1 files changed, 70 insertions, 0 deletions
diff --git a/compiler/rustc_mir/src/transform/coverage/debug.rs b/compiler/rustc_mir/src/transform/coverage/debug.rs
new file mode 100644
index 00000000000..0cd2e413da9
--- /dev/null
+++ b/compiler/rustc_mir/src/transform/coverage/debug.rs
@@ -0,0 +1,70 @@
+use super::graph::BasicCoverageBlocks;
+use super::spans::CoverageSpan;
+
+use crate::util::pretty;
+use crate::util::spanview::{self, SpanViewable};
+
+use rustc_middle::mir::{self, TerminatorKind};
+use rustc_middle::ty::TyCtxt;
+
+/// Generates the MIR pass `CoverageSpan`-specific spanview dump file.
+pub(crate) fn dump_coverage_spanview(
+    tcx: TyCtxt<'tcx>,
+    mir_body: &mir::Body<'tcx>,
+    basic_coverage_blocks: &BasicCoverageBlocks,
+    pass_name: &str,
+    coverage_spans: &Vec<CoverageSpan>,
+) {
+    let mir_source = mir_body.source;
+    let def_id = mir_source.def_id();
+
+    let span_viewables = span_viewables(tcx, mir_body, basic_coverage_blocks, &coverage_spans);
+    let mut file = pretty::create_dump_file(tcx, "html", None, pass_name, &0, mir_source)
+        .expect("Unexpected error creating MIR spanview HTML file");
+    let crate_name = tcx.crate_name(def_id.krate);
+    let item_name = tcx.def_path(def_id).to_filename_friendly_no_crate();
+    let title = format!("{}.{} - Coverage Spans", crate_name, item_name);
+    spanview::write_document(tcx, def_id, span_viewables, &title, &mut file)
+        .expect("Unexpected IO error dumping coverage spans as HTML");
+}
+
+/// Converts the computed `BasicCoverageBlock`s into `SpanViewable`s.
+fn span_viewables(
+    tcx: TyCtxt<'tcx>,
+    mir_body: &mir::Body<'tcx>,
+    basic_coverage_blocks: &BasicCoverageBlocks,
+    coverage_spans: &Vec<CoverageSpan>,
+) -> Vec<SpanViewable> {
+    let mut span_viewables = Vec::new();
+    for coverage_span in coverage_spans {
+        let tooltip = coverage_span.format_coverage_statements(tcx, mir_body);
+        let CoverageSpan { span, bcb_leader_bb: bb, .. } = coverage_span;
+        let bcb = &basic_coverage_blocks[*bb];
+        let id = bcb.id();
+        let leader_bb = bcb.leader_bb();
+        span_viewables.push(SpanViewable { bb: leader_bb, span: *span, id, tooltip });
+    }
+    span_viewables
+}
+
+/// Returns a simple string representation of a `TerminatorKind` variant, indenpendent of any
+/// values it might hold.
+pub(crate) fn term_type(kind: &TerminatorKind<'tcx>) -> &'static str {
+    match kind {
+        TerminatorKind::Goto { .. } => "Goto",
+        TerminatorKind::SwitchInt { .. } => "SwitchInt",
+        TerminatorKind::Resume => "Resume",
+        TerminatorKind::Abort => "Abort",
+        TerminatorKind::Return => "Return",
+        TerminatorKind::Unreachable => "Unreachable",
+        TerminatorKind::Drop { .. } => "Drop",
+        TerminatorKind::DropAndReplace { .. } => "DropAndReplace",
+        TerminatorKind::Call { .. } => "Call",
+        TerminatorKind::Assert { .. } => "Assert",
+        TerminatorKind::Yield { .. } => "Yield",
+        TerminatorKind::GeneratorDrop => "GeneratorDrop",
+        TerminatorKind::FalseEdge { .. } => "FalseEdge",
+        TerminatorKind::FalseUnwind { .. } => "FalseUnwind",
+        TerminatorKind::InlineAsm { .. } => "InlineAsm",
+    }
+}