Source sweep: Use cmStrCat for string concatenation

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)`

1 files changed, 3 insertions, 6 deletions

diff --git a/Source/cmDepends.cxx b/Source/cmDepends.cxx
index 6623d9421f..06a442bffa 100644
--- a/Source/cmDepends.cxx
+++ b/Source/cmDepends.cxx
@@ -236,18 +236,15 @@ void cmDepends::SetIncludePathFromLanguage(const std::string& lang)
 {
   // Look for the new per "TARGET_" variant first:
   const char* includePath = nullptr;
-  std::string includePathVar = "CMAKE_";
-  includePathVar += lang;
-  includePathVar += "_TARGET_INCLUDE_PATH";
+  std::string includePathVar =
+    cmStrCat("CMAKE_", lang, "_TARGET_INCLUDE_PATH");
   cmMakefile* mf = this->LocalGenerator->GetMakefile();
   includePath = mf->GetDefinition(includePathVar);
   if (includePath) {
     cmExpandList(includePath, this->IncludePath);
   } else {
     // Fallback to the old directory level variable if no per-target var:
-    includePathVar = "CMAKE_";
-    includePathVar += lang;
-    includePathVar += "_INCLUDE_PATH";
+    includePathVar = cmStrCat("CMAKE_", lang, "_INCLUDE_PATH");
     includePath = mf->GetDefinition(includePathVar);
     if (includePath) {
       cmExpandList(includePath, this->IncludePath);