[Coverage] Fix crash when visiting PseudoObjectExpr.

[zequanwu]

Summary

This is a split of D147073.

Fixes #45481

[zequanwu]

Add the crash repro as test case.

[aaron.ballman]

Thank you, this looks much better to me! LGTM, but please add a release note about the fix when landing.

[zequanwu]

Added the missing release note at rG5bab9097ce5b093289e8d40809d02f002febe910.

clang/lib/CodeGen/CoverageMappingGen.cpp

void VisitBinLOr(const BinaryOperator *E) {
     createBranchRegion(E->getRHS(), subtractCounters(RHSExecCnt, RHSFalseCnt),
                        RHSFalseCnt);
   }
 
   void VisitLambdaExpr(const LambdaExpr *LE) {
     // Lambdas are treated as their own functions for now, so we shouldn't
     // propagate counts into them.
   }
+
+  void VisitPseudoObjectExpr(const PseudoObjectExpr *POE) {
+    // Just visit syntatic expression as this is what users actually write.
+    VisitStmt(POE->getSyntacticForm());
+  }
+
+  void VisitOpaqueValueExpr(const OpaqueValueExpr* OVE) {
+    Visit(OVE->getSourceExpr());
+  }
 };
 
 } // end anonymous namespace
 
 static void dump(llvm::raw_ostream &OS, StringRef FunctionName,
                  ArrayRef<CounterExpression> Expressions,
                  ArrayRef<CounterMappingRegion> Regions) {
   OS << FunctionName << ":\n";

clang/test/CoverageMapping/if.cpp

-// RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -std=c++2b -triple %itanium_abi_triple -main-file-name if.cpp %s | FileCheck %s
+// RUN: %clang_cc1 -fms-extensions -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -std=c++2b -triple %itanium_abi_triple -main-file-name if.cpp %s | FileCheck %s
 
 int nop() { return 0; }
+struct S {
+   int i;
+   int putprop(int j) {
+      i = j;
+      return i;
+   }
+   __declspec(property(put = putprop)) int the_prop;
+};
 
 // CHECK-LABEL: _Z3foov:
                                 // CHECK-NEXT: [[@LINE+3]]:12 -> [[@LINE+8]]:2 = #0
                                 // CHECK-NEXT: [[@LINE+3]]:15 -> [[@LINE+3]]:19 = #0
                                 // CHECK-NEXT: Branch,File 0, [[@LINE+2]]:15 -> [[@LINE+2]]:19 = 0, 0
 void foo() {                    // CHECK-NEXT: Gap,File 0, [[@LINE+1]]:21 -> [[@LINE+1]]:22 = #2
   if (int j = true ? nop()      // CHECK-NEXT: [[@LINE]]:22 -> [[@LINE]]:27 = #2
                    : nop();     // CHECK-NEXT: [[@LINE]]:22 -> [[@LINE]]:27 = (#0 - #2)
i = i == 0?                   // CHECK-NEXT: Gap,File 0, [[@LINE]]:14 -> [[@LINE+1]]:9 = #5
                                 // CHECK-NEXT: Branch,File 0, [[@LINE+2]]:7 -> [[@LINE+2]]:13 = #6, (#0 - #6)
                                 // CHECK-NEXT: File 0, [[@LINE+1]]:14 -> [[@LINE+1]]:20 = #6
   i = i == 0?i + 12:i + 10;     // CHECK-NEXT: File 0, [[@LINE]]:21 -> [[@LINE]]:27 = (#0 - #6)
 
   // GH-57377
   constexpr int c_i = check_consteval(0);
   check_consteval(i);
 
-  return 0;
+  // GH-45481
+  S s;                    
+  s.the_prop = 0? 1 : 2;        // CHECK-NEXT: File 0, [[@LINE]]:16 -> [[@LINE]]:17 = #0
+                                // CHECK-NEXT: Branch,File 0, [[@LINE-1]]:16 -> [[@LINE-1]]:17 = 0, 0
+                                // CHECK-NEXT: Gap,File 0, [[@LINE-2]]:18 -> [[@LINE-2]]:19 = #7
+                                // CHECK-NEXT: File 0, [[@LINE-3]]:19 -> [[@LINE-3]]:20 = #7
+                                // CHECK-NEXT: File 0, [[@LINE-4]]:23 -> [[@LINE-4]]:24 = (#0 - #7)
+  if (s.the_prop = 1) {         // CHECK-NEXT: File 0, [[@LINE]]:7 -> [[@LINE]]:21 = #0
+     return 1;                  // CHECK-NEXT: Branch,File 0, [[@LINE-1]]:7 -> [[@LINE-1]]:21 = #8, (#0 - #8)
+  }                             // CHECK-NEXT: Gap,File 0, [[@LINE-2]]:22 -> [[@LINE-2]]:23 = #8
+                                // CHECK-NEXT: File 0, [[@LINE-3]]:23 -> [[@LINE-1]]:4 = #8
 }
 
 #define FOO true
 
 // CHECK-LABEL: _Z7ternaryv:
 void ternary() {
   true ? FOO : FOO; // CHECK-NOT: Gap,{{.*}}, [[@LINE]]:8 ->
 }

clang/test/CoverageMapping/strong_order.cpp

+// RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -std=c++2b -triple %itanium_abi_triple -main-file-name if.cpp %s
+
+// No crash for following example.
+// See https://github.com/llvm/llvm-project/issues/45481
+namespace std {
+class strong_ordering;
+
+// Mock how STD defined unspecified parameters for the operators below.
+struct _CmpUnspecifiedParam {
+  consteval
+  _CmpUnspecifiedParam(int _CmpUnspecifiedParam::*) noexcept {}
+};
+
+struct strong_ordering {
+  signed char value;
+
+  friend constexpr bool operator==(strong_ordering v,
+                                   _CmpUnspecifiedParam) noexcept {
+    return v.value == 0;
+  }
+  friend constexpr bool operator<(strong_ordering v,
+                                  _CmpUnspecifiedParam) noexcept {
+    return v.value < 0;
+  }
+  friend constexpr bool operator>(strong_ordering v,
+                                  _CmpUnspecifiedParam) noexcept {
+    return v.value > 0;
+  }
+  friend constexpr bool operator>=(strong_ordering v,
+                                   _CmpUnspecifiedParam) noexcept {
+    return v.value >= 0;
+  }
+  static const strong_ordering equal, greater, less;
+};
+constexpr strong_ordering strong_ordering::equal = {0};
+constexpr strong_ordering strong_ordering::greater = {1};
+constexpr strong_ordering strong_ordering::less = {-1};
+} // namespace std
+
+struct S {
+    friend bool operator<(const S&, const S&);
+    friend bool operator==(const S&, const S&);
+};
+
+struct MyStruct {
+    friend bool operator==(MyStruct const& lhs, MyStruct const& rhs) = delete;
+    friend std::strong_ordering operator<=>(MyStruct const& lhs, MyStruct const& rhs) = default;
+    S value;
+};
+
+void foo(MyStruct bar){
+    (void)(bar <=> bar);
+}