787730 - building tests fails with clang 3.2

Status: RESOLVED FIXED

(Core :: General, defect)

Comment 1

[Jan Beich]

Attachment: Bug 787730 - Don't assume NULL to be a character.

dom/plugins/test/testplugin/nptest.cpp:3595:24: error: assigning
      to 'char' from incompatible type 'nullptr_t'
    *((char*) siteEnd) = NULL;
                       ^ ~~~~
dom/plugins/test/testplugin/nptest.cpp:3597:25: error: assigning
      to 'char' from incompatible type 'nullptr_t'
    *((char*) flagsEnd) = NULL;
                        ^ ~~~~
dom/plugins/test/testplugin/nptest.cpp:3598:21: error: assigning
      to 'char' from incompatible type 'nullptr_t'
    *((char*) next) = NULL;
                    ^ ~~~~

Comment 2

[Jan Beich]

Attachment: Bug 787730 - Don't assume NULL is numeric.

storage/test/test_AsXXX_helpers.cpp:39:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(row->AsSharedUTF8String(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:42:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(row->AsSharedWString(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:45:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(row->AsSharedBlob(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:72:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(stmt->AsSharedUTF8String(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:75:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(stmt->AsSharedWString(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:78:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(stmt->AsSharedBlob(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:86:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(valueArray->AsSharedUTF8String(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:89:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(valueArray->AsSharedWString(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
storage/test/test_AsXXX_helpers.cpp:92:3: error: use of
      overloaded operator '<<' is ambiguous (with operand types 'std::ostringstream'
      (aka 'basic_ostringstream<char>') and 'nullptr_t')
  do_check_eq(valueArray->AsSharedBlob(0, &len), NULL);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Comment 3

[Jan Beich]

Attachment: Bug 787730 - Don't assume NULL to be a character.

Actually, both cases want 'char'.

Comment 4

[(no longer active)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/4485a0ef19bd

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/4485a0ef19bd

Comment 6

[Daniel Holbert [:dholbert]]

This bug's patch was incorrect, for test_AsXXX_helpers.cpp.

The lines there were originally comparing two pointers, and apparently a compiler complained that the null pointer had an ambiguous pointer-type.

The correct fix for that would be to cast it to the correct pointer-type. The fix that landed here, though, was to swap it out for a non-pointer type, which apparently breaks some compilers because now we're comparing a pointer to a non-pointer.

Comment 7

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #6)
> The fix that landed here, though, was to swap it out for a non-pointer type,
> which apparently breaks some compilers because now we're comparing a pointer
> to a non-pointer.

In particular, it broke Jesse's clang build, with errors like:
{
test_AsXXX_helpers.cpp:42:3: error: comparison between pointer and integer
      ('const PRUnichar *' (aka 'const unsigned short *') and 'int')
  do_check_eq(row->AsSharedWString(0, &len), '\0');
  ^           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  ~~~~
}

(Aside: it's also really weird to be comparing a string pointer to '\0'. The former is a pointer-to-characters; the latter is a character, so it looks like we're trying to do string comparison by pointer-equality or something.)

Comment 8

[(no longer active)]

(In reply to comment #7)
> (In reply to Daniel Holbert [:dholbert] from comment #6)
> > The fix that landed here, though, was to swap it out for a non-pointer type,
> > which apparently breaks some compilers because now we're comparing a pointer
> > to a non-pointer.
> 
> In particular, it broke Jesse's clang build, with errors like:
> {
> test_AsXXX_helpers.cpp:42:3: error: comparison between pointer and integer
>       ('const PRUnichar *' (aka 'const unsigned short *') and 'int')
>   do_check_eq(row->AsSharedWString(0, &len), '\0');
>   ^           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  ~~~~
> }

It didn't build just Jesse's build, it broke everybody's who is using a recent clang (me included.)

Comment 9

[Jesse Ruderman]

I filed bug 884022 on this bustage.