Since we are already detecting the path to the native SDK,
if available, also fetch SDK's version and route that to the linker.
The linker can then use it to correctly populate LC_BUILD_VERSION
load command.
Due to a deficiency in LLD, we need to special-case BPF to a simple
file copy when generating relocatables. Normally, we would expect
`lld -r` to work. However, because LLD wants to resolve BPF relocations
which it shouldn't, it fails before even generating the relocatable.
Co-authored-by: Matthew Knight <mattnite@protonmail.com>
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.
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.
* 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
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
Previously, we have confused callee-saved with caller-saved registers
(the actual register sets were swapped). This commit fixes that
for both `.x86` and `.x86_64` native backends.
This commit also fixes the register allocation logic in `genBinMathOp`
for `.x86_64` native backend where in a situation such that we require
to spill a register, we would end up spilling the register that is
already involved in the instruction as the other operand. In such a
case, we make a note of this and spill a subsequent register instead.
* wasm: Move wasm's codegen to arch/wasm/CodeGen.zig
* wasm: Define Wasm's Mir
This declares the initial most-used instructions for wasm as
well as the data that represents them.
TODO: Add binary operand opcodes.
By re-using the wasm opcode values, we can emit each opcode very easily
by simply using `@enumToInt()`. However, this poses a possible problem:
If we use all of wasm's opcodes, it leaves us no room to use synthetic opcodes such as debugging instructions.
We could use reserved opcodes, but the wasm spec may use them at some point.
TODO: Check if we should perhaps use a 16bit tag where the highest bits are used for synthetic opcodes.
* wasm: Define basic Emit structure
* wasm: Implement corresponding Emit functions for MIR
* wasm: Initial lowering to MIR
- This implements lowering to MIR from AIR for storing and loading of locals
as well as emitting immediates.
- Relocating function indexes has been simplified a lot as well as we no
longer need to patch offsets and we write a relocatable value instead.
- Locals are now emitted at the beginning of the function section entry
meaning all offsets we generate are stable.
* wasm: Lower all AIR instructions to MIR
* wasm: Implement remaining MIR instructions
* wasm: Fix function relocations
* wasm: Get all tests working
* wasm: Make `Data` 4 bytes instead of 8.
- 64bit immediates are now stored in 2 seperate u32's.
- 64bit floats are now stored in 2 seperate u32's.
- `mem_arg` is now stored as a seperate payload in extra.
1. Changed Zig pointers to functions to be typedef'd so then we can
treat them the same as other types.
2. Distinguished between const slices (zig_L prefix) and mut slices
(zig_M prefix).
3. Changed lowering of Zig "const pointers" (e.g. *const u8) to to C
"pointers to const" (e.g. const char *) rather than C "const
pointers" (e.g. char * const)
4. Ensured that all typedefs are "linked" even if the decl doesn't
require any forward declarations
5. Added test that exercises function pointer type rendering
6. Changed .slice_ptr instruction to allocate pointer local rather than
a uintptr_t local
This effectively allows us to compile
```zig
pub fn main() void {}
```
which then calls into `std.start`.
Changes required to make this happen:
* handle signed int to immediate in x86_64 and aarch64 codegen
* ensure that on arm64 macOS, `.x19` is a caller-preserved register -
I'm not sure about that one at all and would like to brainstorm it
with anyone interested and especially Joachim.
* finally, fix a bug in the linker - mark new got entry as dirty upon
atom growth.
--import-memory import memory from the environment
--initial-memory=[bytes] initial size of the linear memory
--max-memory=[bytes] maximum size of the linear memory
--global-base=[addr] where to start to place global data
See #8633
Because ArrayList.initCapacity uses 'precise' capacity allocation, this should save memory on average, and definitely will save memory in cases where ArrayList is used where a regular allocated slice could have also be used.
If these functions are called more than once, then the array list would no longer be guaranteed to have enough capacity during the appendAssumeCapacity calls. With ensureUnusedCapacity, they will always be guaranteed to have enough capacity regardless of how many times the function is called.
These calls are all late-initialization of ArrayList's that were initialized outside the current scope. This allows us to still get the potential memory-saving benefits of the 'precision' of initCapacity.
Add an option to allow the '-z notext' option to be passed to the linker
via. the compiler frontend, which is a flag that tells the linker that
relocations in read-only sections are permitted. Certain targets such as
Solana BPF rely on this flag.
Expose all linker options i.e. '-z nodelete', '-z now', '-z relro' in
the compiler frontend. Usage documentation has been updated accordingly.
Expose the '-z notext' flag in the standard library build runner.
The ensureUnusedCapacity did not reserve a big enough number. I changed
it to no longer guess the capacity because I saw that the number of
possible items was not determinable ahead of time and this can therefore
avoid allocating more memory than necessary.
The C backend is the only backend that requires each decl to be output
in an order that satisfies the dependency graph. Here it is implemented
with a simple algorithm based on a `remaining_decls` set, using the
`dependencies` edges that are already stored for each Decl.
This satisfies incremental compilation as well as how `zig test` works,
which calls `updateDecl` on `test_functions`.
* without this, when an included relocatable references a common symbol
from another translation unit would not be correctly removed from
the unresolved lookup table triggering a misleading assertion down
the line
* assert upon removal that we indeed removed a ref instead of silently
ignoring in debug
* add test case that covers this issue
Each element of the output JSON has the VM address of the generated
binary nondecreasing (some elements might occupy the same VM address
for example the atom and the relocation might coincide in the address
space).
The generated JSON can be inspected manually or via a preview tool
`zig-snapshots` that I am currently working on and will allow the user
to inspect interactively the state of the linker together with the
positioning of sections, symbols, atoms and relocations within each
snapshot state, and in the future, between snapshots too. This should
allow for quicker debugging of the linker which is nontrivial when
run in the incremental mode.
Note that the state will only be dumped if the compiler is built with
`-Dlink-snapshot` flag on, and then the compiler is passed `--debug-link-snapshot`
flag upon compiling a source/project.
* do not add linkage scope to aliased exported symbols - this is
not respected on macOS
* special-case `MachO.openPath` in `link.File.openPath` as on macOS
we always link with zld
* redirect to `MachO.flushObject` when linking relocatable objects
in MachO linker whereas move the entire linking logic into
`MachO.flushModule`
* apply late symbol resolution for globals - instead of resolving
the exact location of a symbol in locals, globals or undefs,
we postpone the exact resolution until we have a full picture
for relocation resolution.
* fixup stubs to defined symbols - this is currently a hack rather
than a final solution. I'll need to work out the details to make
it more approachable. Currently, we preemptively create a stub
for a lazy bound global and fix up stub offsets in stub helper
routine if the global turns out to be undefined only. This is quite
wasteful in terms of space as we create stub, stub helper and lazy ptr
atoms but don't use them for defined globals.
* change log scope to .link for macho.
* remove redundant code paths from Object and Atom.
* drastically simplify the contents of Relocation struct (i.e., it is
now a simple superset of macho.relocation_info), clean up relocation
parsing and resolution logic.
There was duplicated logic for whether to include compiler_rt in the
linker line both in the frontend and in the linker backends. Now the
logic is only in the frontend; the linker puts it on the linker line if
the frontend provides it.
Fixes the CI failures.
* AstGen: fix emitting `store_to_inferred_ptr` when it should be emitting
`store` for a variable that has an explicit alignment.
* Compilation: fix a couple memory leaks
* Sema: implement support for locals that have specified alignment.
* Sema: implement `@intCast` when it needs to emit an AIR instruction.
* Sema: implement `@alignOf`
* Implement debug printing for extended alloc ZIR instructions.
* Remove the builtins `@addWithSaturation`, `@subWithSaturation`,
`@mulWithSaturation`, and `@shlWithSaturation` now that we have
first-class syntax for saturating arithmetic.
* langref: Clarify the behavior of `@shlExact`.
* Ast: rename `bit_shift_left` to `shl` and `bit_shift_right` to `shr`
for consistency.
* Air: rename to include underscore separator with consistency with
the rest of the ops.
* Air: add shl_exact instruction
* Use non-extended tags for saturating arithmetic, to keep it
simple so that all the arithmetic operations can be done the same
way.
- Sema: unify analyzeArithmetic with analyzeSatArithmetic
- implement comptime `+|`, `-|`, and `*|`
- allow float operands to saturating arithmetic
* `<<|` allows any integer type for the RHS.
* C backend: fix rebase conflicts
* LLVM backend: reduce the amount of branching for arithmetic ops
* zig.h: fix magic number not matching actual size of C integer types
