whose decl objects are lazily created the first time they are referenced.
Builtin functions are described by the clang/AST/Builtins.def file, which
makes it easy to add new ones.

This is missing two important pieces:
1. Support for the rest of the gcc builtins.
2. Support for target-specific builtins (e.g. __builtin_ia32_emms).

Just adding this builtins reduces the number of implicit function definitions
by 6, reducing the # diagnostics from 550 to 544 when parsing carbon.h.

I need to add all the i386-specific ones to eliminate several hundred more.
ugh.

llvm-svn: 39327

llvm-svn: 39326

translation-unit scope, so we only warn about each implicitly defined
function once.  This cuts the number of errors parsing carbon.h from 616 to 550.

llvm-svn: 39325

proto, then a function body, and they have the same type, don't emit an error.
This reduces #errors from 654->616

llvm-svn: 39324

int foo;
int foo();

llvm-svn: 39323

llvm-svn: 39322

use the folding set.  This eliminates 359 slow lookups from carbon.h (the
rest) but doesn't substantially speed up parse.

llvm-svn: 39320

search.  This reduces 'dumb' lookups from 1225 to 359, speeding up parse
of carbon.h from 0.173 to 0.156s (10%).

llvm-svn: 39319

llvm-svn: 39316

llvm-svn: 39313

"obviously braindead" linear searches.  reduces the number of slow
type lookups from 10K to 883 on carbon.h, speeding up parsing from 3.5 to
1.26s.

llvm-svn: 39312

a foldingset instead.  This reduces the number of slow type lookups from
32K to 10K, which speeds up parsing of carbon.h from 11s to 3.5s.

llvm-svn: 39311

This speeds up parsing carbon.h from 16.0s to 11.3s, reducing slow
lookups from 63K to 32K.

llvm-svn: 39308

llvm-svn: 39307

ASTContext::getTagDeclType by not having to do a linear search.  With this,
parse time for carbon.h drops from 21.8s to 16.0s and # slow lookups drop from
83K to 63K.

llvm-svn: 39306

*** AST Context Stats:
  30594 types total.
    19 builtin types
    3929 pointer types
    308 array types
    18883 function types with proto
    8 function types with no proto
    2988 typename (typedef) types
    4459 tagged types
      1476 struct types
      80 union types
      0 class types
      2903 enum types
  83298 slow type lookups

Next up, making type canonicalization not trivially silly.

llvm-svn: 39305

llvm-svn: 39304

struct q { int a, a; };

with:

t.c:3:19: error: duplicate member 'a'
struct q { int a, a; };
                  ^
t.c:3:16: error: previous definition is here
struct q { int a, a; };
               ^

llvm-svn: 39303

This emits these diagnostics:

t.c:4:14: error: redefinition of 'a'
enum foo22 { a, b };
             ^
t.c:3:5: error: previous definition is here
int a;
    ^
t.c:8:17: error: redefinition of enumerator 'b'
enum foo23 { c, b };
                ^
t.c:4:17: error: previous definition is here
enum foo22 { a, b };
                ^
4 diagnostics generated.


for:

int a;
enum foo22 { a, b };
enum foo23 { c, b };

llvm-svn: 39302

the EnumDecl when the enum type is complete.  This allows us to detect
redefinitions of enums.

llvm-svn: 39300

t.c:2:6: warning: ISO C forbids forward references to 'enum' types
enum foo22* X;
     ^

llvm-svn: 39299

llvm-svn: 39297

t.c:10:15: warning: 'bonk' may not be nested in a struct due to flexible array member
  struct bink bonk;
              ^
t.c:13:14: error: 'struct bink' may not be used as an array element due to flexible array member
struct bink A[123];
             ^
for:

struct bink {
  struct bink *a;
  int X[];  // ok.
};

struct foo {
  int A;
  struct bink bonk;
};

struct bink A[123];

llvm-svn: 39296

struct bork {
  int X[];
};

struct bink {
  struct bink a;
  int X[];  // ok.
};

to:
t.c:3:7: error: flexible array 'X' not allowed in otherwise empty struct
  int X[];
      ^
t.c:7:15: error: field 'a' has incomplete type
  struct bink a;
              ^

llvm-svn: 39295

t.c:5:8: error: field 'foo' declared as a function
  void foo();
       ^

llvm-svn: 39294

like:
struct S { struct S {} X; };

with:
t.c:2:19: error: nested redefinition of 'struct'
struct S { struct S {} X; };
                  ^
t.c:2:1: error: previous definition is here
struct S { struct S {} X; };
^

llvm-svn: 39292

llvm-svn: 39291

C99 6.2.5.

llvm-svn: 39289

Diagnose redefintion of tag types, e.g.:

t.c:7:8: error: redefinition of 'blah'
struct blah {};
       ^
t.c:1:8: error: previous definition is here
struct blah {
       ^
2 diagnostics generated.

llvm-svn: 39286

converting a declspec with TST = struct/union.  Pretty print as well.

llvm-svn: 39284

llvm-svn: 39283

Use it to hold the declaration object for a struct/union.

llvm-svn: 39282

llvm-svn: 39278

rename it to ParseTag.

llvm-svn: 39277

struct blah * P;
union blah *P2;

we now emit:

t.c:2:1: error: redefinition of 'blah' with tag that does not match previous use
union blah *P2;
^
t.c:1:8: error: previous use is here
struct blah * P;
       ^

llvm-svn: 39275

or a definition/declaration of a tag.  This is required to handle
C99 6.7.2.3p11 properly.

llvm-svn: 39274

case and handle identifiers in the same namespace correctly.  This implements
test/Parser/c-namespace.c

llvm-svn: 39272

Make name lookup properly obey C namespaces, simplify decl construction byeliminating the 'next' pointer from the ctor, and add initial support forparsing struct/union tags.

llvm-svn: 39266

eliminating the 'next' pointer from the ctor, and add initial support for
parsing struct/union tags.

llvm-svn: 39265

llvm-svn: 39260