cmMakefile: Let AddDefinition accept a value as 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.

1 files changed, 5 insertions, 6 deletions

diff --git a/Source/cmCreateTestSourceList.cxx b/Source/cmCreateTestSourceList.cxx
index b78493f..427db72 100644
--- a/Source/cmCreateTestSourceList.cxx
+++ b/Source/cmCreateTestSourceList.cxx
@@ -125,16 +125,15 @@ bool cmCreateTestSourceList::InitialPass(std::vector<std::string> const& args,
   }
   if (!extraInclude.empty()) {
     this->Makefile->AddDefinition("CMAKE_TESTDRIVER_EXTRA_INCLUDES",
-                                  extraInclude.c_str());
+                                  extraInclude);
   }
   if (!function.empty()) {
-    this->Makefile->AddDefinition("CMAKE_TESTDRIVER_ARGVC_FUNCTION",
-                                  function.c_str());
+    this->Makefile->AddDefinition("CMAKE_TESTDRIVER_ARGVC_FUNCTION", function);
   }
   this->Makefile->AddDefinition("CMAKE_FORWARD_DECLARE_TESTS",
-                                forwardDeclareCode.c_str());
+                                forwardDeclareCode);
   this->Makefile->AddDefinition("CMAKE_FUNCTION_TABLE_ENTIRES",
-                                functionMapCode.c_str());
+                                functionMapCode);
   bool res = true;
   if (!this->Makefile->ConfigureFile(configFile, driver, false, true, false)) {
     res = false;
@@ -154,6 +153,6 @@ bool cmCreateTestSourceList::InitialPass(std::vector<std::string> const& args,
     sourceListValue += *i;
   }
 
-  this->Makefile->AddDefinition(sourceList, sourceListValue.c_str());
+  this->Makefile->AddDefinition(sourceList, sourceListValue);
   return res;
 }