ENH: Refactor custom command rule hashing

This simplifies computation of custom command rule hashes to hash
content exactly chosen as the custom commands are generated.
Unfortunately this will change the hashes of existing build trees from
earlier CMake versions, but this is not a big deal.  The change is
necessary so that in the future we can make optional adjustments to
custom command lines at generate time without changing the hashes every
time the option is changed.

1 files changed, 5 insertions, 10 deletions

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index be9b0df..b0a6e83 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -2004,8 +2004,7 @@ cmGlobalGenerator::GetDirectoryContent(std::string const& dir, bool needDisk)
 //----------------------------------------------------------------------------
 void
 cmGlobalGenerator::AddRuleHash(const std::vector<std::string>& outputs,
-                               std::vector<std::string>::const_iterator first,
-                               std::vector<std::string>::const_iterator last)
+                               std::string const& content)
 {
 #if defined(CMAKE_BUILD_WITH_CMAKE)
   // Ignore if there are no outputs.
@@ -2017,16 +2016,12 @@ cmGlobalGenerator::AddRuleHash(const std::vector<std::string>& outputs,
   // Compute a hash of the rule.
   RuleHash hash;
   {
-  unsigned char const* data;
-  int length;
+  unsigned char const* data =
+    reinterpret_cast<unsigned char const*>(content.c_str());
+  int length = static_cast<int>(content.length());
   cmsysMD5* sum = cmsysMD5_New();
   cmsysMD5_Initialize(sum);
-  for(std::vector<std::string>::const_iterator i = first; i != last; ++i)
-    {
-    data = reinterpret_cast<unsigned char const*>(i->c_str());
-    length = static_cast<int>(i->length());
-    cmsysMD5_Append(sum, data, length);
-    }
+  cmsysMD5_Append(sum, data, length);
   cmsysMD5_FinalizeHex(sum, hash.Data);
   cmsysMD5_Delete(sum);
   }