The C++ rules briefly allowed this, but the rule changed nearly 10 years
ago and we never updated our implementation to match. However, we've
warned on this by default for a long time, and no other compiler accepts
(even as an extension).
When a null constant is used in a macro, walk through the macro stack to
determine where the null constant is written and where the context is located.
Only warn if both locations are within the same macro expansion. This helps
function-like macros which involve pointers be treated as if they were
functions.
llvm-svn: 260776
Move the function to get a macro name from DiagnosticRenderer.cpp to Lexer.cpp
so that other files can use it. Lexer now has two functions to get the
immediate macro name, the newly added one is better for diagnostic purposes.
Make -Wnull-conversion use this function for better NULL macro detection.
llvm-svn: 258778
-Wnull-conversion warning.
These functions are basically equivalent to other pointer returning fuctions
which are already excluded by -Wnull-conversion.
llvm-svn: 257231
By storing the instantiated expression back in the ParmVarDecl,
we remove the last need for separately storing the sub-expression
of a CXXDefaultArgExpr. This makes PCH/Modules merging quite
simple: CXXDefaultArgExpr records are serialized as references
to the ParmVarDecl, and we ignore redundant attempts to overwrite
the instantiated expression.
This has some extremely marginal impact on user-facing semantics.
However, the major effect is that it avoids IRGen errors about
conflicting definitions due to lambdas in the argument being
instantiated multiple times while sharing the same mangling.
It should also slightly improve memory usage and module file size.
rdar://23810407
llvm-svn: 256983
When the condition in an if statement, while statement, or for loop is created
during template instantiation, it calls MakeFullExpr with only the condition
expression. However, when these conditions are created for non-templated
code in the Parser, an additional SourceLocation is passed to MakeFullExpr.
The impact of this was that non-dependent templated code could produce
diagnostics that the same code outside templates would not. Adding the missing
SourceLocation makes diagnostics consistent between templated and non-templated
code.
llvm-svn: 256976
This now correctly covers, I believe, all the pointer types:
* 'any' pointers (both function and data normal pointers and ObjC object pointers)
* member pointers (both function and data)
* block pointers
llvm-svn: 158931
This improves the conversion diagnostics (by correctly pointing to the loop
construct for conversions that may've been caused by the contextual conversion
to bool caused by a condition expression) and also causes the NULL conversion
warnings to be correctly suppressed when crossing a macro boundary in such a
context. (previously, since the conversion context location was incorrect, the
suppression could not be performed)
Reported by Nico Weber as feedback to r156826.
llvm-svn: 156901
This fixes the included test case & was reported by Nico Weber.
It's a little bit nasty using the difference in the conversion context, but
seems to me like a not unreasonable solution. I did have to fix up the
conversion context for conditional operators (it seems correct to me to include
the context for which we're actually doing the comparison - across all the
nested conditionals, rather than the innermost conditional which might not
actually have the problematic implicit conversion at all) and template default
arguments (this is a bit of a hack, since we don't have the source location of
the '=' anymore, so I just used the start of the parameter - open to
suggestions there)
llvm-svn: 156861
Moves the bool bail-out down a little in SemaChecking - so now
-Wnull-conversion and -Wliteral-conversion can fire when the target type is
bool.
Also improve the wording/details in the -Wliteral-conversion warning to match
the -Wconstant-conversion.
llvm-svn: 156826
I broke this in r155838 by not actually instantiating non-dependent default arg
expressions. The motivation for that change was to avoid producing duplicate
conversion warnings for such default args (we produce them once when we parse
the template - there's no need to produce them at each instantiation) but
without actually instantiating the default arg, things break in weird ways.
Technically, I think we could still get the right diagnostic experience without
the bugs if we instantiated the non-dependent args (for non-dependent params
only) immediately, rather than lazily. But I'm not sure if such a refactoring/
change would be desirable so here's the conservative fix for now.
llvm-svn: 155893
Apparently we weren't checking default arguments when they were instantiated.
This adds the check, fixes the lack of instantiation caching (which seems like
it was mostly implemented but just missed the last step), and avoids
implementing non-dependent default args (for non-dependent parameter types) as
uninstantiated default arguments (so that we don't warn once for every
instantiation when it's not instantiation dependent).
Reviewed by Richard Smith.
llvm-svn: 155838
For "int i = NULL;" we would produce:
null.cpp:5:11: warning: implicit conversion of NULL constant to integer [-Wconversion]
int i = NULL;
~ ^~~~
null.cpp:1:14: note: expanded from macro 'NULL'
\#define NULL __null
^~~~~~
But we really shouldn't trace that macro expansion back into the header, yet we
still want macro back traces for code like this:
\#define FOO NULL
int i = FOO;
or
\#define FOO int i = NULL;
FOO
While providing appropriate tagging at different levels of the expansion, etc.
The included test case exercises these cases & does some basic validation (to
ensure we don't have macro expansion notes where we shouldn't, and do where we
should) - but doesn't go as far as to validate the source location/ranges
used in those notes and warnings.
llvm-svn: 152940
Original commit message:
Provide -Wnull-conversion separately from -Wconversion.
Like GCC, provide a NULL conversion to non-pointer conversion as a separate
flag, on by default. GCC's flag is "conversion-null" which we provide for
cross compatibility, but in the interests of consistency (with
-Wint-conversion, -Wbool-conversion, etc) the canonical Clang flag is called
-Wnull-conversion.
Patch by Lubos Lunak.
Review feedback by myself, Chandler Carruth, and Chad Rosier.
llvm-svn: 152774
Like GCC, provide a NULL conversion to non-pointer conversion as a separate
flag, on by default. GCC's flag is "conversion-null" which we provide for
cross compatibility, but in the interests of consistency (with
-Wint-conversion, -Wbool-conversion, etc) the canonical Clang flag is called
-Wnull-conversion.
Patch by Lubos Lunak.
Review feedback by myself, Chandler Carruth, and Chad Rosier.
llvm-svn: 152745
Richard Smith