Commit Graph

215 Commits

Author SHA1 Message Date
Eli Friedman eed8ad2057 Add Sema support for __builtin_setjmp/__builtin_longjmp. The primary
reason for adding these is to error out in CodeGen when trying to generate
them instead of silently emitting a call to a non-existent function.

(Note that it is not valid to lower these to setjmp/longjmp; in addition 
to that lowering being different from the intent, setjmp and longjmp 
require a larger buffer.)

llvm-svn: 70658
2009-05-03 04:46:36 +00:00
Chris Lattner cc5d1c2e4e implement -Wformat-security properly, which is enabled by default.
This enables one specific class of non-literal format warnings.

llvm-svn: 70368
2009-04-29 04:59:47 +00:00
Chris Lattner e009a881ea code simplification, no functionality change.
llvm-svn: 70367
2009-04-29 04:49:34 +00:00
Chris Lattner e3fa5aa91c minor code cleanup
llvm-svn: 70361
2009-04-29 04:12:34 +00:00
Mike Stump 5c3285b6fb Fixup semantic analysis for nested blocks, and allow block literal
expressions that can be of static duration to be returned.
Radar 6786551

llvm-svn: 69331
2009-04-17 00:09:41 +00:00
Steve Naroff 439a3e4106 Fix <rdar://problem/6786597> varargs not supported for Blocks under clang.
Teach Sema::SemaBuiltinVAStart() about blocks.

llvm-svn: 69201
2009-04-15 19:33:47 +00:00
Steve Naroff fb46e8658c Move/update recent FIXME (wrt UTF-8 checking for ObjC @-strings).
llvm-svn: 68982
2009-04-13 20:26:29 +00:00
Steve Naroff 8d816d6cb5 CodeGenModule::GetAddrOfConstantCFString():
- Finish up support for converting UTF8->UTF16 to support ObjC @"string" constants.

Remove warning from CheckObjCString.

As the FIXME in the test case indicates, I still have a bug to work out (apparently with \u handling).

llvm-svn: 68245
2009-04-01 21:16:31 +00:00
Ted Kremenek dfd72c2b44 Fix <rdar://problem/6704086> by allowing the format string checking in Sema to
allow non-literal format strings that are variables that (a) permanently bind to
a string constant and (b) whose string constants are resolvable within the same
translation unit.

llvm-svn: 67404
2009-03-20 21:35:28 +00:00
Ted Kremenek 9723bcf60f When checking printf-arguments for functions with '__attribute__ ((format (printf, X, Y)))'
set HasVAListArg to true when 'Y' is 0 (i.e., ignore the data arguments).

This fixes <rdar://problem/6623513>.

llvm-svn: 65642
2009-02-27 17:58:43 +00:00
Douglas Gregor deaad8cc34 Create a new TypeNodes.def file that enumerates all of the types,
giving them rough classifications (normal types, never-canonical
types, always-dependent types, abstract type representations) and
making it far easier to make sure that we've hit all of the cases when
decoding types. 

Switched some switch() statements on the type class over to using this
mechanism, and filtering out those things we don't care about. For
example, CodeGen should never see always-dependent or non-canonical
types, while debug info generation should never see always-dependent
types. More switch() statements on the type class need to be moved 
over to using this approach, so that we'll get warnings when we add a
new type then fail to account for it somewhere in the compiler.

As part of this, some types have been renamed:

  TypeOfExpr -> TypeOfExprType
  FunctionTypeProto -> FunctionProtoType
  FunctionTypeNoProto -> FunctionNoProtoType

There shouldn't be any functionality change...

llvm-svn: 65591
2009-02-26 23:50:07 +00:00
Daniel Dunbar 96f8677e11 Arguments to unordered comparison builtins may need implicit casts.
- <rdar://problem/6094103> sema fails to promote type arguments to __builtin_isgreater (and friends)

llvm-svn: 65059
2009-02-19 19:28:43 +00:00
Chris Lattner 3dd56f96c3 final string diagnostic issue (that I know about):
we used to not account for escapes in strings with
string concat.  Before:

t.m:5:20: warning: field width should have type 'int', but argument has type 'unsigned int'
  printf("\n\n" "\n\n%*d", (unsigned) 1, 1);
                   ^       ~~~~~~~~~~~~

after:

t.m:5:23: warning: field width should have type 'int', but argument has type 'unsigned int'
  printf("\n\n" "\n\n%*d", (unsigned) 1, 1);
                      ^    ~~~~~~~~~~~~

llvm-svn: 64941
2009-02-18 19:26:42 +00:00
Chris Lattner ddb7191920 Next step toward making string diagnostics correct: handle
escapes in the string for subtoken positioning.  This gives
us working examples like:

t.m:5:16: warning: field width should have type 'int', but argument has type 'unsigned int'
  printf("\n\n%*d", (unsigned) 1, 1);
               ^    ~~~~~~~~~~~~

where before the caret pointed two spaces to the left.

llvm-svn: 64940
2009-02-18 19:21:10 +00:00
Chris Lattner ec396b5114 Fix some issues handling sub-token locations that come from macro expansions.
We now emit:

t.m:6:15: warning: field width should have type 'int', but argument has type 'unsigned int'
  printf(STR, (unsigned) 1, 1);
         ^    ~~~~~~~~~~~~
t.m:3:18: note: instantiated from:
#define STR "abc%*ddef"
                 ^

which has the correct location in the string literal in the note line.

llvm-svn: 64936
2009-02-18 18:52:52 +00:00
Chris Lattner 259971431d only get the spelling of a token to get its length if
it needs cleaning.

llvm-svn: 64932
2009-02-18 18:40:20 +00:00
Chris Lattner f638b97fe0 use the full spelling of a string literal token so that trigraphs
and escaped newlines don't throw off the offset computation.

On this testcase:
  printf("abc\
def"
         "%*d", (unsigned) 1, 1);

Before:
t.m:5:5: warning: field width should have type 'int', but argument has type 'unsigned int'
def"
    ^

after:
t.m:6:12: warning: field width should have type 'int', but argument has type 'unsigned int'
         "%*d", (unsigned) 1, 1);
           ^    ~~~~~~~~~~~~

llvm-svn: 64930
2009-02-18 18:34:12 +00:00
Chris Lattner a26fb347a0 Start improving diagnostics that relate to subcharacters of string literals.
First step, handle diagnostics in StringLiteral's that are due to token pasting.

For example, we now handle:
  id str2 = @"foo" 
            "bar"
           @"baz"
           " b\0larg";  // expected-warning {{literal contains NUL character}}

Correctly:

test/SemaObjC/exprs.m:17:15: warning: CFString literal contains NUL character
           " b\0larg";  // expected-warning {{literal contains NUL character}}
           ~~~^~~~~~~

There are several other related issues still to be done.

llvm-svn: 64924
2009-02-18 17:49:48 +00:00
Chris Lattner 6436fb6acb rename CheckBuiltinCFStringArgument -> CheckObjCString
llvm-svn: 64894
2009-02-18 06:01:06 +00:00
Douglas Gregor e711f7052e Add hook to add attributes to function declarations that we know
about, whether they are builtins or not. Use this to add the
appropriate "format" attribute to NSLog, NSLogv, asprintf, and
vasprintf, and to translate builtin attributes (from Builtins.def)
into actual attributes on the function declaration.

Use the "printf" format attribute on function declarations to
determine whether we should do format string checking, rather than
looking at an ad hoc list of builtins and "known" function names.

Be a bit more careful about when we consider a function a "builtin" in
C++.

llvm-svn: 64561
2009-02-14 18:57:46 +00:00
Douglas Gregor 538c3d8459 Make it possible for builtins to expression FILE* arguments, so that
we can define builtins such as fprintf, vfprintf, and
__builtin___fprintf_chk. Give a nice error message when we need to
implicitly declare a function like fprintf.

llvm-svn: 64526
2009-02-14 01:52:53 +00:00
Douglas Gregor ac5d4c5f8e Extend builtin "attribute" syntax to include a notation for
printf-like functions, both builtin functions and those in the
C library. The function-call checker now queries this attribute do
determine if we have a printf-like function, rather than scanning
through the list of "known functions IDs". However, there are 5
functions they are not yet "builtins", so the function-call checker
handles them specifically still:

  - fprintf and vfprintf: the builtins mechanism cannot (yet)
    express FILE* arguments, so these can't be encoded.
  - NSLog: the builtins mechanism cannot (yet) express NSString*
    arguments, so this (and NSLogv) can't be encoded.
  - asprintf and vasprintf: these aren't part of the C99 standard
    library, so we really shouldn't be defining them as builtins in
    the general case (and we don't seem to have the machinery to make
    them builtins only on certain targets and depending on whether
    extensions are enabled).

llvm-svn: 64512
2009-02-14 00:32:47 +00:00
Douglas Gregor b9063fc1b3 Implicitly declare certain C library functions (malloc, strcpy, memmove,
etc.) when we perform name lookup on them. This ensures that we
produce the correct signature for these functions, which has two
practical impacts:

  1) When we're supporting the "implicit function declaration" feature
  of C99, these functions will be implicitly declared with the right
  signature rather than as a function returning "int" with no
  prototype. See PR3541 for the reason why this is important (hint:
  GCC always predeclares these functions).
 
  2) If users attempt to redeclare one of these library functions with
  an incompatible signature, we produce a hard error.

This patch does a little bit of work to give reasonable error
messages. For example, when we hit case #1 we complain that we're
implicitly declaring this function with a specific signature, and then
we give a note that asks the user to include the appropriate header
(e.g., "please include <stdlib.h> or explicitly declare 'malloc'"). In
case #2, we show the type of the implicit builtin that was incorrectly
declared, so the user can see the problem. We could do better here:
for example, when displaying this latter error message we say
something like:

  'strcpy' was implicitly declared here with type 'char *(char *, char
  const *)'

but we should really print out a fake code line showing the
declaration, like this:

  'strcpy' was implicitly declared here as:

    char *strcpy(char *, char const *)

This would also be good for printing built-in candidates with C++
operator overloading.

The set of C library functions supported by this patch includes all
functions from the C99 specification's <stdlib.h> and <string.h> that
(a) are predefined by GCC and (b) have signatures that could cause
codegen issues if they are treated as functions with no prototype
returning and int. Future work could extend this set of functions to
other C library functions that we know about.

llvm-svn: 64504
2009-02-13 23:20:09 +00:00
Ted Kremenek 5a201951ca Overhaul of Stmt allocation:
- Made allocation of Stmt objects using vanilla new/delete a *compiler
  error* by making this new/delete "protected" within class Stmt.
- Now the only way to allocate Stmt objects is by using the new
  operator that takes ASTContext& as an argument.  This ensures that
  all Stmt nodes are allocated from the same (pool) allocator.
- Naturally, these two changes required that *all* creation sites for
  AST nodes use new (ASTContext&).  This is a large patch, but the
  majority of the changes are just this mechanical adjustment.
- The above changes also mean that AST nodes can no longer be
  deallocated using 'delete'.  Instead, one most do
  StmtObject->Destroy(ASTContext&) or do
  ASTContextObject.Deallocate(StmtObject) (the latter not running the
  'Destroy' method).

Along the way I also...
- Made CompoundStmt allocate its array of Stmt* using the allocator in
  ASTContext (previously it used std::vector).  There are a whole
  bunch of other Stmt classes that need to be similarly changed to
  ensure that all memory allocated for ASTs comes from the allocator
  in ASTContext.
- Added a new smart pointer ExprOwningPtr to Sema.h.  This replaces
  the uses of llvm::OwningPtr within Sema, as llvm::OwningPtr used
  'delete' to free memory instead of a Stmt's 'Destroy' method.

Big thanks to Doug Gregor for helping with the acrobatics of making
'new/delete' private and the new smart pointer ExprOwningPtr!

llvm-svn: 63997
2009-02-07 01:47:29 +00:00
Chris Lattner 60f36223a9 move library-specific diagnostic headers into library private dirs. Reduce
redundant #includes.  Patch by Anders Johnsen!

llvm-svn: 63271
2009-01-29 05:15:15 +00:00
Chris Lattner 7368d581c1 Split the single monolithic DiagnosticKinds.def file into one
.def file for each library.  This means that adding a diagnostic
to sema doesn't require all the other libraries to be rebuilt.

Patch by Anders Johnsen!

llvm-svn: 63111
2009-01-27 18:30:58 +00:00
Sebastian Redl c215cfc3e1 Convert more expression actions to smart pointers.
Fix type of logical negation for C++.

llvm-svn: 62475
2009-01-19 00:08:26 +00:00
Ted Kremenek 6dfeb55897 Patch by Roman Divacky:
Extend string-literal checking for printf() format string to handle conditional
ternary operators where both sides are literals.

This fixes PR 3319: http://llvm.org/bugs/show_bug.cgi?id=3319

llvm-svn: 62117
2009-01-12 23:09:09 +00:00
Douglas Gregor c7acfdfe9a Add QualifiedDeclRefExpr, which retains additional source-location
information for declarations that were referenced via a qualified-id,
e.g., N::C::value. We keep track of the location of the start of the
nested-name-specifier. Note that the difference between
QualifiedDeclRefExpr and DeclRefExpr does have an effect on the
semantics of function calls in two ways:
  1) The use of a qualified-id instead of an unqualified-id suppresses
     argument-dependent lookup
  2) If the name refers to a virtual function, the qualified-id
  version will call the function determined statically while the
  unqualified-id version will call the function determined dynamically
  (by looking up the appropriate function in the vtable).

Neither of these features is implemented yet, but we do print out
qualified names for QualifiedDeclRefExprs as part of the AST printing.

llvm-svn: 61789
2009-01-06 05:10:23 +00:00
Eli Friedman bb2b3be9e1 Make error handling for va_start a bit more robust. Fixes PR3213.
llvm-svn: 61055
2008-12-15 22:05:35 +00:00
Chris Lattner 79413956d4 change getCurFunctionDecl to skip through Block contexts to find
the containing block.  Introduce a new getCurFunctionOrMethodDecl
method to check to see if we're in a function or objc method.
Minor cleanups to other related places.  This fixes rdar://6405429.

llvm-svn: 60564
2008-12-04 23:50:19 +00:00
Chris Lattner 1e5665e6be Change a whole lot of diagnostics to take QualType's directly
instead of converting them to strings first.  This also fixes a
bunch of minor inconsistencies in the diagnostics emitted by clang
and adds a bunch of FIXME's to DiagnosticKinds.def.

llvm-svn: 59948
2008-11-24 06:25:27 +00:00
Chris Lattner e3d20d9545 Convert IdentifierInfo's to be printed the same as DeclarationNames
with implicit quotes around them.  This has a bunch of follow-on 
effects and requires tweaking to a whole lot of code.  This causes
a regression in two tests (xfailed) by causing it to emit things like:

  Line 10: duplicate interface declaration for category 'MyClass1' ('Category1')

instead of:

  Line 10: duplicate interface declaration for category 'MyClass1(Category1)'

I will fix this in a follow-up commit.

As part of this, I had to start switching stuff to use ->getDeclName() instead
of Decl::getName() for consistency.  This is good, but I was planning to do this
as an independent patch.  There will be several follow-on patches
to clean up some of the mess, but this patch is already too big.

llvm-svn: 59917
2008-11-23 21:45:46 +00:00
Chris Lattner cedef8d111 merge some simple call diagnostics.
llvm-svn: 59831
2008-11-21 18:44:24 +00:00
Chris Lattner 29e812b905 remove another old-school Diag method.
llvm-svn: 59712
2008-11-20 06:06:08 +00:00
Chris Lattner 4bd8dd8568 stop calling II::getName() unnecesarily in sema
llvm-svn: 59609
2008-11-19 08:23:25 +00:00
Chris Lattner f490e15729 remove one more old-style Diag method.
llvm-svn: 59589
2008-11-19 05:27:50 +00:00
Chris Lattner 3b05413e9d Switch several more Sema Diag methods over. This simplifies the
__builtin_prefetch code to only emit one diagnostic per builtin_prefetch.
While this has nothing to do with the rest of the patch, the code seemed
like overkill when I was updating it.

llvm-svn: 59588
2008-11-19 05:08:23 +00:00
Douglas Gregor ae2fbad373 Updated IdentifierResolver to deal with DeclarationNames. The names of
C++ constructors, destructors, and conversion functions now have a
FETokenInfo field that IdentifierResolver can access, so that these
special names are handled just like ordinary identifiers. A few other
Sema routines now use DeclarationNames instead of IdentifierInfo*'s.

To validate this design, this code also implements parsing and
semantic analysis for id-expressions that name conversion functions,
e.g.,

  return operator bool();

The new parser action ActOnConversionFunctionExpr takes the result of
parsing "operator type-id" and turning it into an expression, using
the IdentifierResolver with the DeclarationName of the conversion
function. ActOnDeclarator pushes those conversion function names into
scope so that the IdentifierResolver can find them, of course.

llvm-svn: 59462
2008-11-17 20:34:05 +00:00
Douglas Gregor 8e1cf608dc Implement initialization of a reference (C++ [dcl.init.ref]) as part
of copy initialization. Other pieces of the puzzle:

  - Try/Perform-ImplicitConversion now handles implicit conversions
    that don't involve references.
  - Try/Perform-CopyInitialization uses
    CheckSingleAssignmentConstraints for C. PerformCopyInitialization
    is now used for all argument passing and returning values from a
    function.
  - Diagnose errors with declaring references and const values without
    an initializer. (Uses a new Action callback, ActOnUninitializedDecl).
  
We do not yet have implicit conversion sequences for reference
binding, which means that we don't have any overloading support for
reference parameters yet.

llvm-svn: 58353
2008-10-29 00:13:59 +00:00
Douglas Gregor f19b2319c9 Rename ExplicitCCastExpr to CStyleCastExpr
llvm-svn: 58331
2008-10-28 15:36:24 +00:00
Douglas Gregor e200adc503 Refactor the expression class hierarchy for casts. Most importantly:
- CastExpr is the root of all casts
  - ImplicitCastExpr is (still) used for all explicit casts
  - ExplicitCastExpr is now the root of all *explicit* casts
  - ExplicitCCastExpr (new name needed!?) is a C-style cast in C or C++
  - CXXFunctionalCastExpr inherits from ExplicitCastExpr
  - CXXNamedCastExpr inherits from ExplicitCastExpr and is the root of all
    of the C++ named cast expression types (static_cast, dynamic_cast, etc.)
  - Added classes CXXStaticCastExpr, CXXDynamicCastExpr, 
    CXXReinterpretCastExpr, and CXXConstCastExpr to 

Also, fixed returned-stack-addr.cpp, which broke once when we fixed
reinterpret_cast to diagnose double->int* conversions and again when
we eliminated implicit conversions to reference types. The fix is in
both testcase and SemaChecking.cpp.

Most of this patch is simply support for the renaming. There's very
little actual change in semantics.

llvm-svn: 58264
2008-10-27 19:41:14 +00:00
Daniel Dunbar dd9b2d16f9 Add support for format string checking of object-size checking
versions of sprintf and friends.
 - Added FIXME that this mechanism should be generalized.

llvm-svn: 56962
2008-10-02 18:44:07 +00:00
Steve Naroff 3b1e172d7e Sema::ActOnBlockReturnStmt(): Need to perform the UsualUnaryConversions on the return type.
Sema::CheckReturnStackAddr(): Make sure we skip over implicit casts.
Added some more test cases...

llvm-svn: 56254
2008-09-16 22:25:10 +00:00
Steve Naroff 2752a17a00 More semantic analysis for blocks...
llvm-svn: 56064
2008-09-10 19:17:48 +00:00
Steve Naroff 8de9c3affe More type checking for blocks. Still incomplete (will hopefully finish up this weekend).
llvm-svn: 55862
2008-09-05 22:11:13 +00:00
Daniel Dunbar b0d34c8e4a Add __builtin_object_size support.
- Currently CodeGen always returns a conservative value for this (-1
   or 0 depending on the context).

llvm-svn: 55735
2008-09-03 21:13:56 +00:00
Argyrios Kyrtzidis 3bab3d21f9 Add ExplicitCastExpr to replace the current CastExpr, and have ImplicitCastExpr and ExplicitCastExpr derive from a common base class (CastExpr):
Expr
  -> CastExpr
     -> ExplicitCastExpr
     -> ImplicitCastExpr 

llvm-svn: 54955
2008-08-18 23:01:59 +00:00
Daniel Dunbar 56fdb6ae69 More #include cleaning
- Kill unnecessary #includes in .cpp files. This is an automatic
   sweep so some things removed are actually used, but happen to be
   included by a previous header. I tried to get rid of the obvious
   examples and this was the easiest way to trim the #includes in one
   fell swoop.
 - We now return to regularly scheduled development.

llvm-svn: 54632
2008-08-11 06:23:49 +00:00
Daniel Dunbar 6e8aa537f8 More #include cleaning
- Drop {Decl.h,DeclObjC.h,IdentifierTable.h} from Expr.h
 - Moved Sema::getCurMethodDecl() out of line (dependent on
   ObjCMethodDecl via dyn_cast).

llvm-svn: 54629
2008-08-11 05:35:13 +00:00
Chris Lattner 7ab824e43d tighten up some code and some wording on diagnostics.
llvm-svn: 54607
2008-08-10 02:05:13 +00:00
Ted Kremenek c3b4c52a4d Fix <rdar://problem/6125909>.
Unify logic in return-of-stack-check (Sema) for casts and implicit casts.

llvm-svn: 54439
2008-08-07 00:49:01 +00:00
Chris Lattner 574dee6cac change more instances of QualType::getCanonicalType to call
ASTContext::getCanonicalType instead (PR2189)

llvm-svn: 54105
2008-07-26 22:17:49 +00:00
Ted Kremenek 870f750434 Format string errors should underling the format string, not the function name.
llvm-svn: 54067
2008-07-25 22:03:03 +00:00
Daniel Dunbar b725726c29 Implement nans, prefetch, and trap builtins.
This closes <rdar://problem/6080720>, support for __builtin_constant_p
has been filed separately.

llvm-svn: 53885
2008-07-21 22:59:13 +00:00
Ted Kremenek a174c5270f Extend va_start checking to include __builtin_stdarg_start.
llvm-svn: 53332
2008-07-09 17:58:53 +00:00
Chris Lattner 9a8d1d9e56 Make a few related changes:
1) add a new ASTContext::getFloatTypeSemantics method.
2) Use it from SemaExpr.cpp, CodeGenTypes.cpp and other places.
3) Change the TargetInfo.h get*Format methods to return their 
   fltSemantics byref instead of by pointer.
4) Change CodeGenFunction::EmitBuiltinExpr to allow builtins which
   sometimes expand specially and othertimes fall back to libm.
5) Add support for __builtin_nan("") to codegen, cases that don't pass
   in an empty string are currently lowered to libm calls.
6) Fix codegen of __builtin_infl.

llvm-svn: 52914
2008-06-30 18:32:54 +00:00
Argyrios Kyrtzidis 853fbea313 Replace CurFunctionDecl and CurMethodDecl with methods getCurFunctionDecl() and getCurMethodDecl() that return the appropriate Decl through CurContext.
llvm-svn: 52852
2008-06-28 06:07:14 +00:00
Ted Kremenek 34f664d443 Introduce preliminary support for NSString format-string checking.
Patch by Nikita Zhuk!

llvm-svn: 52336
2008-06-16 18:00:42 +00:00
Eli Friedman f8353034eb Add __builtin_frame_address and __builtin_return_address gcc builtins to
Sema. No codegen yet.

llvm-svn: 51307
2008-05-20 08:23:37 +00:00
Eli Friedman 823622105e Review nit.
llvm-svn: 51196
2008-05-16 17:54:49 +00:00
Eli Friedman a959a59ac6 Clean up ownership per review comment.
llvm-svn: 51195
2008-05-16 17:51:27 +00:00
Ted Kremenek dd547b1ce9 Fixed another regression introduced by r51113 caused by some refactoring
in Sema::CheckFunctionCall:

  http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20080512/005706.html
  
The bug was that the logic from the helper methods used by CheckFunctionCall
were being inverted (a subtle bug).  This would cause the parser to discard
any valid AST nodes involving several builtins (see patch).

This removes the last regression failure I'm seeing in the test suite: Analysis-Apple/NoReturn.

llvm-svn: 51168
2008-05-15 22:24:49 +00:00
Eli Friedman a1b4ed8003 Implementation of __builtin_shufflevector, a portable builtin capable of
expressing the full flexibility of the LLVM shufflevector instruction.  
The expected immediate usage is in *mmintrin.h, so that they don't 
depend on the mess of gcc-inherited (and not completely implemented)
shuffle builtins.

llvm-svn: 51113
2008-05-14 19:38:39 +00:00
Chris Lattner 7a51313d8a Make a major restructuring of the clang tree: introduce a top-level
lib dir and move all the libraries into it.  This follows the main
llvm tree, and allows the libraries to be built in parallel.  The
top level now enforces that all the libs are built before Driver,
but we don't care what order the libs are built in.  This speeds
up parallel builds, particularly incremental ones.

llvm-svn: 48402
2008-03-15 23:59:48 +00:00