find_program: Find programs that are executable but not readable

This fix was first made by commit 86e6349ef7 (find_program: Find
programs that are executable but not readable, 2020-04-04,
v3.18.0-rc1~372^2) but was reverted for compatibility.  Re-introduce it
with a policy for compatibility.

Fixes: #10468

1 files changed, 47 insertions, 1 deletions

diff --git a/Source/cmFindProgramCommand.cxx b/Source/cmFindProgramCommand.cxx
index 4f3fcdd..77728ec 100644
--- a/Source/cmFindProgramCommand.cxx
+++ b/Source/cmFindProgramCommand.cxx
@@ -4,6 +4,7 @@
 
 #include "cmMakefile.h"
 #include "cmMessageType.h"
+#include "cmPolicies.h"
 #include "cmStateTypes.h"
 #include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
@@ -19,6 +20,7 @@ struct cmFindProgramHelper
   cmFindProgramHelper(cmMakefile* makefile, cmFindBase const* base)
     : DebugSearches("find_program", base)
     , Makefile(makefile)
+    , PolicyCMP0109(makefile->GetPolicyStatus(cmPolicies::CMP0109))
   {
 #if defined(_WIN32) || defined(__CYGWIN__) || defined(__MINGW32__)
     // Consider platform-specific extensions.
@@ -48,6 +50,8 @@ struct cmFindProgramHelper
   cmFindBaseDebugState DebugSearches;
   cmMakefile* Makefile;
 
+  cmPolicies::PolicyStatus PolicyCMP0109;
+
   void AddName(std::string const& name) { this->Names.push_back(name); }
   void SetName(std::string const& name)
   {
@@ -85,7 +89,7 @@ struct cmFindProgramHelper
       this->TestNameExt = cmStrCat(name, ext);
       this->TestPath =
         cmSystemTools::CollapseFullPath(this->TestNameExt, path);
-      bool exists = cmSystemTools::FileExists(this->TestPath, true);
+      bool exists = this->FileIsExecutable(this->TestPath);
       exists ? this->DebugSearches.FoundAt(this->TestPath)
              : this->DebugSearches.FailedAt(this->TestPath);
       if (exists) {
@@ -95,6 +99,48 @@ struct cmFindProgramHelper
     }
     return false;
   }
+  bool FileIsExecutable(std::string const& file) const
+  {
+    switch (this->PolicyCMP0109) {
+      case cmPolicies::OLD:
+        return cmSystemTools::FileExists(file, true);
+      case cmPolicies::NEW:
+      case cmPolicies::REQUIRED_ALWAYS:
+      case cmPolicies::REQUIRED_IF_USED:
+        return cmSystemTools::FileIsExecutable(file);
+      default:
+        break;
+    }
+    bool const isExeOld = cmSystemTools::FileExists(file, true);
+    bool const isExeNew = cmSystemTools::FileIsExecutable(file);
+    if (isExeNew == isExeOld) {
+      return isExeNew;
+    }
+    if (isExeNew) {
+      this->Makefile->IssueMessage(
+        MessageType::AUTHOR_WARNING,
+        cmStrCat(cmPolicies::GetPolicyWarning(cmPolicies::CMP0109),
+                 "\n"
+                 "The file\n"
+                 "  ",
+                 file,
+                 "\n"
+                 "is executable but not readable.  "
+                 "CMake is ignoring it for compatibility."));
+    } else {
+      this->Makefile->IssueMessage(
+        MessageType::AUTHOR_WARNING,
+        cmStrCat(cmPolicies::GetPolicyWarning(cmPolicies::CMP0109),
+                 "\n"
+                 "The file\n"
+                 "  ",
+                 file,
+                 "\n"
+                 "is readable but not executable.  "
+                 "CMake is using it for compatibility."));
+    }
+    return isExeOld;
+  }
 };
 
 cmFindProgramCommand::cmFindProgramCommand(cmExecutionStatus& status)