[clang] 565e37c - [Coroutines] Fix code coverage for coroutine

[Xun Li via cfe-commits]

Author: Xun Li
Date: 2020-07-01T10:11:40-07:00
New Revision: 565e37c7702d181804c12d36b6010c513c9b3417

URL: https://github.com/llvm/llvm-project/commit/565e37c7702d181804c12d36b6010c513c9b3417
DIFF: https://github.com/llvm/llvm-project/commit/565e37c7702d181804c12d36b6010c513c9b3417.diff

LOG: [Coroutines] Fix code coverage for coroutine

Summary:
Previously, source-based coverage analysis does not work properly for coroutine.
This patch adds processing of coroutine body and co_return in the coverage analysis, so that we can handle them properly.
For coroutine body, we should only look at the actual function body and ignore the compiler-generated things; for co_return, we need to terminate the region similar to return statement.
Added a test, and confirms that it now works properly. (without this patch, the statement after the if statement will be treated wrongly)

Reviewers: lewissbaker, modocache, junparser

Reviewed By: modocache

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82928

Added: 
    clang/test/CoverageMapping/coroutine.cpp

Modified: 
    clang/lib/CodeGen/CoverageMappingGen.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index cdbfc88e7b70..78b268f423cb 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -908,6 +908,18 @@ struct CounterCoverageMappingBuilder
     terminateRegion(S);
   }
 
+  void VisitCoroutineBodyStmt(const CoroutineBodyStmt *S) {
+    extendRegion(S);
+    Visit(S->getBody());
+  }
+
+  void VisitCoreturnStmt(const CoreturnStmt *S) {
+    extendRegion(S);
+    if (S->getOperand())
+      Visit(S->getOperand());
+    terminateRegion(S);
+  }
+
   void VisitCXXThrowExpr(const CXXThrowExpr *E) {
     extendRegion(E);
     if (E->getSubExpr())

diff  --git a/clang/test/CoverageMapping/coroutine.cpp b/clang/test/CoverageMapping/coroutine.cpp
new file mode 100644
index 000000000000..ec1d64e0f970
--- /dev/null
+++ b/clang/test/CoverageMapping/coroutine.cpp
@@ -0,0 +1,45 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fcoroutines-ts -std=c++14 -emit-llvm -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping %s | FileCheck %s
+
+namespace std::experimental {
+template <typename... T>
+struct coroutine_traits;
+
+template <class Promise = void>
+struct coroutine_handle {
+  coroutine_handle() = default;
+  static coroutine_handle from_address(void *) noexcept { return {}; }
+};
+template <>
+struct coroutine_handle<void> {
+  static coroutine_handle from_address(void *) { return {}; }
+  coroutine_handle() = default;
+  template <class PromiseType>
+  coroutine_handle(coroutine_handle<PromiseType>) noexcept {}
+};
+} // namespace std::experimental
+
+struct suspend_always {
+  bool await_ready() noexcept;
+  void await_suspend(std::experimental::coroutine_handle<>) noexcept;
+  void await_resume() noexcept;
+};
+
+template <>
+struct std::experimental::coroutine_traits<int, int> {
+  struct promise_type {
+    int get_return_object();
+    suspend_always initial_suspend();
+    suspend_always final_suspend() noexcept;
+    void return_value(int);
+  };
+};
+
+// CHECK-LABEL: _Z2f1i:
+int f1(int x) {       // CHECK-NEXT: File 0, [[@LINE]]:15 -> [[@LINE+7]]:2 = #0
+  if (x > 42) {       // CHECK-NEXT: File 0, [[@LINE]]:7 -> [[@LINE]]:13 = #0
+    ++x;              // CHECK-NEXT: Gap,File 0, [[@LINE-1]]:14 -> [[@LINE-1]]:15 = #1
+  } else {            // CHECK-NEXT: File 0, [[@LINE-2]]:15 -> [[@LINE]]:4 = #1
+    co_return x + 42; // CHECK-NEXT: Gap,File 0, [[@LINE-1]]:4 -> [[@LINE-1]]:10 = (#0 - #1)
+  }                   // CHECK-NEXT: File 0, [[@LINE-2]]:10 -> [[@LINE]]:4 = (#0 - #1)
+  co_return x;        // CHECK-NEXT: Gap,File 0, [[@LINE-1]]:4 -> [[@LINE]]:3 = #1
+} // CHECK-NEXT: File 0, [[@LINE-1]]:3 -> [[@LINE]]:2 = #1