Teach find_library and find_package to search lib32 paths (#11260)

Add a ``FIND_LIBRARY_USE_LIB32_PATHS`` global property analogous to the
``FIND_LIBRARY_USE_LIB64_PATHS`` property.  This helps find commands on
multilib systems that use ``lib32`` directories and either do not have
``lib`` symlinks or point ``lib`` to ``lib64``.

1 files changed, 11 insertions, 0 deletions

diff --git a/Source/cmFindPackageCommand.cxx b/Source/cmFindPackageCommand.cxx
index 7908afe958..1a44d73dc4 100644
--- a/Source/cmFindPackageCommand.cxx
+++ b/Source/cmFindPackageCommand.cxx
@@ -43,6 +43,7 @@ cmFindPackageCommand::cmFindPackageCommand()
   this->UseConfigFiles = true;
   this->UseFindModules = true;
   this->DebugMode = false;
+  this->UseLib32Paths = false;
   this->UseLib64Paths = false;
   this->PolicyScope = true;
   this->VersionMajor = 0;
@@ -110,6 +111,13 @@ bool cmFindPackageCommand::InitialPass(std::vector<std::string> const& args,
     this->LibraryArchitecture = arch;
   }
 
+  // Lookup whether lib32 paths should be used.
+  if (this->Makefile->PlatformIs32Bit() &&
+      this->Makefile->GetState()->GetGlobalPropertyAsBool(
+        "FIND_LIBRARY_USE_LIB32_PATHS")) {
+    this->UseLib32Paths = true;
+  }
+
   // Lookup whether lib64 paths should be used.
   if (this->Makefile->PlatformIs64Bit() &&
       this->Makefile->GetState()->GetGlobalPropertyAsBool(
@@ -1907,6 +1915,9 @@ bool cmFindPackageCommand::SearchPrefix(std::string const& prefix_in)
   if (!this->LibraryArchitecture.empty()) {
     common.push_back("lib/" + this->LibraryArchitecture);
   }
+  if (this->UseLib32Paths) {
+    common.push_back("lib32");
+  }
   if (this->UseLib64Paths) {
     common.push_back("lib64");
   }