[lld] [llvm] [lld][AArch64][Build Attributes] Add support for AArch64 Build Attributes (PR #147970)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 10 07:21:47 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lld
Author: Mark Murray (MarkMurrayARM)
<details>
<summary>Changes</summary>
This patch enables lld to read AArch64 Build Attributes and convert them into GNU Properties.
Changes:
- Parses AArch64 Build Attributes from input object files.
- Converts known attributes into corresponding GNU Properties.
- Merges attributes when linking multiple objects.
Spec reference:
https://github.com/ARM-software/abi-aa/pull/230/files#r1030
---
Full diff: https://github.com/llvm/llvm-project/pull/147970.diff
9 Files Affected:
- (modified) lld/ELF/InputFiles.cpp (+75-6)
- (added) lld/test/ELF/aarch64-build-attributes-be.s (+29)
- (added) lld/test/ELF/aarch64-build-attributes-err.s (+35)
- (added) lld/test/ELF/aarch64-build-attributes-invalid.s (+18)
- (added) lld/test/ELF/aarch64-build-attributes-malformed.s (+18)
- (added) lld/test/ELF/aarch64-build-attributes-mixed.s (+67)
- (modified) lld/test/ELF/aarch64-build-attributes.s (+41-17)
- (modified) llvm/include/llvm/Support/AArch64AttributeParser.h (+11)
- (modified) llvm/lib/Support/AArch64AttributeParser.cpp (+27)
``````````diff
diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 71e72e7184b9f..eb69746575478 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -21,6 +21,7 @@
#include "llvm/ADT/STLExtras.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Object/IRObjectFile.h"
+#include "llvm/Support/AArch64AttributeParser.h"
#include "llvm/Support/ARMAttributeParser.h"
#include "llvm/Support/ARMBuildAttributes.h"
#include "llvm/Support/Endian.h"
@@ -537,6 +538,43 @@ uint32_t ObjFile<ELFT>::getSectionIndex(const Elf_Sym &sym) const {
this);
}
+template <class ELFT>
+static void
+handleAArch64BAAndGnuProperties(ObjFile<ELFT> *file, Ctx &ctx,
+ const AArch64BuildAttrSubsections &baInfo) {
+ if (file->aarch64PauthAbiCoreInfo) {
+ // Check for data mismatch
+ if (file->aarch64PauthAbiCoreInfo) {
+ if (baInfo.Pauth.TagPlatform != file->aarch64PauthAbiCoreInfo->platform ||
+ baInfo.Pauth.TagSchema != file->aarch64PauthAbiCoreInfo->version)
+ Err(ctx)
+ << file
+ << " GNU properties and build attributes have conflicting AArch64 PAuth data";
+ }
+ if (baInfo.AndFeatures != file->andFeatures)
+ Err(ctx) << file
+ << " GNU properties and build attributes have conflicting AArch64 PAuth data";
+ } else {
+ // When BuildAttributes are missing, PauthABI value defaults to (TagPlatform
+ // = 0, TagSchema = 0). GNU properties do not write PAuthAbiCoreInfo if GNU
+ // property is not present. To match this behaviour, we only write
+ // PAuthAbiCoreInfo when there is at least one non-zero value. The
+ // specification reserves TagPlatform = 0, TagSchema = 1 values to match the
+ // 'Invalid' GNU property section with platform = 0, version = 0.
+ if (baInfo.Pauth.TagPlatform || baInfo.Pauth.TagSchema) {
+ if (baInfo.Pauth.TagPlatform == 0 && baInfo.Pauth.TagSchema == 1)
+ file->aarch64PauthAbiCoreInfo = {0, 0};
+ else
+ file->aarch64PauthAbiCoreInfo = {baInfo.Pauth.TagPlatform,
+ baInfo.Pauth.TagSchema};
+ }
+ file->andFeatures = baInfo.AndFeatures;
+ }
+}
+
+template <typename ELFT>
+static void readGnuProperty(Ctx &, const InputSection &, ObjFile<ELFT> &);
+
template <class ELFT> void ObjFile<ELFT>::parse(bool ignoreComdats) {
object::ELFFile<ELFT> obj = this->getObj();
// Read a section table. justSymbols is usually false.
@@ -552,8 +590,23 @@ template <class ELFT> void ObjFile<ELFT>::parse(bool ignoreComdats) {
StringRef shstrtab = CHECK2(obj.getSectionStringTable(objSections), this);
uint64_t size = objSections.size();
sections.resize(size);
+
+ AArch64BuildAttrSubsections aarch64BAsubSections;
+ bool hasAArch64BuildAttributes = false;
+
for (size_t i = 0; i != size; ++i) {
const Elf_Shdr &sec = objSections[i];
+ // Read GNU property section into a per-InputFile structure that will be
+ // merged at a later stage. A synthetic section will be created for the
+ // merged contents.
+ if (check(obj.getSectionName(sec, shstrtab)) == ".note.gnu.property") {
+ readGnuProperty(
+ ctx,
+ InputSection(*this, sec, check(obj.getSectionName(sec, shstrtab))),
+ *this);
+ sections[i] = &InputSection::discarded;
+ }
+
if (LLVM_LIKELY(sec.sh_type == SHT_PROGBITS))
continue;
if (LLVM_LIKELY(sec.sh_type == SHT_GROUP)) {
@@ -637,13 +690,23 @@ template <class ELFT> void ObjFile<ELFT>::parse(bool ignoreComdats) {
}
break;
case EM_AARCH64:
- // FIXME: BuildAttributes have been implemented in llvm, but not yet in
- // lld. Remove the section so that it does not accumulate in the output
- // file. When support is implemented we expect not to output a build
- // attributes section in files of type ET_EXEC or ET_SHARED, but ld -r
- // ouptut will need a single merged attributes section.
- if (sec.sh_type == SHT_AARCH64_ATTRIBUTES)
+ // Extract Build Attributes section contents into aarch64BAsubSections.
+ // Input objects may contain both build Build Attributes and GNU
+ // properties. We delay processing Build Attributes until we have finished
+ // reading all sections so that we can check that these are consistent.
+ if (sec.sh_type == SHT_AARCH64_ATTRIBUTES) {
+ ArrayRef<uint8_t> contents = check(obj.getSectionContents(sec));
+ AArch64AttributeParser attributes;
+ if (Error e = attributes.parse(contents, ELFT::Endianness)) {
+ StringRef name = check(obj.getSectionName(sec, shstrtab));
+ InputSection isec(*this, sec, name);
+ Warn(ctx) << &isec << ": " << std::move(e);
+ } else {
+ aarch64BAsubSections = extractBuildAttributesSubsections(attributes);
+ hasAArch64BuildAttributes = true;
+ }
sections[i] = &InputSection::discarded;
+ }
// Producing a static binary with MTE globals is not currently supported,
// remove all SHT_AARCH64_MEMTAG_GLOBALS_STATIC sections as they're unused
// medatada, and we don't want them to end up in the output file for
@@ -655,6 +718,12 @@ template <class ELFT> void ObjFile<ELFT>::parse(bool ignoreComdats) {
}
}
+ // Handle AArch64 Build Attributes and GNU properties:
+ // - Err on mismatched values.
+ // - Store missing values as GNU properties.
+ if (hasAArch64BuildAttributes)
+ handleAArch64BAAndGnuProperties<ELFT>(this, ctx, aarch64BAsubSections);
+
// Read a symbol table.
initializeSymbols(obj);
}
diff --git a/lld/test/ELF/aarch64-build-attributes-be.s b/lld/test/ELF/aarch64-build-attributes-be.s
new file mode 100644
index 0000000000000..8ae9ce5d7f60b
--- /dev/null
+++ b/lld/test/ELF/aarch64-build-attributes-be.s
@@ -0,0 +1,29 @@
+// REQUIRES: aarch64
+// RUN: llvm-mc -triple=aarch64_be %s -filetype=obj -o %t.o
+// RUN: ld.lld %t.o --shared -o %t.so
+// RUN: llvm-readelf -n %t.so | FileCheck %s --check-prefix=NOTE
+
+// RUN: llvm-mc -triple=aarch64_be %s -filetype=obj -o %t.o
+// RUN: ld.lld %t.o --shared -o %t.so
+// RUN: llvm-readelf -n %t.so | FileCheck %s --check-prefix=NOTE
+// RUN: ld.lld %t.o -o %t
+// RUN: llvm-readelf -n %t.so | FileCheck %s --check-prefix=NOTE
+// RUN: ld.lld -r %t.o -o %t2.o
+// RUN: llvm-readelf -n %t.so | FileCheck %s --check-prefix=NOTE
+
+/// Test that lld can read big-endian build-attributes.
+
+// NOTE: Displaying notes found in: .note.gnu.property
+// NOTE-NEXT: Owner Data size Description
+// NOTE-NEXT: GNU 0x00000028 NT_GNU_PROPERTY_TYPE_0 (property note)
+// NOTE-NEXT: Properties: aarch64 feature: BTI, PAC, GCS
+// NOTE-NEXT: AArch64 PAuth ABI core info: platform 0x89abcdef (unknown), version 0x89abcdef
+
+
+.aeabi_subsection aeabi_pauthabi, required, uleb128
+.aeabi_attribute Tag_PAuth_Platform, 0x123456789ABCDEF
+.aeabi_attribute Tag_PAuth_Schema, 0x123456789ABCDEF
+.aeabi_subsection aeabi_feature_and_bits, optional, uleb128
+.aeabi_attribute Tag_Feature_BTI, 1
+.aeabi_attribute Tag_Feature_PAC, 1
+.aeabi_attribute Tag_Feature_GCS, 1
diff --git a/lld/test/ELF/aarch64-build-attributes-err.s b/lld/test/ELF/aarch64-build-attributes-err.s
new file mode 100644
index 0000000000000..029cb1a68a5e7
--- /dev/null
+++ b/lld/test/ELF/aarch64-build-attributes-err.s
@@ -0,0 +1,35 @@
+// REQUIRES: aarch64
+
+// RUN: llvm-mc -triple=aarch64 %s -filetype=obj -o %t.o
+// RUN: not ld.lld %t.o -o /dev/null 2>&1 | FileCheck %s --check-prefix=ERR
+
+// ERR: Pauth Data mismatch: file contains both GNU properties and AArch64 build attributes sections with different Pauth data
+// ERR-NEXT: Features Data mismatch: file contains both GNU properties and AArch64 build attributes sections with different And Features data
+
+.aeabi_subsection aeabi_pauthabi, required, uleb128
+.aeabi_attribute Tag_PAuth_Platform, 5
+.aeabi_attribute Tag_PAuth_Schema, 5
+.aeabi_subsection aeabi_feature_and_bits, optional, uleb128
+.aeabi_attribute Tag_Feature_BTI, 1
+.aeabi_attribute Tag_Feature_PAC, 1
+.aeabi_attribute Tag_Feature_GCS, 1
+
+.section ".note.gnu.property", "a"
+.long 0x4
+.long 0x10
+.long 0x5
+.asciz "GNU"
+.long 0xc0000000 // GNU_PROPERTY_AARCH64_FEATURE_1_AND
+.long 0x4
+.long 0x2 // GNU_PROPERTY_AARCH64_FEATURE_1_PAC
+.long 0x0
+
+.section ".note.gnu.property", "a"
+.long 0x4
+.long 0x18
+.long 0x5
+.asciz "GNU"
+.long 0xc0000001
+.long 0x10
+.quad 0x12345678 // platform
+.quad 0x87654321 // version
diff --git a/lld/test/ELF/aarch64-build-attributes-invalid.s b/lld/test/ELF/aarch64-build-attributes-invalid.s
new file mode 100644
index 0000000000000..7cd4723087de2
--- /dev/null
+++ b/lld/test/ELF/aarch64-build-attributes-invalid.s
@@ -0,0 +1,18 @@
+// REQUIRES: aarch64
+
+// RUN: llvm-mc -triple=aarch64 -filetype=obj %s -o %t.o
+// RUN: ld.lld -r %t.o -o %t.invalid.o
+// RUN: llvm-readelf -n %t.invalid.o | FileCheck %s
+
+/// According to the BuildAttributes specification Build Attributes
+/// A (TagPlatform, TagSchema)of (0, 1) maps to an explicit PAuth property
+/// of platform = 0, version = 0 ('Invalid').
+
+// CHECK: Displaying notes found in: .note.gnu.property
+// CHECK-NEXT: Owner Data size Description
+// CHECK-NEXT: GNU 0x00000018 NT_GNU_PROPERTY_TYPE_0 (property note)
+// CHECK-NEXT: Properties: AArch64 PAuth ABI core info: platform 0x0 (invalid), version 0x0
+
+.aeabi_subsection aeabi_pauthabi, required, uleb128
+.aeabi_attribute Tag_PAuth_Platform, 0
+.aeabi_attribute Tag_PAuth_Schema, 1
diff --git a/lld/test/ELF/aarch64-build-attributes-malformed.s b/lld/test/ELF/aarch64-build-attributes-malformed.s
new file mode 100644
index 0000000000000..f40da1ab7e8a1
--- /dev/null
+++ b/lld/test/ELF/aarch64-build-attributes-malformed.s
@@ -0,0 +1,18 @@
+# REQUIRES: aarch64
+
+# RUN: llvm-mc -triple=aarch64 -filetype=obj %s -o %t.o
+# RUN: ld.lld %t.o /dev/null 2>&1 | FileCheck %s
+
+# CHECK: (.ARM.attributes): unexpected end of data at offset 0x3f while reading [0x3d, 0x41)
+
+.section .ARM.attributes,"",%0x70000003
+.byte 0x41 // Tag 'A' (format version)
+.long 0x00000019 // Subsection length
+.asciz "aeabi_pauthabi" // Subsection name
+.byte 0x00, 0x00 // Optionality and Type
+.byte 0x01, 0x01, 0x02, 0x01 // PAuth_Platform and PAuth_Schema
+.long 0x00000023 // Subsection length
+.asciz "aeabi_feature_and_bits" // Subsection name
+.byte 0x01, 0x00 // Optionality and Type
+.byte 0x00, 0x01, 0x01, 0x01, 0x02, 0x01 // BTI, PAC, GCS
+.byte 0x00, 0x00 // This is the malformation, data is too long.
diff --git a/lld/test/ELF/aarch64-build-attributes-mixed.s b/lld/test/ELF/aarch64-build-attributes-mixed.s
new file mode 100644
index 0000000000000..68e9a1fbffda5
--- /dev/null
+++ b/lld/test/ELF/aarch64-build-attributes-mixed.s
@@ -0,0 +1,67 @@
+// REQUIRES: aarch64
+
+// RUN: rm -rf %t && split-file %s %t && cd %t
+
+// RUN: llvm-mc -triple=aarch64 -filetype=obj %s -o %t11.o
+// RUN: llvm-mc -triple=aarch64 -filetype=obj merged-property.s -o %t12.o
+// RUN: llvm-mc -triple=aarch64 -filetype=obj merged-property2.s -o %t13.o
+// RUN: ld.lld -r %t11.o %t12.o %t13.o -o %t.merged1.o
+// RUN: llvm-readelf -n %t.merged1.o | FileCheck %s --check-prefix=NOTE-MIXED
+
+/// This test verifies merging of AArch64 build attributes and GNU property notes.
+/// Three object files are combined: one with build attributes (PAuth information, BTI, PAC, GCS),
+/// and two with GNU property notes encoding the same feature bits.
+/// PAuth ABI info is provided in one of the files and it is expected to be preserved in the merged output.
+
+// NOTE-MIXED: Displaying notes found in: .note.gnu.property
+// NOTE-MIXED-NEXT: Owner Data size Description
+// NOTE-MIXED-NEXT: GNU 0x00000028 NT_GNU_PROPERTY_TYPE_0 (property note)
+// NOTE-MIXED-NEXT: Properties: aarch64 feature: BTI, PAC
+// NOTE-MIXED-NEXT: AArch64 PAuth ABI core info: platform 0x31 (unknown), version 0x13
+
+// CHECK: .note.gnu.property
+// CHECK-NOT: .ARM.attributes
+
+.aeabi_subsection aeabi_pauthabi, required, uleb128
+.aeabi_attribute Tag_PAuth_Platform, 49
+.aeabi_attribute Tag_PAuth_Schema, 19
+.aeabi_subsection aeabi_feature_and_bits, optional, uleb128
+.aeabi_attribute Tag_Feature_BTI, 1
+.aeabi_attribute Tag_Feature_PAC, 1
+.aeabi_attribute Tag_Feature_GCS, 1
+
+
+//--- merged-property.s
+.section ".note.gnu.property", "a"
+ .long 0x4 // Name length is always 4 ("GNU")
+ .long end - begin // Data length
+ .long 0x5 // Type: NT_GNU_PROPERTY_TYPE_0
+ .asciz "GNU" // Name
+ .p2align 0x3
+begin:
+ .long 0xc0000000 // GNU_PROPERTY_AARCH64_FEATURE_1_AND
+ .long 0x4
+ .long 0x7 // pr_data: BTI (1), PAC (2), GCS (4) = 0b111 = 7
+ .long 0x0
+ // PAuth ABI property note
+ .long 0xc0000001 // GNU_PROPERTY_AARCH64_FEATURE_PAUTH
+ .long 0x10 // Data length
+ .quad 0x31 // PAuth ABI platform
+ .quad 0x13 // PAuth ABI version
+ .p2align 0x3 // Align to 8 byte for 64 bit
+end:
+
+//--- merged-property2.s
+.section .note.gnu.property, "a"
+ .align 0x4
+ .long 0x4 // Name length is always 4 ("GNU")
+ .long end2 - begin2 // Data length
+ .long 0x5 // Type: NT_GNU_PROPERTY_TYPE_0
+ .asciz "GNU" // Name
+begin2:
+ .align 0x4
+ .long 0xc0000000 // Type: GNU_PROPERTY_AARCH64_FEATURE_1_AND
+ .long 0x4 // Data length
+ .long 0x7 // pr_data: BTI (1), PAC (2), GCS (4) = 0b111 = 7
+ .long 0x0
+end2:
diff --git a/lld/test/ELF/aarch64-build-attributes.s b/lld/test/ELF/aarch64-build-attributes.s
index 24e15f94e3d4a..f2d542150897e 100644
--- a/lld/test/ELF/aarch64-build-attributes.s
+++ b/lld/test/ELF/aarch64-build-attributes.s
@@ -1,26 +1,50 @@
// REQUIRES: aarch64
-// RUN: llvm-mc -triple=aarch64 %s -filetype=obj -o %t.o
-// RUN: ld.lld %t.o --shared -o %t.so
-// RUN: llvm-readelf --sections %t.so | FileCheck %s
-// RUN: ld.lld %t.o -o %t
-// RUN: llvm-readelf --sections %t | FileCheck %s
-// RUN: ld.lld -r %t.o -o %t2.o
-// RUN: llvm-readelf --sections %t2.o | FileCheck %s
-
-/// File has a Build attributes section. This should not appear in
-/// ET_EXEC or ET_SHARED files as there is no requirement for it to
-/// do so. FIXME, the ld -r (relocatable link) should output a single
-/// merged build attributes section. When full support is added in
-/// ld.lld this test should be updated.
+// RUN: rm -rf %t && split-file %s %t && cd %t
+// RUN: llvm-mc -triple=aarch64 -filetype=obj %s -o %t1.o
+// RUN: llvm-mc -triple=aarch64 -filetype=obj pauth-bti-gcs.s -o %t2.o
+// RUN: llvm-mc -triple=aarch64 -filetype=obj pauth-bti-pac.s -o %t3.o
+// RUN: ld.lld -r %t1.o %t2.o %t3.o -o %t.merged.o
+// RUN: llvm-readelf -n %t.merged.o | FileCheck %s --check-prefix=NOTE
+
+/// This test merges three object files with AArch64 build attributes.
+/// All contain identical PAuth ABI info (platform/version), which must be preserved.
+/// Only BTI is common across all three in the AND feature set, so the merged output
+/// must show BTI only. PAC and GCS are present in subsets and should not appear.
+
+// NOTE: Displaying notes found in: .note.gnu.property
+// NOTE-NEXT: Owner Data size Description
+// NOTE-NEXT: GNU 0x00000028 NT_GNU_PROPERTY_TYPE_0 (property note)
+// NOTE-NEXT: Properties: aarch64 feature: BTI
+// NOTE-NEXT: AArch64 PAuth ABI core info: platform 0x31 (unknown), version 0x13
+
+// CHECK: .note.gnu.property
// CHECK-NOT: .ARM.attributes
+.aeabi_subsection aeabi_pauthabi, required, uleb128
+.aeabi_attribute Tag_PAuth_Platform, 49
+.aeabi_attribute Tag_PAuth_Schema, 19
.aeabi_subsection aeabi_feature_and_bits, optional, uleb128
.aeabi_attribute Tag_Feature_BTI, 1
.aeabi_attribute Tag_Feature_PAC, 1
.aeabi_attribute Tag_Feature_GCS, 1
-.global _start
-.type _start, %function
-_start:
-ret
+
+//--- pauth-bti-gcs.s
+.aeabi_subsection aeabi_pauthabi, required, uleb128
+.aeabi_attribute Tag_PAuth_Platform, 49
+.aeabi_attribute Tag_PAuth_Schema, 19
+.aeabi_subsection aeabi_feature_and_bits, optional, uleb128
+.aeabi_attribute Tag_Feature_BTI, 1
+.aeabi_attribute Tag_Feature_PAC, 0
+.aeabi_attribute Tag_Feature_GCS, 1
+
+
+//--- pauth-bti-pac.s
+.aeabi_subsection aeabi_pauthabi, required, uleb128
+.aeabi_attribute Tag_PAuth_Platform, 49
+.aeabi_attribute Tag_PAuth_Schema, 19
+.aeabi_subsection aeabi_feature_and_bits, optional, uleb128
+.aeabi_attribute Tag_Feature_BTI, 1
+.aeabi_attribute Tag_Feature_PAC, 1
+.aeabi_attribute Tag_Feature_GCS, 0
diff --git a/llvm/include/llvm/Support/AArch64AttributeParser.h b/llvm/include/llvm/Support/AArch64AttributeParser.h
index aa82ca13668d5..796dbfd6f4162 100644
--- a/llvm/include/llvm/Support/AArch64AttributeParser.h
+++ b/llvm/include/llvm/Support/AArch64AttributeParser.h
@@ -25,6 +25,17 @@ class AArch64AttributeParser : public ELFExtendedAttrParser {
: ELFExtendedAttrParser(nullptr, returnTagsNamesMap()) {}
};
+// Used for extracting AArch64 Build Attributes
+struct AArch64BuildAttrSubsections {
+ struct PauthSubSection {
+ uint64_t TagPlatform = 0;
+ uint64_t TagSchema = 0;
+ } Pauth;
+ uint32_t AndFeatures = 0;
+};
+
+AArch64BuildAttrSubsections
+extractBuildAttributesSubsections(const llvm::AArch64AttributeParser &);
} // namespace llvm
#endif // LLVM_SUPPORT_AARCH64ATTRIBUTEPARSER_H
diff --git a/llvm/lib/Support/AArch64AttributeParser.cpp b/llvm/lib/Support/AArch64AttributeParser.cpp
index c675ef2a3b3df..eed8dba5d250a 100644
--- a/llvm/lib/Support/AArch64AttributeParser.cpp
+++ b/llvm/lib/Support/AArch64AttributeParser.cpp
@@ -8,6 +8,7 @@
//===---------------------------------------------------------------------===//
#include "llvm/Support/AArch64AttributeParser.h"
+#include "llvm/Support/AArch64BuildAttributes.h"
std::vector<llvm::SubsectionAndTagToTagName> &
llvm::AArch64AttributeParser::returnTagsNamesMap() {
@@ -19,3 +20,29 @@ llvm::AArch64AttributeParser::returnTagsNamesMap() {
{"aeabi_feature_and_bits", 2, "Tag_Feature_GCS"}};
return TagsNamesMap;
}
+
+llvm::AArch64BuildAttrSubsections llvm::extractBuildAttributesSubsections(
+ const llvm::AArch64AttributeParser &Attributes) {
+
+ llvm::AArch64BuildAttrSubsections SubSections;
+ auto GetPauthValue = [&Attributes](unsigned Tag) {
+ return Attributes.getAttributeValue("aeabi_pauthabi", Tag).value_or(0);
+ };
+ SubSections.Pauth.TagPlatform =
+ GetPauthValue(llvm::AArch64BuildAttributes::TAG_PAUTH_PLATFORM);
+ SubSections.Pauth.TagSchema =
+ GetPauthValue(llvm::AArch64BuildAttributes::TAG_PAUTH_SCHEMA);
+
+ auto GetFeatureValue = [&Attributes](unsigned Tag) {
+ return Attributes.getAttributeValue("aeabi_feature_and_bits", Tag)
+ .value_or(0);
+ };
+ SubSections.AndFeatures |=
+ GetFeatureValue(llvm::AArch64BuildAttributes::TAG_FEATURE_BTI);
+ SubSections.AndFeatures |=
+ GetFeatureValue(llvm::AArch64BuildAttributes::TAG_FEATURE_PAC) << 1;
+ SubSections.AndFeatures |=
+ GetFeatureValue(llvm::AArch64BuildAttributes::TAG_FEATURE_GCS) << 2;
+
+ return SubSections;
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/147970
More information about the llvm-commits
mailing list