macho: port arm64 and x86_64 compact unwind defs verbatim

We do not need more for the purpose of parsing and synthesising
unwind info by the linker. If we ever decide to generate unwind
info for Zig by the compiler, we can re-add packed struct defs
again.

1 files changed, 50 insertions, 91 deletions

diff --git a/lib/std/macho.zig b/lib/std/macho.zig
index bb80e78a92..f6a04b2ab8 100644
--- a/lib/std/macho.zig
+++ b/lib/std/macho.zig
@@ -2004,96 +2004,55 @@ pub const UnwindInfoCompressedEntry = packed struct {
     encodingIndex: u8,
 };
 
-// TODO add corresponding x86_64 tagged union
-pub const UnwindEncodingArm64 = union(enum) {
-    frame: Frame,
-    frameless: Frameless,
-    dwarf: Dwarf,
-
-    pub const Frame = packed struct {
-        x_reg_pairs: packed struct {
-            x19_x20: u1,
-            x21_x22: u1,
-            x23_x24: u1,
-            x25_x26: u1,
-            x27_x28: u1,
-        },
-        d_reg_pairs: packed struct {
-            d8_d9: u1,
-            d10_d11: u1,
-            d12_d13: u1,
-            d14_d15: u1,
-        },
-        unused: u15,
-        mode: Mode = .frame,
-        personality_index: u2,
-        has_lsda: u1,
-        start: u1,
-    };
-
-    pub const Frameless = packed struct {
-        unused: u12 = 0,
-        stack_size: u12,
-        mode: Mode = .frameless,
-        personality_index: u2,
-        has_lsda: u1,
-        start: u1,
-    };
-
-    pub const Dwarf = packed struct {
-        section_offset: u24,
-        mode: Mode = .dwarf,
-        personality_index: u2,
-        has_lsda: u1,
-        start: u1,
-    };
-
-    pub const Mode = enum(u4) {
-        frameless = 0x2,
-        dwarf = 0x3,
-        frame = 0x4,
-        _,
-    };
-
-    pub const mode_mask: u32 = 0x0F000000;
-
-    pub fn fromU32(enc: u32) !UnwindEncodingArm64 {
-        const m = (enc & mode_mask) >> 24;
-        return switch (@intToEnum(Mode, m)) {
-            .frame => .{ .frame = @bitCast(Frame, enc) },
-            .frameless => .{ .frameless = @bitCast(Frameless, enc) },
-            .dwarf => .{ .dwarf = @bitCast(Dwarf, enc) },
-            else => return error.UnknownEncoding,
-        };
-    }
-
-    pub fn toU32(enc: UnwindEncodingArm64) u32 {
-        return switch (enc) {
-            inline else => |x| @bitCast(u32, x),
-        };
-    }
-
-    pub fn start(enc: UnwindEncodingArm64) bool {
-        return switch (enc) {
-            inline else => |x| x.start == 0b1,
-        };
-    }
-
-    pub fn hasLsda(enc: UnwindEncodingArm64) bool {
-        return switch (enc) {
-            inline else => |x| x.has_lsda == 0b1,
-        };
-    }
-
-    pub fn personalityIndex(enc: UnwindEncodingArm64) u2 {
-        return switch (enc) {
-            inline else => |x| x.personality_index,
-        };
-    }
+pub const UNWIND_IS_NOT_FUNCTION_START: u32 = 0x80000000;
+pub const UNWIND_HAS_LSDA: u32 = 0x40000000;
+pub const UNWIND_PERSONALITY_MASK: u32 = 0x30000000;
+
+// x86_64
+pub const UNWIND_X86_64_MODE_MASK: u32 = 0x0F000000;
+pub const UNWIND_X86_64_MODE = enum(u4) {
+    RBP_FRAME = 1,
+    STACK_IMMD = 2,
+    STACK_IND = 3,
+    DWARF = 4,
+};
+pub const UNWIND_X86_64_RBP_FRAME_REGISTERS: u32 = 0x00007FFF;
+pub const UNWIND_X86_64_RBP_FRAME_OFFSET: u32 = 0x00FF0000;
+
+pub const UNWIND_X86_64_FRAMELESS_STACK_SIZE: u32 = 0x00FF0000;
+pub const UNWIND_X86_64_FRAMELESS_STACK_ADJUST: u32 = 0x0000E000;
+pub const UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT: u32 = 0x00001C00;
+pub const UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION: u32 = 0x000003FF;
+
+pub const UNWIND_X86_64_DWARF_SECTION_OFFSET: u32 = 0x00FFFFFF;
+
+pub const UNWIND_X86_64_REG = enum(u3) {
+    NONE = 0,
+    RBX = 1,
+    R12 = 2,
+    R13 = 3,
+    R14 = 4,
+    R15 = 5,
+    RBP = 6,
+};
 
-    pub fn mode(enc: UnwindEncodingArm64) Mode {
-        return switch (enc) {
-            inline else => |x| x.mode,
-        };
-    }
+// arm64
+pub const UNWIND_ARM64_MODE_MASK: u32 = 0x0F000000;
+pub const UNWIND_ARM64_MODE = enum(u4) {
+    FRAMELESS = 2,
+    DWARF = 3,
+    FRAME = 4,
 };
+
+pub const UNWIND_ARM64_FRAME_X19_X20_PAIR: u32 = 0x00000001;
+pub const UNWIND_ARM64_FRAME_X21_X22_PAIR: u32 = 0x00000002;
+pub const UNWIND_ARM64_FRAME_X23_X24_PAIR: u32 = 0x00000004;
+pub const UNWIND_ARM64_FRAME_X25_X26_PAIR: u32 = 0x00000008;
+pub const UNWIND_ARM64_FRAME_X27_X28_PAIR: u32 = 0x00000010;
+pub const UNWIND_ARM64_FRAME_D8_D9_PAIR: u32 = 0x00000100;
+pub const UNWIND_ARM64_FRAME_D10_D11_PAIR: u32 = 0x00000200;
+pub const UNWIND_ARM64_FRAME_D12_D13_PAIR: u32 = 0x00000400;
+pub const UNWIND_ARM64_FRAME_D14_D15_PAIR: u32 = 0x00000800;
+
+pub const UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK: u32 = 0x00FFF000;
+pub const UNWIND_ARM64_DWARF_SECTION_OFFSET: u32 = 0x00FFFFFF;