[Coverage] Fix mapping for do-while loops with terminating statements (llvm#139777)

The current region mapping for do-while loops that contain statements
such as break or continue results in inaccurate line coverage reports
for the line following the loop.

This change handles terminating statements the same way that other loop
constructs do, correcting the region mapping for accurate reports. It
also fixes a fragile test relying on exact line numbers.

Fixes llvm#139122

Author: justincady

clang/lib/CodeGen/CoverageMappingGen.cpp

@@ -1703,14 +1703,13 @@ struct CounterCoverageMappingBuilder
     if (!IsCounterEqual(OutCount, ParentCount)) {
       pushRegion(OutCount);
       GapRegionCounter = OutCount;
+      if (BodyHasTerminateStmt)
+        HasTerminateStmt = true;
     }
 
     // Create Branch Region around condition.
     if (!llvm::EnableSingleByteCoverage)
       createBranchRegion(S->getCond(), BodyCount, BranchCount.Skipped);
-
-    if (BodyHasTerminateStmt)
-      HasTerminateStmt = true;
   }
 
   void VisitForStmt(const ForStmt *S) {

clang/test/CoverageMapping/terminate-statements.cpp

@@ -348,10 +348,20 @@ int elsecondnoret(void) {
 
 // CHECK-LABEL: _Z18statementexprnoretb:
 int statementexprnoret(bool crash) {
-  int rc = ({ if (crash) abort(); 0; }); // CHECK: File 0, 351:35 -> 352:12 = (#0 - #1)
+  int rc = ({ if (crash) abort(); 0; }); // CHECK: File 0, [[@LINE]]:35 -> [[@LINE+1]]:12 = (#0 - #1)
   return rc;                             // CHECK-NOT: Gap
 }
 
+// CHECK-LABEL: _Z13do_with_breaki:
+int do_with_break(int n) {
+  do {
+    if (n == 87) {
+      break;
+    }               // CHECK: File 0, [[@LINE-2]]:18 -> [[@LINE]]:6 = #2
+  } while (0);      // CHECK: File 0, [[@LINE]]:12 -> [[@LINE]]:13 = ((#0 + #1) - #2)
+  return 0;         // CHECK-NOT: Gap,File 0, [[@LINE-1]]:15
+}
+
 int main() {
   foo(0);
   foo(1);
@@ -375,5 +385,6 @@ int main() {
   abstractcondnoret();
   elsecondnoret();
   statementexprnoret(false);
+  do_with_break(0);
   return 0;
 }

compiler-rt/test/profile/Linux/coverage-do-while.c

@@ -0,0 +1,21 @@
+// REQUIRES: lld-available
+// XFAIL: powerpc64-target-arch
+
+// RUN: %clangxx_profgen -fuse-ld=lld -fcoverage-mapping -o %t %s
+// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t
+// RUN: llvm-profdata merge -o %t.profdata %t.profraw
+// RUN: llvm-cov show %t -instr-profile=%t.profdata 2>&1 | FileCheck %s
+
+#include <stdio.h>
+
+// clang-format off
+int main(int argc, char **argv) {           // CHECK:  [[@LINE]]| 1|int main(
+  do {                                      // CHECK:  [[@LINE]]| 1|  do {
+    if (argc == 87) {                       // CHECK:  [[@LINE]]| 1|    if (argc
+      break;                                // CHECK:  [[@LINE]]| 0|      break
+    }                                       // CHECK:  [[@LINE]]| 0|    }
+  } while (0);                              // CHECK:  [[@LINE]]| 1|  } while
+  printf("coverage after do is present\n"); // CHECK:  [[@LINE]]| 1|  printf(
+  return 0;                                 // CHECK:  [[@LINE]]| 1|  return
+}                                           // CHECK:  [[@LINE]]| 1|}
+// clang-format on