Merge topic 'ninja-compiler-PATH-windows'

e01990999a Ninja: On Windows, select the compiler occurring first in PATH

Acked-by: Kitware Robot <[email protected]>
Merge-request: !4625

Help/release/dev/ninja-compiler-PATH-windows.rst

@@ -0,0 +1,7 @@
+ninja-compiler-PATH-windows
+---------------------------
+
+* On Windows, the :generator:`Ninja` and :generator:`Ninja Multi-Config`
+  generators, when a compiler is not explicitly specified, now select
+  the first compiler (of any name) found in directories listed by the
+  ``PATH`` environment variable.

Modules/CMakeDetermineCompiler.cmake

@@ -53,6 +53,20 @@ macro(_cmake_find_compiler lang)
       NO_DEFAULT_PATH
       DOC "${lang} compiler")
   endif()
+  if(CMAKE_HOST_WIN32 AND CMAKE_GENERATOR MATCHES "Ninja")
+    # On Windows command-line builds, the Makefile generators each imply
+    # a preferred compiler tool.  The Ninja generator does not imply a
+    # compiler tool, so use the compiler that occurs first in PATH.
+    find_program(CMAKE_${lang}_COMPILER
+      NAMES ${CMAKE_${lang}_COMPILER_LIST}
+      NAMES_PER_DIR
+      DOC "${lang} compiler"
+      NO_PACKAGE_ROOT_PATH
+      NO_CMAKE_PATH
+      NO_CMAKE_ENVIRONMENT_PATH
+      NO_CMAKE_SYSTEM_PATH
+      )
+  endif()
   find_program(CMAKE_${lang}_COMPILER NAMES ${CMAKE_${lang}_COMPILER_LIST} DOC "${lang} compiler")
   if(CMAKE_${lang}_COMPILER_INIT AND NOT CMAKE_${lang}_COMPILER)
     set_property(CACHE CMAKE_${lang}_COMPILER PROPERTY VALUE "${CMAKE_${lang}_COMPILER_INIT}")

Tests/RunCMake/Ninja/RunCMakeTest.cmake

@@ -18,6 +18,12 @@ else()
   message(FATAL_ERROR "'ninja --version' reported:\n${ninja_out}")
 endif()
 
+if(CMAKE_HOST_WIN32)
+  run_cmake(SelectCompilerWindows)
+else()
+  run_cmake(SelectCompilerUNIX)
+endif()
+
 function(run_NinjaToolMissing)
   set(RunCMake_MAKE_PROGRAM ninja-tool-missing)
   run_cmake(NinjaToolMissing)

Tests/RunCMake/Ninja/SelectCompiler/1/gcc

@@ -0,0 +1,2 @@
+#!/bin/sh
+false

Tests/RunCMake/Ninja/SelectCompiler/2/cc

@@ -0,0 +1,2 @@
+#!/bin/sh
+false

Tests/RunCMake/Ninja/SelectCompilerUNIX-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/Ninja/SelectCompilerUNIX-stderr.txt

@@ -0,0 +1,6 @@
+^CMake Error at .*/Modules/CMakeTestCCompiler.cmake:[0-9]+ \(message\):
+  The C compiler
+
+    "[^"]*/Tests/RunCMake/Ninja/SelectCompiler/2/cc"
+
+  is not able to compile a simple test program.

Tests/RunCMake/Ninja/SelectCompilerUNIX.cmake

@@ -0,0 +1,3 @@
+set(ENV{PATH} "${CMAKE_CURRENT_SOURCE_DIR}/SelectCompiler/1:${CMAKE_CURRENT_SOURCE_DIR}/SelectCompiler/2:$ENV{PATH}")
+unset(ENV{CC})
+enable_language(C)

Tests/RunCMake/Ninja/SelectCompilerWindows-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/Ninja/SelectCompilerWindows-stderr.txt

@@ -0,0 +1,6 @@
+^CMake Error at .*/Modules/CMakeTestCCompiler.cmake:[0-9]+ \(message\):
+  The C compiler
+
+    "[^"]*/Tests/RunCMake/Ninja/SelectCompiler/1/gcc"
+
+  is not able to compile a simple test program.

Tests/RunCMake/Ninja/SelectCompilerWindows.cmake

@@ -0,0 +1,3 @@
+set(ENV{PATH} "${CMAKE_CURRENT_SOURCE_DIR}/SelectCompiler/1;${CMAKE_CURRENT_SOURCE_DIR}/SelectCompiler/2;$ENV{PATH}")
+unset(ENV{CC})
+enable_language(C)