In 7e23b3245a9bf6e002009e6c18c10a9995671afa I made -O flags to the
linker emit a warning that the argument does nothing. That was not
correct however; LLD does have some logic that does different things
depending on -O0, -O1, and -O2. It defaults to -O1, and it does less
optimizations with -O0 and more with -O2.
With this commit, e.g. `-Wl,-O1` is supported by the `zig cc` frontend,
and by default we pass `-O0` to LLD in debug mode, and `-O3` in release
modes.
I also fixed a bug in the LLD ELF linker line which was incorrectly
passing `-O` flags instead of `--lto-O` flags for LTO.
* Improve the logic for determining whether emitting an import lib is
eligible, and improve the error message when the user provides
contradictory arguments.
* Integrate with the EmitLoc / Emit system that already exists, and use
the `-femit-implib[=path]`/`-fno-emit-implib` convention that already
exists.
* Proper integration with the caching system.
* CLI: fix bug in error reporting for resolving EmitLoc values for
other parameters.
This mechanism for sending arbitrary linker args to LLD has no place in
the Zig frontend, because our goal is for the frontend to understand all
the arguments and not treat linker args like a black box.
For example we have self-hosted linking in addition to LLD, so we want to
have the options make sense to both linking codepaths, not just the LLD one.
Passing -O linker args will now result in a warning that the arg does
nothing.
We assume we are compiled on a base-2 radix floating point system. This
is a reasonable assumption. musl libc as an example also assumes this.
We implement scalbn as an alias for ldexp, since ldexp is defined as 2
regardless of the float radix. This is opposite to musl which defines
scalbn in terms of ldexp.
Closes#9799.
Handle clang's linker flag `-weak_framework` as a standard framework to
link. This requires further investigation especially to do with weak
imports and how to tie one with the other.
* add support for compiling Objective-C++ code
Prior to this change, calling `step.addCSourceFiles` with Obj-C++ file extensions
(`.mm`) would result in an error due to Zig not being aware of that extension.
Clang supports an `-ObjC++` compilation mode flag, but it was only possible to use
if you violated standards and renamed your `.mm` Obj-C++ files to `.m` (Obj-C) to
workaround Zig being unaware of the extension.
This change makes Zig aware of `.mm` files so they can be compiled, enabling compilation
of projects such as [Google's Dawn WebGPU](https://dawn.googlesource.com/dawn/) using
a `build.zig` file only.
Helps hexops/mach#21
Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
* test/standalone: add ObjC++ compilation/linking test
Based on the existing objc example, just tweaked for ObjC++.
Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
* Introduce a mechanism into Sema for emitting a compile error when an
integer is too big and we need it to fit into a usize.
* Add `@intCast` where necessary
* link/MachO: fix an unnecessary allocation when all that was happening
was appending zeroes to an ArrayList.
* Add `error.Overflow` as a possible error to some codepaths, allowing
usage of `math.intCast`.
closes#9710
Ensure all previous test cases are still passing, as well as add some basic tests for now
for testing pointers to the stack.
This means we can start implementing wasm's C ABI found at: https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md
We also simplified the block logic by always using 'void' block types and instead writing the value to a local,
which can then be referenced by continues instructions, as done currently by AIR.
Besides this, we also no longer need to insert blocks at an offset, as we simply write the saved temporary
after we create the block.
Rather than writing the alignment in its natural form, wasm binaries encode the alignment of types as the exponent of a power of 2.
So rather than performing this encoding during AIR->MIR, we do this while emitting MIR->binary encoding.
This allows us to keep alignment logic to its natural form while doing calculations (Which is what we need during linking as well).
We also implement optionals and pointers to an optional.
This implements basic calling convention resolving. This means that for
types such as an error union, we will now allocate space on the stack to store the result.
This result will then be saved in a temporary local at the callsite.
By calculating the abi size of the struct, we move the stack
pointer and store each field depending on its size (i.e. a 1-byte field will use i32.store8).
This commit adds all required opcodes to perform those stores and loads.
This also gets rid of `mir_offset` as we now save results of binary operations into
locals and emit its result onto the stack within condbr instead. This makes everything a lot
simpler but also more robust.
In the future, we could look into an algorithm to re-use such locals.
For struct fields we use the new `local_with_offset` tag. This stores the struct's
stack pointer as well as the field's offset from that stack pointer.
`allocLocal` will now always allocate a single local, using a given type.
All non-temporary locals will now use stack memory.
When `airAlloc` is called, we create a new local, move the stack pointer,
and write its offset into the local. Arguments act as a register and do not
use any stack space.
We no longer use offsets for binary operations, but instead write the result
into a local. In this case, the local is simply used as a register, and does not
require stack space. This allows us to ensure the order of instructions is correct,
and we no longer require any patching/inserting at a specific offset.
print_air was missing the logic to print the type of a `ty_str`.
The self-hosted wasm linker now emits a mutable global.
This entry represents the stack pointer, which has an initial value of offset table size + data size + stack size.
Stack size can either be set by the user, or has the default of a single wasm page (64KiB).
After this change, the default for dynamic libraries (`-l` or
`--library`) is to only link them if they end up being actually used.
With the Zig CLI, the new options `-needed-l` or `--needed-library` can
be used to force link against a dynamic library.
With `zig cc`, this behavior can be overridden with `-Wl,--no-as-needed`
(and restored with `-Wl,--as-needed`).
Closes#10164
