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Auto merge of #126733 - ZhuUx:llvm-19-adapt, r=Zalathar

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[Coverage][MCDC] Adapt mcdc to llvm 19

Related issue: #126672

Also finish task 4 at #124144

[llvm #82448](https://github.com/llvm/llvm-project/pull/82448) has introduced some break changes into mcdc, causing incompatibility between llvm 18 and 19. This draft adapts to that change and gives up supporting for llvm-18.
This commit is contained in:
bors
2024-10-08 07:08:41 +00:00
parent e6c46db4e9 acd64fa0d9
commit cf24c73141
31 changed files with 570 additions and 569 deletions
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74
compiler/rustc_codegen_llvm/src/builder.rs
View File

@@ -1679,16 +1679,21 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
&mut self,
fn_name: &'ll Value,
hash: &'ll Value,
bitmap_bytes: &'ll Value,
bitmap_bits: &'ll Value,
) {
debug!("mcdc_parameters() with args ({:?}, {:?}, {:?})", fn_name, hash, bitmap_bytes);
debug!("mcdc_parameters() with args ({:?}, {:?}, {:?})", fn_name, hash, bitmap_bits);
assert!(
crate::llvm_util::get_version() >= (19, 0, 0),
"MCDC intrinsics require LLVM 19 or later"
);
let llfn = unsafe { llvm::LLVMRustGetInstrProfMCDCParametersIntrinsic(self.cx().llmod) };
let llty = self.cx.type_func(
&[self.cx.type_ptr(), self.cx.type_i64(), self.cx.type_i32()],
self.cx.type_void(),
);
let args = &[fn_name, hash, bitmap_bytes];
let args = &[fn_name, hash, bitmap_bits];
let args = self.check_call("call", llty, llfn, args);
unsafe {
@@ -1708,28 +1713,25 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
&mut self,
fn_name: &'ll Value,
hash: &'ll Value,
bitmap_bytes: &'ll Value,
bitmap_index: &'ll Value,
mcdc_temp: &'ll Value,
) {
debug!(
"mcdc_tvbitmap_update() with args ({:?}, {:?}, {:?}, {:?}, {:?})",
fn_name, hash, bitmap_bytes, bitmap_index, mcdc_temp
"mcdc_tvbitmap_update() with args ({:?}, {:?}, {:?}, {:?})",
fn_name, hash, bitmap_index, mcdc_temp
);
assert!(
crate::llvm_util::get_version() >= (19, 0, 0),
"MCDC intrinsics require LLVM 19 or later"
);
let llfn =
unsafe { llvm::LLVMRustGetInstrProfMCDCTVBitmapUpdateIntrinsic(self.cx().llmod) };
let llty = self.cx.type_func(
&[
self.cx.type_ptr(),
self.cx.type_i64(),
self.cx.type_i32(),
self.cx.type_i32(),
self.cx.type_ptr(),
],
&[self.cx.type_ptr(), self.cx.type_i64(), self.cx.type_i32(), self.cx.type_ptr()],
self.cx.type_void(),
);
let args = &[fn_name, hash, bitmap_bytes, bitmap_index, mcdc_temp];
let args = &[fn_name, hash, bitmap_index, mcdc_temp];
let args = self.check_call("call", llty, llfn, args);
unsafe {
let _ = llvm::LLVMRustBuildCall(
@@ -1745,41 +1747,15 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
self.store(self.const_i32(0), mcdc_temp, self.tcx.data_layout.i32_align.abi);
}
pub(crate) fn mcdc_condbitmap_update(
&mut self,
fn_name: &'ll Value,
hash: &'ll Value,
cond_loc: &'ll Value,
mcdc_temp: &'ll Value,
bool_value: &'ll Value,
) {
debug!(
"mcdc_condbitmap_update() with args ({:?}, {:?}, {:?}, {:?}, {:?})",
fn_name, hash, cond_loc, mcdc_temp, bool_value
pub(crate) fn mcdc_condbitmap_update(&mut self, cond_index: &'ll Value, mcdc_temp: &'ll Value) {
debug!("mcdc_condbitmap_update() with args ({:?}, {:?})", cond_index, mcdc_temp);
assert!(
crate::llvm_util::get_version() >= (19, 0, 0),
"MCDC intrinsics require LLVM 19 or later"
);
let llfn = unsafe { llvm::LLVMRustGetInstrProfMCDCCondBitmapIntrinsic(self.cx().llmod) };
let llty = self.cx.type_func(
&[
self.cx.type_ptr(),
self.cx.type_i64(),
self.cx.type_i32(),
self.cx.type_ptr(),
self.cx.type_i1(),
],
self.cx.type_void(),
);
let args = &[fn_name, hash, cond_loc, mcdc_temp, bool_value];
self.check_call("call", llty, llfn, args);
unsafe {
let _ = llvm::LLVMRustBuildCall(
self.llbuilder,
llty,
llfn,
args.as_ptr() as *const &llvm::Value,
args.len() as c_uint,
[].as_ptr(),
0 as c_uint,
);
}
let align = self.tcx.data_layout.i32_align.abi;
let current_tv_index = self.load(self.cx.type_i32(), mcdc_temp, align);
let new_tv_index = self.add(current_tv_index, cond_index);
self.store(new_tv_index, mcdc_temp, align);
}
}

13
compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs
View File

@@ -111,7 +111,7 @@ enum RegionKind {
}
mod mcdc {
use rustc_middle::mir::coverage::{ConditionInfo, DecisionInfo};
use rustc_middle::mir::coverage::{ConditionId, ConditionInfo, DecisionInfo};
/// Must match the layout of `LLVMRustMCDCDecisionParameters`.
#[repr(C)]
@@ -167,12 +167,13 @@ mod mcdc {
impl From<ConditionInfo> for BranchParameters {
fn from(value: ConditionInfo) -> Self {
let to_llvm_cond_id = |cond_id: Option<ConditionId>| {
cond_id.and_then(|id| LLVMConditionId::try_from(id.as_usize()).ok()).unwrap_or(-1)
};
let ConditionInfo { condition_id, true_next_id, false_next_id } = value;
Self {
condition_id: value.condition_id.as_u32() as LLVMConditionId,
condition_ids: [
value.false_next_id.as_u32() as LLVMConditionId,
value.true_next_id.as_u32() as LLVMConditionId,
],
condition_id: to_llvm_cond_id(Some(condition_id)),
condition_ids: [to_llvm_cond_id(false_next_id), to_llvm_cond_id(true_next_id)],
}
}
}

29
compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs
View File

@@ -98,14 +98,14 @@ impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> {
};
// If there are no MC/DC bitmaps to set up, return immediately.
if function_coverage_info.mcdc_bitmap_bytes == 0 {
if function_coverage_info.mcdc_bitmap_bits == 0 {
return;
}
let fn_name = self.get_pgo_func_name_var(instance);
let hash = self.const_u64(function_coverage_info.function_source_hash);
let bitmap_bytes = self.const_u32(function_coverage_info.mcdc_bitmap_bytes);
self.mcdc_parameters(fn_name, hash, bitmap_bytes);
let bitmap_bits = self.const_u32(function_coverage_info.mcdc_bitmap_bits as u32);
self.mcdc_parameters(fn_name, hash, bitmap_bits);
// Create pointers named `mcdc.addr.{i}` to stack-allocated condition bitmaps.
let mut cond_bitmaps = vec![];
@@ -185,35 +185,28 @@ impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> {
CoverageKind::ExpressionUsed { id } => {
func_coverage.mark_expression_id_seen(id);
}
CoverageKind::CondBitmapUpdate { id, value, decision_depth } => {
CoverageKind::CondBitmapUpdate { index, decision_depth } => {
drop(coverage_map);
assert_ne!(
id.as_u32(),
0,
"ConditionId of evaluated conditions should never be zero"
);
let cond_bitmap = coverage_context
.try_get_mcdc_condition_bitmap(&instance, decision_depth)
.expect("mcdc cond bitmap should have been allocated for updating");
let cond_loc = bx.const_i32(id.as_u32() as i32 - 1);
let bool_value = bx.const_bool(value);
let fn_name = bx.get_pgo_func_name_var(instance);
let hash = bx.const_u64(function_coverage_info.function_source_hash);
bx.mcdc_condbitmap_update(fn_name, hash, cond_loc, cond_bitmap, bool_value);
let cond_index = bx.const_i32(index as i32);
bx.mcdc_condbitmap_update(cond_index, cond_bitmap);
}
CoverageKind::TestVectorBitmapUpdate { bitmap_idx, decision_depth } => {
drop(coverage_map);
let cond_bitmap = coverage_context
.try_get_mcdc_condition_bitmap(&instance, decision_depth)
.expect("mcdc cond bitmap should have been allocated for merging into the global bitmap");
let bitmap_bytes = function_coverage_info.mcdc_bitmap_bytes;
assert!(bitmap_idx < bitmap_bytes, "bitmap index of the decision out of range");
assert!(
bitmap_idx as usize <= function_coverage_info.mcdc_bitmap_bits,
"bitmap index of the decision out of range"
);
let fn_name = bx.get_pgo_func_name_var(instance);
let hash = bx.const_u64(function_coverage_info.function_source_hash);
let bitmap_bytes = bx.const_u32(bitmap_bytes);
let bitmap_index = bx.const_u32(bitmap_idx);
bx.mcdc_tvbitmap_update(fn_name, hash, bitmap_bytes, bitmap_index, cond_bitmap);
bx.mcdc_tvbitmap_update(fn_name, hash, bitmap_index, cond_bitmap);
}
}
}

1
compiler/rustc_codegen_llvm/src/llvm/ffi.rs
View File

@@ -1614,7 +1614,6 @@ unsafe extern "C" {
pub fn LLVMRustGetInstrProfIncrementIntrinsic(M: &Module) -> &Value;
pub fn LLVMRustGetInstrProfMCDCParametersIntrinsic(M: &Module) -> &Value;
pub fn LLVMRustGetInstrProfMCDCTVBitmapUpdateIntrinsic(M: &Module) -> &Value;
pub fn LLVMRustGetInstrProfMCDCCondBitmapIntrinsic(M: &Module) -> &Value;
pub fn LLVMRustBuildCall<'a>(
B: &Builder<'a>,

45
compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
View File

@@ -88,38 +88,7 @@ struct LLVMRustMCDCParameters {
LLVMRustMCDCBranchParameters BranchParameters;
};
// LLVM representations for `MCDCParameters` evolved from LLVM 18 to 19.
// Look at representations in 18
// https://github.com/rust-lang/llvm-project/blob/66a2881a/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L253-L263
// and representations in 19
// https://github.com/llvm/llvm-project/blob/843cc474faefad1d639f4c44c1cf3ad7dbda76c8/llvm/include/llvm/ProfileData/Coverage/MCDCTypes.h
#if LLVM_VERSION_LT(19, 0)
static coverage::CounterMappingRegion::MCDCParameters
fromRust(LLVMRustMCDCParameters Params) {
auto parameter = coverage::CounterMappingRegion::MCDCParameters{};
switch (Params.Tag) {
case LLVMRustMCDCParametersTag::None:
return parameter;
case LLVMRustMCDCParametersTag::Decision:
parameter.BitmapIdx =
static_cast<unsigned>(Params.DecisionParameters.BitmapIdx),
parameter.NumConditions =
static_cast<unsigned>(Params.DecisionParameters.NumConditions);
return parameter;
case LLVMRustMCDCParametersTag::Branch:
parameter.ID = static_cast<coverage::CounterMappingRegion::MCDCConditionID>(
Params.BranchParameters.ConditionID),
parameter.FalseID =
static_cast<coverage::CounterMappingRegion::MCDCConditionID>(
Params.BranchParameters.ConditionIDs[0]),
parameter.TrueID =
static_cast<coverage::CounterMappingRegion::MCDCConditionID>(
Params.BranchParameters.ConditionIDs[1]);
return parameter;
}
report_fatal_error("Bad LLVMRustMCDCParametersTag!");
}
#else
#if LLVM_VERSION_GE(19, 0)
static coverage::mcdc::Parameters fromRust(LLVMRustMCDCParameters Params) {
switch (Params.Tag) {
case LLVMRustMCDCParametersTag::None:
@@ -214,13 +183,17 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
RustMappingRegions, NumMappingRegions)) {
MappingRegions.emplace_back(
fromRust(Region.Count), fromRust(Region.FalseCount),
#if LLVM_VERSION_LT(19, 0)
// LLVM 19 may move this argument to last.
fromRust(Region.MCDCParameters),
#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
coverage::CounterMappingRegion::MCDCParameters{},
#endif
Region.FileID, Region.ExpandedFileID, // File IDs, then region info.
Region.LineStart, Region.ColumnStart, Region.LineEnd, Region.ColumnEnd,
fromRust(Region.Kind));
fromRust(Region.Kind)
#if LLVM_VERSION_GE(19, 0)
,
fromRust(Region.MCDCParameters)
#endif
);
}
std::vector<coverage::CounterExpression> Expressions;

14
compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
View File

@@ -1539,23 +1539,21 @@ LLVMRustGetInstrProfIncrementIntrinsic(LLVMModuleRef M) {
extern "C" LLVMValueRef
LLVMRustGetInstrProfMCDCParametersIntrinsic(LLVMModuleRef M) {
#if LLVM_VERSION_GE(19, 0)
return wrap(llvm::Intrinsic::getDeclaration(
unwrap(M), llvm::Intrinsic::instrprof_mcdc_parameters));
#else
report_fatal_error("LLVM 19.0 is required for mcdc intrinsic functions");
#endif
}
extern "C" LLVMValueRef
LLVMRustGetInstrProfMCDCTVBitmapUpdateIntrinsic(LLVMModuleRef M) {
#if LLVM_VERSION_GE(19, 0)
return wrap(llvm::Intrinsic::getDeclaration(
unwrap(M), llvm::Intrinsic::instrprof_mcdc_tvbitmap_update));
}
extern "C" LLVMValueRef
LLVMRustGetInstrProfMCDCCondBitmapIntrinsic(LLVMModuleRef M) {
#if LLVM_VERSION_LT(19, 0)
return wrap(llvm::Intrinsic::getDeclaration(
unwrap(M), llvm::Intrinsic::instrprof_mcdc_condbitmap_update));
#else
report_fatal_error("LLVM 18.0 is required for mcdc intrinsic functions");
report_fatal_error("LLVM 19.0 is required for mcdc intrinsic functions");
#endif
}

45
compiler/rustc_middle/src/mir/coverage.rs
View File

@@ -67,7 +67,7 @@ rustc_index::newtype_index! {
}
impl ConditionId {
pub const NONE: Self = Self::from_u32(0);
pub const START: Self = Self::from_usize(0);
}
/// Enum that can hold a constant zero value, the ID of an physical coverage
@@ -128,8 +128,8 @@ pub enum CoverageKind {
/// Marks the point in MIR control flow represented by a evaluated condition.
///
/// This is eventually lowered to `llvm.instrprof.mcdc.condbitmap.update` in LLVM IR.
CondBitmapUpdate { id: ConditionId, value: bool, decision_depth: u16 },
/// This is eventually lowered to instruments updating mcdc temp variables.
CondBitmapUpdate { index: u32, decision_depth: u16 },
/// Marks the point in MIR control flow represented by a evaluated decision.
///
@@ -145,14 +145,8 @@ impl Debug for CoverageKind {
BlockMarker { id } => write!(fmt, "BlockMarker({:?})", id.index()),
CounterIncrement { id } => write!(fmt, "CounterIncrement({:?})", id.index()),
ExpressionUsed { id } => write!(fmt, "ExpressionUsed({:?})", id.index()),
CondBitmapUpdate { id, value, decision_depth } => {
write!(
fmt,
"CondBitmapUpdate({:?}, {:?}, depth={:?})",
id.index(),
value,
decision_depth
)
CondBitmapUpdate { index, decision_depth } => {
write!(fmt, "CondBitmapUpdate(index={:?}, depth={:?})", index, decision_depth)
}
TestVectorBitmapUpdate { bitmap_idx, decision_depth } => {
write!(fmt, "TestVectorUpdate({:?}, depth={:?})", bitmap_idx, decision_depth)
@@ -253,7 +247,7 @@ pub struct Mapping {
pub struct FunctionCoverageInfo {
pub function_source_hash: u64,
pub num_counters: usize,
pub mcdc_bitmap_bytes: u32,
pub mcdc_bitmap_bits: usize,
pub expressions: IndexVec<ExpressionId, Expression>,
pub mappings: Vec<Mapping>,
/// The depth of the deepest decision is used to know how many
@@ -275,8 +269,10 @@ pub struct CoverageInfoHi {
/// data structures without having to scan the entire body first.
pub num_block_markers: usize,
pub branch_spans: Vec<BranchSpan>,
pub mcdc_branch_spans: Vec<MCDCBranchSpan>,
pub mcdc_decision_spans: Vec<MCDCDecisionSpan>,
/// Branch spans generated by mcdc. Because of some limits mcdc builder give up generating
/// decisions including them so that they are handled as normal branch spans.
pub mcdc_degraded_branch_spans: Vec<MCDCBranchSpan>,
pub mcdc_spans: Vec<(MCDCDecisionSpan, Vec<MCDCBranchSpan>)>,
}
#[derive(Clone, Debug)]
@@ -291,30 +287,17 @@ pub struct BranchSpan {
#[derive(TyEncodable, TyDecodable, Hash, HashStable, TypeFoldable, TypeVisitable)]
pub struct ConditionInfo {
pub condition_id: ConditionId,
pub true_next_id: ConditionId,
pub false_next_id: ConditionId,
}
impl Default for ConditionInfo {
fn default() -> Self {
Self {
condition_id: ConditionId::NONE,
true_next_id: ConditionId::NONE,
false_next_id: ConditionId::NONE,
}
}
pub true_next_id: Option<ConditionId>,
pub false_next_id: Option<ConditionId>,
}
#[derive(Clone, Debug)]
#[derive(TyEncodable, TyDecodable, Hash, HashStable, TypeFoldable, TypeVisitable)]
pub struct MCDCBranchSpan {
pub span: Span,
/// If `None`, this actually represents a normal branch span inserted for
/// code that was too complex for MC/DC.
pub condition_info: Option<ConditionInfo>,
pub condition_info: ConditionInfo,
pub true_marker: BlockMarkerId,
pub false_marker: BlockMarkerId,
pub decision_depth: u16,
}
#[derive(Copy, Clone, Debug)]
@@ -328,7 +311,7 @@ pub struct DecisionInfo {
#[derive(TyEncodable, TyDecodable, Hash, HashStable, TypeFoldable, TypeVisitable)]
pub struct MCDCDecisionSpan {
pub span: Span,
pub num_conditions: usize,
pub end_markers: Vec<BlockMarkerId>,
pub decision_depth: u16,
pub num_conditions: usize,
}

32
compiler/rustc_middle/src/mir/pretty.rs
View File

@@ -538,8 +538,8 @@ fn write_coverage_info_hi(
let coverage::CoverageInfoHi {
num_block_markers: _,
branch_spans,
mcdc_branch_spans,
mcdc_decision_spans,
mcdc_degraded_branch_spans,
mcdc_spans,
} = coverage_info_hi;
// Only add an extra trailing newline if we printed at least one thing.
@@ -553,29 +553,35 @@ fn write_coverage_info_hi(
did_print = true;
}
for coverage::MCDCBranchSpan {
span,
condition_info,
true_marker,
false_marker,
decision_depth,
} in mcdc_branch_spans
for coverage::MCDCBranchSpan { span, true_marker, false_marker, .. } in
mcdc_degraded_branch_spans
{
writeln!(
w,
"{INDENT}coverage mcdc branch {{ condition_id: {:?}, true: {true_marker:?}, false: {false_marker:?}, depth: {decision_depth:?} }} => {span:?}",
condition_info.map(|info| info.condition_id)
"{INDENT}coverage branch {{ true: {true_marker:?}, false: {false_marker:?} }} => {span:?}",
)?;
did_print = true;
}
for coverage::MCDCDecisionSpan { span, num_conditions, end_markers, decision_depth } in
mcdc_decision_spans
for (
coverage::MCDCDecisionSpan { span, end_markers, decision_depth, num_conditions: _ },
conditions,
) in mcdc_spans
{
let num_conditions = conditions.len();
writeln!(
w,
"{INDENT}coverage mcdc decision {{ num_conditions: {num_conditions:?}, end: {end_markers:?}, depth: {decision_depth:?} }} => {span:?}"
)?;
for coverage::MCDCBranchSpan { span, condition_info, true_marker, false_marker } in
conditions
{
writeln!(
w,
"{INDENT}coverage mcdc branch {{ condition_id: {:?}, true: {true_marker:?}, false: {false_marker:?} }} => {span:?}",
condition_info.condition_id
)?;
}
did_print = true;
}

6
compiler/rustc_mir_build/src/build/coverageinfo.rs
View File

@@ -175,7 +175,7 @@ impl CoverageInfoBuilder {
let branch_spans =
branch_info.map(|branch_info| branch_info.branch_spans).unwrap_or_default();
let (mcdc_decision_spans, mcdc_branch_spans) =
let (mcdc_spans, mcdc_degraded_branch_spans) =
mcdc_info.map(MCDCInfoBuilder::into_done).unwrap_or_default();
// For simplicity, always return an info struct (without Option), even
@@ -183,8 +183,8 @@ impl CoverageInfoBuilder {
Box::new(CoverageInfoHi {
num_block_markers,
branch_spans,
mcdc_branch_spans,
mcdc_decision_spans,
mcdc_degraded_branch_spans,
mcdc_spans,
})
}
}

117
compiler/rustc_mir_build/src/build/coverageinfo/mcdc.rs
View File

@@ -12,16 +12,16 @@ use rustc_span::Span;
use crate::build::Builder;
use crate::errors::MCDCExceedsConditionLimit;
/// The MCDC bitmap scales exponentially (2^n) based on the number of conditions seen,
/// So llvm sets a maximum value prevents the bitmap footprint from growing too large without the user's knowledge.
/// This limit may be relaxed if the [upstream change](https://github.com/llvm/llvm-project/pull/82448) is merged.
const MAX_CONDITIONS_IN_DECISION: usize = 6;
/// LLVM uses `i16` to represent condition id. Hence `i16::MAX` is the hard limit for number of
/// conditions in a decision.
const MAX_CONDITIONS_IN_DECISION: usize = i16::MAX as usize;
#[derive(Default)]
struct MCDCDecisionCtx {
/// To construct condition evaluation tree.
decision_stack: VecDeque<ConditionInfo>,
processing_decision: Option<MCDCDecisionSpan>,
conditions: Vec<MCDCBranchSpan>,
}
struct MCDCState {
@@ -106,22 +106,27 @@ impl MCDCState {
}),
};
let parent_condition = decision_ctx.decision_stack.pop_back().unwrap_or_default();
let lhs_id = if parent_condition.condition_id == ConditionId::NONE {
let parent_condition = decision_ctx.decision_stack.pop_back().unwrap_or_else(|| {
assert_eq!(
decision.num_conditions, 0,
"decision stack must be empty only for empty decision"
);
decision.num_conditions += 1;
ConditionId::from(decision.num_conditions)
} else {
parent_condition.condition_id
};
ConditionInfo {
condition_id: ConditionId::START,
true_next_id: None,
false_next_id: None,
}
});
let lhs_id = parent_condition.condition_id;
decision.num_conditions += 1;
let rhs_condition_id = ConditionId::from(decision.num_conditions);
decision.num_conditions += 1;
let (lhs, rhs) = match op {
LogicalOp::And => {
let lhs = ConditionInfo {
condition_id: lhs_id,
true_next_id: rhs_condition_id,
true_next_id: Some(rhs_condition_id),
false_next_id: parent_condition.false_next_id,
};
let rhs = ConditionInfo {
@@ -135,7 +140,7 @@ impl MCDCState {
let lhs = ConditionInfo {
condition_id: lhs_id,
true_next_id: parent_condition.true_next_id,
false_next_id: rhs_condition_id,
false_next_id: Some(rhs_condition_id),
};
let rhs = ConditionInfo {
condition_id: rhs_condition_id,
@@ -150,44 +155,64 @@ impl MCDCState {
decision_ctx.decision_stack.push_back(lhs);
}
fn take_condition(
fn try_finish_decision(
&mut self,
span: Span,
true_marker: BlockMarkerId,
false_marker: BlockMarkerId,
) -> (Option<ConditionInfo>, Option<MCDCDecisionSpan>) {
degraded_branches: &mut Vec<MCDCBranchSpan>,
) -> Option<(MCDCDecisionSpan, Vec<MCDCBranchSpan>)> {
let Some(decision_ctx) = self.decision_ctx_stack.last_mut() else {
bug!("Unexpected empty decision_ctx_stack")
};
let Some(condition_info) = decision_ctx.decision_stack.pop_back() else {
return (None, None);
let branch = MCDCBranchSpan {
span,
condition_info: ConditionInfo {
condition_id: ConditionId::START,
true_next_id: None,
false_next_id: None,
},
true_marker,
false_marker,
};
degraded_branches.push(branch);
return None;
};
let Some(decision) = decision_ctx.processing_decision.as_mut() else {
bug!("Processing decision should have been created before any conditions are taken");
};
if condition_info.true_next_id == ConditionId::NONE {
if condition_info.true_next_id.is_none() {
decision.end_markers.push(true_marker);
}
if condition_info.false_next_id == ConditionId::NONE {
if condition_info.false_next_id.is_none() {
decision.end_markers.push(false_marker);
}
decision_ctx.conditions.push(MCDCBranchSpan {
span,
condition_info,
true_marker,
false_marker,
});
if decision_ctx.decision_stack.is_empty() {
(Some(condition_info), decision_ctx.processing_decision.take())
let conditions = std::mem::take(&mut decision_ctx.conditions);
decision_ctx.processing_decision.take().map(|decision| (decision, conditions))
} else {
(Some(condition_info), None)
None
}
}
}
pub(crate) struct MCDCInfoBuilder {
branch_spans: Vec<MCDCBranchSpan>,
decision_spans: Vec<MCDCDecisionSpan>,
degraded_spans: Vec<MCDCBranchSpan>,
mcdc_spans: Vec<(MCDCDecisionSpan, Vec<MCDCBranchSpan>)>,
state: MCDCState,
}
impl MCDCInfoBuilder {
pub(crate) fn new() -> Self {
Self { branch_spans: vec![], decision_spans: vec![], state: MCDCState::new() }
Self { degraded_spans: vec![], mcdc_spans: vec![], state: MCDCState::new() }
}
pub(crate) fn visit_evaluated_condition(
@@ -201,50 +226,44 @@ impl MCDCInfoBuilder {
let true_marker = inject_block_marker(source_info, true_block);
let false_marker = inject_block_marker(source_info, false_block);
let decision_depth = self.state.decision_depth();
let (mut condition_info, decision_result) =
self.state.take_condition(true_marker, false_marker);
// take_condition() returns Some for decision_result when the decision stack
// is empty, i.e. when all the conditions of the decision were instrumented,
// and the decision is "complete".
if let Some(decision) = decision_result {
match decision.num_conditions {
if let Some((decision, conditions)) = self.state.try_finish_decision(
source_info.span,
true_marker,
false_marker,
&mut self.degraded_spans,
) {
let num_conditions = conditions.len();
assert_eq!(
num_conditions, decision.num_conditions,
"final number of conditions is not correct"
);
match num_conditions {
0 => {
unreachable!("Decision with no condition is not expected");
}
1..=MAX_CONDITIONS_IN_DECISION => {
self.decision_spans.push(decision);
self.mcdc_spans.push((decision, conditions));
}
_ => {
// Do not generate mcdc mappings and statements for decisions with too many conditions.
// Therefore, first erase the condition info of the (N-1) previous branch spans.
let rebase_idx = self.branch_spans.len() - (decision.num_conditions - 1);
for branch in &mut self.branch_spans[rebase_idx..] {
branch.condition_info = None;
}
// Then, erase this last branch span's info too, for a total of N.
condition_info = None;
self.degraded_spans.extend(conditions);
tcx.dcx().emit_warn(MCDCExceedsConditionLimit {
span: decision.span,
num_conditions: decision.num_conditions,
num_conditions,
max_conditions: MAX_CONDITIONS_IN_DECISION,
});
}
}
}
self.branch_spans.push(MCDCBranchSpan {
span: source_info.span,
condition_info,
true_marker,
false_marker,
decision_depth,
});
}
pub(crate) fn into_done(self) -> (Vec<MCDCDecisionSpan>, Vec<MCDCBranchSpan>) {
(self.decision_spans, self.branch_spans)
pub(crate) fn into_done(
self,
) -> (Vec<(MCDCDecisionSpan, Vec<MCDCBranchSpan>)>, Vec<MCDCBranchSpan>) {
(self.mcdc_spans, self.degraded_spans)
}
}

2
compiler/rustc_mir_transform/messages.ftl
View File

@@ -9,6 +9,8 @@ mir_transform_const_mut_borrow = taking a mutable reference to a `const` item
.note2 = the mutable reference will refer to this temporary, not the original `const` item
.note3 = mutable reference created due to call to this method
mir_transform_exceeds_mcdc_test_vector_limit = number of total test vectors in one function will exceed limit ({$max_num_test_vectors}) if this decision is instrumented, so MC/DC analysis ignores it
mir_transform_ffi_unwind_call = call to {$foreign ->
[true] foreign function
*[false] function pointer

235
compiler/rustc_mir_transform/src/coverage/mappings.rs
View File

@@ -1,10 +1,11 @@
use std::collections::BTreeSet;
use rustc_data_structures::fx::FxIndexMap;
use rustc_data_structures::graph::DirectedGraph;
use rustc_index::IndexVec;
use rustc_index::bit_set::BitSet;
use rustc_middle::mir::coverage::{
BlockMarkerId, BranchSpan, ConditionInfo, CoverageInfoHi, CoverageKind,
BlockMarkerId, BranchSpan, ConditionId, ConditionInfo, CoverageInfoHi, CoverageKind,
};
use rustc_middle::mir::{self, BasicBlock, StatementKind};
use rustc_middle::ty::TyCtxt;
@@ -14,6 +15,7 @@ use crate::coverage::ExtractedHirInfo;
use crate::coverage::graph::{BasicCoverageBlock, CoverageGraph, START_BCB};
use crate::coverage::spans::extract_refined_covspans;
use crate::coverage::unexpand::unexpand_into_body_span;
use crate::errors::MCDCExceedsTestVectorLimit;
/// Associates an ordinary executable code span with its corresponding BCB.
#[derive(Debug)]
@@ -38,10 +40,11 @@ pub(super) struct MCDCBranch {
pub(super) span: Span,
pub(super) true_bcb: BasicCoverageBlock,
pub(super) false_bcb: BasicCoverageBlock,
/// If `None`, this actually represents a normal branch mapping inserted
/// for code that was too complex for MC/DC.
pub(super) condition_info: Option<ConditionInfo>,
pub(super) decision_depth: u16,
pub(super) condition_info: ConditionInfo,
// Offset added to test vector idx if this branch is evaluated to true.
pub(super) true_index: usize,
// Offset added to test vector idx if this branch is evaluated to false.
pub(super) false_index: usize,
}
/// Associates an MC/DC decision with its join BCBs.
@@ -49,11 +52,15 @@ pub(super) struct MCDCBranch {
pub(super) struct MCDCDecision {
pub(super) span: Span,
pub(super) end_bcbs: BTreeSet<BasicCoverageBlock>,
pub(super) bitmap_idx: u32,
pub(super) num_conditions: u16,
pub(super) bitmap_idx: usize,
pub(super) num_test_vectors: usize,
pub(super) decision_depth: u16,
}
// LLVM uses `i32` to index the bitmap. Thus `i32::MAX` is the hard limit for number of all test vectors
// in a function.
const MCDC_MAX_BITMAP_SIZE: usize = i32::MAX as usize;
#[derive(Default)]
pub(super) struct ExtractedMappings {
/// Store our own copy of [`CoverageGraph::num_nodes`], so that we don't
@@ -62,9 +69,9 @@ pub(super) struct ExtractedMappings {
pub(super) num_bcbs: usize,
pub(super) code_mappings: Vec<CodeMapping>,
pub(super) branch_pairs: Vec<BranchPair>,
pub(super) mcdc_bitmap_bytes: u32,
pub(super) mcdc_branches: Vec<MCDCBranch>,
pub(super) mcdc_decisions: Vec<MCDCDecision>,
pub(super) mcdc_bitmap_bits: usize,
pub(super) mcdc_degraded_branches: Vec<MCDCBranch>,
pub(super) mcdc_mappings: Vec<(MCDCDecision, Vec<MCDCBranch>)>,
}
/// Extracts coverage-relevant spans from MIR, and associates them with
@@ -77,9 +84,9 @@ pub(super) fn extract_all_mapping_info_from_mir<'tcx>(
) -> ExtractedMappings {
let mut code_mappings = vec![];
let mut branch_pairs = vec![];
let mut mcdc_bitmap_bytes = 0;
let mut mcdc_branches = vec![];
let mut mcdc_decisions = vec![];
let mut mcdc_bitmap_bits = 0;
let mut mcdc_degraded_branches = vec![];
let mut mcdc_mappings = vec![];
if hir_info.is_async_fn || tcx.sess.coverage_no_mir_spans() {
// An async function desugars into a function that returns a future,
@@ -102,20 +109,21 @@ pub(super) fn extract_all_mapping_info_from_mir<'tcx>(
extract_mcdc_mappings(
mir_body,
tcx,
hir_info.body_span,
basic_coverage_blocks,
&mut mcdc_bitmap_bytes,
&mut mcdc_branches,
&mut mcdc_decisions,
&mut mcdc_bitmap_bits,
&mut mcdc_degraded_branches,
&mut mcdc_mappings,
);
ExtractedMappings {
num_bcbs: basic_coverage_blocks.num_nodes(),
code_mappings,
branch_pairs,
mcdc_bitmap_bytes,
mcdc_branches,
mcdc_decisions,
mcdc_bitmap_bits,
mcdc_degraded_branches,
mcdc_mappings,
}
}
@@ -126,9 +134,9 @@ impl ExtractedMappings {
num_bcbs,
code_mappings,
branch_pairs,
mcdc_bitmap_bytes: _,
mcdc_branches,
mcdc_decisions,
mcdc_bitmap_bits: _,
mcdc_degraded_branches,
mcdc_mappings,
} = self;
// Identify which BCBs have one or more mappings.
@@ -144,7 +152,10 @@ impl ExtractedMappings {
insert(true_bcb);
insert(false_bcb);
}
for &MCDCBranch { true_bcb, false_bcb, .. } in mcdc_branches {
for &MCDCBranch { true_bcb, false_bcb, .. } in mcdc_degraded_branches
.iter()
.chain(mcdc_mappings.iter().map(|(_, branches)| branches.into_iter()).flatten())
{
insert(true_bcb);
insert(false_bcb);
}
@@ -152,8 +163,8 @@ impl ExtractedMappings {
// MC/DC decisions refer to BCBs, but don't require those BCBs to have counters.
if bcbs_with_counter_mappings.is_empty() {
debug_assert!(
mcdc_decisions.is_empty(),
"A function with no counter mappings shouldn't have any decisions: {mcdc_decisions:?}",
mcdc_mappings.is_empty(),
"A function with no counter mappings shouldn't have any decisions: {mcdc_mappings:?}",
);
}
@@ -230,11 +241,12 @@ pub(super) fn extract_branch_pairs(
pub(super) fn extract_mcdc_mappings(
mir_body: &mir::Body<'_>,
tcx: TyCtxt<'_>,
body_span: Span,
basic_coverage_blocks: &CoverageGraph,
mcdc_bitmap_bytes: &mut u32,
mcdc_branches: &mut impl Extend<MCDCBranch>,
mcdc_decisions: &mut impl Extend<MCDCDecision>,
mcdc_bitmap_bits: &mut usize,
mcdc_degraded_branches: &mut impl Extend<MCDCBranch>,
mcdc_mappings: &mut impl Extend<(MCDCDecision, Vec<MCDCBranch>)>,
) {
let Some(coverage_info_hi) = mir_body.coverage_info_hi.as_deref() else { return };
@@ -257,43 +269,146 @@ pub(super) fn extract_mcdc_mappings(
Some((span, true_bcb, false_bcb))
};
mcdc_branches.extend(coverage_info_hi.mcdc_branch_spans.iter().filter_map(
|&mir::coverage::MCDCBranchSpan {
span: raw_span,
condition_info,
true_marker,
false_marker,
decision_depth,
}| {
let (span, true_bcb, false_bcb) =
check_branch_bcb(raw_span, true_marker, false_marker)?;
Some(MCDCBranch { span, true_bcb, false_bcb, condition_info, decision_depth })
},
));
let to_mcdc_branch = |&mir::coverage::MCDCBranchSpan {
span: raw_span,
condition_info,
true_marker,
false_marker,
}| {
let (span, true_bcb, false_bcb) = check_branch_bcb(raw_span, true_marker, false_marker)?;
Some(MCDCBranch {
span,
true_bcb,
false_bcb,
condition_info,
true_index: usize::MAX,
false_index: usize::MAX,
})
};
mcdc_decisions.extend(coverage_info_hi.mcdc_decision_spans.iter().filter_map(
|decision: &mir::coverage::MCDCDecisionSpan| {
let span = unexpand_into_body_span(decision.span, body_span)?;
let mut get_bitmap_idx = |num_test_vectors: usize| -> Option<usize> {
let bitmap_idx = *mcdc_bitmap_bits;
let next_bitmap_bits = bitmap_idx.saturating_add(num_test_vectors);
(next_bitmap_bits <= MCDC_MAX_BITMAP_SIZE).then(|| {
*mcdc_bitmap_bits = next_bitmap_bits;
bitmap_idx
})
};
mcdc_degraded_branches
.extend(coverage_info_hi.mcdc_degraded_branch_spans.iter().filter_map(to_mcdc_branch));
let end_bcbs = decision
.end_markers
.iter()
.map(|&marker| bcb_from_marker(marker))
.collect::<Option<_>>()?;
mcdc_mappings.extend(coverage_info_hi.mcdc_spans.iter().filter_map(|(decision, branches)| {
if branches.len() == 0 {
return None;
}
let decision_span = unexpand_into_body_span(decision.span, body_span)?;
// Each decision containing N conditions needs 2^N bits of space in
// the bitmap, rounded up to a whole number of bytes.
// The decision's "bitmap index" points to its first byte in the bitmap.
let bitmap_idx = *mcdc_bitmap_bytes;
*mcdc_bitmap_bytes += (1_u32 << decision.num_conditions).div_ceil(8);
Some(MCDCDecision {
let end_bcbs = decision
.end_markers
.iter()
.map(|&marker| bcb_from_marker(marker))
.collect::<Option<_>>()?;
let mut branch_mappings: Vec<_> = branches.into_iter().filter_map(to_mcdc_branch).collect();
if branch_mappings.len() != branches.len() {
mcdc_degraded_branches.extend(branch_mappings);
return None;
}
let num_test_vectors = calc_test_vectors_index(&mut branch_mappings);
let Some(bitmap_idx) = get_bitmap_idx(num_test_vectors) else {
tcx.dcx().emit_warn(MCDCExceedsTestVectorLimit {
span: decision_span,
max_num_test_vectors: MCDC_MAX_BITMAP_SIZE,
});
mcdc_degraded_branches.extend(branch_mappings);
return None;
};
// LLVM requires span of the decision contains all spans of its conditions.
// Usually the decision span meets the requirement well but in cases like macros it may not.
let span = branch_mappings
.iter()
.map(|branch| branch.span)
.reduce(|lhs, rhs| lhs.to(rhs))
.map(
|joint_span| {
if decision_span.contains(joint_span) { decision_span } else { joint_span }
},
)
.expect("branch mappings are ensured to be non-empty as checked above");
Some((
MCDCDecision {
span,
end_bcbs,
bitmap_idx,
num_conditions: decision.num_conditions as u16,
num_test_vectors,
decision_depth: decision.decision_depth,
})
},
));
},
branch_mappings,
))
}));
}
// LLVM checks the executed test vector by accumulating indices of tested branches.
// We calculate number of all possible test vectors of the decision and assign indices
// to branches here.
// See [the rfc](https://discourse.llvm.org/t/rfc-coverage-new-algorithm-and-file-format-for-mc-dc/76798/)
// for more details about the algorithm.
// This function is mostly like [`TVIdxBuilder::TvIdxBuilder`](https://github.com/llvm/llvm-project/blob/d594d9f7f4dc6eb748b3261917db689fdc348b96/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp#L226)
fn calc_test_vectors_index(conditions: &mut Vec<MCDCBranch>) -> usize {
let mut indegree_stats = IndexVec::<ConditionId, usize>::from_elem_n(0, conditions.len());
// `num_paths` is `width` described at the llvm rfc, which indicates how many paths reaching the condition node.
let mut num_paths_stats = IndexVec::<ConditionId, usize>::from_elem_n(0, conditions.len());
let mut next_conditions = conditions
.iter_mut()
.map(|branch| {
let ConditionInfo { condition_id, true_next_id, false_next_id } = branch.condition_info;
[true_next_id, false_next_id]
.into_iter()
.filter_map(std::convert::identity)
.for_each(|next_id| indegree_stats[next_id] += 1);
(condition_id, branch)
})
.collect::<FxIndexMap<_, _>>();
let mut queue = std::collections::VecDeque::from_iter(
next_conditions.swap_remove(&ConditionId::START).into_iter(),
);
num_paths_stats[ConditionId::START] = 1;
let mut decision_end_nodes = Vec::new();
while let Some(branch) = queue.pop_front() {
let ConditionInfo { condition_id, true_next_id, false_next_id } = branch.condition_info;
let (false_index, true_index) = (&mut branch.false_index, &mut branch.true_index);
let this_paths_count = num_paths_stats[condition_id];
// Note. First check the false next to ensure conditions are touched in same order with llvm-cov.
for (next, index) in [(false_next_id, false_index), (true_next_id, true_index)] {
if let Some(next_id) = next {
let next_paths_count = &mut num_paths_stats[next_id];
*index = *next_paths_count;
*next_paths_count = next_paths_count.saturating_add(this_paths_count);
let next_indegree = &mut indegree_stats[next_id];
*next_indegree -= 1;
if *next_indegree == 0 {
queue.push_back(next_conditions.swap_remove(&next_id).expect(
"conditions with non-zero indegree before must be in next_conditions",
));
}
} else {
decision_end_nodes.push((this_paths_count, condition_id, index));
}
}
}
assert!(next_conditions.is_empty(), "the decision tree has untouched nodes");
let mut cur_idx = 0;
// LLVM hopes the end nodes are sorted in descending order by `num_paths` so that it can
// optimize bitmap size for decisions in tree form such as `a && b && c && d && ...`.
decision_end_nodes.sort_by_key(|(num_paths, _, _)| usize::MAX - *num_paths);
for (num_paths, condition_id, index) in decision_end_nodes {
assert_eq!(
num_paths, num_paths_stats[condition_id],
"end nodes should not be updated since they were visited"
);
assert_eq!(*index, usize::MAX, "end nodes should not be assigned index before");
*index = cur_idx;
cur_idx += num_paths;
}
cur_idx
}

154
compiler/rustc_mir_transform/src/coverage/mod.rs
View File

@@ -114,16 +114,16 @@ fn instrument_function_for_coverage<'tcx>(tcx: TyCtxt<'tcx>, mir_body: &mut mir:
inject_mcdc_statements(mir_body, &basic_coverage_blocks, &extracted_mappings);
let mcdc_num_condition_bitmaps = extracted_mappings
.mcdc_decisions
.mcdc_mappings
.iter()
.map(|&mappings::MCDCDecision { decision_depth, .. }| decision_depth)
.map(|&(mappings::MCDCDecision { decision_depth, .. }, _)| decision_depth)
.max()
.map_or(0, |max| usize::from(max) + 1);
mir_body.function_coverage_info = Some(Box::new(FunctionCoverageInfo {
function_source_hash: hir_info.function_source_hash,
num_counters: coverage_counters.num_counters(),
mcdc_bitmap_bytes: extracted_mappings.mcdc_bitmap_bytes,
mcdc_bitmap_bits: extracted_mappings.mcdc_bitmap_bits,
expressions: coverage_counters.into_expressions(),
mappings,
mcdc_num_condition_bitmaps,
@@ -161,9 +161,9 @@ fn create_mappings<'tcx>(
num_bcbs: _,
code_mappings,
branch_pairs,
mcdc_bitmap_bytes: _,
mcdc_branches,
mcdc_decisions,
mcdc_bitmap_bits: _,
mcdc_degraded_branches,
mcdc_mappings,
} = extracted_mappings;
let mut mappings = Vec::new();
@@ -186,26 +186,79 @@ fn create_mappings<'tcx>(
},
));
mappings.extend(mcdc_branches.iter().filter_map(
|&mappings::MCDCBranch { span, true_bcb, false_bcb, condition_info, decision_depth: _ }| {
let term_for_bcb =
|bcb| coverage_counters.term_for_bcb(bcb).expect("all BCBs with spans were given counters");
// MCDC branch mappings are appended with their decisions in case decisions were ignored.
mappings.extend(mcdc_degraded_branches.iter().filter_map(
|&mappings::MCDCBranch {
span,
true_bcb,
false_bcb,
condition_info: _,
true_index: _,
false_index: _,
}| {
let source_region = region_for_span(span)?;
let true_term = term_for_bcb(true_bcb);
let false_term = term_for_bcb(false_bcb);
let kind = match condition_info {
Some(mcdc_params) => MappingKind::MCDCBranch { true_term, false_term, mcdc_params },
None => MappingKind::Branch { true_term, false_term },
};
Some(Mapping { kind, source_region })
Some(Mapping { kind: MappingKind::Branch { true_term, false_term }, source_region })
},
));
mappings.extend(mcdc_decisions.iter().filter_map(
|&mappings::MCDCDecision { span, bitmap_idx, num_conditions, .. }| {
let source_region = region_for_span(span)?;
let kind = MappingKind::MCDCDecision(DecisionInfo { bitmap_idx, num_conditions });
Some(Mapping { kind, source_region })
},
));
for (decision, branches) in mcdc_mappings {
let num_conditions = branches.len() as u16;
let conditions = branches
.into_iter()
.filter_map(
|&mappings::MCDCBranch {
span,
true_bcb,
false_bcb,
condition_info,
true_index: _,
false_index: _,
}| {
let source_region = region_for_span(span)?;
let true_term = term_for_bcb(true_bcb);
let false_term = term_for_bcb(false_bcb);
Some(Mapping {
kind: MappingKind::MCDCBranch {
true_term,
false_term,
mcdc_params: condition_info,
},
source_region,
})
},
)
.collect::<Vec<_>>();
if conditions.len() == num_conditions as usize
&& let Some(source_region) = region_for_span(decision.span)
{
// LLVM requires end index for counter mapping regions.
let kind = MappingKind::MCDCDecision(DecisionInfo {
bitmap_idx: (decision.bitmap_idx + decision.num_test_vectors) as u32,
num_conditions,
});
mappings.extend(
std::iter::once(Mapping { kind, source_region }).chain(conditions.into_iter()),
);
} else {
mappings.extend(conditions.into_iter().map(|mapping| {
let MappingKind::MCDCBranch { true_term, false_term, mcdc_params: _ } =
mapping.kind
else {
unreachable!("all mappings here are MCDCBranch as shown above");
};
Mapping {
kind: MappingKind::Branch { true_term, false_term },
source_region: mapping.source_region,
}
}))
}
}
mappings
}
@@ -274,44 +327,41 @@ fn inject_mcdc_statements<'tcx>(
basic_coverage_blocks: &CoverageGraph,
extracted_mappings: &ExtractedMappings,
) {
// Inject test vector update first because `inject_statement` always insert new statement at
// head.
for &mappings::MCDCDecision {
span: _,
ref end_bcbs,
bitmap_idx,
num_conditions: _,
decision_depth,
} in &extracted_mappings.mcdc_decisions
{
for end in end_bcbs {
let end_bb = basic_coverage_blocks[*end].leader_bb();
for (decision, conditions) in &extracted_mappings.mcdc_mappings {
// Inject test vector update first because `inject_statement` always insert new statement at head.
for &end in &decision.end_bcbs {
let end_bb = basic_coverage_blocks[end].leader_bb();
inject_statement(
mir_body,
CoverageKind::TestVectorBitmapUpdate { bitmap_idx, decision_depth },
CoverageKind::TestVectorBitmapUpdate {
bitmap_idx: decision.bitmap_idx as u32,
decision_depth: decision.decision_depth,
},
end_bb,
);
}
}
for &mappings::MCDCBranch { span: _, true_bcb, false_bcb, condition_info, decision_depth } in
&extracted_mappings.mcdc_branches
{
let Some(condition_info) = condition_info else { continue };
let id = condition_info.condition_id;
let true_bb = basic_coverage_blocks[true_bcb].leader_bb();
inject_statement(
mir_body,
CoverageKind::CondBitmapUpdate { id, value: true, decision_depth },
true_bb,
);
let false_bb = basic_coverage_blocks[false_bcb].leader_bb();
inject_statement(
mir_body,
CoverageKind::CondBitmapUpdate { id, value: false, decision_depth },
false_bb,
);
for &mappings::MCDCBranch {
span: _,
true_bcb,
false_bcb,
condition_info: _,
true_index,
false_index,
} in conditions
{
for (index, bcb) in [(false_index, false_bcb), (true_index, true_bcb)] {
let bb = basic_coverage_blocks[bcb].leader_bb();
inject_statement(
mir_body,
CoverageKind::CondBitmapUpdate {
index: index as u32,
decision_depth: decision.decision_depth,
},
bb,
);
}
}
}
}

8
compiler/rustc_mir_transform/src/errors.rs
View File

@@ -89,6 +89,14 @@ pub(crate) struct FnItemRef {
pub ident: String,
}
#[derive(Diagnostic)]
#[diag(mir_transform_exceeds_mcdc_test_vector_limit)]
pub(crate) struct MCDCExceedsTestVectorLimit {
#[primary_span]
pub(crate) span: Span,
pub(crate) max_num_test_vectors: usize,
}
pub(crate) struct MustNotSupend<'a, 'tcx> {
pub tcx: TyCtxt<'tcx>,
pub yield_sp: Span,