astgen: update more expression types to new mem layout

additionally introduce a new file to centralize all the data about
builtin functions that we have, including:
 * enum tag identifying the builtin function
 * number of parameters.
 * whether the expression may need a memory location.
 * whether the expression allows an lvalue (currently only true for
   `@field`).
Now there is only one ComptimeStringMap that has this data as the value,
and we dispatch on the enum tag in order to asgen the builtin function.
In particular this simplifies the logic for checking the number of
parameters.

This removes some untested code paths from if and while, which need to
be restored with #7929 in mind.

After this there are only a handful left of expression types to rework
to the new memory layout, and then it will be only compile errors left
to solve.

1 files changed, 841 insertions, 0 deletions

diff --git a/src/BuiltinFn.zig b/src/BuiltinFn.zig
new file mode 100644
index 0000000000..9776edfef3
--- /dev/null
+++ b/src/BuiltinFn.zig
@@ -0,0 +1,841 @@
+const std = @import("std");
+
+pub const Tag = enum {
+    add_with_overflow,
+    align_cast,
+    align_of,
+    as,
+    async_call,
+    atomic_load,
+    atomic_rmw,
+    atomic_store,
+    bit_cast,
+    bit_offset_of,
+    bool_to_int,
+    bit_size_of,
+    breakpoint,
+    mul_add,
+    byte_swap,
+    bit_reverse,
+    byte_offset_of,
+    call,
+    c_define,
+    c_import,
+    c_include,
+    clz,
+    cmpxchg_strong,
+    cmpxchg_weak,
+    compile_error,
+    compile_log,
+    ctz,
+    c_undef,
+    div_exact,
+    div_floor,
+    div_trunc,
+    embed_file,
+    enum_to_int,
+    error_name,
+    error_return_trace,
+    error_to_int,
+    err_set_cast,
+    @"export",
+    fence,
+    field,
+    field_parent_ptr,
+    float_cast,
+    float_to_int,
+    frame,
+    Frame,
+    frame_address,
+    frame_size,
+    has_decl,
+    has_field,
+    import,
+    int_cast,
+    int_to_enum,
+    int_to_error,
+    int_to_float,
+    int_to_ptr,
+    memcpy,
+    memset,
+    wasm_memory_size,
+    wasm_memory_grow,
+    mod,
+    mul_with_overflow,
+    panic,
+    pop_count,
+    ptr_cast,
+    ptr_to_int,
+    rem,
+    return_address,
+    set_align_stack,
+    set_cold,
+    set_eval_branch_quota,
+    set_float_mode,
+    set_runtime_safety,
+    shl_exact,
+    shl_with_overflow,
+    shr_exact,
+    shuffle,
+    size_of,
+    splat,
+    reduce,
+    src,
+    sqrt,
+    sin,
+    cos,
+    exp,
+    exp2,
+    log,
+    log2,
+    log10,
+    fabs,
+    floor,
+    ceil,
+    trunc,
+    round,
+    sub_with_overflow,
+    tag_name,
+    This,
+    truncate,
+    Type,
+    type_info,
+    type_name,
+    TypeOf,
+    union_init,
+};
+
+tag: Tag,
+
+/// `true` if the builtin call can take advantage of a result location pointer.
+needs_mem_loc: bool = false,
+/// `true` if the builtin call can be the left-hand side of an expression (assigned to).
+allows_lvalue: bool = false,
+/// The number of parameters to this builtin function. `null` means variable number
+/// of parameters.
+param_count: ?u8,
+
+pub const list = std.ComptimeStringMap(@This(), .{
+    .{
+        "@addWithOverflow",
+        .{
+            .tag = .add_with_overflow,
+            .param_count = 4,
+        },
+    },
+    .{
+        "@alignCast",
+        .{
+            .tag = align_cast,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@alignOf",
+        .{
+            .tag = .align_of,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@as",
+        .{
+            .tag = .as,
+            .needs_mem_loc = true,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@asyncCall",
+        .{
+            .tag = .async_call,
+            .param_count = null,
+        },
+    },
+    .{
+        "@atomicLoad",
+        .{
+            .tag = .atomic_load,
+            .param_count = 3,
+        },
+    },
+    .{
+        "@atomicRmw",
+        .{
+            .tag = .atomic_rmw,
+            .param_count = 5,
+        },
+    },
+    .{
+        "@atomicStore",
+        .{
+            .tag = .atomic_store,
+            .param_count = 4,
+        },
+    },
+    .{
+        "@bitCast",
+        .{
+            .tag = .bit_cast,
+            .needs_mem_loc = true,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@bitOffsetOf",
+        .{
+            .tag = .bit_offset_of,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@boolToInt",
+        .{
+            .tag = .bool_to_int,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@bitSizeOf",
+        .{
+            .tag = .bit_size_of,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@breakpoint",
+        .{
+            .tag = .breakpoint,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@mulAdd",
+        .{
+            .tag = .mul_add,
+            .param_count = 4,
+        },
+    },
+    .{
+        "@byteSwap",
+        .{
+            .tag = .byte_swap,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@bitReverse",
+        .{
+            .tag = .bit_reverse,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@byteOffsetOf",
+        .{
+            .tag = .byte_offset_of,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@call",
+        .{
+            .tag = .call,
+            .needs_mem_loc = true,
+            .param_count = 3,
+        },
+    },
+    .{
+        "@cDefine",
+        .{
+            .tag = .c_define,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@cImport",
+        .{
+            .tag = .c_import,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@cInclude",
+        .{
+            .tag = .c_include,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@clz",
+        .{
+            .tag = .clz,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@cmpxchgStrong",
+        .{
+            .tag = .cmpxchg_strong,
+            .param_count = 6,
+        },
+    },
+    .{
+        "@cmpxchgWeak",
+        .{
+            .tag = .cmpxchg_weak,
+            .param_count = 6,
+        },
+    },
+    .{
+        "@compileError",
+        .{
+            .tag = .compile_error,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@compileLog",
+        .{
+            .tag = .compile_log,
+            .param_count = null,
+        },
+    },
+    .{
+        "@ctz",
+        .{
+            .tag = .ctz,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@cUndef",
+        .{
+            .tag = .c_undef,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@divExact",
+        .{
+            .tag = .div_exact,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@divFloor",
+        .{
+            .tag = .div_floor,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@divTrunc",
+        .{
+            .tag = .div_trunc,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@embedFile",
+        .{
+            .tag = .embed_file,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@enumToInt",
+        .{
+            .tag = .enum_to_int,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@errorName",
+        .{
+            .tag = .error_name,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@errorReturnTrace",
+        .{
+            .tag = .error_return_trace,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@errorToInt",
+        .{
+            .tag = .error_to_int,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@errSetCast",
+        .{
+            .tag = .err_set_cast,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@export",
+        .{
+            .tag = .@"export",
+            .param_count = 2,
+        },
+    },
+    .{
+        "@fence",
+        .{
+            .tag = .fence,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@field",
+        .{
+            .tag = .field,
+            .needs_mem_loc = true,
+            .param_count = 2,
+            .allows_lvalue = true,
+        },
+    },
+    .{
+        "@fieldParentPtr",
+        .{
+            .tag = .field_parent_ptr,
+            .param_count = 3,
+        },
+    },
+    .{
+        "@floatCast",
+        .{
+            .tag = .float_cast,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@floatToInt",
+        .{
+            .tag = .float_to_int,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@frame",
+        .{
+            .tag = .frame,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@Frame",
+        .{
+            .tag = .Frame,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@frameAddress",
+        .{
+            .tag = .frame_address,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@frameSize",
+        .{
+            .tag = .frame_size,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@hasDecl",
+        .{
+            .tag = .has_decl,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@hasField",
+        .{
+            .tag = .has_field,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@import",
+        .{
+            .tag = .import,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@intCast",
+        .{
+            .tag = .int_cast,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@intToEnum",
+        .{
+            .tag = .int_to_enum,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@intToError",
+        .{
+            .tag = .int_to_error,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@intToFloat",
+        .{
+            .tag = .int_to_float,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@intToPtr",
+        .{
+            .tag = .int_to_ptr,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@memcpy",
+        .{
+            .tag = .memcpy,
+            .param_count = 3,
+        },
+    },
+    .{
+        "@memset",
+        .{
+            .tag = .memset,
+            .param_count = 3,
+        },
+    },
+    .{
+        "@wasmMemorySize",
+        .{
+            .tag = .wasm_memory_size,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@wasmMemoryGrow",
+        .{
+            .tag = .wasm_memory_grow,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@mod",
+        .{
+            .tag = .mod,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@mulWithOverflow",
+        .{
+            .tag = .mul_with_overflow,
+            .param_count = 4,
+        },
+    },
+    .{
+        "@panic",
+        .{
+            .tag = .panic,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@popCount",
+        .{
+            .tag = .pop_count,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@ptrCast",
+        .{
+            .tag = .ptr_cast,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@ptrToInt",
+        .{
+            .tag = .ptr_to_int,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@rem",
+        .{
+            .tag = .rem,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@returnAddress",
+        .{
+            .tag = .return_address,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@setAlignStack",
+        .{
+            .tag = .set_align_stack,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@setCold",
+        .{
+            .tag = .set_cold,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@setEvalBranchQuota",
+        .{
+            .tag = .set_eval_branch_quota,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@setFloatMode",
+        .{
+            .tag = .set_float_mode,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@setRuntimeSafety",
+        .{
+            .tag = .set_runtime_safety,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@shlExact",
+        .{
+            .tag = .shl_exact,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@shlWithOverflow",
+        .{
+            .tag = .shl_with_overflow,
+            .param_count = 4,
+        },
+    },
+    .{
+        "@shrExact",
+        .{
+            .tag = .shr_exact,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@shuffle",
+        .{
+            .tag = .shuffle,
+            .param_count = 4,
+        },
+    },
+    .{
+        "@sizeOf",
+        .{
+            .tag = .size_of,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@splat",
+        .{
+            .tag = .splat,
+            .needs_mem_loc = true,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@reduce",
+        .{
+            .tag = .reduce,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@src",
+        .{
+            .tag = .src,
+            .needs_mem_loc = true,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@sqrt",
+        .{
+            .tag = .sqrt,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@sin",
+        .{
+            .tag = .sin,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@cos",
+        .{
+            .tag = .cos,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@exp",
+        .{
+            .tag = .exp,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@exp2",
+        .{
+            .tag = .exp2,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@log",
+        .{
+            .tag = .log,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@log2",
+        .{
+            .tag = .log2,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@log10",
+        .{
+            .tag = .log10,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@fabs",
+        .{
+            .tag = .fabs,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@floor",
+        .{
+            .tag = .floor,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@ceil",
+        .{
+            .tag = .ceil,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@trunc",
+        .{
+            .tag = .trunc,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@round",
+        .{
+            .tag = .round,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@subWithOverflow",
+        .{
+            .tag = .sub_with_overflow,
+            .param_count = 4,
+        },
+    },
+    .{
+        "@tagName",
+        .{
+            .tag = .tag_name,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@This",
+        .{
+            .tag = .This,
+            .param_count = 0,
+        },
+    },
+    .{
+        "@truncate",
+        .{
+            .tag = .truncate,
+            .param_count = 2,
+        },
+    },
+    .{
+        "@Type",
+        .{
+            .tag = .Type,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@typeInfo",
+        .{
+            .tag = .type_info,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@typeName",
+        .{
+            .tag = .type_name,
+            .param_count = 1,
+        },
+    },
+    .{
+        "@TypeOf",
+        .{
+            .tag = .TypeOf,
+            .param_count = null,
+        },
+    },
+    .{
+        "@unionInit",
+        .{
+            .tag = .union_init,
+            .needs_mem_loc = true,
+            .param_count = 3,
+        },
+    },
+});