Require CMAKE_<LANG>_COMPILER to be found as a full path

All generators now support detection of the full path to the compiler, so
require it to be so.  This will allow CMake<LANG>Information.cmake and
other logic to assume the full path to the compiler tool is available.

The Makefile generators already rejected CMAKE_<LANG>_COMPILER values
that did not name an existing compiler.  Extend this error message to
all generators, make it occur as early as possible, and improve the
message with advice about how to set the compiler.  If the full path to
the compiler is not known, finish enabling languages with a fatal error
so configuration does not continue.

For now, allow the RC language compiler to not be a full path.  Later we
will need to detect the full path to "rc" under the VS IDE.

Add a RunCMake.CompilerNotFound test to cover failure cases.
Fix the RunCMake.CompilerChange test EmptyCompiler case to work
when configuration does not continue past enable_language.

24 files changed, 124 insertions, 4 deletions

diff --git a/Tests/RunCMake/CMakeLists.txt b/Tests/RunCMake/CMakeLists.txt
index 8148cb6..4752798 100644
--- a/Tests/RunCMake/CMakeLists.txt
+++ b/Tests/RunCMake/CMakeLists.txt
@@ -60,6 +60,7 @@ add_RunCMake_test(CTest)
 if(UNIX AND "${CMAKE_TEST_GENERATOR}" MATCHES "Unix Makefiles")
   add_RunCMake_test(CompilerChange)
 endif()
+add_RunCMake_test(CompilerNotFound)
 add_RunCMake_test(Configure)
 add_RunCMake_test(DisallowedCommands)
 add_RunCMake_test(ExternalData)
diff --git a/Tests/RunCMake/CompilerChange/EmptyCompiler-override.cmake b/Tests/RunCMake/CompilerChange/EmptyCompiler-override.cmake
new file mode 100644
index 0000000..28d29e0
--- /dev/null
+++ b/Tests/RunCMake/CompilerChange/EmptyCompiler-override.cmake
@@ -0,0 +1,2 @@
+message(STATUS "CMAKE_C_COMPILER is \"${CMAKE_C_COMPILER}\"")
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/cc.cmake" "set(CMAKE_C_COMPILER \"${CMAKE_C_COMPILER}\")\n")
diff --git a/Tests/RunCMake/CompilerChange/EmptyCompiler-stderr.txt b/Tests/RunCMake/CompilerChange/EmptyCompiler-stderr.txt
index 4745b25..cf3b1b3 100644
--- a/Tests/RunCMake/CompilerChange/EmptyCompiler-stderr.txt
+++ b/Tests/RunCMake/CompilerChange/EmptyCompiler-stderr.txt
@@ -1,5 +1,13 @@
 You have changed variables that require your cache to be deleted.
 Configure will be re-run and you may have to reset some variables.
 The following variables have changed:
-CMAKE_C_COMPILER= *(
-|$)
+CMAKE_C_COMPILER= *
++
+CMake Error at EmptyCompiler.cmake:2 \(enable_language\):
+  No CMAKE_C_COMPILER could be found.
+
+  Tell CMake where to find the compiler by setting either the environment
+  variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
+  the compiler, or to the compiler name if it is in the PATH.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:6 \(include\)$
diff --git a/Tests/RunCMake/CompilerChange/EmptyCompiler.cmake b/Tests/RunCMake/CompilerChange/EmptyCompiler.cmake
index c87ec49..06e9e03 100644
--- a/Tests/RunCMake/CompilerChange/EmptyCompiler.cmake
+++ b/Tests/RunCMake/CompilerChange/EmptyCompiler.cmake
@@ -1,3 +1,2 @@
+set(CMAKE_USER_MAKE_RULES_OVERRIDE_C ${CMAKE_CURRENT_LIST_DIR}/EmptyCompiler-override.cmake)
 enable_language(C)
-message(STATUS "CMAKE_C_COMPILER is \"${CMAKE_C_COMPILER}\"")
-file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/cc.cmake" "set(CMAKE_C_COMPILER \"${CMAKE_C_COMPILER}\")\n")
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerC-result.txt b/Tests/RunCMake/CompilerNotFound/BadCompilerC-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerC-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerC-stderr.txt b/Tests/RunCMake/CompilerNotFound/BadCompilerC-stderr.txt
new file mode 100644
index 0000000..c98842d
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerC-stderr.txt
@@ -0,0 +1,12 @@
+CMake Error at BadCompilerC.cmake:2 \(enable_language\):
+  The CMAKE_C_COMPILER:
+
+    no-C-compiler
+
+  is not a full path and was not found in the PATH.
+
+  Tell CMake where to find the compiler by setting either the environment
+  variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
+  the compiler, or to the compiler name if it is in the PATH.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)$
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerC.cmake b/Tests/RunCMake/CompilerNotFound/BadCompilerC.cmake
new file mode 100644
index 0000000..10fe59a
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerC.cmake
@@ -0,0 +1,3 @@
+set(CMAKE_C_COMPILER "no-C-compiler")
+enable_language(C)
+message(FATAL_ERROR "This error should not be reached.")
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerCXX-result.txt b/Tests/RunCMake/CompilerNotFound/BadCompilerCXX-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerCXX-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerCXX-stderr.txt b/Tests/RunCMake/CompilerNotFound/BadCompilerCXX-stderr.txt
new file mode 100644
index 0000000..7ef4f5e
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerCXX-stderr.txt
@@ -0,0 +1,12 @@
+CMake Error at BadCompilerCXX.cmake:2 \(enable_language\):
+  The CMAKE_CXX_COMPILER:
+
+    no-CXX-compiler
+
+  is not a full path and was not found in the PATH.
+
+  Tell CMake where to find the compiler by setting either the environment
+  variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
+  to the compiler, or to the compiler name if it is in the PATH.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)$
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerCXX.cmake b/Tests/RunCMake/CompilerNotFound/BadCompilerCXX.cmake
new file mode 100644
index 0000000..3b1e890
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerCXX.cmake
@@ -0,0 +1,3 @@
+set(CMAKE_CXX_COMPILER "no-CXX-compiler")
+enable_language(CXX)
+message(FATAL_ERROR "This error should not be reached.")
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX-result.txt b/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX-stderr.txt b/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX-stderr.txt
new file mode 100644
index 0000000..eecff54
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX-stderr.txt
@@ -0,0 +1,25 @@
+CMake Error at BadCompilerCandCXX.cmake:3 \(project\):
+  The CMAKE_C_COMPILER:
+
+    no-C-compiler
+
+  is not a full path and was not found in the PATH.
+
+  Tell CMake where to find the compiler by setting either the environment
+  variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
+  the compiler, or to the compiler name if it is in the PATH.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at BadCompilerCandCXX.cmake:3 \(project\):
+  The CMAKE_CXX_COMPILER:
+
+    no-CXX-compiler
+
+  is not a full path and was not found in the PATH.
+
+  Tell CMake where to find the compiler by setting either the environment
+  variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
+  to the compiler, or to the compiler name if it is in the PATH.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)$
diff --git a/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX.cmake b/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX.cmake
new file mode 100644
index 0000000..2b6fa61
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/BadCompilerCandCXX.cmake
@@ -0,0 +1,4 @@
+set(CMAKE_C_COMPILER "no-C-compiler")
+set(CMAKE_CXX_COMPILER "no-CXX-compiler")
+project(BadCompilerCandCXXInner C CXX)
+message(FATAL_ERROR "This error should not be reached.")
diff --git a/Tests/RunCMake/CompilerNotFound/CMakeLists.txt b/Tests/RunCMake/CompilerNotFound/CMakeLists.txt
new file mode 100644
index 0000000..12cd3c7
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/CMakeLists.txt
@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 2.8.4)
+project(${RunCMake_TEST} NONE)
+include(${RunCMake_TEST}.cmake)
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE-result.txt b/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE-stderr.txt b/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE-stderr.txt
new file mode 100644
index 0000000..88bb95e
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE-stderr.txt
@@ -0,0 +1,5 @@
+CMake Error at NoCompilerC-IDE.cmake:2 \(enable_language\):
+  No CMAKE_C_COMPILER could be found.
+
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)$
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE.cmake b/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE.cmake
new file mode 100644
index 0000000..45e1a68
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerC-IDE.cmake
@@ -0,0 +1,3 @@
+set(CMAKE_C_COMPILER_ID_ERROR_FOR_TEST "#error NoCompilerC-IDE")
+enable_language(C)
+message(FATAL_ERROR "This error should not be reached.")
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE-result.txt b/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE-stderr.txt b/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE-stderr.txt
new file mode 100644
index 0000000..4c92323
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE-stderr.txt
@@ -0,0 +1,5 @@
+CMake Error at NoCompilerCXX-IDE.cmake:2 \(enable_language\):
+  No CMAKE_CXX_COMPILER could be found.
+
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)$
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE.cmake b/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE.cmake
new file mode 100644
index 0000000..85025a0
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerCXX-IDE.cmake
@@ -0,0 +1,3 @@
+set(CMAKE_CXX_COMPILER_ID_ERROR_FOR_TEST "#error NoCompilerCXX-IDE")
+enable_language(CXX)
+message(FATAL_ERROR "This error should not be reached.")
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE-result.txt b/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE-stderr.txt b/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE-stderr.txt
new file mode 100644
index 0000000..21c69f5
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE-stderr.txt
@@ -0,0 +1,11 @@
+CMake Error at NoCompilerCandCXX-IDE.cmake:3 \(project\):
+  No CMAKE_C_COMPILER could be found.
+
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at NoCompilerCandCXX-IDE.cmake:3 \(project\):
+  No CMAKE_CXX_COMPILER could be found.
+
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)$
diff --git a/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE.cmake b/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE.cmake
new file mode 100644
index 0000000..78256a9
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/NoCompilerCandCXX-IDE.cmake
@@ -0,0 +1,4 @@
+set(CMAKE_C_COMPILER_ID_ERROR_FOR_TEST "#error NoCompilerCandCXX-IDE")
+set(CMAKE_CXX_COMPILER_ID_ERROR_FOR_TEST "#error NoCompilerCandCXX-IDE")
+project(NoCompilerCandCXXInner C CXX)
+message(FATAL_ERROR "This error should not be reached.")
diff --git a/Tests/RunCMake/CompilerNotFound/RunCMakeTest.cmake b/Tests/RunCMake/CompilerNotFound/RunCMakeTest.cmake
new file mode 100644
index 0000000..8b84f39
--- /dev/null
+++ b/Tests/RunCMake/CompilerNotFound/RunCMakeTest.cmake
@@ -0,0 +1,11 @@
+include(RunCMake)
+
+if("${RunCMake_GENERATOR}" MATCHES "Visual Studio|Xcode")
+  run_cmake(NoCompilerC-IDE)
+  run_cmake(NoCompilerCXX-IDE)
+  run_cmake(NoCompilerCandCXX-IDE)
+else()
+  run_cmake(BadCompilerC)
+  run_cmake(BadCompilerCXX)
+  run_cmake(BadCompilerCandCXX)
+endif()