This adds the following functions to `cmStringAlgorithms`:
- `cmIsSpace`
- `cmTrimWhitespace` (moved from `cmSystemTools::TrimWhitespace`)
- `cmEscapeQuotes` (moved from `cmSystemTools::EscapeQuotes`)
- `cmTokenize` (moved from `cmSystemTools::tokenize` and adapted to
accept `cm::string_view`)
Changes
-------
In `cmSystemTools` this
- renames the method `ExpandList` to `ExpandLists` and makes it iterator based
and adds the methods
- `std::vector<std::string> ExpandedLists(InputIt first, InputIt last)`
- `std::vector<std::string> ExpandedListArgument(const std::string& arg,
bool emptyArgs)`
Both return the `std::vector<std::string>` instead of taking a return vector
reference like `cmSystemTools::ExpandLists` and
`cmSystemTools::ExpandListArgument`.
Motivation
----------
Since C++17 return value optimization is mandatory, so returning a
`std:vector<std::string>` from a function should be (at least) as fast as
passing a return vector reference to the function.
The new methods can replace `cmSystemTools::ExpandLists` and
`cmSystemTools::ExpandListArgument` in many cases, which leads to
shorter and simpler syntax.
E.g. the commonly used pattern
```
if (const char* value = X->GetProperty("A_KEY_STRING")) {
std::vector<std::string> valuesList;
cmSystemTools::ExpandListArgument(value, valuesList);
for (std::string const& i : valuesList) {
doSomething(i);
}
}
```
becomes
```
if (const char* value = X->GetProperty("A_KEY_STRING")) {
for (std::string const& i :
cmSystemTools::ExpandedListArgument(value)) {
doSomething(i);
}
}
```
On non-Windows platforms libuv assumes that file descriptors 0-2 are
always used for standard pipes and never for anything else. Otherwise,
libuv may re-use one of these descriptors and then fail an assertion
when closing it. Similarly, On Windows platforms our ConsoleBuf
implementation assumes that the standard handles are always open.
If CMake is run with any standard pipes closed, open them with
`/dev/null` or `NUL` to satisfy these assumptions.
Fixes: #19219
This brings the functionality of `cmake -E create_symlink` and more to scripts.
The default behavior is to create hard links.
The `SYMBOLIC` argument can be used to create symlinks instead.
The `COPY_ON_ERROR` argument enables a fallback to copying the file in case the link fails.
The `RESULT <var>` retrieves the error message generated by the system.
It is set to "0" on success.
Fixes: #16926
The allows `-E create_symlink` to work on Windows. It utilizes
`uv_fs_symlink`. I am still unsure exactly which Windows platforms will
work without requiring Administrator privileges or needing a user/group
with the "Create Symbolic Links" User Rights. It does work with my
Windows 10 Pro with Developer Mode turned on. In the test suite check
that the symlink either worked or failed with a permissions error.
Use recent changes in cmSystemTools::FileExists to check that a symlink
is broken.
