From aed8ef5a4d81bb66917ca31a589d5922c9bcf065 Mon Sep 17 00:00:00 2001
From: Rich Kadel <richkadel@google.com>
Date: Tue, 11 May 2021 20:56:23 -0700
Subject: [PATCH] `coverageinfo` query needs to use the same MIR as codegen

I ran into an error trying to fix dead block coverage and realized the
`coverageinfo` query is getting a different MIR compared to the
codegenned MIR, which can sometimes be a problem during mapgen.

I changed that query to use the `InstandeDef` (which includes the
generic parameter substitutions, prosibly specific to const params)
instead of the `DefId` (without unknown/default const substitutions).
---
 compiler/rustc_codegen_ssa/src/coverageinfo/map.rs |  4 ++--
 compiler/rustc_codegen_ssa/src/mir/coverageinfo.rs |  2 +-
 compiler/rustc_middle/src/query/mod.rs             |  5 ++---
 compiler/rustc_mir/src/transform/coverage/mod.rs   | 12 +-----------
 compiler/rustc_mir/src/transform/coverage/query.rs |  4 ++--
 5 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/compiler/rustc_codegen_ssa/src/coverageinfo/map.rs b/compiler/rustc_codegen_ssa/src/coverageinfo/map.rs
index 4458fd68678..08442c588f8 100644
--- a/compiler/rustc_codegen_ssa/src/coverageinfo/map.rs
+++ b/compiler/rustc_codegen_ssa/src/coverageinfo/map.rs
@@ -49,9 +49,9 @@ pub fn unused(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) -> Self {
     }
 
     fn create(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>, is_used: bool) -> Self {
-        let coverageinfo = tcx.coverageinfo(instance.def_id());
+        let coverageinfo = tcx.coverageinfo(instance.def);
         debug!(
-            "FunctionCoverage::new(instance={:?}) has coverageinfo={:?}. is_used={}",
+            "FunctionCoverage::create(instance={:?}) has coverageinfo={:?}. is_used={}",
             instance, coverageinfo, is_used
         );
         Self {
diff --git a/compiler/rustc_codegen_ssa/src/mir/coverageinfo.rs b/compiler/rustc_codegen_ssa/src/mir/coverageinfo.rs
index 621ec0519c9..a283bf1de76 100644
--- a/compiler/rustc_codegen_ssa/src/mir/coverageinfo.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/coverageinfo.rs
@@ -31,7 +31,7 @@ pub fn codegen_coverage(&self, bx: &mut Bx, coverage: Coverage, scope: SourceSco
                         bx.add_coverage_counter(instance, id, code_region);
                     }
 
-                    let coverageinfo = bx.tcx().coverageinfo(instance.def_id());
+                    let coverageinfo = bx.tcx().coverageinfo(instance.def);
 
                     let fn_name = bx.get_pgo_func_name_var(instance);
                     let hash = bx.const_u64(function_source_hash);
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 3c5440f5b68..e0dd8d5806e 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -335,10 +335,9 @@
 
     /// Returns coverage summary info for a function, after executing the `InstrumentCoverage`
     /// MIR pass (assuming the -Zinstrument-coverage option is enabled).
-    query coverageinfo(key: DefId) -> mir::CoverageInfo {
-        desc { |tcx| "retrieving coverage info from MIR for `{}`", tcx.def_path_str(key) }
+    query coverageinfo(key: ty::InstanceDef<'tcx>) -> mir::CoverageInfo {
+        desc { |tcx| "retrieving coverage info from MIR for `{}`", tcx.def_path_str(key.def_id()) }
         storage(ArenaCacheSelector<'tcx>)
-        cache_on_disk_if { key.is_local() }
     }
 
     /// Returns the name of the file that contains the function body, if instrumented for coverage.
diff --git a/compiler/rustc_mir/src/transform/coverage/mod.rs b/compiler/rustc_mir/src/transform/coverage/mod.rs
index dc21bfbb445..71c244fdd4a 100644
--- a/compiler/rustc_mir/src/transform/coverage/mod.rs
+++ b/compiler/rustc_mir/src/transform/coverage/mod.rs
@@ -156,16 +156,6 @@ fn inject_counters(&'a mut self) {
         let fn_sig_span = self.fn_sig_span;
         let body_span = self.body_span;
 
-<<<<<<< HEAD
-        debug!(
-            "instrumenting {:?}, fn sig span: {}, body span: {}",
-            def_id,
-            source_map.span_to_diagnostic_string(fn_sig_span),
-            source_map.span_to_diagnostic_string(body_span)
-        );
-
-=======
->>>>>>> 476104d0f54 (Simplified body_span and filtered span code)
         let mut graphviz_data = debug::GraphvizData::new();
         let mut debug_used_expressions = debug::UsedExpressions::new();
 
@@ -572,7 +562,7 @@ fn get_body_span<'tcx>(
             if expn_data.is_root() {
                 break;
             }
-            if let ExpnKind::Macro{..} = expn_data.kind {
+            if let ExpnKind::Macro { .. } = expn_data.kind {
                 body_span = expn_data.call_site;
             } else {
                 break;
diff --git a/compiler/rustc_mir/src/transform/coverage/query.rs b/compiler/rustc_mir/src/transform/coverage/query.rs
index 2ba9d1bdc0c..760f16eae6b 100644
--- a/compiler/rustc_mir/src/transform/coverage/query.rs
+++ b/compiler/rustc_mir/src/transform/coverage/query.rs
@@ -120,8 +120,8 @@ fn visit_coverage(&mut self, coverage: &Coverage) {
     }
 }
 
-fn coverageinfo<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> CoverageInfo {
-    let mir_body = mir_body(tcx, def_id);
+fn coverageinfo<'tcx>(tcx: TyCtxt<'tcx>, instance_def: ty::InstanceDef<'tcx>) -> CoverageInfo {
+    let mir_body = tcx.instance_mir(instance_def);
 
     let mut coverage_visitor = CoverageVisitor {
         // num_counters always has at least the `ZERO` counter.