Commit Graph

7 Commits

Author SHA1 Message Date
Hubert Tong c6ffe4d76f [clang] Fix message text for `-Wpointer-sign` to account for plain char
The `-Wpointer-sign` warning text is inappropriate for describing the
incompatible pointer conversion between plain `char` and explicitly
`signed`/`unsigned` `char` (whichever plain `char` has the same range
as) and vice versa.

Specifically, in part, it reads "converts between pointers to integer
types with different sign". This patch changes that portion to read
instead as "converts between pointers to integer types where one is of
the unique plain 'char' type and the other is not" when one of the types
is plain `char`.

C17 subclause 6.5.16.1 indicates that the conversions resulting in
`-Wpointer-sign` warnings in assignment-like contexts are constraint
violations. This means that strict conformance requires a diagnostic for
the case where the message text is wrong before this patch. The lack of
an even more specialized warning group is consistent with GCC.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D93999
2021-01-11 18:41:14 -05:00
Hubert Tong f635bcd161 NFC: Pre-commit test: -Wpointer-sign with plain char to [un]signed char
Add tests with bad message text for `-Wpointer-sign` and run them with
both signed and unsigned versions of plain `char`.
2021-01-11 18:41:14 -05:00
Douglas Gregor 4f4946aaaa 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
2010-04-22 00:20:18 +00:00
Douglas Gregor c68e140657 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
2010-04-09 00:35:39 +00:00
Daniel Dunbar 8fbe78f6fc 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
2009-12-15 20:14:24 +00:00
Daniel Dunbar a45cf5b6b0 Rename clang to clang-cc.
Tests and drivers updated, still need to shuffle dirs.

llvm-svn: 67602
2009-03-24 02:24:46 +00:00
Eli Friedman 80160bd483 Partial implementation of PR3342: break out pointer sign
incompatibilities in assignments from other pointer incompatibilities.  
Based off of the patch in PR3342.  (This doesn't implement -Wno-pointer-sign,
but I don't know the driver code very well.)

llvm-svn: 67494
2009-03-22 23:59:44 +00:00