[libc-commits] [libc] Implement `sigsetjmp` and `siglongjmp` for darwin/aarch64 (PR #139555)
Aly ElAshram via libc-commits
libc-commits at lists.llvm.org
Fri May 16 07:47:31 PDT 2025
https://github.com/AlyElashram updated https://github.com/llvm/llvm-project/pull/139555
>From f86b525eefcabaef7d2706f14eb4f8d4e222efa4 Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Mon, 12 May 2025 16:52:21 +0300
Subject: [PATCH 01/10] Add setjmp longjmp and sigsetjmp.cpp
---
libc/src/setjmp/darwin/aarch64/longjmp.cpp | 87 +++++++++++++++++++
libc/src/setjmp/darwin/aarch64/setjmp.cpp | 89 ++++++++++++++++++++
libc/src/setjmp/darwin/aarch64/sigsetjmp.cpp | 40 +++++++++
3 files changed, 216 insertions(+)
create mode 100644 libc/src/setjmp/darwin/aarch64/longjmp.cpp
create mode 100644 libc/src/setjmp/darwin/aarch64/setjmp.cpp
create mode 100644 libc/src/setjmp/darwin/aarch64/sigsetjmp.cpp
diff --git a/libc/src/setjmp/darwin/aarch64/longjmp.cpp b/libc/src/setjmp/darwin/aarch64/longjmp.cpp
new file mode 100644
index 0000000000000..eca4303f58034
--- /dev/null
+++ b/libc/src/setjmp/darwin/aarch64/longjmp.cpp
@@ -0,0 +1,87 @@
+//===-- Implementation of longjmp for AArch64 -----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/setjmp/longjmp.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+// TODO: if MTE stack tagging is in use (-fsanitize=memtag-stack), we need to
+// iterate over the region between the old and new values of sp, using STG or
+// ST2G instructions to clear the memory tags on the invalidated region of the
+// stack. But this requires a means of finding out that we're in that mode, and
+// as far as I can see there isn't currently a predefined macro for that.
+//
+// (__ARM_FEATURE_MEMORY_TAGGING only indicates whether the target architecture
+// supports the MTE instructions, not whether the compiler is configured to use
+// them.)
+
+[[gnu::naked]] LLVM_LIBC_FUNCTION(void, longjmp,
+ ([[maybe_unused]] jmp_buf buf,
+ [[maybe_unused]] int val)) {
+ // If BTI branch protection is in use, the compiler will automatically insert
+ // a BTI here, so we don't need to make any extra effort to do so.
+
+ // If PAC branch protection is in use, there's no need to sign the return
+ // address at the start of longjmp, because we're not going to use it anyway!
+
+ asm(
+ // Reload the callee-saved GPRs, including fp and lr.
+ R"(
+ ldp x19, x20, [x0, #0*16]
+ ldp x21, x22, [x0, #1*16]
+ ldp x23, x24, [x0, #2*16]
+ ldp x25, x26, [x0, #3*16]
+ ldp x27, x28, [x0, #4*16]
+ ldp x29, x30, [x0, #5*16]
+ )"
+ // We would usually reload the platform register x18 here
+ // but due to the apple ABI we are not allowed to use the x18 register
+ // so we reload the stack pointer only.
+ // https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Respect-the-purpose-of-specific-CPU-registers
+ R"(
+ ldr x2, [x0, #6*16]
+ mov sp, x2
+ )"
+
+#if __ARM_FP
+ // Reload the callee-saved FP registers.
+ R"(
+ ldp d8, d9, [x0, #7*16]
+ ldp d10, d11, [x0, #8*16]
+ ldp d12, d13, [x0, #9*16]
+ ldp d14, d15, [x0, #10*16]
+ )"
+#endif
+
+ // Calculate the return value.
+ R"(
+ cmp w1, #0
+ cinc w0, w1, eq
+ )"
+
+#if (__ARM_FEATURE_PAC_DEFAULT & 7) == 5
+ // Authenticate the return address using the PAC A key, since the
+ // compilation options ask for PAC protection even on leaf functions.
+ R"(
+ autiasp
+ )"
+#elif (__ARM_FEATURE_PAC_DEFAULT & 7) == 6
+ // Same, but using the PAC B key.
+ R"(
+ autibsp
+ )"
+#endif
+
+ R"(
+ ret
+ )");
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/setjmp/darwin/aarch64/setjmp.cpp b/libc/src/setjmp/darwin/aarch64/setjmp.cpp
new file mode 100644
index 0000000000000..678203996b6d8
--- /dev/null
+++ b/libc/src/setjmp/darwin/aarch64/setjmp.cpp
@@ -0,0 +1,89 @@
+//===-- Implementation of setjmp for darwin AArch64 -----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/setjmp/setjmp_impl.h"
+
+
+
+namespace LIBC_NAMESPACE_DECL {
+
+[[gnu::naked]] LLVM_LIBC_FUNCTION(int, setjmp, ([[maybe_unused]] jmp_buf buf)) {
+ // If BTI branch protection is in use, the compiler will automatically insert
+ // a BTI here, so we don't need to make any extra effort to do so.
+
+ asm(
+#if __ARM_FEATURE_PAC_DEFAULT & 1
+ // Sign the return address using the PAC A key.
+ R"(
+ paciasp
+ )"
+#elif __ARM_FEATURE_PAC_DEFAULT & 2
+ // Sign the return address using the PAC B key.
+ R"(
+ pacibsp
+ )"
+#endif
+
+ // Store all the callee-saved GPRs, including fp (x29) and also lr (x30).
+ // Of course lr isn't normally callee-saved (the call instruction itself
+ // can't help clobbering it), but we certainly need to save it for this
+ // purpose.
+ R"(
+ stp x19, x20, [x0, #0*16]
+ stp x21, x22, [x0, #1*16]
+ stp x23, x24, [x0, #2*16]
+ stp x25, x26, [x0, #3*16]
+ stp x27, x28, [x0, #4*16]
+ stp x29, x30, [x0, #5*16]
+ )"
+
+ // While we usually store the platform register x18
+ // the darwin ABI inhibts usage of it
+ // Store just the stack pointer.
+ R"(
+ add x1, sp, #0
+ str x1, [x0, #6*16]
+ )"
+
+#if __ARM_FP
+ // Store the callee-saved FP registers. AAPCS64 only requires the low 64
+ // bits of v8-v15 to be preserved, i.e. each of d8,...,d15.
+ R"(
+ stp d8, d9, [x0, #7*16]
+ stp d10, d11, [x0, #8*16]
+ stp d12, d13, [x0, #9*16]
+ stp d14, d15, [x0, #10*16]
+ )"
+#endif
+
+ // Set up return value of zero.
+ R"(
+ mov x0, #0
+ )"
+
+#if (__ARM_FEATURE_PAC_DEFAULT & 7) == 5
+ // Authenticate the return address using the PAC A key, since the
+ // compilation options ask for PAC protection even on leaf functions.
+ R"(
+ autiasp
+ )"
+#elif (__ARM_FEATURE_PAC_DEFAULT & 7) == 6
+ // Same, but using the PAC B key.
+ R"(
+ autibsp
+ )"
+#endif
+
+ R"(
+ ret
+ )");
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/setjmp/darwin/aarch64/sigsetjmp.cpp b/libc/src/setjmp/darwin/aarch64/sigsetjmp.cpp
new file mode 100644
index 0000000000000..88b5a28e1105d
--- /dev/null
+++ b/libc/src/setjmp/darwin/aarch64/sigsetjmp.cpp
@@ -0,0 +1,40 @@
+//===-- Implementation of darwin/aarch64 sigsetjmp ------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/setjmp/sigsetjmp.h"
+#include "hdr/offsetof_macros.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/setjmp/setjmp_impl.h"
+#include "src/setjmp/sigsetjmp_epilogue.h"
+
+namespace LIBC_NAMESPACE_DECL {
+[[gnu::naked]]
+LLVM_LIBC_FUNCTION(int, sigsetjmp, (sigjmp_buf, int)) {
+
+ // The difference between sigsetjmp and setjmp is storing the signal mask of
+ // the calling thread
+
+ asm(R"(
+ cbz w1, %c[setjmp]
+
+ str x30, [x0, %c[retaddr]]
+ str x19, [x0, %c[extra]]
+ mov x19, x0
+ bl %c[setjmp]
+
+ mov w1, w0
+ mov x0, x19
+ ldr x30, [x0, %c[retaddr]]
+ ldr x19, [x0, %c[extra]]
+ b %c[epilogue])" ::[retaddr] "i"(offsetof(__jmp_buf, sig_retaddr)),
+ [extra] "i"(offsetof(__jmp_buf, sig_extra)), [setjmp] "i"(setjmp),
+ [epilogue] "i"(sigsetjmp_epilogue)
+ : "x0", "x1", "x19", "x30");
+}
+} // namespace LIBC_NAMESPACE_DECL
>From 8c5c68ac7c8a55801f82d71dfd5f426d7dfcc6fd Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Mon, 12 May 2025 16:52:46 +0300
Subject: [PATCH 02/10] Add setjmp to entrypoints and headers in darwin
---
libc/config/darwin/arm/entrypoints.txt | 4 ++++
libc/config/darwin/arm/headers.txt | 1 +
2 files changed, 5 insertions(+)
diff --git a/libc/config/darwin/arm/entrypoints.txt b/libc/config/darwin/arm/entrypoints.txt
index 308fc49d681d7..07199db6d1ae6 100644
--- a/libc/config/darwin/arm/entrypoints.txt
+++ b/libc/config/darwin/arm/entrypoints.txt
@@ -20,6 +20,10 @@ set(TARGET_LIBC_ENTRYPOINTS
# errno.h entrypoints
libc.src.errno.errno
+ # setjmp.h entrypoints
+ libc.src.setjmp
+
+
# string.h entrypoints
libc.src.string.memccpy
libc.src.string.memchr
diff --git a/libc/config/darwin/arm/headers.txt b/libc/config/darwin/arm/headers.txt
index 86e7145972324..8f3d6029c9b6a 100644
--- a/libc/config/darwin/arm/headers.txt
+++ b/libc/config/darwin/arm/headers.txt
@@ -7,6 +7,7 @@ set(TARGET_PUBLIC_HEADERS
libc.include.inttypes
libc.include.limits
libc.include.math
+ libc.include.setjmp
libc.include.stdlib
libc.include.string
libc.include.strings
>From 174cb0b7412ad58dce5cc33190d93b29a2e92dc9 Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Mon, 12 May 2025 17:25:04 +0300
Subject: [PATCH 03/10] Add the sigsetjmp epilogue for darwin aarch64
---
.../darwin/aarch64/sigsetjmp_epilogue.cpp | 21 +++++++++++++++++++
1 file changed, 21 insertions(+)
create mode 100644 libc/src/setjmp/darwin/aarch64/sigsetjmp_epilogue.cpp
diff --git a/libc/src/setjmp/darwin/aarch64/sigsetjmp_epilogue.cpp b/libc/src/setjmp/darwin/aarch64/sigsetjmp_epilogue.cpp
new file mode 100644
index 0000000000000..b2ca4d99ed82b
--- /dev/null
+++ b/libc/src/setjmp/darwin/aarch64/sigsetjmp_epilogue.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of sigsetjmp_epilogue ------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/setjmp/sigsetjmp_epilogue.h"
+#include "src/__support/OSUtil/syscall.h"
+#include "src/__support/common.h"
+#include "src/signal/sigprocmask.h"
+
+namespace LIBC_NAMESPACE_DECL {
+[[gnu::returns_twice]] int sigsetjmp_epilogue(jmp_buf buffer, int retval) {
+ syscall_impl<long>(sigprocmask, SIG_SETMASK,
+ /* set= */ retval ? &buffer->sigmask : nullptr,
+ /* old_set= */ retval ? nullptr : &buffer->sigmask);
+ return retval;
+}
+} // namespace LIBC_NAMESPACE_DECL
>From b28e6b664ad23e5ba1194eea1eebb9780ac12245 Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Mon, 12 May 2025 17:31:47 +0300
Subject: [PATCH 04/10] Formatting
---
libc/src/setjmp/darwin/aarch64/setjmp.cpp | 2 --
1 file changed, 2 deletions(-)
diff --git a/libc/src/setjmp/darwin/aarch64/setjmp.cpp b/libc/src/setjmp/darwin/aarch64/setjmp.cpp
index 678203996b6d8..2842590850217 100644
--- a/libc/src/setjmp/darwin/aarch64/setjmp.cpp
+++ b/libc/src/setjmp/darwin/aarch64/setjmp.cpp
@@ -10,8 +10,6 @@
#include "src/__support/macros/config.h"
#include "src/setjmp/setjmp_impl.h"
-
-
namespace LIBC_NAMESPACE_DECL {
[[gnu::naked]] LLVM_LIBC_FUNCTION(int, setjmp, ([[maybe_unused]] jmp_buf buf)) {
>From a8589134291bbd94f6dbd8d1aadf7f0698a31848 Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Mon, 12 May 2025 17:32:56 +0300
Subject: [PATCH 05/10] cmake file for darwin aarch64
---
libc/src/setjmp/darwin/aarch64/CMakeLists.txt | 51 +++++++++++++++++++
1 file changed, 51 insertions(+)
create mode 100644 libc/src/setjmp/darwin/aarch64/CMakeLists.txt
diff --git a/libc/src/setjmp/darwin/aarch64/CMakeLists.txt b/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
new file mode 100644
index 0000000000000..6f9d865ede7cc
--- /dev/null
+++ b/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
@@ -0,0 +1,51 @@
+if(setjmp_config_options)
+ list(PREPEND setjmp_config_options "COMPILE_OPTIONS")
+endif()
+
+add_entrypoint_object(
+ setjmp
+ SRCS
+ setjmp.cpp
+ HDRS
+ ../../setjmp_impl.h
+ DEPENDS
+ libc.hdr.types.jmp_buf
+ ${setjmp_config_options}
+)
+
+add_entrypoint_object(
+ longjmp
+ SRCS
+ longjmp.cpp
+ HDRS
+ ../../longjmp.h
+ DEPENDS
+ libc.hdr.types.jmp_buf
+ ${setjmp_config_options}
+)
+
+add_entrypoint_object(
+ sigsetjmp
+ SRCS
+ sigsetjmp.cpp
+ HDRS
+ ../../sigsetjmp.h
+ DEPENDS
+ libc.hdr.types.jmp_buf
+ libc.hdr.types.sigset_t
+ libc.hdr.offsetof_macros
+ libc.src.setjmp.sigsetjmp_epilogue
+ libc.src.setjmp.setjmp
+)
+add_object_library(
+ sigsetjmp_epilogue
+ HDRS
+ ../../sigsetjmp_epilogue.h
+ SRCS
+ sigsetjmp_epilogue.cpp
+ DEPENDS
+ libc.src.__support.common
+ libc.src.__support.OSUtil.osutil
+ libc.hdr.types.jmp_buf
+ libc.hdr.types.sigset_t
+)
\ No newline at end of file
>From bbb0570bd7fb4807e8661d47a773157fd67b818c Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Mon, 12 May 2025 17:36:58 +0300
Subject: [PATCH 06/10] cmake file formatting
---
libc/src/setjmp/darwin/aarch64/CMakeLists.txt | 58 +++++++++----------
1 file changed, 29 insertions(+), 29 deletions(-)
diff --git a/libc/src/setjmp/darwin/aarch64/CMakeLists.txt b/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
index 6f9d865ede7cc..37058e9fb905e 100644
--- a/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
+++ b/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
@@ -14,38 +14,38 @@ add_entrypoint_object(
)
add_entrypoint_object(
- longjmp
- SRCS
- longjmp.cpp
- HDRS
- ../../longjmp.h
- DEPENDS
- libc.hdr.types.jmp_buf
- ${setjmp_config_options}
+ longjmp
+ SRCS
+ longjmp.cpp
+ HDRS
+ ../../longjmp.h
+ DEPENDS
+ libc.hdr.types.jmp_buf
+ ${setjmp_config_options}
)
add_entrypoint_object(
- sigsetjmp
- SRCS
- sigsetjmp.cpp
- HDRS
- ../../sigsetjmp.h
- DEPENDS
- libc.hdr.types.jmp_buf
- libc.hdr.types.sigset_t
- libc.hdr.offsetof_macros
- libc.src.setjmp.sigsetjmp_epilogue
- libc.src.setjmp.setjmp
+ sigsetjmp
+ SRCS
+ sigsetjmp.cpp
+ HDRS
+ ../../sigsetjmp.h
+ DEPENDS
+ libc.hdr.types.jmp_buf
+ libc.hdr.types.sigset_t
+ libc.hdr.offsetof_macros
+ libc.src.setjmp.sigsetjmp_epilogue
+ libc.src.setjmp.setjmp
)
add_object_library(
- sigsetjmp_epilogue
- HDRS
- ../../sigsetjmp_epilogue.h
- SRCS
- sigsetjmp_epilogue.cpp
- DEPENDS
- libc.src.__support.common
- libc.src.__support.OSUtil.osutil
- libc.hdr.types.jmp_buf
- libc.hdr.types.sigset_t
+ sigsetjmp_epilogue
+ HDRS
+ ../../sigsetjmp_epilogue.h
+ SRCS
+ sigsetjmp_epilogue.cpp
+ DEPENDS
+ libc.src.__support.common
+ libc.src.__support.OSUtil.osutil
+ libc.hdr.types.jmp_buf
+ libc.hdr.types.sigset_t
)
\ No newline at end of file
>From 80c925b8bd2ea76f92976c735e4bf4f34673f216 Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Fri, 16 May 2025 17:37:55 +0300
Subject: [PATCH 07/10] Remove setjmp and longjmp ,and reuse the aarch64
implementation with a new config.json
---
libc/config/darwin/arm/config.json | 8 ++
libc/src/setjmp/darwin/aarch64/longjmp.cpp | 87 ----------------------
libc/src/setjmp/darwin/aarch64/setjmp.cpp | 87 ----------------------
3 files changed, 8 insertions(+), 174 deletions(-)
create mode 100644 libc/config/darwin/arm/config.json
delete mode 100644 libc/src/setjmp/darwin/aarch64/longjmp.cpp
delete mode 100644 libc/src/setjmp/darwin/aarch64/setjmp.cpp
diff --git a/libc/config/darwin/arm/config.json b/libc/config/darwin/arm/config.json
new file mode 100644
index 0000000000000..e7d186e8ba64a
--- /dev/null
+++ b/libc/config/darwin/arm/config.json
@@ -0,0 +1,8 @@
+{
+ "setjmp": {
+ "LIBC_CONF_SETJMP_AARCH64_RESTORE_PLATFORM_REGISTER": {
+ "value": false,
+ "doc": "Avoid setjmp saving the value of x18, and longjmp restoring it. The Apple AArch64 ABI specifies that this register is reserved and should not be used"
+ }
+ }
+}
\ No newline at end of file
diff --git a/libc/src/setjmp/darwin/aarch64/longjmp.cpp b/libc/src/setjmp/darwin/aarch64/longjmp.cpp
deleted file mode 100644
index eca4303f58034..0000000000000
--- a/libc/src/setjmp/darwin/aarch64/longjmp.cpp
+++ /dev/null
@@ -1,87 +0,0 @@
-//===-- Implementation of longjmp for AArch64 -----------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "src/setjmp/longjmp.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
-
-namespace LIBC_NAMESPACE_DECL {
-
-// TODO: if MTE stack tagging is in use (-fsanitize=memtag-stack), we need to
-// iterate over the region between the old and new values of sp, using STG or
-// ST2G instructions to clear the memory tags on the invalidated region of the
-// stack. But this requires a means of finding out that we're in that mode, and
-// as far as I can see there isn't currently a predefined macro for that.
-//
-// (__ARM_FEATURE_MEMORY_TAGGING only indicates whether the target architecture
-// supports the MTE instructions, not whether the compiler is configured to use
-// them.)
-
-[[gnu::naked]] LLVM_LIBC_FUNCTION(void, longjmp,
- ([[maybe_unused]] jmp_buf buf,
- [[maybe_unused]] int val)) {
- // If BTI branch protection is in use, the compiler will automatically insert
- // a BTI here, so we don't need to make any extra effort to do so.
-
- // If PAC branch protection is in use, there's no need to sign the return
- // address at the start of longjmp, because we're not going to use it anyway!
-
- asm(
- // Reload the callee-saved GPRs, including fp and lr.
- R"(
- ldp x19, x20, [x0, #0*16]
- ldp x21, x22, [x0, #1*16]
- ldp x23, x24, [x0, #2*16]
- ldp x25, x26, [x0, #3*16]
- ldp x27, x28, [x0, #4*16]
- ldp x29, x30, [x0, #5*16]
- )"
- // We would usually reload the platform register x18 here
- // but due to the apple ABI we are not allowed to use the x18 register
- // so we reload the stack pointer only.
- // https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Respect-the-purpose-of-specific-CPU-registers
- R"(
- ldr x2, [x0, #6*16]
- mov sp, x2
- )"
-
-#if __ARM_FP
- // Reload the callee-saved FP registers.
- R"(
- ldp d8, d9, [x0, #7*16]
- ldp d10, d11, [x0, #8*16]
- ldp d12, d13, [x0, #9*16]
- ldp d14, d15, [x0, #10*16]
- )"
-#endif
-
- // Calculate the return value.
- R"(
- cmp w1, #0
- cinc w0, w1, eq
- )"
-
-#if (__ARM_FEATURE_PAC_DEFAULT & 7) == 5
- // Authenticate the return address using the PAC A key, since the
- // compilation options ask for PAC protection even on leaf functions.
- R"(
- autiasp
- )"
-#elif (__ARM_FEATURE_PAC_DEFAULT & 7) == 6
- // Same, but using the PAC B key.
- R"(
- autibsp
- )"
-#endif
-
- R"(
- ret
- )");
-}
-
-} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/setjmp/darwin/aarch64/setjmp.cpp b/libc/src/setjmp/darwin/aarch64/setjmp.cpp
deleted file mode 100644
index 2842590850217..0000000000000
--- a/libc/src/setjmp/darwin/aarch64/setjmp.cpp
+++ /dev/null
@@ -1,87 +0,0 @@
-//===-- Implementation of setjmp for darwin AArch64 -----------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
-#include "src/setjmp/setjmp_impl.h"
-
-namespace LIBC_NAMESPACE_DECL {
-
-[[gnu::naked]] LLVM_LIBC_FUNCTION(int, setjmp, ([[maybe_unused]] jmp_buf buf)) {
- // If BTI branch protection is in use, the compiler will automatically insert
- // a BTI here, so we don't need to make any extra effort to do so.
-
- asm(
-#if __ARM_FEATURE_PAC_DEFAULT & 1
- // Sign the return address using the PAC A key.
- R"(
- paciasp
- )"
-#elif __ARM_FEATURE_PAC_DEFAULT & 2
- // Sign the return address using the PAC B key.
- R"(
- pacibsp
- )"
-#endif
-
- // Store all the callee-saved GPRs, including fp (x29) and also lr (x30).
- // Of course lr isn't normally callee-saved (the call instruction itself
- // can't help clobbering it), but we certainly need to save it for this
- // purpose.
- R"(
- stp x19, x20, [x0, #0*16]
- stp x21, x22, [x0, #1*16]
- stp x23, x24, [x0, #2*16]
- stp x25, x26, [x0, #3*16]
- stp x27, x28, [x0, #4*16]
- stp x29, x30, [x0, #5*16]
- )"
-
- // While we usually store the platform register x18
- // the darwin ABI inhibts usage of it
- // Store just the stack pointer.
- R"(
- add x1, sp, #0
- str x1, [x0, #6*16]
- )"
-
-#if __ARM_FP
- // Store the callee-saved FP registers. AAPCS64 only requires the low 64
- // bits of v8-v15 to be preserved, i.e. each of d8,...,d15.
- R"(
- stp d8, d9, [x0, #7*16]
- stp d10, d11, [x0, #8*16]
- stp d12, d13, [x0, #9*16]
- stp d14, d15, [x0, #10*16]
- )"
-#endif
-
- // Set up return value of zero.
- R"(
- mov x0, #0
- )"
-
-#if (__ARM_FEATURE_PAC_DEFAULT & 7) == 5
- // Authenticate the return address using the PAC A key, since the
- // compilation options ask for PAC protection even on leaf functions.
- R"(
- autiasp
- )"
-#elif (__ARM_FEATURE_PAC_DEFAULT & 7) == 6
- // Same, but using the PAC B key.
- R"(
- autibsp
- )"
-#endif
-
- R"(
- ret
- )");
-}
-
-} // namespace LIBC_NAMESPACE_DECL
>From c55aea9bae7c2eab42dd24ac384037e369c5fd0f Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Fri, 16 May 2025 17:38:21 +0300
Subject: [PATCH 08/10] Update CMakeLists.txt to include the darwin/aarch64
directory.
---
libc/src/setjmp/CMakeLists.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/libc/src/setjmp/CMakeLists.txt b/libc/src/setjmp/CMakeLists.txt
index 239254fa57dc6..958960796940d 100644
--- a/libc/src/setjmp/CMakeLists.txt
+++ b/libc/src/setjmp/CMakeLists.txt
@@ -1,3 +1,4 @@
+add_subdirectory(darwin/aarch64)
if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
add_object_library(
>From 24f05bd6a556f426ba8644cdb3494aa20ecb025b Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Fri, 16 May 2025 17:38:50 +0300
Subject: [PATCH 09/10] Reuse the aarch64 implementation when building setjmp
for darwin aarch64
---
libc/src/setjmp/darwin/aarch64/CMakeLists.txt | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libc/src/setjmp/darwin/aarch64/CMakeLists.txt b/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
index 37058e9fb905e..7a15922124413 100644
--- a/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
+++ b/libc/src/setjmp/darwin/aarch64/CMakeLists.txt
@@ -5,7 +5,7 @@ endif()
add_entrypoint_object(
setjmp
SRCS
- setjmp.cpp
+ ../../aarch64/setjmp.cpp
HDRS
../../setjmp_impl.h
DEPENDS
@@ -16,7 +16,7 @@ add_entrypoint_object(
add_entrypoint_object(
longjmp
SRCS
- longjmp.cpp
+ ../../aarch64/longjmp.cpp
HDRS
../../longjmp.h
DEPENDS
>From 155cd2239fa43338e0cde0de5231ea618283591c Mon Sep 17 00:00:00 2001
From: AlyElashram <alyahelashram at gmail.com>
Date: Fri, 16 May 2025 17:47:16 +0300
Subject: [PATCH 10/10] Update adding the subdirectory for darwin/aarch64
---
libc/src/setjmp/CMakeLists.txt | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/libc/src/setjmp/CMakeLists.txt b/libc/src/setjmp/CMakeLists.txt
index 958960796940d..21f1be967234f 100644
--- a/libc/src/setjmp/CMakeLists.txt
+++ b/libc/src/setjmp/CMakeLists.txt
@@ -1,4 +1,3 @@
-add_subdirectory(darwin/aarch64)
if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
add_object_library(
@@ -13,6 +12,10 @@ if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_ARCHITECTURE})
add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_ARCHITECTURE})
endif()
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS}/${LIBC_TARGET_ARCHITECTURE})
+ add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS}/${LIBC_TARGET_ARCHITECTURE})
+endif()
+
add_entrypoint_object(
setjmp
ALIAS
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