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use crate::llvm;
use crate::abi::Abi;
use crate::builder::Builder;
use crate::common::CodegenCx;
use libc::c_uint;
use llvm::coverageinfo::CounterMappingRegion;
use rustc_codegen_ssa::coverageinfo::map::{CounterExpression, FunctionCoverage};
use rustc_codegen_ssa::traits::{
BaseTypeMethods, BuilderMethods, ConstMethods, CoverageInfoBuilderMethods, CoverageInfoMethods,
MiscMethods, StaticMethods,
};
use rustc_data_structures::fx::FxHashMap;
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
use rustc_llvm::RustString;
use rustc_middle::bug;
use rustc_middle::mir::coverage::{
CodeRegion, CounterValueReference, ExpressionOperandId, InjectedExpressionId, Op,
};
use rustc_middle::ty;
use rustc_middle::ty::layout::FnAbiOf;
use rustc_middle::ty::subst::InternalSubsts;
use rustc_middle::ty::Instance;
use std::cell::RefCell;
use std::ffi::CString;
use std::iter;
pub mod mapgen;
const UNUSED_FUNCTION_COUNTER_ID: CounterValueReference = CounterValueReference::START;
const VAR_ALIGN_BYTES: usize = 8;
pub struct CrateCoverageContext<'ll, 'tcx> {
pub(crate) function_coverage_map: RefCell<FxHashMap<Instance<'tcx>, FunctionCoverage<'tcx>>>,
pub(crate) pgo_func_name_var_map: RefCell<FxHashMap<Instance<'tcx>, &'ll llvm::Value>>,
}
impl<'ll, 'tcx> CrateCoverageContext<'ll, 'tcx> {
pub fn new() -> Self {
Self {
function_coverage_map: Default::default(),
pgo_func_name_var_map: Default::default(),
}
}
pub fn take_function_coverage_map(&self) -> FxHashMap<Instance<'tcx>, FunctionCoverage<'tcx>> {
self.function_coverage_map.replace(FxHashMap::default())
}
}
impl<'ll, 'tcx> CoverageInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
fn coverageinfo_finalize(&self) {
mapgen::finalize(self)
}
fn get_pgo_func_name_var(&self, instance: Instance<'tcx>) -> &'ll llvm::Value {
if let Some(coverage_context) = self.coverage_context() {
debug!("getting pgo_func_name_var for instance={:?}", instance);
let mut pgo_func_name_var_map = coverage_context.pgo_func_name_var_map.borrow_mut();
pgo_func_name_var_map
.entry(instance)
.or_insert_with(|| create_pgo_func_name_var(self, instance))
} else {
bug!("Could not get the `coverage_context`");
}
}
fn define_unused_fn(&self, def_id: DefId) {
let instance = declare_unused_fn(self, def_id);
codegen_unused_fn_and_counter(self, instance);
add_unused_function_coverage(self, instance, def_id);
}
}
impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> {
fn set_function_source_hash(
&mut self,
instance: Instance<'tcx>,
function_source_hash: u64,
) -> bool {
if let Some(coverage_context) = self.coverage_context() {
debug!(
"ensuring function source hash is set for instance={:?}; function_source_hash={}",
instance, function_source_hash,
);
let mut coverage_map = coverage_context.function_coverage_map.borrow_mut();
coverage_map
.entry(instance)
.or_insert_with(|| FunctionCoverage::new(self.tcx, instance))
.set_function_source_hash(function_source_hash);
true
} else {
false
}
}
fn add_coverage_counter(
&mut self,
instance: Instance<'tcx>,
id: CounterValueReference,
region: CodeRegion,
) -> bool {
if let Some(coverage_context) = self.coverage_context() {
debug!(
"adding counter to coverage_map: instance={:?}, id={:?}, region={:?}",
instance, id, region,
);
let mut coverage_map = coverage_context.function_coverage_map.borrow_mut();
coverage_map
.entry(instance)
.or_insert_with(|| FunctionCoverage::new(self.tcx, instance))
.add_counter(id, region);
true
} else {
false
}
}
fn add_coverage_counter_expression(
&mut self,
instance: Instance<'tcx>,
id: InjectedExpressionId,
lhs: ExpressionOperandId,
op: Op,
rhs: ExpressionOperandId,
region: Option<CodeRegion>,
) -> bool {
if let Some(coverage_context) = self.coverage_context() {
debug!(
"adding counter expression to coverage_map: instance={:?}, id={:?}, {:?} {:?} {:?}; \
region: {:?}",
instance, id, lhs, op, rhs, region,
);
let mut coverage_map = coverage_context.function_coverage_map.borrow_mut();
coverage_map
.entry(instance)
.or_insert_with(|| FunctionCoverage::new(self.tcx, instance))
.add_counter_expression(id, lhs, op, rhs, region);
true
} else {
false
}
}
fn add_coverage_unreachable(&mut self, instance: Instance<'tcx>, region: CodeRegion) -> bool {
if let Some(coverage_context) = self.coverage_context() {
debug!(
"adding unreachable code to coverage_map: instance={:?}, at {:?}",
instance, region,
);
let mut coverage_map = coverage_context.function_coverage_map.borrow_mut();
coverage_map
.entry(instance)
.or_insert_with(|| FunctionCoverage::new(self.tcx, instance))
.add_unreachable_region(region);
true
} else {
false
}
}
}
fn declare_unused_fn<'tcx>(cx: &CodegenCx<'_, 'tcx>, def_id: DefId) -> Instance<'tcx> {
let tcx = cx.tcx;
let instance = Instance::new(
def_id,
InternalSubsts::for_item(tcx, def_id, |param, _| {
if let ty::GenericParamDefKind::Lifetime = param.kind {
tcx.lifetimes.re_erased.into()
} else {
tcx.mk_param_from_def(param)
}
}),
);
let llfn = cx.declare_fn(
tcx.symbol_name(instance).name,
cx.fn_abi_of_fn_ptr(
ty::Binder::dummy(tcx.mk_fn_sig(
iter::once(tcx.mk_unit()),
tcx.mk_unit(),
false,
hir::Unsafety::Unsafe,
Abi::Rust,
)),
ty::List::empty(),
),
);
llvm::set_linkage(llfn, llvm::Linkage::PrivateLinkage);
llvm::set_visibility(llfn, llvm::Visibility::Default);
assert!(cx.instances.borrow_mut().insert(instance, llfn).is_none());
instance
}
fn codegen_unused_fn_and_counter<'tcx>(cx: &CodegenCx<'_, 'tcx>, instance: Instance<'tcx>) {
let llfn = cx.get_fn(instance);
let llbb = Builder::append_block(cx, llfn, "unused_function");
let mut bx = Builder::build(cx, llbb);
let fn_name = bx.get_pgo_func_name_var(instance);
let hash = bx.const_u64(0);
let num_counters = bx.const_u32(1);
let index = bx.const_u32(u32::from(UNUSED_FUNCTION_COUNTER_ID));
debug!(
"codegen intrinsic instrprof.increment(fn_name={:?}, hash={:?}, num_counters={:?},
index={:?}) for unused function: {:?}",
fn_name, hash, num_counters, index, instance
);
bx.instrprof_increment(fn_name, hash, num_counters, index);
bx.ret_void();
}
fn add_unused_function_coverage<'tcx>(
cx: &CodegenCx<'_, 'tcx>,
instance: Instance<'tcx>,
def_id: DefId,
) {
let tcx = cx.tcx;
let mut function_coverage = FunctionCoverage::unused(tcx, instance);
for (index, &code_region) in tcx.covered_code_regions(def_id).iter().enumerate() {
if index == 0 {
function_coverage.add_counter(UNUSED_FUNCTION_COUNTER_ID, code_region.clone());
} else {
function_coverage.add_unreachable_region(code_region.clone());
}
}
if let Some(coverage_context) = cx.coverage_context() {
coverage_context.function_coverage_map.borrow_mut().insert(instance, function_coverage);
} else {
bug!("Could not get the `coverage_context`");
}
}
fn create_pgo_func_name_var<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
instance: Instance<'tcx>,
) -> &'ll llvm::Value {
let mangled_fn_name = CString::new(cx.tcx.symbol_name(instance).name)
.expect("error converting function name to C string");
let llfn = cx.get_fn(instance);
unsafe { llvm::LLVMRustCoverageCreatePGOFuncNameVar(llfn, mangled_fn_name.as_ptr()) }
}
pub(crate) fn write_filenames_section_to_buffer<'a>(
filenames: impl IntoIterator<Item = &'a CString>,
buffer: &RustString,
) {
let c_str_vec = filenames.into_iter().map(|cstring| cstring.as_ptr()).collect::<Vec<_>>();
unsafe {
llvm::LLVMRustCoverageWriteFilenamesSectionToBuffer(
c_str_vec.as_ptr(),
c_str_vec.len(),
buffer,
);
}
}
pub(crate) fn write_mapping_to_buffer(
virtual_file_mapping: Vec<u32>,
expressions: Vec<CounterExpression>,
mapping_regions: Vec<CounterMappingRegion>,
buffer: &RustString,
) {
unsafe {
llvm::LLVMRustCoverageWriteMappingToBuffer(
virtual_file_mapping.as_ptr(),
virtual_file_mapping.len() as c_uint,
expressions.as_ptr(),
expressions.len() as c_uint,
mapping_regions.as_ptr(),
mapping_regions.len() as c_uint,
buffer,
);
}
}
pub(crate) fn hash_str(strval: &str) -> u64 {
let strval = CString::new(strval).expect("null error converting hashable str to C string");
unsafe { llvm::LLVMRustCoverageHashCString(strval.as_ptr()) }
}
pub(crate) fn hash_bytes(bytes: Vec<u8>) -> u64 {
unsafe { llvm::LLVMRustCoverageHashByteArray(bytes.as_ptr().cast(), bytes.len()) }
}
pub(crate) fn mapping_version() -> u32 {
unsafe { llvm::LLVMRustCoverageMappingVersion() }
}
pub(crate) fn save_cov_data_to_mod<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
cov_data_val: &'ll llvm::Value,
) {
let covmap_var_name = llvm::build_string(|s| unsafe {
llvm::LLVMRustCoverageWriteMappingVarNameToString(s);
})
.expect("Rust Coverage Mapping var name failed UTF-8 conversion");
debug!("covmap var name: {:?}", covmap_var_name);
let covmap_section_name = llvm::build_string(|s| unsafe {
llvm::LLVMRustCoverageWriteMapSectionNameToString(cx.llmod, s);
})
.expect("Rust Coverage section name failed UTF-8 conversion");
debug!("covmap section name: {:?}", covmap_section_name);
let llglobal = llvm::add_global(cx.llmod, cx.val_ty(cov_data_val), &covmap_var_name);
llvm::set_initializer(llglobal, cov_data_val);
llvm::set_global_constant(llglobal, true);
llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
llvm::set_section(llglobal, &covmap_section_name);
llvm::set_alignment(llglobal, VAR_ALIGN_BYTES);
cx.add_used_global(llglobal);
}
pub(crate) fn save_func_record_to_mod<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,
func_name_hash: u64,
func_record_val: &'ll llvm::Value,
is_used: bool,
) {
let func_record_var_name =
format!("__covrec_{:X}{}", func_name_hash, if is_used { "u" } else { "" });
debug!("function record var name: {:?}", func_record_var_name);
let func_record_section_name = llvm::build_string(|s| unsafe {
llvm::LLVMRustCoverageWriteFuncSectionNameToString(cx.llmod, s);
})
.expect("Rust Coverage function record section name failed UTF-8 conversion");
debug!("function record section name: {:?}", func_record_section_name);
let llglobal = llvm::add_global(cx.llmod, cx.val_ty(func_record_val), &func_record_var_name);
llvm::set_initializer(llglobal, func_record_val);
llvm::set_global_constant(llglobal, true);
llvm::set_linkage(llglobal, llvm::Linkage::LinkOnceODRLinkage);
llvm::set_visibility(llglobal, llvm::Visibility::Hidden);
llvm::set_section(llglobal, &func_record_section_name);
llvm::set_alignment(llglobal, VAR_ALIGN_BYTES);
llvm::set_comdat(cx.llmod, llglobal, &func_record_var_name);
cx.add_used_global(llglobal);
}