Make distinct error limit configurable

[Vexu]

I chose to use a CLI argument instead of a const in the root file since changing it would invalidate most functions in an incremental compilation.

Closes #786

[andrewrk]

I chose to use a CLI argument instead of a const in the root file since changing it would invalidate most functions in an incremental compilation.

Changing it on the CLI creates an entirely separate cache namespace, so it's essentially the same thing. I don't think it should be a CLI argument.

[Vexu]

Making it a const in the root file (or more likely in builtin.zig) requires it to be the first thing analyzed every update and that anything that touches errors depend on that one declaration even when most of the time it would be uncommon to change it while working on something. And unlike the other declarations that can be overwritten there this would change how the language itself worked.

[andrewrk]

OK, I think you make a fair argument. Let's do the CLI flag then 👍

[andrewrk]

Reverted in 328ec15 due to:

$ grep -IR Type.err_int ../src/
../src/codegen.zig:                        .ty = Type.err_int,
../src/codegen.zig:                        .val = try mod.intValue(Type.err_int, 0),
../src/codegen/llvm.zig:        const rhs = try o.builder.intValue(Builder.Type.err_int, errors_len);
../src/codegen/llvm.zig:            .anyerror_type => Builder.Type.err_int,
../src/codegen/llvm.zig:            => Builder.Type.err_int,
../src/codegen/llvm.zig:                    const error_type = Builder.Type.err_int;
../src/codegen/llvm.zig:                    const error_align = Type.err_int.abiAlignment(mod);
../src/codegen/llvm.zig:                    const error_size = Type.err_int.abiSize(mod);
../src/codegen/llvm.zig:                .error_set_type, .inferred_error_set_type => Builder.Type.err_int,
../src/codegen/llvm.zig:                const llvm_int = try o.builder.intConst(Builder.Type.err_int, int);
../src/codegen/llvm.zig:                    .payload => (try mod.intValue(Type.err_int, 0)).toIntern(),
../src/codegen/llvm.zig:                const error_align = Type.err_int.abiAlignment(mod);
../src/codegen/llvm.zig:                const err_align = Type.err_int.abiAlignment(mod);
../src/codegen/llvm.zig:                _ = try self.wip.ret(try o.builder.intValue(Builder.Type.err_int, 0));
../src/codegen/llvm.zig:                _ = try self.wip.ret(try o.builder.intValue(Builder.Type.err_int, 0));
../src/codegen/llvm.zig:                        try fg.wip.load(.normal, Builder.Type.err_int, err_union, .default, "")
../src/codegen/llvm.zig:                        Builder.Type.err_int,
../src/codegen/llvm.zig:            const zero = try o.builder.intValue(Builder.Type.err_int, 0);
../src/codegen/llvm.zig:        const zero = try o.builder.intValue(Builder.Type.err_int, 0);
../src/codegen/llvm.zig:            break :loaded try self.wip.load(.normal, Builder.Type.err_int, err_field_ptr, .default, "");
../src/codegen/llvm.zig:                return o.builder.intValue(Builder.Type.err_int, 0);
../src/codegen/llvm.zig:            return self.wip.load(.normal, Builder.Type.err_int, operand, .default, "");
../src/codegen/llvm.zig:            return self.wip.load(.normal, Builder.Type.err_int, err_field_ptr, .default, "");
../src/codegen/llvm.zig:        const non_error_val = try o.builder.intValue(Builder.Type.err_int, 0);
../src/codegen/llvm.zig:            const error_alignment = Type.err_int.abiAlignment(mod).toLlvm();
../src/codegen/llvm.zig:        const ok_err_code = try o.builder.intValue(Builder.Type.err_int, 0);
../src/codegen/llvm.zig:            const error_alignment = Type.err_int.abiAlignment(mod).toLlvm();
../src/codegen/llvm.zig:            const error_alignment = Type.err_int.abiAlignment(mod).toLlvm();
../src/codegen/llvm.zig:            const this_tag_int_value = try o.builder.intConst(Builder.Type.err_int, err_int);
../src/codegen/llvm.zig:            try o.builder.fnType(.i1, &.{Builder.Type.err_int}, .normal),
../src/codegen/llvm.zig:        return if (return_type.isError(mod)) Builder.Type.err_int else .void;
../src/codegen/llvm.zig:    return @intFromBool(Type.err_int.abiAlignment(mod).compare(.gt, payload_ty.abiAlignment(mod)));
../src/codegen/llvm.zig:    return @intFromBool(Type.err_int.abiAlignment(mod).compare(.lte, payload_ty.abiAlignment(mod)));
../src/codegen/c.zig:                            Type.err_int,
../src/codegen/c.zig:                            try mod.intValue(Type.err_int, 0),
../src/codegen/c.zig:                        Type.err_int,
../src/codegen/c.zig:                        try mod.intValue(Type.err_int, 0),
../src/codegen/c.zig:                            .ErrorSet => try mod.intValue(Type.err_int, 0),
../src/codegen/c.zig:        TypedValue{ .ty = Type.err_int, .val = try mod.intValue(Type.err_int, 0) }
../src/codegen/c.zig:            try f.object.dg.renderValue(writer, Type.err_int, try mod.intValue(Type.err_int, 0), .Initializer);
../src/codegen/c.zig:        try f.object.dg.renderValue(writer, Type.err_int, try mod.intValue(Type.err_int, 0), .Other);
../src/codegen/c.zig:    try f.object.dg.renderValue(writer, Type.err_int, try mod.intValue(Type.err_int, 0), .Other);
../src/codegen/c.zig:        try f.object.dg.renderValue(writer, Type.err_int, try mod.intValue(Type.err_int, 0), .Other);
../src/codegen/c.zig:        try f.object.dg.renderValue(writer, Type.err_int, try mod.intValue(Type.err_int, 0), .Other);
../src/codegen/c.zig:    try f.object.dg.renderValue(writer, Type.err_int, try mod.intValue(Type.err_int, 0), .Other);
../src/codegen/spirv.zig:                    .payload => Type.err_int,
../src/codegen/spirv.zig:                    .payload => try mod.intValue(Type.err_int, 0),
../src/arch/wasm/CodeGen.zig:                    .ty = Type.err_int,
../src/arch/wasm/CodeGen.zig:                    .val = try mod.intValue(Type.err_int, 0),
../src/arch/wasm/CodeGen.zig:    const errors_len_val = try func.load(errors_len, Type.err_int, 0);
../src/arch/wasm/CodeGen.zig:    const result = try func.cmp(.stack, errors_len_val, Type.err_int, .lt);
../src/Sema.zig:            return mod.undefRef(Type.err_int);
../src/Sema.zig:            Type.err_int,
../src/Sema.zig:                0 => return Air.internedToRef((try mod.intValue(Type.err_int, 0)).toIntern()),
../src/Sema.zig:                    return mod.intRef(Type.err_int, int);
../src/Sema.zig:    return block.addBitCast(Type.err_int, operand);
../src/Sema.zig:    const operand = try sema.coerce(block, Type.err_int, uncasted_operand, operand_src);
../src/Sema.zig:        const zero_val = Air.internedToRef((try mod.intValue(Type.err_int, 0)).toIntern());
../src/Sema.zig:            const err_int = try block.addBitCast(Type.err_int, err_code);
../src/Sema.zig:            const err_int_inst = try block.addBitCast(Type.err_int, operand);