Add compiler target compile options.

For clang, this allows passing -target <triple> to the compiler, and
for qcc, -V<arch> using toolchain files containing something like

 set(triple arm-linux-gnueabihf)
 set(CMAKE_C_COMPILER "/usr/bin/clang")
 set(CMAKE_C_COMPILER_TARGET ${triple})
 set(CMAKE_CXX_COMPILER "/usr/bin/clang++")
 set(CMAKE_CXX_COMPILER_TARGET ${triple})

or

 set(arch gcc_ntoarmv7le)
 set(CMAKE_C_COMPILER /opt/qnx650/host/linux/x86/usr/bin/qcc)
 set(CMAKE_C_COMPILER_TARGET ${arch})
 set(CMAKE_CXX_COMPILER /opt/qnx650/host/linux/x86/usr/bin/QCC)
 set(CMAKE_CXX_COMPILER_TARGET ${arch})

Both clang and qcc are inherently cross compiler( driver)s.

When cross-compiling with clang, use the CMAKE_${lang}_COMPILER_TARGET
as the _CMAKE_TOOLCHAIN_PREFIX to find the appropriate binutils.

When cross-compiling with QNX qcc, use the CMAKE_${lang}_COMPILER_TARGET
to set the appropriate _CMAKE_TOOLCHAIN_PREFIX.

1 files changed, 14 insertions, 0 deletions

diff --git a/Source/cmCoreTryCompile.cxx b/Source/cmCoreTryCompile.cxx
index 479a699..5bf8ce5 100644
--- a/Source/cmCoreTryCompile.cxx
+++ b/Source/cmCoreTryCompile.cxx
@@ -405,6 +405,20 @@ int cmCoreTryCompile::TryCompileCode(std::vector<std::string> const& argv)
       flag += this->Makefile->GetSafeDefinition("CMAKE_OSX_DEPLOYMENT_TARGET");
       cmakeFlags.push_back(flag);
       }
+    if (const char *cxxDef
+              = this->Makefile->GetDefinition("CMAKE_CXX_COMPILER_TARGET"))
+      {
+      std::string flag="-DCMAKE_CXX_COMPILER_TARGET=";
+      flag += cxxDef;
+      cmakeFlags.push_back(flag);
+      }
+    if (const char *cDef
+                = this->Makefile->GetDefinition("CMAKE_C_COMPILER_TARGET"))
+      {
+      std::string flag="-DCMAKE_C_COMPILER_TARGET=";
+      flag += cDef;
+      cmakeFlags.push_back(flag);
+      }
     if(this->Makefile->GetDefinition("CMAKE_POSITION_INDEPENDENT_CODE")!=0)
       {
       fprintf(fout, "set(CMAKE_POSITION_INDEPENDENT_CODE \"ON\")\n");