } } */
+/* { dg-error "invalid arguments for '-fpatchable-function-entry'" "" { target
*-*-* } 0 } */
+
+void
+foo (void)
+{
+}
diff --git a/gcc/testsuite/c-c++-common/patchable_function_entry-error-3.c
b/gcc/testsuite/c-c++-common/patchable_function_entry-error-3.c
new file mode 100644
index 00000000000..b6e449425d2
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/patchable_function_entry-error-3.c
@@ -0,0 +1,20 @@
+/* { dg-do compile { target { ! { nvptx*-*-* visium-*-* } } } } */
+/* { dg-additional-options "-fno-pie" { target sparc*-*-* } } */
+
+void
+ __attribute__((patchable_function_entry(65536)))
+foo1 (void) /* { dg-error "invalid values for 'patchable_function_entry'" } */
+{
+}
+
+void
+ __attribute__((patchable_function_entry(65536,1)))
+foo2 (void) /* { dg-error "invalid values for 'patchable_function_entry'" } */
+{
+}
+
+void
+ __attribute__((patchable_function_entry(65536,65536)))
+foo3 (void) /* { dg-error "invalid values for 'patchable_function_entry'" } */
+{
+}
diff --git a/gcc/varasm.c b/gcc/varasm.c
index dc6da6c0b5b..93251f07d6e 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -1857,34 +1857,8 @@ assemble_start_function (tree decl, const char *fnname)
if (DECL_PRESERVE_P (decl))
targetm.asm_out.mark_decl_preserved (fnname);
- unsigned HOST_WIDE_INT patch_area_size = function_entry_patch_area_size;
- unsigned HOST_WIDE_INT patch_area_entry = function_entry_patch_area_start;
-
- tree patchable_function_entry_attr
- = lookup_attribute ("patchable_function_entry", DECL_ATTRIBUTES (decl));
- if (patchable_function_entry_attr)
- {
- tree pp_val = TREE_VALUE (patchable_function_entry_attr);
- tree patchable_function_entry_value1 = TREE_VALUE (pp_val);
-
- patch_area_size = tree_to_uhwi (patchable_function_entry_value1);
- patch_area_entry = 0;
- if (TREE_CHAIN (pp_val) != NULL_TREE)
- {
- tree patchable_function_entry_value2
- = TREE_VALUE (TREE_CHAIN (pp_val));
- patch_area_entry = tree_to_uhwi (patchable_function_entry_value2);
- }
- }
-
- if (patch_area_entry > patch_area_size)
- {
- if (patch_area_size > 0)
- warning (OPT_Wattributes,
- "patchable function entry %wu exceeds size %wu",
- patch_area_entry, patch_area_size);
- patch_area_entry = 0;
- }
+ unsigned short patch_area_size = cfun->patch_area_size;
+ unsigned short patch_area_entry = cfun->patch_area_entry;
/* Emit the patching area before the entry label, if any. */
if (patch_area_entry > 0)
--
2.24.1
