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, 6 insertions, 0 deletions

diff --git a/Modules/CMakeDetermineCCompiler.cmake b/Modules/CMakeDetermineCCompiler.cmake
index 0d47a60a91..438a98a5d6 100644
--- a/Modules/CMakeDetermineCCompiler.cmake
+++ b/Modules/CMakeDetermineCCompiler.cmake
@@ -158,6 +158,12 @@ if (CMAKE_CROSSCOMPILING  AND NOT _CMAKE_TOOLCHAIN_PREFIX)
     get_filename_component(COMPILER_BASENAME "${CMAKE_C_COMPILER}" NAME)
     if (COMPILER_BASENAME MATCHES "^(.+-)(clang|g?cc)(-[0-9]+\\.[0-9]+\\.[0-9]+)?(\\.exe)?$")
       set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_MATCH_1})
+    elseif("${CMAKE_C_COMPILER_ID}" MATCHES "Clang")
+      set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_C_COMPILER_TARGET}-)
+    elseif(COMPILER_BASENAME MATCHES "qcc(\\.exe)?$")
+      if(CMAKE_C_COMPILER_TARGET MATCHES "gcc_nto([^_le]+)(le)?.*$")
+        set(_CMAKE_TOOLCHAIN_PREFIX nto${CMAKE_MATCH_1}-)
+      endif()
     endif ()
 
     # if "llvm-" is part of the prefix, remove it, since llvm doesn't have its own binutils