From 5ecbe7fcf8bceb91d43a21be872aaef44c01073a Mon Sep 17 00:00:00 2001
From: Nikita Popov <nikita.ppv@gmail.com>
Date: Mon, 5 Apr 2021 10:45:04 +0200
Subject: [PATCH] Explicitly register instrprof pass

Don't use "passes" for this purpose, explicitly insert it into
the correct place in the pipeline instead.
---
 compiler/rustc_codegen_llvm/src/back/write.rs    |  7 ++++++-
 compiler/rustc_codegen_llvm/src/llvm/ffi.rs      |  1 +
 compiler/rustc_codegen_ssa/src/back/write.rs     |  8 ++------
 compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp | 12 +++++++++++-
 4 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 673f5c3c3623..96d24e4f298c 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -472,6 +472,7 @@ pub(crate) unsafe fn optimize_with_new_llvm_pass_manager(
         sanitizer_options.as_ref(),
         pgo_gen_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()),
         pgo_use_path.as_ref().map_or(std::ptr::null(), |s| s.as_ptr()),
+        config.instrument_coverage,
         llvm_selfprofiler,
         selfprofile_before_pass_callback,
         selfprofile_after_pass_callback,
@@ -545,7 +546,7 @@ pub(crate) unsafe fn optimize(
                     llvm::LLVMRustAddPass(fpm, find_pass("lint").unwrap());
                     continue;
                 }
-                if pass_name == "insert-gcov-profiling" || pass_name == "instrprof" {
+                if pass_name == "insert-gcov-profiling" {
                     // Instrumentation must be inserted before optimization,
                     // otherwise LLVM may optimize some functions away which
                     // breaks llvm-cov.
@@ -566,6 +567,10 @@ pub(crate) unsafe fn optimize(
                 }
             }
 
+            if config.instrument_coverage {
+                llvm::LLVMRustAddPass(mpm, find_pass("instrprof").unwrap());
+            }
+
             add_sanitizer_passes(config, &mut extra_passes);
 
             // Some options cause LLVM bitcode to be emitted, which uses ThinLTOBuffers, so we need
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 32b1526f6e44..9a7be0319446 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -2203,6 +2203,7 @@ extern "C" {
         SanitizerOptions: Option<&SanitizerOptions>,
         PGOGenPath: *const c_char,
         PGOUsePath: *const c_char,
+        InstrumentCoverage: bool,
         llvm_selfprofiler: *mut c_void,
         begin_callback: SelfProfileBeforePassCallback,
         end_callback: SelfProfileAfterPassCallback,
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index dce8ab6f0267..dd50a2988594 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -84,6 +84,7 @@ pub struct ModuleConfig {
 
     pub pgo_gen: SwitchWithOptPath,
     pub pgo_use: Option<PathBuf>,
+    pub instrument_coverage: bool,
 
     pub sanitizer: SanitizerSet,
     pub sanitizer_recover: SanitizerSet,
@@ -174,12 +175,6 @@ impl ModuleConfig {
                     if sess.opts.debugging_opts.profile && !is_compiler_builtins {
                         passes.push("insert-gcov-profiling".to_owned());
                     }
-
-                    // The rustc option `-Zinstrument_coverage` injects intrinsic calls to
-                    // `llvm.instrprof.increment()`, which requires the LLVM `instrprof` pass.
-                    if sess.instrument_coverage() {
-                        passes.push("instrprof".to_owned());
-                    }
                     passes
                 },
                 vec![]
@@ -193,6 +188,7 @@ impl ModuleConfig {
                 SwitchWithOptPath::Disabled
             ),
             pgo_use: if_regular!(sess.opts.cg.profile_use.clone(), None),
+            instrument_coverage: if_regular!(sess.instrument_coverage(), false),
 
             sanitizer: if_regular!(sess.opts.debugging_opts.sanitizer, SanitizerSet::empty()),
             sanitizer_recover: if_regular!(
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index 65a988629c3b..7191e9a779c6 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Transforms/Instrumentation.h"
 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
 #include "llvm/Support/TimeProfiler.h"
+#include "llvm/Transforms/Instrumentation/InstrProfiling.h"
 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
@@ -744,7 +745,7 @@ LLVMRustOptimizeWithNewPassManager(
     bool MergeFunctions, bool UnrollLoops, bool SLPVectorize, bool LoopVectorize,
     bool DisableSimplifyLibCalls, bool EmitLifetimeMarkers,
     LLVMRustSanitizerOptions *SanitizerOptions,
-    const char *PGOGenPath, const char *PGOUsePath,
+    const char *PGOGenPath, const char *PGOUsePath, bool InstrumentCoverage,
     void* LlvmSelfProfiler,
     LLVMRustSelfProfileBeforePassCallback BeforePassCallback,
     LLVMRustSelfProfileAfterPassCallback AfterPassCallback) {
@@ -834,6 +835,15 @@ LLVMRustOptimizeWithNewPassManager(
     );
   }
 
+  if (InstrumentCoverage) {
+    PipelineStartEPCallbacks.push_back(
+      [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
+        InstrProfOptions Options;
+        MPM.addPass(InstrProfiling(Options, false));
+      }
+    );
+  }
+
   if (SanitizerOptions) {
     if (SanitizerOptions->SanitizeMemory) {
       MemorySanitizerOptions Options(