(https://github.com/ruby/fiddle/pull/123)
This commit adds two new methods, `Fiddle::Pointer.read` and
`Fiddle::Pointer.write`. Both methods take an address, and will read or
write bytes at that address respectively.
For example we can read from an address without making a Pointer object:
```ruby
Fiddle::Pointer.read(address, 5) # read 5 bytes
```
We can also write to an address without allocating a Pointer object:
```ruby
Fiddle::Pointer.write(address, "bytes") # write 5 bytes
```
This allows us to read / write memory at arbitrary addresses without
instantiating a new `Fiddle::Pointer` object.
Examples where this API would be useful
[1](f03481d28b/lib/tenderjit/fiddle_hacks.rb (L26-L28))
[2](77c8daa2d4/lib/ruby_vm/rjit/c_pointer.rb (L193))
[3](77c8daa2d4/lib/ruby_vm/rjit/c_pointer.rb (L284))
I also added a writer method for the same reasons as the reader.
---------
04238cefed
Co-authored-by: Sutou Kouhei <kou@clear-code.com>
I would like to check if a symbol is defined before trying to access it.
Some symbols aren't available on all platforms, so instead of raising an
exception, I want to check if it's defined first.
Today we have to do:
```ruby
begin
addr = Fiddle::Handle.sym("something")
# do something
rescue Fiddle::DLError
end
```
I want to write this:
```ruby
if Fiddle::Handle.sym_defined?("something")
addr = Fiddle::Handle.sym("something")
# do something
end
```
9d3371de13
Co-authored-by: Sutou Kouhei <kou@clear-code.com>
This helps to reduce repetition in code. Instead of doing "TYPE_*"
everywhere, you can do `include Fiddle::Types`, and write the type name
directly.
This PR is to help reduce repetition when writing Fiddle code. Right now
we have to type `TYPE_` everywhere, and you also have to include all of
`Fiddle` to access `TYPE_*` constants. With this change, you can just
include `Fiddle::Types` and it will shorten your code and also you only
have to include those constants.
Here is an example before:
```ruby
require "fiddle"
module MMAP
# All Fiddle constants included
include Fiddle
def self.make_function name, args, ret
ptr = Handle::DEFAULT[name]
func = Function.new ptr, args, ret, name: name
define_singleton_method name, &func.to_proc
end
make_function "munmap", [TYPE_VOIDP, # addr
TYPE_SIZE_T], # len
TYPE_INT
make_function "mmap", [TYPE_VOIDP,
TYPE_SIZE_T,
TYPE_INT,
TYPE_INT,
TYPE_INT,
TYPE_INT], TYPE_VOIDP
make_function "mprotect", [TYPE_VOIDP, TYPE_SIZE_T, TYPE_INT], TYPE_INT
end
```
After:
```ruby
require "fiddle"
module MMAP
# Only type names included
include Fiddle::Types
def self.make_function name, args, ret
ptr = Fiddle::Handle::DEFAULT[name]
func = Fiddle::Function.new ptr, args, ret, name: name
define_singleton_method name, &func.to_proc
end
make_function "munmap", [VOIDP, # addr
SIZE_T], # len
INT
make_function "mmap", [VOIDP, SIZE_T, INT, INT, INT, INT], VOIDP
make_function "mprotect", [VOIDP, SIZE_T, INT], INT
end
```
We only need to import the type names, and you don't have to type
`TYPE_` over and over. I think this makes Fiddle code easier to read.
49fa7233e5
Co-authored-by: Sutou Kouhei <kou@clear-code.com>
This commit adds constants for unsigned values. Currently we can use `-`
to mean "unsigned", but I think having a specific name makes Fiddle more
user friendly. This commit continues to support `-`, but introduces
negative constants with "unsigned" names
I think this will help to eliminate [this
code](3a56bf0bcc/lib/mjit/c_type.rb (L31-L38))
2bef0f1082
Co-authored-by: Sutou Kouhei <kou@clear-code.com>
* Add "offsetof" to Struct classes
I need to get the offset of a member inside a struct without allocating
the struct. This patch adds an "offsetof" class method to structs that
are generated.
The usage is like this:
```ruby
MyStruct = struct [
"int64_t i",
"char c",
]
MyStruct.offsetof("i") # => 0
MyStruct.offsetof("c") # => 8
```
* Update test/fiddle/test_c_struct_builder.rb
Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
4e3b60c5b6
Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
This lets us cast a Fiddle::Function to a block, allowing is to write
things like:
```ruby
f = Fiddle::Function.new(@libc['strcpy'], [TYPE_VOIDP, TYPE_VOIDP], TYPE_VOIDP)
define_method :strcpy, &f
```
I don't use tool/sync_default_gem.rb because the last sync was incomplete.
Co-authored-by: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
Co-authored-by: sinisterchipmunk <sinisterchipmunk@gmail.com>
Co-authored-by: Sutou Kouhei <kou@clear-code.com>
This reverts commit bd47a8d660.
`libc_so` and `libm_so` are `nil` at line 124 because Big Sur doesn't have `/usr/lib/libSystem.B.dylib`.
The reassignment at line 127 is necessary in this case.
