Issue #1905 - Part 3g - Final set of changes connecting ARM64 support for Mac. Back out some of the xptcstubs changes that are not viable for our codebase.

config/external/ffi/moz.build

@@ -121,6 +121,8 @@ else:
             DEFINES['SYMBOL_UNDERSCORE'] = True
         else:
             ffi_srcs = ('ffi.c', 'darwin.S', 'ffi64.c', 'darwin64.S')
+    elif CONFIG['FFI_TARGET'] == 'AARCH64_DARWIN':
+        ffi_srcs = ('sysv.S', 'ffi.c')
 
     SOURCES += [
         '/js/src/ctypes/libffi/src/%s/%s' % (CONFIG['FFI_TARGET_DIR'], s)

js/ffi.configure

@@ -38,8 +38,11 @@ def ffi_target(target):
         else:
             target_name = 'X86_WIN32'
     elif target.os == 'OSX':
-        target_dir = 'x86'
-        target_name = 'X86_DARWIN'
+        if target.cpu == 'aarch64':
+            target_name = 'AARCH64_DARWIN'
+        else:
+            target_name = 'X86_DARWIN'
+        target_dir = 'aarch64'
     elif target.cpu == 'arm':
         target_dir = 'arm'
         target_name = 'ARM'

js/src/wasm/WasmSignalHandlers.cpp

@@ -370,6 +370,12 @@ struct macos_arm_context {
     arm_neon_state_t float_;
 };
 #  define EMULATOR_CONTEXT macos_arm_context
+# elif defined(__aarch64__)
+struct macos_aarch64_context {
+    arm_thread_state64_t thread;
+    arm_neon_state64_t float_;
+};
+#  define EMULATOR_CONTEXT macos_aarch64_context
 # else
 #  error Unsupported architecture
 # endif
@@ -887,7 +893,7 @@ ContextToPC(EMULATOR_CONTEXT* context)
     static_assert(sizeof(context->thread.uts.ts32.__eip) == sizeof(void*),
                   "stored IP should be compile-time pointer-sized");
     return reinterpret_cast<uint8_t**>(&context->thread.uts.ts32.__eip);
-# elif defined(JS_CPU_ARM)
+# elif defined(JS_CPU_ARM) || defined(__aarch64__)
     static_assert(sizeof(context->thread.__pc) == sizeof(void*),
                   "stored IP should be compile-time pointer-sized");
     return reinterpret_cast<uint8_t**>(&context->thread.__pc);
@@ -948,6 +954,11 @@ HandleMachException(JSRuntime* rt, const ExceptionRequest& request)
     unsigned int float_state_count = ARM_NEON_STATE_COUNT;
     int thread_state = ARM_THREAD_STATE;
     int float_state = ARM_NEON_STATE;
+# elif defined(__aarch64__)
+    unsigned int thread_state_count = ARM_THREAD_STATE64_COUNT;
+    unsigned int float_state_count = ARM_NEON_STATE64_COUNT;
+    int thread_state = ARM_THREAD_STATE64;
+    int float_state = ARM_NEON_STATE64;
 # else
 #  error Unsupported architecture
 # endif

xpcom/reflect/xptcall/md/unix/xptcstubs_aarch64.cpp

@@ -4,6 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "xptcprivate.h"
+#include "xptiprivate.h"
 
 #ifndef __AARCH64EL__
 #error "Only little endian compatibility was tested"
@@ -33,10 +34,12 @@ extern "C" nsresult ATTRIBUTE_USED
 PrepareAndDispatch(nsXPTCStubBase* self, uint32_t methodIndex, void* args,
                    uint64_t *gprData, double *fprData)
 {
+#define PARAM_BUFFER_COUNT        16
 #define PARAM_GPR_COUNT            8
 #define PARAM_FPR_COUNT            8
 
     nsXPTCMiniVariant paramBuffer[PARAM_BUFFER_COUNT];
+    nsXPTCMiniVariant* dispatchParams = NULL;
     const nsXPTMethodInfo* info;
 
     NS_ASSERTION(self,"no self");
@@ -46,7 +49,13 @@ PrepareAndDispatch(nsXPTCStubBase* self, uint32_t methodIndex, void* args,
 
     uint32_t paramCount = info->GetParamCount();
 
-    const uint8_t indexOfJSContext = info->IndexOfJSContext();
+    // setup variant array pointer
+    if (paramCount > PARAM_BUFFER_COUNT) {
+        dispatchParams = new nsXPTCMiniVariant[paramCount];
+    } else {
+        dispatchParams = paramBuffer;
+    }
+    NS_ASSERTION(dispatchParams,"no place for params");
 
     void* ap = args;
     uint32_t next_gpr = 1; // skip first arg which is 'self'
@@ -54,16 +63,7 @@ PrepareAndDispatch(nsXPTCStubBase* self, uint32_t methodIndex, void* args,
     for (uint32_t i = 0; i < paramCount; i++) {
         const nsXPTParamInfo& param = info->GetParam(i);
         const nsXPTType& type = param.GetType();
-        nsXPTCMiniVariant* dp = &paramBuffer[i];
-
-        if (i == indexOfJSContext) {
-            if (next_gpr < PARAM_GPR_COUNT)
-                next_gpr++;
-            else {
-                void* value;
-                get_value_and_advance(&value, ap);
-            }
-        }
+        nsXPTCMiniVariant* dp = &dispatchParams[i];
 
         if (param.IsOut() || !type.IsArithmetic()) {
             if (next_gpr < PARAM_GPR_COUNT) {
@@ -187,8 +187,11 @@ PrepareAndDispatch(nsXPTCStubBase* self, uint32_t methodIndex, void* args,
         }
     }
 
-    nsresult result = self->mOuter->CallMethod((uint16_t)methodIndex, info,
-                                               paramBuffer);
+    nsresult result = self->mOuter->CallMethod((uint16_t)methodIndex, info, dispatchParams);
+
+    if (dispatchParams != paramBuffer) {
+        delete [] dispatchParams;
+    }
 
     return result;
 }