use rustc_hir::LangItem;
use rustc_middle::query::TyCtxtAt;
use rustc_middle::ty::layout::LayoutOf;
use rustc_middle::ty::{self, Mutability};
use rustc_middle::{bug, mir};
use rustc_span::symbol::Symbol;
use tracing::trace;
use crate::const_eval::{mk_eval_cx_to_read_const_val, CanAccessMutGlobal, CompileTimeInterpCx};
use crate::interpret::*;
fn alloc_caller_location<'tcx>(
ecx: &mut CompileTimeInterpCx<'tcx>,
filename: Symbol,
line: u32,
col: u32,
) -> MPlaceTy<'tcx> {
let loc_details = ecx.tcx.sess.opts.unstable_opts.location_detail;
let file = if loc_details.file {
ecx.allocate_str(filename.as_str(), MemoryKind::CallerLocation, Mutability::Not).unwrap()
} else {
ecx.allocate_str("<redacted>", MemoryKind::CallerLocation, Mutability::Not).unwrap()
};
let file = file.map_provenance(CtfeProvenance::as_immutable);
let line = if loc_details.line { Scalar::from_u32(line) } else { Scalar::from_u32(0) };
let col = if loc_details.column { Scalar::from_u32(col) } else { Scalar::from_u32(0) };
let loc_ty = ecx
.tcx
.type_of(ecx.tcx.require_lang_item(LangItem::PanicLocation, None))
.instantiate(*ecx.tcx, ecx.tcx.mk_args(&[ecx.tcx.lifetimes.re_erased.into()]));
let loc_layout = ecx.layout_of(loc_ty).unwrap();
let location = ecx.allocate(loc_layout, MemoryKind::CallerLocation).unwrap();
ecx.write_immediate(file.to_ref(ecx), &ecx.project_field(&location, 0).unwrap())
.expect("writing to memory we just allocated cannot fail");
ecx.write_scalar(line, &ecx.project_field(&location, 1).unwrap())
.expect("writing to memory we just allocated cannot fail");
ecx.write_scalar(col, &ecx.project_field(&location, 2).unwrap())
.expect("writing to memory we just allocated cannot fail");
location
}
pub(crate) fn const_caller_location_provider(
tcx: TyCtxtAt<'_>,
file: Symbol,
line: u32,
col: u32,
) -> mir::ConstValue<'_> {
trace!("const_caller_location: {}:{}:{}", file, line, col);
let mut ecx = mk_eval_cx_to_read_const_val(
tcx.tcx,
tcx.span,
ty::ParamEnv::reveal_all(),
CanAccessMutGlobal::No,
);
let loc_place = alloc_caller_location(&mut ecx, file, line, col);
if intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &loc_place).is_err() {
bug!("intern_const_alloc_recursive should not error in this case")
}
mir::ConstValue::Scalar(Scalar::from_maybe_pointer(loc_place.ptr(), &tcx))
}