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``.

5 files changed, 27 insertions, 5 deletions

diff --git a/Source/cmFindLibraryCommand.cxx b/Source/cmFindLibraryCommand.cxx
index a4d4dbb..3094fcf 100644
--- a/Source/cmFindLibraryCommand.cxx
+++ b/Source/cmFindLibraryCommand.cxx
@@ -40,11 +40,10 @@ bool cmFindLibraryCommand::InitialPass(std::vector<std::string> const& argsIn,
     return true;
   }
 
-  if (const char* abi_name =
-        this->Makefile->GetDefinition("CMAKE_INTERNAL_PLATFORM_ABI")) {
-    std::string abi = abi_name;
-    if (abi.find("ELF N32") != abi.npos) {
-      // Convert lib to lib32.
+  if (this->Makefile->GetState()->GetGlobalPropertyAsBool(
+        "FIND_LIBRARY_USE_LIB32_PATHS")) {
+    // add special 32 bit paths if this is a 32 bit compile.
+    if (this->Makefile->PlatformIs32Bit()) {
       this->AddArchitecturePaths("32");
     }
   }
diff --git a/Source/cmFindPackageCommand.cxx b/Source/cmFindPackageCommand.cxx
index 7908afe..1a44d73 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");
   }
diff --git a/Source/cmFindPackageCommand.h b/Source/cmFindPackageCommand.h
index eff6b80..9019f1b 100644
--- a/Source/cmFindPackageCommand.h
+++ b/Source/cmFindPackageCommand.h
@@ -148,6 +148,7 @@ private:
   bool NoUserRegistry;
   bool NoSystemRegistry;
   bool DebugMode;
+  bool UseLib32Paths;
   bool UseLib64Paths;
   bool PolicyScope;
   std::string LibraryArchitecture;
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index ca30b3d..eaf6a7d 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -2076,6 +2076,14 @@ bool cmMakefile::IsSet(const std::string& name) const
   return true;
 }
 
+bool cmMakefile::PlatformIs32Bit() const
+{
+  if (const char* sizeof_dptr = this->GetDefinition("CMAKE_SIZEOF_VOID_P")) {
+    return atoi(sizeof_dptr) == 4;
+  }
+  return false;
+}
+
 bool cmMakefile::PlatformIs64Bit() const
 {
   if (const char* sizeof_dptr = this->GetDefinition("CMAKE_SIZEOF_VOID_P")) {
diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index c665b1f..1d9ccd0 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -437,6 +437,9 @@ public:
   bool IsOn(const std::string& name) const;
   bool IsSet(const std::string& name) const;
 
+  /** Return whether the target platform is 32-bit. */
+  bool PlatformIs32Bit() const;
+
   /** Return whether the target platform is 64-bit.  */
   bool PlatformIs64Bit() const;