Fix "[clang][UBSan] Add implicit conversion check for bitfields" (#87761)

Fix since #75481 got reverted.

- Explicitly set BitfieldBits to 0 to avoid uninitialized field member
for the integer checks:
```diff
-       llvm::ConstantInt::get(Builder.getInt8Ty(), Check.first)};
+      llvm::ConstantInt::get(Builder.getInt8Ty(), Check.first),
+      llvm::ConstantInt::get(Builder.getInt32Ty(), 0)};
```
- `Value **Previous` was erroneously `Value *Previous` in
`CodeGenFunction::EmitWithOriginalRHSBitfieldAssignment`, fixed now.
- Update following:
```diff
-     if (Kind == CK_IntegralCast) {
+     if (Kind == CK_IntegralCast || Kind == CK_LValueToRValue) {
```
CK_LValueToRValue when going from, e.g., char to char, and
CK_IntegralCast otherwise.
- Make sure that `Value *Previous = nullptr;` is initialized (see
https://github.com/llvm/llvm-project/commit/1189e87951e59a81ee097eae847c06008276fef1)
- Add another extensive testcase
`ubsan/TestCases/ImplicitConversion/bitfield-conversion.c`

---------

Co-authored-by: Vitaly Buka <vitalybuka@gmail.com>

3 files changed, 667 insertions, 10 deletions

diff --git a/compiler-rt/lib/ubsan/ubsan_handlers.cpp b/compiler-rt/lib/ubsan/ubsan_handlers.cpp
index 0f16507d5d88..27d01653f088 100644
--- a/compiler-rt/lib/ubsan/ubsan_handlers.cpp
+++ b/compiler-rt/lib/ubsan/ubsan_handlers.cpp
@@ -555,13 +555,11 @@ static void handleImplicitConversion(ImplicitConversionData *Data,
                                      ReportOptions Opts, ValueHandle Src,
                                      ValueHandle Dst) {
   SourceLocation Loc = Data->Loc.acquire();
-  ErrorType ET = ErrorType::GenericUB;
-
   const TypeDescriptor &SrcTy = Data->FromType;
   const TypeDescriptor &DstTy = Data->ToType;
-
   bool SrcSigned = SrcTy.isSignedIntegerTy();
   bool DstSigned = DstTy.isSignedIntegerTy();
+  ErrorType ET = ErrorType::GenericUB;
 
   switch (Data->Kind) {
   case ICCK_IntegerTruncation: { // Legacy, no longer used.
@@ -594,14 +592,23 @@ static void handleImplicitConversion(ImplicitConversionData *Data,
 
   ScopedReport R(Opts, Loc, ET);
 
+  // In the case we have a bitfield, we want to explicitly say so in the
+  // error message.
   // FIXME: is it possible to dump the values as hex with fixed width?
-
-  Diag(Loc, DL_Error, ET,
-       "implicit conversion from type %0 of value %1 (%2-bit, %3signed) to "
-       "type %4 changed the value to %5 (%6-bit, %7signed)")
-      << SrcTy << Value(SrcTy, Src) << SrcTy.getIntegerBitWidth()
-      << (SrcSigned ? "" : "un") << DstTy << Value(DstTy, Dst)
-      << DstTy.getIntegerBitWidth() << (DstSigned ? "" : "un");
+  if (Data->BitfieldBits)
+    Diag(Loc, DL_Error, ET,
+         "implicit conversion from type %0 of value %1 (%2-bit, %3signed) to "
+         "type %4 changed the value to %5 (%6-bit bitfield, %7signed)")
+        << SrcTy << Value(SrcTy, Src) << SrcTy.getIntegerBitWidth()
+        << (SrcSigned ? "" : "un") << DstTy << Value(DstTy, Dst)
+        << Data->BitfieldBits << (DstSigned ? "" : "un");
+  else
+    Diag(Loc, DL_Error, ET,
+         "implicit conversion from type %0 of value %1 (%2-bit, %3signed) to "
+         "type %4 changed the value to %5 (%6-bit, %7signed)")
+        << SrcTy << Value(SrcTy, Src) << SrcTy.getIntegerBitWidth()
+        << (SrcSigned ? "" : "un") << DstTy << Value(DstTy, Dst)
+        << DstTy.getIntegerBitWidth() << (DstSigned ? "" : "un");
 }
 
 void __ubsan::__ubsan_handle_implicit_conversion(ImplicitConversionData *Data,
diff --git a/compiler-rt/lib/ubsan/ubsan_handlers.h b/compiler-rt/lib/ubsan/ubsan_handlers.h
index 3bd5046de3d7..bae661a56833 100644
--- a/compiler-rt/lib/ubsan/ubsan_handlers.h
+++ b/compiler-rt/lib/ubsan/ubsan_handlers.h
@@ -147,6 +147,7 @@ struct ImplicitConversionData {
   const TypeDescriptor &FromType;
   const TypeDescriptor &ToType;
   /* ImplicitConversionCheckKind */ unsigned char Kind;
+  unsigned int BitfieldBits;
 };
 
 /// \brief Implict conversion that changed the value.
diff --git a/compiler-rt/test/ubsan/TestCases/ImplicitConversion/bitfield-conversion.c b/compiler-rt/test/ubsan/TestCases/ImplicitConversion/bitfield-conversion.c
new file mode 100644
index 000000000000..a0c5ba55c43d
--- /dev/null
+++ b/compiler-rt/test/ubsan/TestCases/ImplicitConversion/bitfield-conversion.c
@@ -0,0 +1,649 @@
+// RUN: %clang   -x c   -fsanitize=implicit-bitfield-conversion -O0 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang   -x c   -fsanitize=implicit-bitfield-conversion -O1 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang   -x c   -fsanitize=implicit-bitfield-conversion -O2 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang   -x c   -fsanitize=implicit-bitfield-conversion -O3 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang   -x c   -fsanitize=implicit-conversion          -O0 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+
+// RUN: %clangxx -x c++ -fsanitize=implicit-bitfield-conversion -O0 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clangxx -x c++ -fsanitize=implicit-bitfield-conversion -O1 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clangxx -x c++ -fsanitize=implicit-bitfield-conversion -O2 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clangxx -x c++ -fsanitize=implicit-bitfield-conversion -O3 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+// RUN: %clangxx -x c++ -fsanitize=implicit-conversion          -O0 %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define UINT4_MIN 0
+#define UINT4_MAX (1 << 4) - 1
+#define UINT5_MIN 0
+#define UINT5_MAX (1 << 5) - 1
+#define INT7_MIN -(1 << 6)
+#define INT7_MAX (1 << 6) - 1
+
+typedef struct _X {
+  uint8_t a : 4;
+  uint32_t b : 5;
+  int8_t c : 7;
+  int32_t d : 16;
+  uint8_t e : 8;
+  uint16_t f : 16;
+  uint32_t g : 32;
+  int8_t h : 8;
+  int16_t i : 16;
+  int32_t j : 32;
+  uint32_t k : 1;
+  int32_t l : 1;
+  _Bool m : 1;
+} X;
+
+void test_a() {
+  X x;
+  uint32_t min = UINT4_MIN;
+  uint32_t max = UINT4_MAX;
+
+  uint8_t v8 = max + 1;
+  uint16_t v16 = (UINT8_MAX + 1) + (max + 1);
+  uint32_t v32 = (UINT8_MAX + 1) + (max + 1);
+
+  // Assignment
+  x.a = v8;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint8_t' (aka 'unsigned char') of value 16 (8-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (4-bit bitfield, unsigned)
+  x.a = v16;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint16_t' (aka 'unsigned short') of value 272 (16-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (4-bit bitfield, unsigned)
+  x.a = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 272 (32-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (4-bit bitfield, unsigned)
+
+  // PrePostIncDec
+  x.a = min;
+  x.a--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value -1 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 15 (4-bit bitfield, unsigned)
+  x.a = min;
+  --x.a;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value -1 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 15 (4-bit bitfield, unsigned)
+
+  x.a = max;
+  x.a++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value 16 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (4-bit bitfield, unsigned)
+  x.a = max;
+  ++x.a;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value 16 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (4-bit bitfield, unsigned)
+
+  x.a = min + 1;
+  x.a++;
+  x.a = min + 1;
+  ++x.a;
+
+  x.a = min + 1;
+  x.a--;
+  x.a = min + 1;
+  --x.a;
+
+  x.a = max - 1;
+  x.a++;
+  x.a = max - 1;
+  ++x.a;
+
+  x.a = max - 1;
+  x.a--;
+  x.a = max - 1;
+  --x.a;
+
+  // Compound assignment
+  x.a = 0;
+  x.a += max;
+  x.a = 0;
+  x.a += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 16 (32-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (4-bit bitfield, unsigned)
+
+  x.a = max;
+  x.a -= max;
+  x.a = max;
+  x.a -= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 4294967295 (32-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 15 (4-bit bitfield, unsigned)
+
+  x.a = 1;
+  x.a *= max;
+  x.a = 1;
+  x.a *= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 16 (32-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (4-bit bitfield, unsigned)
+}
+
+void test_b() {
+  X x;
+  uint32_t min = UINT5_MIN;
+  uint32_t max = UINT5_MAX;
+
+  uint8_t v8 = max + 1;
+  uint16_t v16 = max + 1;
+  uint32_t v32 = max + 1;
+
+  // Assignment
+  x.b = v8;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint8_t' (aka 'unsigned char') of value 32 (8-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (5-bit bitfield, unsigned)
+  x.b = v16;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint16_t' (aka 'unsigned short') of value 32 (16-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (5-bit bitfield, unsigned)
+  x.b = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 32 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (5-bit bitfield, unsigned)
+
+  // PrePostIncDec
+  x.b = min;
+  x.b--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 4294967295 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 31 (5-bit bitfield, unsigned)
+  x.b = min;
+  --x.b;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 4294967295 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 31 (5-bit bitfield, unsigned)
+
+  x.b = max;
+  x.b++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 32 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (5-bit bitfield, unsigned)
+  x.b = max;
+  ++x.b;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 32 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (5-bit bitfield, unsigned)
+
+  x.b = min + 1;
+  x.b++;
+  x.b = min + 1;
+  ++x.b;
+
+  x.b = min + 1;
+  x.b--;
+  x.b = min + 1;
+  --x.b;
+
+  x.b = max - 1;
+  x.b++;
+  x.b = max - 1;
+  ++x.b;
+
+  x.b = max - 1;
+  x.b--;
+  x.b = max - 1;
+  --x.b;
+
+  // Compound assignment
+  x.b = 0;
+  x.b += max;
+  x.b = 0;
+  x.b += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 32 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (5-bit bitfield, unsigned)
+
+  x.b = max;
+  x.b -= max;
+  x.b = max;
+  x.b -= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 4294967295 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 31 (5-bit bitfield, unsigned)
+
+  x.b = 1;
+  x.b *= max;
+  x.b = 1;
+  x.b *= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 32 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (5-bit bitfield, unsigned)
+}
+
+void test_c() {
+  X x;
+  int32_t min = INT7_MIN;
+  int32_t max = INT7_MAX;
+
+  uint8_t v8 = max + 1;
+  uint16_t v16 = (UINT8_MAX + 1) + (max + 1);
+  uint32_t v32 = (UINT8_MAX + 1) + (max + 1);
+
+  // Assignment
+  x.c = v8;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint8_t' (aka 'unsigned char') of value 64 (8-bit, unsigned) to type 'int8_t' (aka 'signed char') changed the value to -64 (7-bit bitfield, signed)
+  x.c = v16;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint16_t' (aka 'unsigned short') of value 320 (16-bit, unsigned) to type 'int8_t' (aka 'signed char') changed the value to -64 (7-bit bitfield, signed)
+  x.c = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 320 (32-bit, unsigned) to type 'int8_t' (aka 'signed char') changed the value to -64 (7-bit bitfield, signed)
+
+  // PrePostIncDec
+  x.c = min;
+  x.c--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value -65 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to 63 (7-bit bitfield, signed)
+  x.c = min;
+  --x.c;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value -65 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to 63 (7-bit bitfield, signed)
+
+  x.c = max;
+  x.c++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value 64 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -64 (7-bit bitfield, signed)
+  x.c = max;
+  ++x.c;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value 64 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -64 (7-bit bitfield, signed)
+
+  x.c = min + 1;
+  x.c++;
+  x.c = min + 1;
+  ++x.c;
+
+  x.c = min + 1;
+  x.c--;
+  x.c = min + 1;
+  --x.c;
+
+  x.c = max - 1;
+  x.c++;
+  x.c = max - 1;
+  ++x.c;
+
+  x.c = max - 1;
+  x.c--;
+  x.c = max - 1;
+  --x.c;
+
+  // Compound assignment
+  x.c = 0;
+  x.c += max;
+  x.c = 0;
+  x.c += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value 64 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -64 (7-bit bitfield, signed)
+
+  x.c = 0;
+  x.c -= (-min);
+  x.c = 0;
+  x.c -= (-min + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value -65 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to 63 (7-bit bitfield, signed)
+
+  x.c = 1;
+  x.c *= max;
+  x.c = 1;
+  x.c *= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value 64 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -64 (7-bit bitfield, signed)
+}
+
+void test_d() {
+  X x;
+  int32_t min = INT16_MIN;
+  int32_t max = INT16_MAX;
+
+  uint32_t v32 = max + 1;
+
+  // Assignment
+  x.d = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 32768 (32-bit, unsigned) to type 'int32_t' (aka 'int') changed the value to -32768 (16-bit bitfield, signed)
+
+  // PrePostIncDec
+  x.d = min;
+  x.d--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value -32769 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to 32767 (16-bit bitfield, signed)
+  x.d = min;
+  --x.d;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value -32769 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to 32767 (16-bit bitfield, signed)
+
+  x.d = max;
+  x.d++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value 32768 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to -32768 (16-bit bitfield, signed)
+  x.d = max;
+  ++x.d;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value 32768 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to -32768 (16-bit bitfield, signed)
+
+  x.d = min + 1;
+  x.d++;
+  x.d = min + 1;
+  ++x.d;
+
+  x.d = min + 1;
+  x.d--;
+  x.d = min + 1;
+  --x.d;
+
+  x.d = max - 1;
+  x.d++;
+  x.d = max - 1;
+  ++x.d;
+
+  x.d = max - 1;
+  x.d--;
+  x.d = max - 1;
+  --x.d;
+
+  // Compound assignment
+  x.d = 0;
+  x.d += max;
+  x.d = 0;
+  x.d += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value 32768 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to -32768 (16-bit bitfield, signed)
+
+  x.d = 0;
+  x.d -= (-min);
+  x.d = 0;
+  x.d -= (-min + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value -32769 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to 32767 (16-bit bitfield, signed)
+
+  x.d = 1;
+  x.d *= max;
+  x.d = 1;
+  x.d *= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value 32768 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to -32768 (16-bit bitfield, signed)
+}
+
+void test_e() {
+  X x;
+  uint32_t min = 0;
+  uint32_t max = UINT8_MAX;
+
+  uint16_t v16 = max + 1;
+  uint32_t v32 = max + 1;
+
+  // Assignment
+  x.e = v16;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint16_t' (aka 'unsigned short') of value 256 (16-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (8-bit bitfield, unsigned)
+  x.e = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 256 (32-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (8-bit bitfield, unsigned)
+
+  // PrePostIncDec
+  x.e = min;
+  x.e--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value -1 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 255 (8-bit bitfield, unsigned)
+  x.e = min;
+  --x.e;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value -1 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 255 (8-bit bitfield, unsigned)
+  x.e = min + 1;
+  x.e--;
+
+  x.e = max;
+  x.e++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value 256 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (8-bit bitfield, unsigned)
+  x.e = max;
+  ++x.e;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value 256 (32-bit, signed) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (8-bit bitfield, unsigned)
+  x.e = max - 1;
+  x.e++;
+
+  // Compound assignment
+  x.e = 0;
+  x.e += max;
+  x.e = 0;
+  x.e += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 256 (32-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 0 (8-bit bitfield, unsigned)
+
+  x.e = max;
+  x.e -= max;
+  x.e = max;
+  x.e -= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 4294967295 (32-bit, unsigned) to type 'uint8_t' (aka 'unsigned char') changed the value to 255 (8-bit bitfield, unsigned)
+}
+
+void test_f() {
+  X x;
+  uint32_t min = 0;
+  uint32_t max = UINT16_MAX;
+
+  uint32_t v32 = max + 1;
+
+  // Assignment
+  x.f = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 65536 (32-bit, unsigned) to type 'uint16_t' (aka 'unsigned short') changed the value to 0 (16-bit bitfield, unsigned)
+
+  // PrePostIncDec
+  x.f = min;
+  x.f--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value -1 (32-bit, signed) to type 'uint16_t' (aka 'unsigned short') changed the value to 65535 (16-bit bitfield, unsigned)
+  x.f = min;
+  --x.f;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value -1 (32-bit, signed) to type 'uint16_t' (aka 'unsigned short') changed the value to 65535 (16-bit bitfield, unsigned)
+  x.f = min + 1;
+  x.f--;
+
+  x.f = max;
+  x.f++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value 65536 (32-bit, signed) to type 'uint16_t' (aka 'unsigned short') changed the value to 0 (16-bit bitfield, unsigned)
+  x.f = max;
+  ++x.f;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value 65536 (32-bit, signed) to type 'uint16_t' (aka 'unsigned short') changed the value to 0 (16-bit bitfield, unsigned)
+  x.f = max - 1;
+  x.f++;
+
+  // Compound assignment
+  x.f = 0;
+  x.f += max;
+  x.f = 0;
+  x.f += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 65536 (32-bit, unsigned) to type 'uint16_t' (aka 'unsigned short') changed the value to 0 (16-bit bitfield, unsigned)
+
+  x.f = max;
+  x.f -= max;
+  x.f = max;
+  x.f -= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 4294967295 (32-bit, unsigned) to type 'uint16_t' (aka 'unsigned short') changed the value to 65535 (16-bit bitfield, unsigned)
+}
+
+void test_g() {
+  X x;
+  uint64_t min = 0;
+  uint64_t max = UINT32_MAX;
+
+  uint64_t v64 = max + 1;
+
+  // Assignment
+  x.g = v64;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint64_t' (aka 'unsigned {{long|long long}}') of value 4294967296 (64-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (32-bit bitfield, unsigned)
+
+  // PrePostIncDec
+  x.g = min;
+  x.g--;
+  x.g = min;
+  --x.g;
+  x.g = min + 1;
+  x.g--;
+
+  x.g = max;
+  x.g++;
+  x.g = max;
+  ++x.g;
+  x.g = max - 1;
+  x.g++;
+
+  // Compound assignment
+  x.g = 0;
+  x.g += max;
+  x.g = 0;
+  x.g += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint64_t' (aka 'unsigned {{long|long long}}') of value 4294967296 (64-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (32-bit bitfield, unsigned)
+
+  x.g = max;
+  x.g -= max;
+  x.g = max;
+  x.g -= (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint64_t' (aka 'unsigned {{long|long long}}') of value 18446744073709551615 (64-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 4294967295 (32-bit bitfield, unsigned)
+}
+
+void test_h() {
+  X x;
+  int32_t min = INT8_MIN;
+  int32_t max = INT8_MAX;
+
+  int16_t v16 = max + 1;
+  int32_t v32 = max + 1;
+
+  // Assignment
+  x.h = v16;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int16_t' (aka 'short') of value 128 (16-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -128 (8-bit bitfield, signed)
+  x.h = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value 128 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -128 (8-bit bitfield, signed)
+
+  // PrePostIncDec
+  x.h = min;
+  x.h--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value -129 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to 127 (8-bit bitfield, signed)
+  x.h = min;
+  --x.h;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value -129 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to 127 (8-bit bitfield, signed)
+  x.h = min + 1;
+  x.h--;
+
+  x.h = max;
+  x.h++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value 128 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -128 (8-bit bitfield, signed)
+  x.h = max;
+  ++x.h;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value 128 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -128 (8-bit bitfield, signed)
+  x.h = max - 1;
+  x.h++;
+
+  // Compound assignment
+  x.h = 0;
+  x.h += max;
+  x.h = 0;
+  x.h += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value 128 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to -128 (8-bit bitfield, signed)
+
+  x.h = 0;
+  x.h -= (-min);
+  x.h = 0;
+  x.h -= (-min + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value -129 (32-bit, signed) to type 'int8_t' (aka 'signed char') changed the value to 127 (8-bit bitfield, signed)
+}
+
+void test_i() {
+  X x;
+  int32_t min = INT16_MIN;
+  int32_t max = INT16_MAX;
+
+  int32_t v32 = max + 1;
+
+  // Assignment
+  x.i = v32;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value 32768 (32-bit, signed) to type 'int16_t' (aka 'short') changed the value to -32768 (16-bit bitfield, signed)
+
+  // PrePostIncDec
+  x.i = min;
+  x.i--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value -32769 (32-bit, signed) to type 'int16_t' (aka 'short') changed the value to 32767 (16-bit bitfield, signed)
+  x.i = min;
+  --x.i;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value -32769 (32-bit, signed) to type 'int16_t' (aka 'short') changed the value to 32767 (16-bit bitfield, signed)
+  x.i = min + 1;
+  x.i--;
+
+  x.i = max;
+  x.i++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int' of value 32768 (32-bit, signed) to type 'int16_t' (aka 'short') changed the value to -32768 (16-bit bitfield, signed)
+  x.i = max;
+  ++x.i;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:3: runtime error: implicit conversion from type 'int' of value 32768 (32-bit, signed) to type 'int16_t' (aka 'short') changed the value to -32768 (16-bit bitfield, signed)
+  x.i = max - 1;
+  x.i++;
+
+  // Compound assignment
+  x.i = 0;
+  x.i += max;
+  x.i = 0;
+  x.i += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value 32768 (32-bit, signed) to type 'int16_t' (aka 'short') changed the value to -32768 (16-bit bitfield, signed)
+
+  x.i = 0;
+  x.i -= (-min);
+  x.i = 0;
+  x.i -= (-min + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int' of value -32769 (32-bit, signed) to type 'int16_t' (aka 'short') changed the value to 32767 (16-bit bitfield, signed)
+}
+
+void test_j() {
+  X x;
+  int64_t min = INT32_MIN;
+  int64_t max = INT32_MAX;
+
+  int64_t v64 = max + 1;
+
+  // Assignment
+  x.j = v64;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int64_t' (aka '{{long|long long}}') of value 2147483648 (64-bit, signed) to type 'int32_t' (aka 'int') changed the value to -2147483648 (32-bit bitfield, signed)
+
+  // PrePostIncDec
+  x.j = min;
+  x.j--;
+  x.j = min;
+  --x.j;
+  x.j = min + 1;
+  x.j--;
+
+  x.j = max;
+  x.j++;
+  x.j = max;
+  ++x.j;
+  x.j = max - 1;
+  x.j++;
+
+  // Compound assignment
+  x.j = 0;
+  x.j += max;
+  x.j = 0;
+  x.j += (max + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int64_t' (aka '{{long|long long}}') of value 2147483648 (64-bit, signed) to type 'int32_t' (aka 'int') changed the value to -2147483648 (32-bit bitfield, signed)
+
+  x.j = 0;
+  x.j -= (-min);
+  x.j = 0;
+  x.j -= (-min + 1);
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int64_t' (aka '{{long|long long}}') of value -2147483649 (64-bit, signed) to type 'int32_t' (aka 'int') changed the value to 2147483647 (32-bit bitfield, signed)
+}
+
+void test_k_l() {
+  X x;
+  int32_t one = 1;
+  int32_t neg_one = -1;
+
+  // k
+  uint8_t v8 = 2;
+  x.k = v8;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint8_t' (aka 'unsigned char') of value 2 (8-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (1-bit bitfield, unsigned)
+  x.k = one;
+  x.k = neg_one;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value -1 (32-bit, signed) to type 'uint32_t' (aka 'unsigned int') changed the value to 1 (1-bit bitfield, unsigned)
+
+  x.k = 0;
+  x.k--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 4294967295 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 1 (1-bit bitfield, unsigned)
+  x.k = 1;
+  x.k--;
+
+  x.k = 1;
+  x.k++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'uint32_t' (aka 'unsigned int') of value 2 (32-bit, unsigned) to type 'uint32_t' (aka 'unsigned int') changed the value to 0 (1-bit bitfield, unsigned)
+  x.k = 0;
+  x.k++;
+
+  // l
+  x.l = v8;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'uint8_t' (aka 'unsigned char') of value 2 (8-bit, unsigned) to type 'int32_t' (aka 'int') changed the value to 0 (1-bit bitfield, signed)
+  x.l = one;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:7: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value 1 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to -1 (1-bit bitfield, signed)
+  x.l = neg_one;
+
+  x.l = 0;
+  x.l--;
+  x.l = -1;
+  x.l--;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value -2 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to 0 (1-bit bitfield, signed)
+
+  x.l = 0;
+  x.l++;
+  // CHECK: {{.*}}bitfield-conversion.c:[[@LINE-1]]:6: runtime error: implicit conversion from type 'int32_t' (aka 'int') of value 1 (32-bit, signed) to type 'int32_t' (aka 'int') changed the value to -1 (1-bit bitfield, signed)
+  x.l = -1;
+  x.l++;
+}
+
+void test_m() {
+  X x;
+
+  uint8_t v8 = 2;
+  x.m = v8;
+}
+
+int main() {
+  test_a();
+  test_b();
+  test_c();
+  test_d();
+  test_e();
+  test_f();
+  test_g();
+  test_h();
+  test_i();
+  test_j();
+  test_k_l();
+  test_m();
+  return 0;
+}