cmGeneratorExpression::Evaluate is a shortcut when only the evaluated string is
needed or an instance of cmCompiledGeneratorExpression cannot be cached.
Fixes: #19686
Provide a standardized way to handle the C++ "standard" headers
customized to be used with current CMake C++ standard constraints.
Offer under directory `cm` headers which can be used as direct
replacements of the standard ones. For example:
#include <cm/string_view>
can be used safely for CMake development in place of the `<string_view>`
standard header.
Fixes: #19491
This patch is generated by a python script that uses regular expressions to
search for string concatenation patterns of the kind
```
std::string str = <ARG0>;
str += <ARG1>;
str += <ARG2>;
...
```
and replaces them with a single `cmStrCat` call
```
std::string str = cmStrCat(<ARG0>, <ARG1>, <ARG2>, ...);
```
If any `<ARGX>` is itself a concatenated string of the kind
```
a + b + c + ...;
```
then `<ARGX>` is split into multiple arguments for the `cmStrCat` call.
If there's a sequence of literals in the `<ARGX>`, then all literals in the
sequence are concatenated and merged into a single literal argument for
the `cmStrCat` call.
Single character strings are converted to single char arguments for
the `cmStrCat` call.
`std::to_string(...)` wrappings are removed from `cmStrCat` arguments,
because it supports numeric types as well as string types.
`arg.substr(x)` arguments to `cmStrCat` are replaced with
`cm::string_view(arg).substr(x)`
This replaces invocations of
- `cmSystemTools::IsInternallyOn` with `cmIsInternallyOn`
- `cmSystemTools::IsNOTFOUND` with `cmIsNOTFOUND`
- `cmSystemTools::IsOn` with `cmIsOn`
- `cmSystemTools::IsOff` with `cmIsOff`
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`)
This changes `cmMakefile::AddDefinition` to take a `cm::string_view` as value
argument instead of a `const char *`.
Benefits are:
- `std::string` can be passed to `cmMakefile::AddDefinition` directly without
the `c_str()` plus string length recomputation fallback.
- Lengths of literals passed to `cmMakefile::AddDefinition` can be computed at
compile time.
In various sources uses of `cmMakefile::AddDefinition` are adapted to avoid
`std::string::c_str` calls and the `std::string` is passed directly.
Uses of `cmMakefile::AddDefinition`, where a `nullptr` `const char*` might
be passed to `cmMakefile::AddDefinition` are extended with `nullptr` checks.
The value of `CMAKE_VS_PLATFORM_NAME` is computed by Visual Studio
generators based on `CMAKE_GENERATOR_PLATFORM` or some default.
Prior to the VS 2019 generator, the default was always `Win32`.
However, for the `Visual Studio 16 2019` generator, the default is
based on the host platform.
Store the default in a new `CMAKE_VS_PLATFORM_NAME_DEFAULT` variable for
use by project code. This is particularly useful in toolchain files
because they are allowed to set `CMAKE_GENERATOR_PLATFORM` and so
`CMAKE_VS_PLATFORM_NAME` is not yet known. Of course the toolchain file
author knows whether it will set `CMAKE_GENERATOR_PLATFORM`, and if not
then `CMAKE_VS_PLATFORM_NAME_DEFAULT` provides the platform name that
will be used.
Fixes: #19177
This refactors a std::vector<std::string> into a class so that
we can extend the features to represent things such as multiple
chained commands in the future.
Make the constructors protected since they should be produced through
factories. Also rename `platform{ => InGenerator}Name` to clarify
the meaning of the argument.
Convert from char* to std::string in flag tables.
Change termination condition from nullptr to empty string in command flag.
Update tables to store empty strings.
While we already support `cmake --build . -- -j`, the options after `--`
are specific to the native build tool. Add new options `--parallel
[<N>]` and `-j [<N>]` to abstract this and map to the proper option
for the native build tool.
None of these usages of `std::list` were inserting or removing elements
in the middle of the structure, so there were no benefits to using it.
Other uses were related to C pointers being stable in a list of strings
whereas in a vector of strings, small pointer optimizations could be
moved and become invalid after a modification to the hosting vector.
None of these uses modified the vector after handing out a C string to
an external store.
