This commit updates `<Builder as AsmBuilderMethods>::codegen_inline_asm`
to convert `sym` operands into `"X" (&func_or_static)` input operands
to indicate the dependency on the referenced symbols and prevent them
from being eliminated.
We follow the suit of the LLVM codegen with a mixture of its differing
techniques for `asm!` and `global_asm!`. The codegen module generates
input operands for the `sym` operands (as in `asm!` in cg_llvm).
However, the codegen module replaces all placeholders with mangled
symbol names before passing the assembly template string to the backend
(as in `global_asm!` in cg_llvm), which means these input operands are
never referenced in the final assembly template string.
Unlike the LLVM codegen, the input operand constraint must be `X`
instead of `s`. If the `s` constraint is used, GCC will employ checks to
make sure that the operand can really be represented by a simple
symbolic constant, thus rejecting symbols requiring GOT, etc. to
resolve. Such checks are unnecessary for Rust `sym` as it's up to
programmers to handle such complex cases, e.g., by manually appending
GOT addressing modifiers to the substituted symbol names.
Using the `X` constraint doesn't seem to generate any extra code, so
this will not compromise the property of naked functions.
Updates their unsigned code paths to use the `Builder::gcc_` methods
that automatically lower non-native integer operations to native ones.
Also updates the signed code path of `saturating_add` to support non-
native integer types. That of `saturating_sub` already supports this,
so no major changes have been made.
This was a workaround for compiling proc macros resulting in an abi
incompatibility. By passing --target proc macros will be built by the
llvm backend. This is no longer necessary as the abi incompatibility has
since been fixed.
Implement -Z oom=panic
This PR removes the `#[rustc_allocator_nounwind]` attribute on `alloc_error_handler` which allows it to unwind with a panic instead of always aborting. This is then used to implement `-Z oom=panic` as per RFC 2116 (tracking issue #43596).
Perf and binary size tests show negligible impact.
This commit makes `AdtDef` use `Interned`. Much the commit is tedious
changes to introduce getter functions. The interesting changes are in
`compiler/rustc_middle/src/ty/adt.rs`.
