Rename and update the wording of
`warn_second_arg_of_va_start_not_last_named_param` to best indicate that
it's actually the last non-variadic parameter instead.
Fixes#131171
Closes#119360.
This bug occurs when passing a VLA to `va_arg`. Since the return value
is inferred to be an array, it triggers
`ScalarExprEmitter::VisitCastExpr`, which converts it to a pointer and
subsequently calls `CodeGenFunction::EmitAggExpr`. At this point,
because the inferred type is an `AggExpr` instead of a `ScalarExpr`,
`ScalarExprEmitter::VisitVAArgExpr` is not invoked, and as a result,
`CodeGenFunction::EmitVariablyModifiedType` is also not called, leading
to the size of the VLA not being retrieved.
The solution is to move the call to
`CodeGenFunction::EmitVariablyModifiedType` into
`CodeGenFunction::EmitVAArg`, ensuring that the size of the VLA is
correctly obtained regardless of whether the expression is an `AggExpr`
or a `ScalarExpr`.
C89 had a questionable feature where the compiler would implicitly
declare a function that the user called but was never previously
declared. The resulting function would be globally declared as
extern int func(); -- a function without a prototype which accepts zero
or more arguments.
C99 removed support for this questionable feature due to severe
security concerns. However, there was no deprecation period; C89 had
the feature, C99 didn't. So Clang (and GCC) both supported the
functionality as an extension in C99 and later modes.
C2x no longer supports that function signature as it now requires all
functions to have a prototype, and given the known security issues with
the feature, continuing to support it as an extension is not tenable.
This patch changes the diagnostic behavior for the
-Wimplicit-function-declaration warning group depending on the language
mode in effect. We continue to warn by default in C89 mode (due to the
feature being dangerous to use). However, because this feature will not
be supported in C2x mode, we've diagnosed it as being invalid for so
long, the security concerns with the feature, and the trivial
workaround for users (declare the function), we now default the
extension warning to an error in C99-C17 mode. This still gives users
an easy workaround if they are extensively using the extension in those
modes (they can disable the warning or use -Wno-error to downgrade the
error), but the new diagnostic makes it more clear that this feature is
not supported and should be avoided. In C2x mode, we no longer allow an
implicit function to be defined and treat the situation the same as any
other lookup failure.
Differential Revision: https://reviews.llvm.org/D122983
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the final batch of tests being updated to add prototypes,
hopefully.
We don't have special checks for BI_va_start in
Sema::CheckBuiltinFunctionCall, so setting the 't' flag for va_start in
Builtins.def disables semantic checking for it. That's not desired, and
IRGen crashes when it tries to generate a call to va_start that doesn't
have at least one argument.
Follow-up to r322573
Fixes PR36565
llvm-svn: 326622
Combine the logic doing the ms_abi/sysv_abi checks into one function so
that each check and its logical opposite are near each other. Now we
don't need two Sema entry points for MS va_start and regular va_start.
Refactor the code that checks if the va_start caller is a function,
block, or obj-c method. We do this in three places, and they are all
buggy for variadic lambdas (PR32737). After this change, I have one
place to apply the functional fix.
NFC
llvm-svn: 301968
The underlying type for an enumeration in C is either char, signed int, or unsigned int. In the case the underlying type is chosen to be char (such as when passing -fshort-enums or using __attribute__((packed)) on the enum declaration), the enumeration can result in undefined behavior. However, when the underlying type is signed int or unsigned int (or long long as an extension), there is no undefined behavior because the types are compatible. This patch silences diagnostics for the latter while retaining the diagnostics for the former.
This patch addresses PR29140.
llvm-svn: 281632
designator" diagnostic with more correct and more human-friendly "cannot take
address of rvalue of type 'T'".
For the case of & &T::f, provide a custom diagnostic, rather than unhelpfully
saying "cannot take address of rvalue of type '<overloaded function type>'".
For the case of &array_temporary, treat it just like a class temporary
(including allowing it as an extension); the existing diagnostic wording
for the class temporary case works fine.
llvm-svn: 174262
- Move a test from test/SemaTemplate/instantiate-expr-3.cpp, it did not belong there
- Incomplete and abstract types are considered hard errors
llvm-svn: 132979
- 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
