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.

2 files changed, 29 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");
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 63ec576..c308ba8 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -1043,11 +1043,20 @@ cmLocalGenerator::ExpandRuleVariable(std::string const& variable,
       // If this is the compiler then look for the extra variable
       // _COMPILER_ARG1 which must be the first argument to the compiler
       const char* compilerArg1 = 0;
+      const char* compilerTarget = 0;
+      const char* compilerOptionTarget = 0;
       if(actualReplace == "CMAKE_${LANG}_COMPILER")
         {
         std::string arg1 = actualReplace + "_ARG1";
         cmSystemTools::ReplaceString(arg1, "${LANG}", lang);
         compilerArg1 = this->Makefile->GetDefinition(arg1.c_str());
+        compilerTarget
+              = this->Makefile->GetDefinition(
+                (std::string("CMAKE_") + lang + "_COMPILER_TARGET").c_str());
+        compilerOptionTarget
+              = this->Makefile->GetDefinition(
+                (std::string("CMAKE_") + lang +
+                                          "_COMPILE_OPTIONS_TARGET").c_str());
         }
       if(actualReplace.find("${LANG}") != actualReplace.npos)
         {
@@ -1068,6 +1077,12 @@ cmLocalGenerator::ExpandRuleVariable(std::string const& variable,
             ret += " ";
             ret += compilerArg1;
             }
+          if (compilerTarget && compilerOptionTarget)
+            {
+            ret += " ";
+            ret += compilerOptionTarget;
+            ret += compilerTarget;
+            }
           return ret;
           }
         return replace;