src/librustc_codegen_llvm/coverageinfo/mod.rs

   1 use crate::llvm;
   2
   3 use crate::builder::Builder;
   4 use crate::common::CodegenCx;
   5
   6 use libc::c_uint;
   7 use llvm::coverageinfo::CounterMappingRegion;
   8 use log::debug;
   9 use rustc_codegen_ssa::coverageinfo::map::{CounterExpression, ExprKind, FunctionCoverage, Region};
  10 use rustc_codegen_ssa::traits::{
  11     BaseTypeMethods, CoverageInfoBuilderMethods, CoverageInfoMethods, StaticMethods,
  12 };
  13 use rustc_data_structures::fx::FxHashMap;
  14 use rustc_llvm::RustString;
  15 use rustc_middle::ty::Instance;
  16
  17 use std::cell::RefCell;
  18 use std::ffi::CString;
  19
  20 pub mod mapgen;
  21
  22 const COVMAP_VAR_ALIGN_BYTES: usize = 8;
  23
  24 /// A context object for maintaining all state needed by the coverageinfo module.
  25 pub struct CrateCoverageContext<'tcx> {
  26     // Coverage region data for each instrumented function identified by DefId.
  27     pub(crate) function_coverage_map: RefCell<FxHashMap<Instance<'tcx>, FunctionCoverage<'tcx>>>,
  28 }
  29
  30 impl<'tcx> CrateCoverageContext<'tcx> {
  31     pub fn new() -> Self {
  32         Self { function_coverage_map: Default::default() }
  33     }
  34
  35     pub fn take_function_coverage_map(&self) -> FxHashMap<Instance<'tcx>, FunctionCoverage<'tcx>> {
  36         self.function_coverage_map.replace(FxHashMap::default())
  37     }
  38 }
  39
  40 impl CoverageInfoMethods for CodegenCx<'ll, 'tcx> {
  41     fn coverageinfo_finalize(&self) {
  42         mapgen::finalize(self)
  43     }
  44 }
  45
  46 impl CoverageInfoBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
  47     fn add_counter_region(
  48         &mut self,
  49         instance: Instance<'tcx>,
  50         function_source_hash: u64,
  51         id: u32,
  52         region: Region<'tcx>,
  53     ) {
  54         debug!(
  55             "adding counter to coverage_regions: instance={:?}, function_source_hash={}, id={}, \
  56              at {:?}",
  57             instance, function_source_hash, id, region,
  58         );
  59         let mut coverage_regions = self.coverage_context().function_coverage_map.borrow_mut();
  60         coverage_regions
  61             .entry(instance)
  62             .or_insert_with(|| FunctionCoverage::new(self.tcx, instance))
  63             .add_counter(function_source_hash, id, region);
  64     }
  65
  66     fn add_counter_expression_region(
  67         &mut self,
  68         instance: Instance<'tcx>,
  69         id_descending_from_max: u32,
  70         lhs: u32,
  71         op: ExprKind,
  72         rhs: u32,
  73         region: Region<'tcx>,
  74     ) {
  75         debug!(
  76             "adding counter expression to coverage_regions: instance={:?}, id={}, {} {:?} {}, \
  77              at {:?}",
  78             instance, id_descending_from_max, lhs, op, rhs, region,
  79         );
  80         let mut coverage_regions = self.coverage_context().function_coverage_map.borrow_mut();
  81         coverage_regions
  82             .entry(instance)
  83             .or_insert_with(|| FunctionCoverage::new(self.tcx, instance))
  84             .add_counter_expression(id_descending_from_max, lhs, op, rhs, region);
  85     }
  86
  87     fn add_unreachable_region(&mut self, instance: Instance<'tcx>, region: Region<'tcx>) {
  88         debug!(
  89             "adding unreachable code to coverage_regions: instance={:?}, at {:?}",
  90             instance, region,
  91         );
  92         let mut coverage_regions = self.coverage_context().function_coverage_map.borrow_mut();
  93         coverage_regions
  94             .entry(instance)
  95             .or_insert_with(|| FunctionCoverage::new(self.tcx, instance))
  96             .add_unreachable_region(region);
  97     }
  98 }
  99
 100 pub(crate) fn write_filenames_section_to_buffer(filenames: &Vec<CString>, buffer: &RustString) {
 101     let c_str_vec = filenames.iter().map(|cstring| cstring.as_ptr()).collect::<Vec<_>>();
 102     unsafe {
 103         llvm::LLVMRustCoverageWriteFilenamesSectionToBuffer(
 104             c_str_vec.as_ptr(),
 105             c_str_vec.len(),
 106             buffer,
 107         );
 108     }
 109 }
 110
 111 pub(crate) fn write_mapping_to_buffer(
 112     virtual_file_mapping: Vec<u32>,
 113     expressions: Vec<CounterExpression>,
 114     mut mapping_regions: Vec<CounterMappingRegion>,
 115     buffer: &RustString,
 116 ) {
 117     unsafe {
 118         llvm::LLVMRustCoverageWriteMappingToBuffer(
 119             virtual_file_mapping.as_ptr(),
 120             virtual_file_mapping.len() as c_uint,
 121             expressions.as_ptr(),
 122             expressions.len() as c_uint,
 123             mapping_regions.as_mut_ptr(),
 124             mapping_regions.len() as c_uint,
 125             buffer,
 126         );
 127     }
 128 }
 129
 130 pub(crate) fn compute_hash(name: &str) -> u64 {
 131     let name = CString::new(name).expect("null error converting hashable name to C string");
 132     unsafe { llvm::LLVMRustCoverageComputeHash(name.as_ptr()) }
 133 }
 134
 135 pub(crate) fn mapping_version() -> u32 {
 136     unsafe { llvm::LLVMRustCoverageMappingVersion() }
 137 }
 138
 139 pub(crate) fn save_map_to_mod<'ll, 'tcx>(
 140     cx: &CodegenCx<'ll, 'tcx>,
 141     cov_data_val: &'ll llvm::Value,
 142 ) {
 143     let covmap_var_name = llvm::build_string(|s| unsafe {
 144         llvm::LLVMRustCoverageWriteMappingVarNameToString(s);
 145     })
 146     .expect("Rust Coverage Mapping var name failed UTF-8 conversion");
 147     debug!("covmap var name: {:?}", covmap_var_name);
 148
 149     let covmap_section_name = llvm::build_string(|s| unsafe {
 150         llvm::LLVMRustCoverageWriteSectionNameToString(cx.llmod, s);
 151     })
 152     .expect("Rust Coverage section name failed UTF-8 conversion");
 153     debug!("covmap section name: {:?}", covmap_section_name);
 154
 155     let llglobal = llvm::add_global(cx.llmod, cx.val_ty(cov_data_val), &covmap_var_name);
 156     llvm::set_initializer(llglobal, cov_data_val);
 157     llvm::set_global_constant(llglobal, true);
 158     llvm::set_linkage(llglobal, llvm::Linkage::InternalLinkage);
 159     llvm::set_section(llglobal, &covmap_section_name);
 160     llvm::set_alignment(llglobal, COVMAP_VAR_ALIGN_BYTES);
 161     cx.add_used_global(llglobal);
 162 }