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Diffstat (limited to 'src/codegen/c.zig')
-rw-r--r--src/codegen/c.zig377
1 files changed, 245 insertions, 132 deletions
diff --git a/src/codegen/c.zig b/src/codegen/c.zig
index 589e2f17e0..8d706f8735 100644
--- a/src/codegen/c.zig
+++ b/src/codegen/c.zig
@@ -12,7 +12,7 @@ const C = link.File.C;
const Decl = Module.Decl;
const mem = std.mem;
-const indentation = " ";
+const Writer = std.ArrayList(u8).Writer;
/// Maps a name from Zig source to C. Currently, this will always give the same
/// output for any given input, sometimes resulting in broken identifiers.
@@ -20,43 +20,145 @@ fn map(allocator: *std.mem.Allocator, name: []const u8) ![]const u8 {
return allocator.dupe(u8, name);
}
-fn renderType(ctx: *Context, header: *C.Header, writer: std.ArrayList(u8).Writer, T: Type) !void {
- switch (T.zigTypeTag()) {
+fn renderType(
+ ctx: *Context,
+ header: *C.Header,
+ writer: Writer,
+ t: Type,
+) error{ OutOfMemory, AnalysisFail }!void {
+ switch (t.zigTypeTag()) {
.NoReturn => {
try writer.writeAll("zig_noreturn void");
},
.Void => try writer.writeAll("void"),
.Bool => try writer.writeAll("bool"),
.Int => {
- if (T.tag() == .u8) {
- header.need_stdint = true;
- try writer.writeAll("uint8_t");
- } else if (T.tag() == .u32) {
- header.need_stdint = true;
- try writer.writeAll("uint32_t");
- } else if (T.tag() == .usize) {
- header.need_stddef = true;
- try writer.writeAll("size_t");
+ switch (t.tag()) {
+ .u8 => try writer.writeAll("uint8_t"),
+ .i8 => try writer.writeAll("int8_t"),
+ .u16 => try writer.writeAll("uint16_t"),
+ .i16 => try writer.writeAll("int16_t"),
+ .u32 => try writer.writeAll("uint32_t"),
+ .i32 => try writer.writeAll("int32_t"),
+ .u64 => try writer.writeAll("uint64_t"),
+ .i64 => try writer.writeAll("int64_t"),
+ .usize => try writer.writeAll("uintptr_t"),
+ .isize => try writer.writeAll("intptr_t"),
+ .c_short => try writer.writeAll("short"),
+ .c_ushort => try writer.writeAll("unsigned short"),
+ .c_int => try writer.writeAll("int"),
+ .c_uint => try writer.writeAll("unsigned int"),
+ .c_long => try writer.writeAll("long"),
+ .c_ulong => try writer.writeAll("unsigned long"),
+ .c_longlong => try writer.writeAll("long long"),
+ .c_ulonglong => try writer.writeAll("unsigned long long"),
+ .int_signed, .int_unsigned => {
+ const info = t.intInfo(ctx.target);
+ const sign_prefix = switch (info.signedness) {
+ .signed => "i",
+ .unsigned => "",
+ };
+ inline for (.{ 8, 16, 32, 64, 128 }) |nbits| {
+ if (info.bits <= nbits) {
+ try writer.print("{s}int{d}_t", .{ sign_prefix, nbits });
+ break;
+ }
+ } else {
+ return ctx.fail(ctx.decl.src(), "TODO: C backend: implement integer types larger than 128 bits", .{});
+ }
+ },
+ else => unreachable,
+ }
+ },
+ .Pointer => {
+ if (t.isSlice()) {
+ return ctx.fail(ctx.decl.src(), "TODO: C backend: implement slices", .{});
} else {
- return ctx.fail(ctx.decl.src(), "TODO implement int type {}", .{T});
+ if (t.isConstPtr()) {
+ try writer.writeAll("const ");
+ }
+ if (t.isVolatilePtr()) {
+ try writer.writeAll("volatile ");
+ }
+ try renderType(ctx, header, writer, t.elemType());
+ try writer.writeAll(" *");
}
},
- else => |e| return ctx.fail(ctx.decl.src(), "TODO implement type {}", .{e}),
+ .Array => {
+ try renderType(ctx, header, writer, t.elemType());
+ const sentinel_bit = @boolToInt(t.sentinel() != null);
+ const c_len = t.arrayLen() + sentinel_bit;
+ try writer.print("[{d}]", .{c_len});
+ },
+ else => |e| return ctx.fail(ctx.decl.src(), "TODO: C backend: implement type {s}", .{
+ @tagName(e),
+ }),
}
}
-fn renderValue(ctx: *Context, writer: std.ArrayList(u8).Writer, T: Type, val: Value) !void {
- switch (T.zigTypeTag()) {
+fn renderValue(
+ ctx: *Context,
+ writer: Writer,
+ t: Type,
+ val: Value,
+) error{ OutOfMemory, AnalysisFail }!void {
+ switch (t.zigTypeTag()) {
.Int => {
- if (T.isSignedInt())
- return writer.print("{}", .{val.toSignedInt()});
- return writer.print("{}", .{val.toUnsignedInt()});
+ if (t.isSignedInt())
+ return writer.print("{d}", .{val.toSignedInt()});
+ return writer.print("{d}", .{val.toUnsignedInt()});
+ },
+ .Pointer => switch (val.tag()) {
+ .undef, .zero => try writer.writeAll("0"),
+ .one => try writer.writeAll("1"),
+ .decl_ref => {
+ const decl_ref_payload = val.cast(Value.Payload.DeclRef).?;
+ try writer.print("&{s}", .{decl_ref_payload.decl.name});
+ },
+ .function => {
+ const payload = val.cast(Value.Payload.Function).?;
+ try writer.print("{s}", .{payload.func.owner_decl.name});
+ },
+ .extern_fn => {
+ const payload = val.cast(Value.Payload.ExternFn).?;
+ try writer.print("{s}", .{payload.decl.name});
+ },
+ else => |e| return ctx.fail(
+ ctx.decl.src(),
+ "TODO: C backend: implement Pointer value {s}",
+ .{@tagName(e)},
+ ),
+ },
+ .Array => {
+ // TODO first try specific tag representations for more efficiency
+ // Fall back to inefficient generic implementation.
+ try writer.writeAll("{");
+ var index: usize = 0;
+ const len = t.arrayLen();
+ const elem_ty = t.elemType();
+ while (index < len) : (index += 1) {
+ if (index != 0) try writer.writeAll(",");
+ const elem_val = try val.elemValue(&ctx.arena.allocator, index);
+ try renderValue(ctx, writer, elem_ty, elem_val);
+ }
+ if (t.sentinel()) |sentinel_val| {
+ if (index != 0) try writer.writeAll(",");
+ try renderValue(ctx, writer, elem_ty, sentinel_val);
+ }
+ try writer.writeAll("}");
},
- else => |e| return ctx.fail(ctx.decl.src(), "TODO implement value {}", .{e}),
+ else => |e| return ctx.fail(ctx.decl.src(), "TODO: C backend: implement value {s}", .{
+ @tagName(e),
+ }),
}
}
-fn renderFunctionSignature(ctx: *Context, header: *C.Header, writer: std.ArrayList(u8).Writer, decl: *Decl) !void {
+fn renderFunctionSignature(
+ ctx: *Context,
+ header: *C.Header,
+ writer: Writer,
+ decl: *Decl,
+) !void {
const tv = decl.typed_value.most_recent.typed_value;
try renderType(ctx, header, writer, tv.ty.fnReturnType());
// Use the child allocator directly, as we know the name can be freed before
@@ -81,27 +183,92 @@ fn renderFunctionSignature(ctx: *Context, header: *C.Header, writer: std.ArrayLi
}
pub fn generate(file: *C, decl: *Decl) !void {
- switch (decl.typed_value.most_recent.typed_value.ty.zigTypeTag()) {
- .Fn => try genFn(file, decl),
- .Array => try genArray(file, decl),
- else => |e| return file.fail(decl.src(), "TODO {}", .{e}),
+ const tv = decl.typed_value.most_recent.typed_value;
+
+ var arena = std.heap.ArenaAllocator.init(file.base.allocator);
+ defer arena.deinit();
+ var inst_map = std.AutoHashMap(*Inst, []u8).init(&arena.allocator);
+ defer inst_map.deinit();
+ var ctx = Context{
+ .decl = decl,
+ .arena = &arena,
+ .inst_map = &inst_map,
+ .target = file.base.options.target,
+ };
+ defer {
+ file.error_msg = ctx.error_msg;
+ ctx.deinit();
+ }
+
+ if (tv.val.cast(Value.Payload.Function)) |func_payload| {
+ const writer = file.main.writer();
+ try renderFunctionSignature(&ctx, &file.header, writer, decl);
+
+ try writer.writeAll(" {");
+
+ const func: *Module.Fn = func_payload.func;
+ const instructions = func.analysis.success.instructions;
+ if (instructions.len > 0) {
+ try writer.writeAll("\n");
+ for (instructions) |inst| {
+ const indent_size = 4;
+ const indent_level = 1;
+ try writer.writeByteNTimes(' ', indent_size * indent_level);
+ if (switch (inst.tag) {
+ .assembly => try genAsm(&ctx, file, inst.castTag(.assembly).?),
+ .call => try genCall(&ctx, file, inst.castTag(.call).?),
+ .add => try genBinOp(&ctx, file, inst.cast(Inst.BinOp).?, "+"),
+ .sub => try genBinOp(&ctx, file, inst.cast(Inst.BinOp).?, "-"),
+ .ret => try genRet(&ctx, file, inst.castTag(.ret).?),
+ .retvoid => try genRetVoid(file),
+ .arg => try genArg(&ctx),
+ .dbg_stmt => try genDbgStmt(&ctx, inst.castTag(.dbg_stmt).?),
+ .breakpoint => try genBreak(&ctx, inst.castTag(.breakpoint).?),
+ .unreach => try genUnreach(file, inst.castTag(.unreach).?),
+ .intcast => try genIntCast(&ctx, file, inst.castTag(.intcast).?),
+ else => |e| return ctx.fail(decl.src(), "TODO implement C codegen for {}", .{e}),
+ }) |name| {
+ try ctx.inst_map.putNoClobber(inst, name);
+ }
+ }
+ }
+
+ try writer.writeAll("}\n\n");
+ } else if (tv.val.tag() == .extern_fn) {
+ return; // handled when referenced
+ } else {
+ const writer = file.constants.writer();
+ try writer.writeAll("static ");
+
+ // TODO ask the Decl if it is const
+ // https://github.com/ziglang/zig/issues/7582
+
+ try renderType(&ctx, &file.header, writer, tv.ty);
+ try writer.print(" {s} = ", .{decl.name});
+ try renderValue(&ctx, writer, tv.ty, tv.val);
+ try writer.writeAll(";\n");
}
}
pub fn generateHeader(
- arena: *std.heap.ArenaAllocator,
+ comp: *Compilation,
module: *Module,
header: *C.Header,
decl: *Decl,
) error{ AnalysisFail, OutOfMemory }!void {
switch (decl.typed_value.most_recent.typed_value.ty.zigTypeTag()) {
.Fn => {
- var inst_map = std.AutoHashMap(*Inst, []u8).init(&arena.allocator);
+ var inst_map = std.AutoHashMap(*Inst, []u8).init(comp.gpa);
defer inst_map.deinit();
+
+ var arena = std.heap.ArenaAllocator.init(comp.gpa);
+ defer arena.deinit();
+
var ctx = Context{
.decl = decl,
- .arena = arena,
+ .arena = &arena,
.inst_map = &inst_map,
+ .target = comp.getTarget(),
};
const writer = header.buf.writer();
renderFunctionSignature(&ctx, header, writer, decl) catch |err| {
@@ -116,24 +283,6 @@ pub fn generateHeader(
}
}
-fn genArray(file: *C, decl: *Decl) !void {
- const tv = decl.typed_value.most_recent.typed_value;
- // TODO: prevent inline asm constants from being emitted
- const name = try map(file.base.allocator, mem.span(decl.name));
- defer file.base.allocator.free(name);
- if (tv.val.cast(Value.Payload.Bytes)) |payload|
- if (tv.ty.sentinel()) |sentinel|
- if (sentinel.toUnsignedInt() == 0)
- // TODO: static by default
- try file.constants.writer().print("const char *const {} = \"{}\";\n", .{ name, payload.data })
- else
- return file.fail(decl.src(), "TODO byte arrays with non-zero sentinels", .{})
- else
- return file.fail(decl.src(), "TODO byte arrays without sentinels", .{})
- else
- return file.fail(decl.src(), "TODO non-byte arrays", .{});
-}
-
const Context = struct {
decl: *Decl,
inst_map: *std.AutoHashMap(*Inst, []u8),
@@ -141,6 +290,7 @@ const Context = struct {
argdex: usize = 0,
unnamed_index: usize = 0,
error_msg: *Compilation.ErrorMsg = undefined,
+ target: std.Target,
fn resolveInst(self: *Context, inst: *Inst) ![]u8 {
if (inst.cast(Inst.Constant)) |const_inst| {
@@ -170,55 +320,6 @@ const Context = struct {
}
};
-fn genFn(file: *C, decl: *Decl) !void {
- const writer = file.main.writer();
- const tv = decl.typed_value.most_recent.typed_value;
-
- var arena = std.heap.ArenaAllocator.init(file.base.allocator);
- defer arena.deinit();
- var inst_map = std.AutoHashMap(*Inst, []u8).init(&arena.allocator);
- defer inst_map.deinit();
- var ctx = Context{
- .decl = decl,
- .arena = &arena,
- .inst_map = &inst_map,
- };
- defer {
- file.error_msg = ctx.error_msg;
- ctx.deinit();
- }
-
- try renderFunctionSignature(&ctx, &file.header, writer, decl);
-
- try writer.writeAll(" {");
-
- const func: *Module.Fn = tv.val.cast(Value.Payload.Function).?.func;
- const instructions = func.analysis.success.instructions;
- if (instructions.len > 0) {
- try writer.writeAll("\n");
- for (instructions) |inst| {
- if (switch (inst.tag) {
- .assembly => try genAsm(&ctx, file, inst.castTag(.assembly).?),
- .call => try genCall(&ctx, file, inst.castTag(.call).?),
- .add => try genBinOp(&ctx, file, inst.cast(Inst.BinOp).?, "+"),
- .sub => try genBinOp(&ctx, file, inst.cast(Inst.BinOp).?, "-"),
- .ret => try genRet(&ctx, inst.castTag(.ret).?),
- .retvoid => try genRetVoid(file),
- .arg => try genArg(&ctx),
- .dbg_stmt => try genDbgStmt(&ctx, inst.castTag(.dbg_stmt).?),
- .breakpoint => try genBreak(&ctx, inst.castTag(.breakpoint).?),
- .unreach => try genUnreach(file, inst.castTag(.unreach).?),
- .intcast => try genIntCast(&ctx, file, inst.castTag(.intcast).?),
- else => |e| return ctx.fail(decl.src(), "TODO implement C codegen for {}", .{e}),
- }) |name| {
- try ctx.inst_map.putNoClobber(inst, name);
- }
- }
- }
-
- try writer.writeAll("}\n\n");
-}
-
fn genArg(ctx: *Context) !?[]u8 {
const name = try std.fmt.allocPrint(&ctx.arena.allocator, "arg{}", .{ctx.argdex});
ctx.argdex += 1;
@@ -226,12 +327,24 @@ fn genArg(ctx: *Context) !?[]u8 {
}
fn genRetVoid(file: *C) !?[]u8 {
- try file.main.writer().print(indentation ++ "return;\n", .{});
+ try file.main.writer().print("return;\n", .{});
return null;
}
-fn genRet(ctx: *Context, inst: *Inst.UnOp) !?[]u8 {
- return ctx.fail(ctx.decl.src(), "TODO return", .{});
+fn genRet(ctx: *Context, file: *C, inst: *Inst.UnOp) !?[]u8 {
+ const writer = file.main.writer();
+ try writer.writeAll("return ");
+ try genValue(ctx, writer, inst.operand);
+ try writer.writeAll(";\n");
+ return null;
+}
+
+fn genValue(ctx: *Context, writer: Writer, inst: *Inst) !void {
+ if (inst.value()) |val| {
+ try renderValue(ctx, writer, inst.ty, val);
+ return;
+ }
+ return ctx.fail(ctx.decl.src(), "TODO: C backend: genValue for non-constant value", .{});
}
fn genIntCast(ctx: *Context, file: *C, inst: *Inst.UnOp) !?[]u8 {
@@ -241,7 +354,7 @@ fn genIntCast(ctx: *Context, file: *C, inst: *Inst.UnOp) !?[]u8 {
const writer = file.main.writer();
const name = try ctx.name();
const from = try ctx.resolveInst(inst.operand);
- try writer.writeAll(indentation ++ "const ");
+ try writer.writeAll("const ");
try renderType(ctx, &file.header, writer, inst.base.ty);
try writer.print(" {} = (", .{name});
try renderType(ctx, &file.header, writer, inst.base.ty);
@@ -256,7 +369,7 @@ fn genBinOp(ctx: *Context, file: *C, inst: *Inst.BinOp, comptime operator: []con
const rhs = ctx.resolveInst(inst.rhs);
const writer = file.main.writer();
const name = try ctx.name();
- try writer.writeAll(indentation ++ "const ");
+ try writer.writeAll("const ");
try renderType(ctx, &file.header, writer, inst.base.ty);
try writer.print(" {} = {} " ++ operator ++ " {};\n", .{ name, lhs, rhs });
return name;
@@ -265,41 +378,42 @@ fn genBinOp(ctx: *Context, file: *C, inst: *Inst.BinOp, comptime operator: []con
fn genCall(ctx: *Context, file: *C, inst: *Inst.Call) !?[]u8 {
const writer = file.main.writer();
const header = file.header.buf.writer();
- try writer.writeAll(indentation);
if (inst.func.castTag(.constant)) |func_inst| {
- if (func_inst.val.cast(Value.Payload.Function)) |func_val| {
- const target = func_val.func.owner_decl;
- const target_ty = target.typed_value.most_recent.typed_value.ty;
- const ret_ty = target_ty.fnReturnType().tag();
- if (target_ty.fnReturnType().hasCodeGenBits() and inst.base.isUnused()) {
- try writer.print("(void)", .{});
- }
- const tname = mem.spanZ(target.name);
- if (file.called.get(tname) == null) {
- try file.called.put(tname, void{});
- try renderFunctionSignature(ctx, &file.header, header, target);
- try header.writeAll(";\n");
- }
- try writer.print("{}(", .{tname});
- if (inst.args.len != 0) {
- for (inst.args) |arg, i| {
- if (i > 0) {
- try writer.writeAll(", ");
- }
- if (arg.cast(Inst.Constant)) |con| {
- try renderValue(ctx, writer, arg.ty, con.val);
- } else {
- const val = try ctx.resolveInst(arg);
- try writer.print("{}", .{val});
- }
+ const fn_decl = if (func_inst.val.cast(Value.Payload.ExternFn)) |extern_fn|
+ extern_fn.decl
+ else if (func_inst.val.cast(Value.Payload.Function)) |func_val|
+ func_val.func.owner_decl
+ else
+ unreachable;
+
+ const fn_ty = fn_decl.typed_value.most_recent.typed_value.ty;
+ const ret_ty = fn_ty.fnReturnType().tag();
+ if (fn_ty.fnReturnType().hasCodeGenBits() and inst.base.isUnused()) {
+ try writer.print("(void)", .{});
+ }
+ const fn_name = mem.spanZ(fn_decl.name);
+ if (file.called.get(fn_name) == null) {
+ try file.called.put(fn_name, void{});
+ try renderFunctionSignature(ctx, &file.header, header, fn_decl);
+ try header.writeAll(";\n");
+ }
+ try writer.print("{s}(", .{fn_name});
+ if (inst.args.len != 0) {
+ for (inst.args) |arg, i| {
+ if (i > 0) {
+ try writer.writeAll(", ");
+ }
+ if (arg.cast(Inst.Constant)) |con| {
+ try renderValue(ctx, writer, arg.ty, con.val);
+ } else {
+ const val = try ctx.resolveInst(arg);
+ try writer.print("{}", .{val});
}
}
- try writer.writeAll(");\n");
- } else {
- return ctx.fail(ctx.decl.src(), "TODO non-function call target?", .{});
}
+ try writer.writeAll(");\n");
} else {
- return ctx.fail(ctx.decl.src(), "TODO non-constant call inst?", .{});
+ return ctx.fail(ctx.decl.src(), "TODO: C backend: implement function pointers", .{});
}
return null;
}
@@ -315,13 +429,12 @@ fn genBreak(ctx: *Context, inst: *Inst.NoOp) !?[]u8 {
}
fn genUnreach(file: *C, inst: *Inst.NoOp) !?[]u8 {
- try file.main.writer().writeAll(indentation ++ "zig_unreachable();\n");
+ try file.main.writer().writeAll("zig_unreachable();\n");
return null;
}
fn genAsm(ctx: *Context, file: *C, as: *Inst.Assembly) !?[]u8 {
const writer = file.main.writer();
- try writer.writeAll(indentation);
for (as.inputs) |i, index| {
if (i[0] == '{' and i[i.len - 1] == '}') {
const reg = i[1 .. i.len - 1];
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-28 05:32:09 +0000