Commit 166dffb088
src/link/plan9/a.out.zig
@@ -46,18 +46,10 @@ pub const ExecHdr = extern struct {
}
};
-// uchar value[4];
-// char type;
-// char name[n]; /* NUL-terminated */
-pub const Sym32 = struct {
- value: u32, // big endian in the file
- type: SymType,
- name: []const u8,
-};
// uchar value[8];
// char type;
// char name[n]; /* NUL-terminated */
-pub const Sym64 = struct {
+pub const Sym = struct {
value: u64, // big endian in the file
type: SymType,
name: []const u8,
@@ -93,6 +85,14 @@ pub const SymType = enum(u8) {
z = 0x80 | 'z',
Z = 0x80 | 'Z',
m = 0x80 | 'm',
+ pub fn toGlobal(self: SymType) SymType {
+ return switch (self) {
+ .t => .T,
+ .b => .B,
+ .d => .D,
+ else => unreachable,
+ };
+ }
};
pub const HDR_MAGIC = 0x00008000;
src/link/Plan9.zig
@@ -19,37 +19,73 @@ const assert = std.debug.assert;
base: link.File,
ptr_width: PtrWidth,
error_flags: File.ErrorFlags = File.ErrorFlags{},
+bases: Bases,
decl_table: std.AutoArrayHashMapUnmanaged(*Module.Decl, void) = .{},
/// is just casted down when 32 bit
-syms: std.ArrayListUnmanaged(aout.Sym64) = .{},
+syms: std.ArrayListUnmanaged(aout.Sym) = .{},
call_relocs: std.ArrayListUnmanaged(CallReloc) = .{},
text_buf: std.ArrayListUnmanaged(u8) = .{},
data_buf: std.ArrayListUnmanaged(u8) = .{},
cur_decl: *Module.Decl = undefined,
hdr: aout.ExecHdr = undefined,
+const Bases = struct { text: u32, data: u32 };
+
+fn getAddr(self: Plan9, addr: u32, t: aout.SymType) u32 {
+ return addr + switch (t) {
+ .T, .t => self.bases.text,
+ .D, .d, .B, .b => self.bases.data,
+ else => @panic("get address for more symbol types"),
+ };
+}
+/// opposite of getAddr
+fn takeAddr(self: Plan9, addr: u32, t: aout.SymType) u32 {
+ return addr - switch (t) {
+ .T, .t => self.bases.text,
+ .D, .d, .B, .b => self.bases.data, // TODO is .b correct here?
+ else => @panic("take address for more symbol types"),
+ };
+}
+
+fn getSymAddr(self: Plan9, s: aout.Sym) u32 {
+ return self.getAddr(@intCast(u32, s.value), s.type);
+}
fn headerSize(self: Plan9) u32 {
// fat header (currently unused)
const fat: u8 = if (self.ptr_width == .p64) 8 else 0;
return @sizeOf(aout.ExecHdr) + fat;
}
+
pub const DeclBlock = struct {
- type: enum { text, data },
+ type: aout.SymType,
// offset in the text or data sects
offset: u32,
// offset into syms
sym_index: ?usize,
pub const empty = DeclBlock{
- .type = .text,
+ .type = .t,
.offset = 0,
.sym_index = null,
};
};
-// TODO change base addr based on target (and section?) (right now it just works on amd64)
-const default_base_addr = 0x00200028;
+pub fn defaultBaseAddrs(arch: std.Target.Cpu.Arch) Bases {
+ return switch (arch) {
+ .x86_64 => .{
+ // 0x28 => 40 == header size
+ .text = 0x200028,
+ .data = 0x400000,
+ },
+ .i386 => .{
+ // 0x20 => 32 == header size
+ .text = 0x200020,
+ .data = 0x400000,
+ },
+ else => std.debug.panic("find default base address for {}", .{arch}),
+ };
+}
pub const CallReloc = struct {
caller: *Module.Decl,
@@ -76,6 +112,7 @@ pub fn createEmpty(gpa: *Allocator, options: link.Options) !*Plan9 {
.file = null,
},
.ptr_width = ptr_width,
+ .bases = undefined,
};
return self;
}
@@ -115,31 +152,25 @@ pub fn flushModule(self: *Plan9, comp: *Compilation) !void {
self.cur_decl = decl;
const is_fn = (decl.ty.zigTypeTag() == .Fn);
decl.link.plan9 = if (is_fn) .{
- .offset = @intCast(u32, self.text_buf.items.len),
- .type = .text,
+ .offset = self.getAddr(@intCast(u32, self.text_buf.items.len), .t),
+ .type = .t,
.sym_index = decl.link.plan9.sym_index,
} else .{
- .offset = @intCast(u32, self.data_buf.items.len),
- .type = .data,
+ .offset = self.getAddr(@intCast(u32, self.data_buf.items.len), .d),
+ .type = .t,
.sym_index = decl.link.plan9.sym_index,
};
if (decl.link.plan9.sym_index == null) {
try self.syms.append(self.base.allocator, .{
.value = decl.link.plan9.offset,
- .type = switch (decl.link.plan9.type) {
- .text => .t,
- .data => .d,
- },
+ .type = decl.link.plan9.type,
.name = mem.span(decl.name),
});
decl.link.plan9.sym_index = self.syms.items.len - 1;
} else {
self.syms.items[decl.link.plan9.sym_index.?] = .{
.value = decl.link.plan9.offset,
- .type = switch (decl.link.plan9.type) {
- .text => .t,
- .data => .d,
- },
+ .type = decl.link.plan9.type,
.name = mem.span(decl.name),
};
}
@@ -174,21 +205,21 @@ pub fn flushModule(self: *Plan9, comp: *Compilation) !void {
assert(l.sym_index != null); // we didn't process it already
const endian = self.base.options.target.cpu.arch.endian();
if (self.ptr_width == .p32) {
- const callee_offset = @truncate(u32, reloc.callee.link.plan9.offset + default_base_addr); // TODO this is different if its data
- const off = reloc.offset_in_caller + l.offset;
+ const callee_offset = @intCast(u32, reloc.callee.link.plan9.offset);
+ const off = self.takeAddr(@intCast(u32, reloc.offset_in_caller) + l.offset, reloc.caller.link.plan9.type);
std.mem.writeInt(u32, self.text_buf.items[off - 4 ..][0..4], callee_offset, endian);
} else {
- const callee_offset = reloc.callee.link.plan9.offset + default_base_addr; // TODO this is different if its data
- const off = reloc.offset_in_caller + l.offset;
+ const callee_offset = reloc.callee.link.plan9.offset;
+ const off = self.takeAddr(@intCast(u32, reloc.offset_in_caller) + l.offset, reloc.caller.link.plan9.type);
std.mem.writeInt(u64, self.text_buf.items[off - 8 ..][0..8], callee_offset, endian);
}
}
}
// edata, end, etext
- self.syms.items[0].value = 0x200000; // TODO make this number other place, and what is it?
- self.syms.items[1].value = 0x200000; // TODO make this number other place, and what is it?
- self.syms.items[2].value = self.text_buf.items.len;
+ self.syms.items[0].value = self.getAddr(0x0, .b); // what is this number
+ self.syms.items[1].value = self.getAddr(0x0, .b); // what is this number
+ self.syms.items[2].value = self.getAddr(@intCast(u32, self.text_buf.items.len), .t);
var sym_buf = std.ArrayList(u8).init(self.base.allocator);
defer sym_buf.deinit();
@@ -248,25 +279,19 @@ pub fn updateDeclExports(
}
}
if (std.mem.eql(u8, exp.options.name, "_start")) {
- std.debug.assert(decl.link.plan9.type == .text); // we tried to link a non-function as _start
- self.hdr.entry = Plan9.default_base_addr + self.headerSize() + decl.link.plan9.offset;
+ std.debug.assert(decl.link.plan9.type == .t); // we tried to link a non-function as _start
+ self.hdr.entry = self.bases.text + decl.link.plan9.offset;
}
if (exp.link.plan9) |i| {
self.syms.items[i] = .{
- .value = decl.link.plan9.offset,
- .type = switch (decl.link.plan9.type) {
- .text => .T,
- .data => .D,
- },
+ .value = self.getAddr(decl.link.plan9.offset, decl.link.plan9.type),
+ .type = decl.link.plan9.type.toGlobal(),
.name = exp.options.name,
};
} else {
try self.syms.append(self.base.allocator, .{
- .value = decl.link.plan9.offset,
- .type = switch (decl.link.plan9.type) {
- .text => .T,
- .data => .D,
- },
+ .value = self.getAddr(decl.link.plan9.offset, decl.link.plan9.type),
+ .type = decl.link.plan9.type.toGlobal(),
.name = exp.options.name,
});
exp.link.plan9 = self.syms.items.len - 1;
@@ -300,6 +325,8 @@ pub fn openPath(allocator: *Allocator, sub_path: []const u8, options: link.Optio
if (std.builtin.mode == .Debug or std.builtin.mode == .ReleaseSafe)
self.hdr.entry = 0x0;
+ self.bases = defaultBaseAddrs(options.target.cpu.arch);
+
// first 3 symbols in our table are edata, end, etext
try self.syms.appendSlice(self.base.allocator, &.{
.{
@@ -333,9 +360,9 @@ pub fn writeSyms(self: *Plan9, buf: *std.ArrayList(u8)) !void {
const writer = buf.writer();
for (self.syms.items) |sym| {
if (self.ptr_width == .p32) {
- try writer.writeIntBig(u32, @intCast(u32, sym.value) + default_base_addr);
+ try writer.writeIntBig(u32, @intCast(u32, sym.value));
} else {
- try writer.writeIntBig(u64, sym.value + default_base_addr);
+ try writer.writeIntBig(u64, sym.value);
}
try writer.writeByte(@enumToInt(sym.type));
try writer.writeAll(std.mem.span(sym.name));