Correctly diagnose prototype redeclaration errors in C

We did not implement C99 6.7.5.3p15 fully in that we missed the rule
for compatible function types where a prior declaration has a prototype
an

Correctly diagnose prototype redeclaration errors in C

We did not implement C99 6.7.5.3p15 fully in that we missed the rule
for compatible function types where a prior declaration has a prototype
and a subsequent definition (not just declaration) has an empty
identifier list or an identifier list with a mismatch in parameter
arity. This addresses that situation by issuing an error on code like:

void f(int);
void f() {} // type conflicts with previous declaration

(Note: we already diagnose the other type conflict situations
appropriately, this was the only situation we hadn't covered that I
could find.)

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Add -Wno-strict-prototypes to C tests; NFC

This patch adds -Wno-strict-prototypes to all of the test cases that
use functions without prototypes, but not as the primary concern of the
test. e.g., at

Add -Wno-strict-prototypes to C tests; NFC

This patch adds -Wno-strict-prototypes to all of the test cases that
use functions without prototypes, but not as the primary concern of the
test. e.g., attributes testing whether they can/cannot be applied to a
function without a prototype, etc.

This is done in preparation for enabling -Wstrict-prototypes by
default.

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Keep invalid functions as part of the AST

Differential Revision: http://reviews.llvm.org/D19764

llvm-svn: 272962

Whenever we complain about a failed initialization of a function or
method parameter, provide a note pointing at the parameter itself so
the user does not have to manually look for the function/metho

Whenever we complain about a failed initialization of a function or
method parameter, provide a note pointing at the parameter itself so
the user does not have to manually look for the function/method being
called and match up parameters to arguments. For example, we now get:

t.c:4:5: warning: incompatible pointer types passing 'long *' to
parameter of
type 'int *' [-pedantic]
f(long_ptr);
^~~~~~~~
t.c:1:13: note: passing argument to parameter 'x' here
void f(int *x);
^

llvm-svn: 102038

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Improve diagnostics when we fail to convert from a source type to a
destination type for initialization, assignment, parameter-passing,
etc. The main issue fixed here is that we used rather confusing

Improve diagnostics when we fail to convert from a source type to a
destination type for initialization, assignment, parameter-passing,
etc. The main issue fixed here is that we used rather confusing
wording for diagnostics such as

t.c:2:9: warning: initializing 'char const [2]' discards qualifiers,
expected 'char *' [-pedantic]
char *name = __func__;
^ ~~~~~~~~

We're not initializing a 'char const [2]', we're initializing a 'char
*' with an expression of type 'char const [2]'. Similar problems
existed for other diagnostics in this area, so I've normalized them all
with more precise descriptive text to say what we're
initializing/converting/assigning/etc. from and to. The warning for
the code above is now:

t.c:2:9: warning: initializing 'char *' from an expression of type
'char const [2]' discards qualifiers [-pedantic]
char *name = __func__;
^ ~~~~~~~~

Fixes <rdar://problem/7447179>.

llvm-svn: 100832

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Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead o

Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).

llvm-svn: 91446

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Remove tabs, and whitespace cleanups.

llvm-svn: 81346

Rename clang to clang-cc.

Tests and drivers updated, still need to shuffle dirs.

llvm-svn: 67602

Adopt a more principled approach to invalid declarations:
- If a declaration is an invalid redeclaration of an existing name,
complain about the invalid redeclaration then avoid adding it to

Adopt a more principled approach to invalid declarations:
- If a declaration is an invalid redeclaration of an existing name,
complain about the invalid redeclaration then avoid adding it to
the AST (we can still parse the definition or initializer, if any).
- If the declaration is invalid but there is no prior declaration
with that name, introduce the invalid declaration into the AST
(for later error recovery).
- If the declaration is an invalid redeclaration of a builtin that
starts with __builtin_, we produce an error and drop the
redeclaration. If it is an invalid redeclaration of a library
builtin (e.g., malloc, printf), warn (don't error!) and drop the
redeclaration.

If a user attempts to define a builtin, produce an error and (if it's
a library builtin like malloc) suggest -ffreestanding.

This addresses <rdar://problem/6097585> and PR2892. However, PR3588 is
still going to cause some problems when builtins are redeclared
without a prototype.

llvm-svn: 64639

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Make all the 'redefinition' diagnostics more consistent, and make the
"previously defined here" diagnostics all notes.

llvm-svn: 59920

remove expected-error from #if 0 section of code.

llvm-svn: 59772

Fix PR2042. One remaining issue: we don't currently diagnose

int foobar(int);
int foobar() {}

which requires ifdef'ing out a testcase in predefined-function.c.

llvm-svn: 47236

Sema::MergeFunctionDecl()...make sure diagnostic is accurate (wrt function declarations/definitions). Patch by Carl Lewis!

llvm-svn: 46070

Fix Sema::ActOnDeclarator() to call MergeFunctionDecl for function decls that aren't in scope. Since C functions are in a flat namespace, we need to give them special treatment (when compared with va

Fix Sema::ActOnDeclarator() to call MergeFunctionDecl for function decls that aren't in scope. Since C functions are in a flat namespace, we need to give them special treatment (when compared with variables and typedefs).

llvm-svn: 45789

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Fix ASTContext::typesAreCompatible to allow for int/enum compatibility (C99 6.7.2.2p4).
Fix Sema::MergeFunctionDecl to allow for function type compatibility (by using the predicate on ASTContext). Fu

Fix ASTContext::typesAreCompatible to allow for int/enum compatibility (C99 6.7.2.2p4).
Fix Sema::MergeFunctionDecl to allow for function type compatibility (by using the predicate on ASTContext). Function types don't have to be identical to be compatible...

llvm-svn: 45784

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Improve function decl merging, patch by Oliver Hunt!

llvm-svn: 44253