Richard Earnshaw <richard.earns...@foss.arm.com> writes:
[...]
>
> Sorry, I've just been looking at this again and noted the following:
>
> + if (TARGET_HAVE_PACBTI)
> + {
> + arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 2);
> + arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 2);
> + arm_emit_eabi_attribute ("TAG_BTI_use", 74, bti);
> + arm_emit_eabi_attribute ("TAG_PACRET_use", 76, pac);
> + }
> + else
> + {
> + if (pac || bti)
> + {
> + arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 1);
> + arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 1);
> + arm_emit_eabi_attribute ("TAG_BTI_use", 74, bti);
> + arm_emit_eabi_attribute ("TAG_PACRET_use", 76, pac);
> + }
> + }
> +
>
> Firstly, the if subclause inside the else can be lifted out to an
> 'else if'; secondly, we don't want to emit TAG_BTI_use or
> TAG_PACRET_use if the value is zero (since the default in the absence
> of the tag is zero). So better to have this as:
>
> if (TARGET_HAVE_PACBTI)
> {
> arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 2);
> arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 2);
> }
> else if (pac || bti)
> {
> arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 1);
> arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 1);
> }
>
> if (bti)
> arm_emit_eabi_attribute ("TAG_BTI_use", 74, 1);
> if (pac)
> arm_emit_eabi_attribute ("TAG_PACRET_use", 76, 1);
>
> And then adjust the tests for the zero case to use scan-assembler-not.
>
> R.
Hi Richard,
please find attached the updated patch.
Thanks for reviewing!
Andrea
>From 4fcb3b37445b3a81037029709e8c1aaa903049ea Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea.cora...@arm.com>
Date: Mon, 6 Dec 2021 11:42:24 +0100
Subject: [PATCH] Emit build attributes for PACBTI target feature.
gcc/ChangeLog:
* config/arm/arm.c (arm_file_start): Emit EABI attributes for
Tag_PAC_extension, Tag_BTI_extension, TAG_BTI_use, TAG_PACRET_use.
gcc/testsuite/ChangeLog:
* gcc.target/arm/acle/pacbti-m-predef-1.c: New test.
* gcc.target/arm/acle/pacbti-m-predef-3: Likewise.
* gcc.target/arm/acle/pacbti-m-predef-6.c: Likewise.
* gcc.target/arm/acle/pacbti-m-predef-7.c: Likewise.
Co-Authored-By: Tejas Belagod <tbela...@arm.com>
---
gcc/config/arm/arm.c | 18 ++++++++++++++++++
.../gcc.target/arm/acle/pacbti-m-predef-1.c | 16 ++++++++++++++++
.../gcc.target/arm/acle/pacbti-m-predef-3.c | 16 ++++++++++++++++
.../gcc.target/arm/acle/pacbti-m-predef-6.c | 15 +++++++++++++++
.../gcc.target/arm/acle/pacbti-m-predef-7.c | 16 ++++++++++++++++
5 files changed, 81 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c
create mode 100644 gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c
create mode 100644 gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c
create mode 100644 gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index ee22acddee5..e0b13e9a23e 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -28221,6 +28221,8 @@ static void
arm_file_start (void)
{
int val;
+ bool pac = (aarch_ra_sign_scope != AARCH_FUNCTION_NONE);
+ bool bti = (aarch_enable_bti == 1);
arm_print_asm_arch_directives
(asm_out_file, TREE_TARGET_OPTION (target_option_default_node));
@@ -28291,6 +28293,22 @@ arm_file_start (void)
arm_emit_eabi_attribute ("Tag_ABI_FP_16bit_format", 38,
(int) arm_fp16_format);
+ if (TARGET_HAVE_PACBTI)
+ {
+ arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 2);
+ arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 2);
+ }
+ else if (pac || bti)
+ {
+ arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 1);
+ arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 1);
+ }
+
+ if (bti)
+ arm_emit_eabi_attribute ("TAG_BTI_use", 74, 1);
+ if (pac)
+ arm_emit_eabi_attribute ("TAG_PACRET_use", 76, 1);
+
if (arm_lang_output_object_attributes_hook)
arm_lang_output_object_attributes_hook();
}
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c
b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c
new file mode 100644
index 00000000000..75d3e00ef64
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-additional-options " -mbranch-protection=pac-ret+bti --save-temps" } */
+
+#if !defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be defined."
+#endif
+
+#if !defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be defined."
+#endif
+
+/* { dg-final { scan-assembler-not "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 74, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 76, 1" } } */
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c
b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c
new file mode 100644
index 00000000000..bf6c3ba90c9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-additional-options " -mbranch-protection=pac-ret+leaf --save-temps" }
*/
+
+#if defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be undefined."
+#endif
+
+#if !defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be defined."
+#endif
+
+/* { dg-final { scan-assembler-not "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 1" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 74" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 76, 1" } } */
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c
b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c
new file mode 100644
index 00000000000..82af11ee407
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-additional-options " -mbranch-protection=bti --save-temps" } */
+
+#if !defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be defined."
+#endif
+
+#if defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be undefined."
+#endif
+/* { dg-final { scan-assembler-not "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 74, 1" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 76" } } */
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c
b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c
new file mode 100644
index 00000000000..48a40e64c11
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=armv8.1-m.main+pacbti --save-temps" } */
+
+#if defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be undefined."
+#endif
+
+#if defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be undefined."
+#endif
+
+/* { dg-final { scan-assembler "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 2" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 2" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 74" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 76" } } */
--
2.20.1
