[vm, simarm64] Handle FFI callouts.
TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/60204
Change-Id: I2a7546cea0886b05873dbc59f5c9f049aad963c7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/411960
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
diff --git a/runtime/BUILD.gn b/runtime/BUILD.gn
index 6d91281..450411e 100644
--- a/runtime/BUILD.gn
+++ b/runtime/BUILD.gn
@@ -149,6 +149,9 @@
}
if (dart_force_simulator) {
defines += [ "USING_SIMULATOR" ]
+ if (dart_target_arch == "arm64") {
+ defines += [ "SIMULATOR_FFI" ]
+ }
}
}
diff --git a/runtime/lib/ffi_dynamic_library.cc b/runtime/lib/ffi_dynamic_library.cc
index ec42580..5fb31a3 100644
--- a/runtime/lib/ffi_dynamic_library.cc
+++ b/runtime/lib/ffi_dynamic_library.cc
@@ -29,12 +29,12 @@
namespace dart {
-#if defined(USING_SIMULATOR) || (defined(DART_PRECOMPILER) && !defined(TESTING))
+#if (defined(USING_SIMULATOR) && !defined(SIMULATOR_FFI)) || \
+ (defined(DART_PRECOMPILER) && !defined(TESTING))
DART_NORETURN static void SimulatorUnsupported() {
#if defined(USING_SIMULATOR)
- Exceptions::ThrowUnsupportedError(
- "Not supported on simulated architectures.");
+ Exceptions::ThrowUnsupportedError("Not supported on this simulator.");
#else
Exceptions::ThrowUnsupportedError("Not supported in precompiler.");
#endif
@@ -516,7 +516,7 @@
return Pointer::New(reinterpret_cast<intptr_t>(FfiResolve));
}
-#endif // defined(USING_SIMULATOR) || \
+#endif // (defined(USING_SIMULATOR) && !defined (SIMULATOR_FFI)) || \
// (defined(DART_PRECOMPILER) && !defined(TESTING))
} // namespace dart
diff --git a/runtime/tests/vm/vm.status b/runtime/tests/vm/vm.status
index 019c9d3..06d0c55 100644
--- a/runtime/tests/vm/vm.status
+++ b/runtime/tests/vm/vm.status
@@ -196,6 +196,7 @@
dart/ffi_structs_optimizations_il_test: SkipByDesign # https://dartbug.com/37299 Test uses dart:ffi which is not supported on simulators.
dart/gc/splay_c_finalizer_test: SkipByDesign # No FFI on simulators
dart/isolates/dart_api_create_lightweight_isolate_test: SkipByDesign # https://dartbug.com/37299 Test uses dart:ffi which is not supported on simulators.
+dart/isolates/many_isolates_blocked_at_monitor_test: SkipByDesign # https://dartbug.com/37299 FFI not supported on simulator
dart/isolates/regress_54528_test: SkipByDesign # Invokes gen_kernel/gen_snapshot
dart/isolates/shared_test: SkipByDesign # https://dartbug.com/37299 Test uses dart:ffi which is not supported on simulators.
dart/isolates/thread_pool_test: SkipByDesign # https://dartbug.com/37299 Test uses dart:ffi which is not supported on simulators.
diff --git a/runtime/vm/BUILD.gn b/runtime/vm/BUILD.gn
index 6afe2bb..f4be2d9 100644
--- a/runtime/vm/BUILD.gn
+++ b/runtime/vm/BUILD.gn
@@ -202,6 +202,9 @@
# uses different assembler syntax.
sources += [ "thread_interrupter_android_arm.S" ]
}
+ if (!is_win) {
+ sources += [ "simulator_arm64_trampolines.S" ]
+ }
include_dirs = [ ".." ]
}
diff --git a/runtime/vm/compiler/backend/il_arm64.cc b/runtime/vm/compiler/backend/il_arm64.cc
index bcec263..7849e4d 100644
--- a/runtime/vm/compiler/backend/il_arm64.cc
+++ b/runtime/vm/compiler/backend/il_arm64.cc
@@ -1428,6 +1428,10 @@
__ mov(temp_csp, CSP);
__ mov(CSP, SP);
+#if defined(SIMULATOR_FFI)
+ __ Emit(Instr::kSimulatorFfiRedirectInstruction);
+ ASSERT(branch == R9);
+#endif
__ blr(branch);
// Restore the Dart stack pointer.
diff --git a/runtime/vm/compiler/backend/locations.h b/runtime/vm/compiler/backend/locations.h
index 3a6e46f..1d38e88 100644
--- a/runtime/vm/compiler/backend/locations.h
+++ b/runtime/vm/compiler/backend/locations.h
@@ -712,6 +712,9 @@
if (reg == PC) continue;
#elif defined(TARGET_ARCH_ARM64)
if (reg == R31) continue;
+#if defined(DART_TARGET_OS_MACOS) || defined(DART_TARGET_OS_WINDOWS)
+ if (reg == R18) continue;
+#endif
#elif defined(TARGET_ARCH_RISCV32) || defined(TARGET_ARCH_RISCV64)
if (reg == ZR || reg == TP || reg == GP) continue;
#endif
diff --git a/runtime/vm/compiler/stub_code_compiler_arm64.cc b/runtime/vm/compiler/stub_code_compiler_arm64.cc
index 713b49b..daffde0 100644
--- a/runtime/vm/compiler/stub_code_compiler_arm64.cc
+++ b/runtime/vm/compiler/stub_code_compiler_arm64.cc
@@ -433,6 +433,9 @@
__ Bind(&done);
#endif
+#if defined(SIMULATOR_FFI)
+ __ Emit(Instr::kSimulatorFfiRedirectInstruction);
+#endif
__ blr(R9);
__ mov(SP, CSP);
diff --git a/runtime/vm/constants_arm64.h b/runtime/vm/constants_arm64.h
index ab62555..5788a23 100644
--- a/runtime/vm/constants_arm64.h
+++ b/runtime/vm/constants_arm64.h
@@ -1336,6 +1336,8 @@
static constexpr int32_t kSimulatorBreakCode =
0xdeb2; // For breakpoint in sim.
static constexpr int32_t kSimulatorRedirectCode = 0xca11; // For redirection.
+ static constexpr int32_t kSimulatorFfiRedirectCode =
+ 0xca12; // For redirection.
// Breakpoint instruction filling assembler code buffers in debug mode.
static constexpr int32_t kBreakPointInstruction = // brk(0xdeb0).
@@ -1350,6 +1352,8 @@
// Runtime call redirection instruction used by the simulator.
static constexpr int32_t kSimulatorRedirectInstruction =
HLT | (kSimulatorRedirectCode << kImm16Shift);
+ static constexpr int32_t kSimulatorFfiRedirectInstruction =
+ HLT | (kSimulatorFfiRedirectCode << kImm16Shift);
// Read one particular bit out of the instruction bits.
inline int Bit(int nr) const { return (InstructionBits() >> nr) & 1; }
diff --git a/runtime/vm/simulator_arm.cc b/runtime/vm/simulator_arm.cc
index 9d7be40..f34890d 100644
--- a/runtime/vm/simulator_arm.cc
+++ b/runtime/vm/simulator_arm.cc
@@ -1421,7 +1421,7 @@
Redirection* redirection = Redirection::FromSvcInstruction(instr);
uword external = redirection->external_function();
if (IsTracingExecution()) {
- THR_Print("Call to host function at 0x%" Pd "\n", external);
+ THR_Print("Call to host function at 0x%" Px "\n", external);
}
if (redirection->call_kind() == kRuntimeCall) {
NativeArguments arguments;
diff --git a/runtime/vm/simulator_arm64.cc b/runtime/vm/simulator_arm64.cc
index 2ddc632..29b089653 100644
--- a/runtime/vm/simulator_arm64.cc
+++ b/runtime/vm/simulator_arm64.cc
@@ -950,8 +950,9 @@
R31Type r31t) {
// Register is in range.
ASSERT((reg >= 0) && (reg < kNumberOfCpuRegisters));
-#if !defined(DART_TARGET_OS_FUCHSIA)
- ASSERT(instr == nullptr || reg != R18); // R18 is globally reserved on iOS.
+#if defined(DART_TARGET_OS_MACOS) || defined(DART_TARGET_OS_WINDOWS)
+ // R18 is globally reserved on macOS/iOS, the TEB pointer on Windows.
+ ASSERT(instr == nullptr || reg != R18);
#endif
if ((reg != R31) || (r31t != R31IsZR)) {
@@ -1682,7 +1683,7 @@
Redirection* redirection = Redirection::FromHltInstruction(instr);
uword external = redirection->external_function();
if (IsTracingExecution()) {
- THR_Print("Call to host function at 0x%" Pd "\n", external);
+ THR_Print("Call to host function at 0x%" Px "\n", external);
}
if (redirection->call_kind() == kRuntimeCall) {
@@ -1746,6 +1747,65 @@
}
}
+struct CalloutContext {
+ uword saved_stack_pointer;
+ uword saved_frame_pointer;
+ uword simulator_stack_pointer;
+ uword simulator_frame_pointer;
+ uword integer_arguments[8];
+ uword double_arguments[8];
+ uword r8;
+ uword target;
+};
+
+extern "C" void FfiCalloutTrampoline(CalloutContext*);
+
+void Simulator::DoRedirectedFfiCall(Instr* instr) {
+#if !defined(HOST_ARCH_ARM64)
+ FATAL("Unsupported FFI call");
+#else
+ // We can't instrument the runtime.
+ memory_.FlushAll();
+
+ SimulatorSetjmpBuffer buffer(this);
+ if (!setjmp(buffer.buffer_)) {
+ int64_t saved_pc = get_pc();
+ uword external = get_register(R9);
+ if (IsTracingExecution()) {
+ THR_Print("Call to FFI function at 0x%" Px "\n", external);
+ }
+
+ CalloutContext ctxt;
+ ctxt.simulator_stack_pointer = get_register(R31);
+ ctxt.simulator_frame_pointer = get_register(FP);
+ for (intptr_t i = 0; i < 8; i++) {
+ ctxt.integer_arguments[i] = get_register(static_cast<Register>(R0 + i));
+ ctxt.double_arguments[i] =
+ get_vregisterd(static_cast<VRegister>(V0 + i), 0);
+ }
+ ctxt.r8 = get_register(R8);
+ ctxt.target = external;
+
+ FfiCalloutTrampoline(&ctxt);
+
+ if (IsTracingExecution()) {
+ THR_Print("Return from FFI function at 0x%" Px "\n", external);
+ }
+
+ ClobberVolatileRegisters();
+ set_register(instr, R0, ctxt.integer_arguments[0]);
+ set_register(instr, R1, ctxt.integer_arguments[1]);
+ set_vregisterd(V0, 0, ctxt.double_arguments[0]);
+ set_vregisterd(V1, 0, ctxt.double_arguments[1]);
+
+ // Skip over hlt and blr.
+ set_pc(saved_pc + 2 * Instr::kInstrSize);
+ } else {
+ // Coming via long jump from a throw. Continue to exception handler.
+ }
+#endif
+}
+
void Simulator::ClobberVolatileRegisters() {
// Clear atomic reservation.
exclusive_access_addr_ = exclusive_access_value_ = 0;
@@ -1787,6 +1847,8 @@
dbg.Stop(instr, "breakpoint");
} else if (imm == Instr::kSimulatorRedirectCode) {
DoRedirectedCall(instr);
+ } else if (imm == Instr::kSimulatorFfiRedirectCode) {
+ DoRedirectedFfiCall(instr);
} else {
UnimplementedInstruction(instr);
}
diff --git a/runtime/vm/simulator_arm64.h b/runtime/vm/simulator_arm64.h
index e550e80..bc812cf 100644
--- a/runtime/vm/simulator_arm64.h
+++ b/runtime/vm/simulator_arm64.h
@@ -234,6 +234,7 @@
bool ConditionallyExecute(Instr* instr);
void DoRedirectedCall(Instr* instr);
+ void DoRedirectedFfiCall(Instr* instr);
// Decode instructions.
void InstructionDecode(Instr* instr);
diff --git a/runtime/vm/simulator_arm64_trampolines.S b/runtime/vm/simulator_arm64_trampolines.S
new file mode 100644
index 0000000..ccd19c7
--- /dev/null
+++ b/runtime/vm/simulator_arm64_trampolines.S
@@ -0,0 +1,78 @@
+// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Callout trampoline from the simulator. This is not written as VM stub because
+// we need it be executable in contexts where we cannot JIT. (Alternatively, we
+// could start requiring the VM snapshot to be provided in every mode.)
+
+#if defined(__aarch64__)
+
+.text
+
+#if defined(__APPLE__)
+.globl _FfiCalloutTrampoline
+_FfiCalloutTrampoline:
+#else
+.globl FfiCalloutTrampoline
+.type FfiCalloutTrampoline, %function
+FfiCalloutTrampoline:
+#endif
+ stp fp, lr, [sp, #-16]!
+ mov fp, sp
+
+ // Spill a preserved register to save the context pointer.
+ stp x19, x20, [sp, #-16]!
+ mov x19, x0
+
+ // Copy top frame from Dart stack to C stack
+ ldr x0, [x19, #16] // CalloutContext.simulator_stack_pointer (CSP)
+ ldr x1, [x19, #24] // CalloutContext.simulator_frame_pointer
+ add x1, x1, 15 // Round up the frame pointer, since the Dart frame pointer
+ and x1, x1, ~15 // is not double-word aligned.
+.Lcopy:
+ ldp x2, x3, [x1, #-16]! // From Dart FP
+ stp x2, x3, [sp, #-16]! // To C SP
+ cmp x1, x0
+ b.gt .Lcopy
+
+ // Load the ABI argument registers. Note that Dart FFI does not support
+ // full 128-bit SIMD arguments, so we don't need to set the full V
+ // registers.
+ ldr x0, [x19, #32] // CalloutContext.integer_arguments[0]
+ ldr x1, [x19, #40]
+ ldr x2, [x19, #48]
+ ldr x3, [x19, #56]
+ ldr x4, [x19, #64]
+ ldr x5, [x19, #72]
+ ldr x6, [x19, #80]
+ ldr x7, [x19, #88]
+ ldr d0, [x19, #96] // CalloutContext.double_arguments[0]
+ ldr d1, [x19, #104]
+ ldr d2, [x19, #112]
+ ldr d3, [x19, #120]
+ ldr d4, [x19, #128]
+ ldr d5, [x19, #136]
+ ldr d6, [x19, #144]
+ ldr d7, [x19, #152]
+ ldr x8, [x19, #160] // CalloutContext.r8
+
+ // Call target.
+ ldr lr, [x19, #168] // CalloutContext.target
+ blr lr
+
+ // Save the ABI result registers.
+ str x0, [x19, #32] // CalloutContext.integer_arguments[0]
+ str x1, [x19, #40]
+ str d0, [x19, #96] // CalloutContext.double_arguments[0]
+ str d1, [x19, #104]
+
+ add sp, fp, -16
+ ldp x19, x20, [sp], #16
+ ldp fp, lr, [sp], #16
+ ret
+#if !defined(__APPLE__)
+.size FfiCalloutTrampoline,.-FfiCalloutTrampoline
+#endif
+
+#endif // defined(__aarch64__)
diff --git a/runtime/vm/simulator_riscv.cc b/runtime/vm/simulator_riscv.cc
index 9d3c204..5526c20 100644
--- a/runtime/vm/simulator_riscv.cc
+++ b/runtime/vm/simulator_riscv.cc
@@ -2114,7 +2114,7 @@
Redirection* redirection = Redirection::FromECallInstruction(pc_);
uword external = redirection->external_function();
if (IsTracingExecution()) {
- THR_Print("Call to host function at 0x%" Pd "\n", external);
+ THR_Print("Call to host function at 0x%" Px "\n", external);
}
if (redirection->call_kind() == kRuntimeCall) {
