C11 _Bool bitfield diagnostic

Summary: Implement DR262 (for C). This patch will mainly affect bitfields of type _Bool

Reviewers: fraggamuffin, rsmith

Subscribers: hubert.reinterpretcast, cfe-commits

Differential Revision: http://reviews.llvm.org/D10018

llvm-svn: 247618

clang/include/clang/Basic/DiagnosticGroups.td

@@ -32,6 +32,7 @@ def AutoImport : DiagGroup<"auto-import">;
 def GNUBinaryLiteral : DiagGroup<"gnu-binary-literal">;
 def GNUCompoundLiteralInitializer : DiagGroup<"gnu-compound-literal-initializer">;
 def BitFieldConstantConversion : DiagGroup<"bitfield-constant-conversion">;
+def BitFieldWidth : DiagGroup<"bitfield-width">;
 def ConstantConversion :
   DiagGroup<"constant-conversion", [ BitFieldConstantConversion ] >;
 def LiteralConversion : DiagGroup<"literal-conversion">;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -4314,20 +4314,21 @@ def err_bitfield_has_negative_width : Error<
 def err_anon_bitfield_has_negative_width : Error<
   "anonymous bit-field has negative width (%0)">;
 def err_bitfield_has_zero_width : Error<"named bit-field %0 has zero width">;
-def err_bitfield_width_exceeds_type_size : Error<
-  "size of bit-field %0 (%1 bits) exceeds size of its type (%2 bits)">;
-def err_anon_bitfield_width_exceeds_type_size : Error<
-  "size of anonymous bit-field (%0 bits) exceeds size of its type (%1 bits)">;
+def err_bitfield_width_exceeds_type_width : Error<
+  "width of bit-field %0 (%1 bits) exceeds width of its type (%2 bit%s2)">;
+def err_anon_bitfield_width_exceeds_type_width : Error<
+  "width of anonymous bit-field (%0 bits) exceeds width of its type "
+  "(%1 bit%s1)">;
 def err_incorrect_number_of_vector_initializers : Error<
   "number of elements must be either one or match the size of the vector">;
 
 // Used by C++ which allows bit-fields that are wider than the type.
-def warn_bitfield_width_exceeds_type_size: Warning<
-  "size of bit-field %0 (%1 bits) exceeds the size of its type; value will be "
-  "truncated to %2 bits">;
-def warn_anon_bitfield_width_exceeds_type_size : Warning<
-  "size of anonymous bit-field (%0 bits) exceeds size of its type; value will "
-  "be truncated to %1 bits">;
+def warn_bitfield_width_exceeds_type_width: Warning<
+  "width of bit-field %0 (%1 bits) exceeds the width of its type; value will "
+  "be truncated to %2 bit%s2">, InGroup<BitFieldWidth>;
+def warn_anon_bitfield_width_exceeds_type_width : Warning<
+  "width of anonymous bit-field (%0 bits) exceeds width of its type; value "
+  "will be truncated to %1 bit%s1">, InGroup<BitFieldWidth>;
 
 def warn_missing_braces : Warning<
   "suggest braces around initialization of subobject">,

clang/lib/Sema/SemaDecl.cpp

@@ -12625,26 +12625,26 @@ ExprResult Sema::VerifyBitField(SourceLocation FieldLoc,
   }
 
   if (!FieldTy->isDependentType()) {
-    uint64_t TypeSize = Context.getTypeSize(FieldTy);
-    if (Value.getZExtValue() > TypeSize) {
+    uint64_t TypeWidth = Context.getIntWidth(FieldTy);
+    if (Value.ugt(TypeWidth)) {
       if (!getLangOpts().CPlusPlus || IsMsStruct ||
           Context.getTargetInfo().getCXXABI().isMicrosoft()) {
         if (FieldName) 
-          return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_size)
+          return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_width)
             << FieldName << (unsigned)Value.getZExtValue() 
-            << (unsigned)TypeSize;
+            << (unsigned)TypeWidth;
 
-        return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_size)
-          << (unsigned)Value.getZExtValue() << (unsigned)TypeSize;
+        return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_width)
+          << (unsigned)Value.getZExtValue() << (unsigned)TypeWidth;
       }
 
       if (FieldName)
-        Diag(FieldLoc, diag::warn_bitfield_width_exceeds_type_size)
+        Diag(FieldLoc, diag::warn_bitfield_width_exceeds_type_width)
           << FieldName << (unsigned)Value.getZExtValue() 
-          << (unsigned)TypeSize;
+          << (unsigned)TypeWidth;
       else
-        Diag(FieldLoc, diag::warn_anon_bitfield_width_exceeds_type_size)
-          << (unsigned)Value.getZExtValue() << (unsigned)TypeSize;        
+        Diag(FieldLoc, diag::warn_anon_bitfield_width_exceeds_type_width)
+          << (unsigned)Value.getZExtValue() << (unsigned)TypeWidth;        
     }
   }
 

clang/test/CodeGen/bitfield-2.c

@@ -237,7 +237,7 @@ unsigned long long test_5() {
 /***/
 
 struct s6 {
-  _Bool f0 : 2;
+  unsigned f0 : 2;
 };
 
 struct s6 g6 = { 0xF };

clang/test/CodeGenCXX/warn-padded-packed.cpp

@@ -69,7 +69,7 @@ struct S12 {
 
 struct S13 { // expected-warning {{padding size of 'S13' with 6 bits to alignment boundary}}
   char c;
-  bool b : 10; // expected-warning {{size of bit-field 'b' (10 bits) exceeds the size of its type}}
+  bool b : 10; // expected-warning {{width of bit-field 'b' (10 bits) exceeds the width of its type}}
 };
 
 // The warnings are emitted when the layout of the structs is computed, so we have to use them.

clang/test/Misc/warning-flags.c

@@ -18,7 +18,7 @@ This test serves two purposes:
 
 The list of warnings below should NEVER grow.  It should gradually shrink to 0.
 
-CHECK: Warnings without flags (92):
+CHECK: Warnings without flags (90):
 CHECK-NEXT:   ext_excess_initializers
 CHECK-NEXT:   ext_excess_initializers_in_char_array_initializer
 CHECK-NEXT:   ext_expected_semi_decl_list
@@ -44,10 +44,8 @@ CHECK-NEXT:   pp_pragma_once_in_main_file
 CHECK-NEXT:   pp_pragma_sysheader_in_main_file
 CHECK-NEXT:   w_asm_qualifier_ignored
 CHECK-NEXT:   warn_accessor_property_type_mismatch
-CHECK-NEXT:   warn_anon_bitfield_width_exceeds_type_size
 CHECK-NEXT:   warn_arcmt_nsalloc_realloc
 CHECK-NEXT:   warn_asm_label_on_auto_decl
-CHECK-NEXT:   warn_bitfield_width_exceeds_type_size
 CHECK-NEXT:   warn_c_kext
 CHECK-NEXT:   warn_call_to_pure_virtual_member_function_from_ctor_dtor
 CHECK-NEXT:   warn_call_wrong_number_of_arguments

clang/test/Sema/bitfield.c

@@ -6,7 +6,7 @@ struct a {
   int a : -1; // expected-error{{bit-field 'a' has negative width}}
 
   // rdar://6081627
-  int b : 33; // expected-error{{size of bit-field 'b' (33 bits) exceeds size of its type (32 bits)}}
+  int b : 33; // expected-error{{width of bit-field 'b' (33 bits) exceeds width of its type (32 bits)}}
 
   int c : (1 + 0.25); // expected-error{{expression is not an integer constant expression}}
   int d : (int)(1 + 0.25); 
@@ -22,9 +22,12 @@ struct a {
   int g : (_Bool)1;
 
   // PR4017  
-  char : 10;      // expected-error {{size of anonymous bit-field (10 bits) exceeds size of its type (8 bits)}}
+  char : 10;      // expected-error {{width of anonymous bit-field (10 bits) exceeds width of its type (8 bits)}}
   unsigned : -2;  // expected-error {{anonymous bit-field has negative width (-2)}}
   float : 12;     // expected-error {{anonymous bit-field has non-integral type 'float'}}
+
+  _Bool : 2;   // expected-error {{width of anonymous bit-field (2 bits) exceeds width of its type (1 bit)}}
+  _Bool h : 5; // expected-error {{width of bit-field 'h' (5 bits) exceeds width of its type (1 bit)}}
 };
 
 struct b {unsigned x : 2;} x;

clang/test/SemaCXX/bitfield-layout.cpp

@@ -5,25 +5,25 @@
 
 // Simple tests.
 struct Test1 {
-  char c : 9; // expected-warning {{size of bit-field 'c' (9 bits) exceeds the size of its type; value will be truncated to 8 bits}}
+  char c : 9; // expected-warning {{width of bit-field 'c' (9 bits) exceeds the width of its type; value will be truncated to 8 bits}}
 };
 CHECK_SIZE(Test1, 2);
 CHECK_ALIGN(Test1, 1);
 
 struct Test2 {
-  char c : 16; // expected-warning {{size of bit-field 'c' (16 bits) exceeds the size of its type; value will be truncated to 8 bits}}
+  char c : 16; // expected-warning {{width of bit-field 'c' (16 bits) exceeds the width of its type; value will be truncated to 8 bits}}
 };
 CHECK_SIZE(Test2, 2);
 CHECK_ALIGN(Test2, 2);
 
 struct Test3 {
-  char c : 32; // expected-warning {{size of bit-field 'c' (32 bits) exceeds the size of its type; value will be truncated to 8 bits}}
+  char c : 32; // expected-warning {{width of bit-field 'c' (32 bits) exceeds the width of its type; value will be truncated to 8 bits}}
 };
 CHECK_SIZE(Test3, 4);
 CHECK_ALIGN(Test3, 4);
 
 struct Test4 {
-  char c : 64; // expected-warning {{size of bit-field 'c' (64 bits) exceeds the size of its type; value will be truncated to 8 bits}}
+  char c : 64; // expected-warning {{width of bit-field 'c' (64 bits) exceeds the width of its type; value will be truncated to 8 bits}}
 };
 CHECK_SIZE(Test4, 8);
 CHECK_ALIGN(Test4, 8);

clang/test/SemaCXX/constant-expression-cxx11.cpp

@@ -1801,9 +1801,9 @@ namespace Bitfields {
     bool b : 1;
     unsigned u : 5;
     int n : 5;
-    bool b2 : 3;
-    unsigned u2 : 74; // expected-warning {{exceeds the size of its type}}
-    int n2 : 81; // expected-warning {{exceeds the size of its type}}
+    bool b2 : 3; // expected-warning {{exceeds the width of its type}}
+    unsigned u2 : 74; // expected-warning {{exceeds the width of its type}}
+    int n2 : 81; // expected-warning {{exceeds the width of its type}}
   };
 
   constexpr A a = { false, 33, 31, false, 0xffffffff, 0x7fffffff }; // expected-warning 2{{truncation}}

clang/test/SemaCXX/constant-expression-cxx1y.cpp

@@ -872,7 +872,7 @@ namespace Lifetime {
 
 namespace Bitfields {
   struct A {
-    bool b : 3;
+    bool b : 1;
     int n : 4;
     unsigned u : 5;
   };

clang/test/SemaCXX/ms_wide_bitfield.cpp

@@ -1,9 +1,10 @@
 // RUN: %clang_cc1 -fno-rtti -emit-llvm-only -triple i686-pc-win32 -fdump-record-layouts -fsyntax-only -mms-bitfields -verify %s 2>&1
 
 struct A {
-  char a : 9; // expected-error{{size of bit-field 'a' (9 bits) exceeds size of its type (8 bits)}}
-  int b : 33; // expected-error{{size of bit-field 'b' (33 bits) exceeds size of its type (32 bits)}}
-  bool c : 9; // expected-error{{size of bit-field 'c' (9 bits) exceeds size of its type (8 bits)}}
+  char a : 9; // expected-error{{width of bit-field 'a' (9 bits) exceeds width of its type (8 bits)}}
+  int b : 33; // expected-error{{width of bit-field 'b' (33 bits) exceeds width of its type (32 bits)}}
+  bool c : 9; // expected-error{{width of bit-field 'c' (9 bits) exceeds width of its type (1 bit)}}
+  bool d : 3; // expected-error{{width of bit-field 'd' (3 bits) exceeds width of its type (1 bit)}}
 };
 
 int a[sizeof(A) == 1 ? 1 : -1];

clang/test/SemaObjC/class-bitfield.m

@@ -5,7 +5,7 @@ @interface X
   int a : -1; // expected-error{{bit-field 'a' has negative width}}
 
   // rdar://6081627
-  int b : 33; // expected-error{{size of bit-field 'b' (33 bits) exceeds size of its type (32 bits)}}
+  int b : 33; // expected-error{{width of bit-field 'b' (33 bits) exceeds width of its type (32 bits)}}
 
   int c : (1 + 0.25); // expected-error{{expression is not an integer constant expression}}
   int d : (int)(1 + 0.25);