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, 8 insertions, 13 deletions

diff --git a/Source/cmInstallCommand.cxx b/Source/cmInstallCommand.cxx
index 51689a2..8b428a9 100644
--- a/Source/cmInstallCommand.cxx
+++ b/Source/cmInstallCommand.cxx
@@ -137,8 +137,7 @@ bool cmInstallCommand::InitialPass(std::vector<std::string> const& args,
   }
 
   // Unknown mode.
-  std::string e = "called with unknown mode ";
-  e += args[0];
+  std::string e = cmStrCat("called with unknown mode ", args[0]);
   this->SetError(e);
   return false;
 }
@@ -188,9 +187,8 @@ bool cmInstallCommand::HandleScriptMode(std::vector<std::string> const& args)
       doing_script = false;
       std::string script = arg;
       if (!cmSystemTools::FileIsFullPath(script)) {
-        script = this->Makefile->GetCurrentSourceDirectory();
-        script += "/";
-        script += arg;
+        script =
+          cmStrCat(this->Makefile->GetCurrentSourceDirectory(), '/', arg);
       }
       if (cmSystemTools::FileIsDirectory(script)) {
         this->SetError("given a directory as value of SCRIPT argument.");
@@ -1123,9 +1121,8 @@ bool cmInstallCommand::HandleDirectoryMode(
       std::string dir = args[i];
       std::string::size_type gpos = cmGeneratorExpression::Find(dir);
       if (gpos != 0 && !cmSystemTools::FileIsFullPath(dir)) {
-        dir = this->Makefile->GetCurrentSourceDirectory();
-        dir += "/";
-        dir += args[i];
+        dir =
+          cmStrCat(this->Makefile->GetCurrentSourceDirectory(), '/', args[i]);
       }
 
       // Make sure the name is a directory.
@@ -1424,8 +1421,7 @@ bool cmInstallCommand::HandleExportMode(std::vector<std::string> const& args)
 
   // Construct the file name.
   if (fname.empty()) {
-    fname = exp;
-    fname += ".cmake";
+    fname = cmStrCat(exp, ".cmake");
 
     if (fname.find_first_of(":/\\") != std::string::npos) {
       std::ostringstream e;
@@ -1482,9 +1478,8 @@ bool cmInstallCommand::MakeFilesFullPath(
     std::string file = relFile;
     std::string::size_type gpos = cmGeneratorExpression::Find(file);
     if (gpos != 0 && !cmSystemTools::FileIsFullPath(file)) {
-      file = this->Makefile->GetCurrentSourceDirectory();
-      file += "/";
-      file += relFile;
+      file =
+        cmStrCat(this->Makefile->GetCurrentSourceDirectory(), '/', relFile);
     }
 
     // Make sure the file is not a directory.