Genex: Add a SHELL_PATH expression

Some commands on Windows do not understand forward slash paths and
require backslashes.  In order to help projects generate shell
invocations of such commands, provide a generator expression to convert
paths to the shell-preferred path format for the current generator.
This will allow custom commands to generate paths the same way CMake
does for compiler command invocations.

6 files changed, 61 insertions, 3 deletions

diff --git a/Tests/GeneratorExpression/CMakeLists.txt b/Tests/GeneratorExpression/CMakeLists.txt
index 758165c..27f33a2 100644
--- a/Tests/GeneratorExpression/CMakeLists.txt
+++ b/Tests/GeneratorExpression/CMakeLists.txt
@@ -66,7 +66,7 @@ add_custom_target(check-part1 ALL
     -Dtest_colons_4=$<1:C:\\CMake>
     -Dtest_colons_5=$<1:C:/CMake>
     -P ${CMAKE_CURRENT_SOURCE_DIR}/check-part1.cmake
-  COMMAND ${CMAKE_COMMAND} -E echo "check done (part 1 of 3)"
+  COMMAND ${CMAKE_COMMAND} -E echo "check done (part 1 of 4)"
   VERBATIM
   )
 
@@ -137,7 +137,7 @@ add_custom_target(check-part2 ALL
     -Dtest_arbitrary_content_comma_9=$<1:a,,b,,>
     -Dtest_arbitrary_content_comma_10=$<1:,,a,,b,,>
     -P ${CMAKE_CURRENT_SOURCE_DIR}/check-part2.cmake
-  COMMAND ${CMAKE_COMMAND} -E echo "check done (part 2 of 3)"
+  COMMAND ${CMAKE_COMMAND} -E echo "check done (part 2 of 4)"
   VERBATIM
 )
 
@@ -221,7 +221,27 @@ add_custom_target(check-part3 ALL
     -Dequal22=$<EQUAL:10,-012>
     -Dequal23=$<EQUAL:-10,-012>
     -P ${CMAKE_CURRENT_SOURCE_DIR}/check-part3.cmake
-  COMMAND ${CMAKE_COMMAND} -E echo "check done (part 3 of 3)"
+  COMMAND ${CMAKE_COMMAND} -E echo "check done (part 3 of 4)"
+  VERBATIM
+  )
+
+if(WIN32)
+  set(test_shell_path c:/shell/path)
+else()
+  set(test_shell_path /shell/path)
+endif()
+set(path_prefix BYPASS_FURTHER_CONVERSION)
+
+add_custom_target(check-part4 ALL
+  COMMAND ${CMAKE_COMMAND}
+    # Prefix path to bypass its further conversion when being processed by
+    # CMake as command-line argument
+    -Dtest_shell_path=${path_prefix}$<SHELL_PATH:${test_shell_path}>
+    -Dpath_prefix=${path_prefix}
+    -DWIN32=${WIN32}
+    -DCMAKE_GENERATOR=${CMAKE_GENERATOR}
+    -P ${CMAKE_CURRENT_SOURCE_DIR}/check-part4.cmake
+  COMMAND ${CMAKE_COMMAND} -E echo "check done (part 4 of 4)"
   VERBATIM
   )
 
diff --git a/Tests/GeneratorExpression/check-part4.cmake b/Tests/GeneratorExpression/check-part4.cmake
new file mode 100644
index 0000000..9e516d5
--- /dev/null
+++ b/Tests/GeneratorExpression/check-part4.cmake
@@ -0,0 +1,15 @@
+include(${CMAKE_CURRENT_LIST_DIR}/check-common.cmake)
+
+string(REPLACE ${path_prefix} "" test_shell_path ${test_shell_path})
+
+if(WIN32)
+  if(CMAKE_GENERATOR STREQUAL "MSYS Makefiles")
+    check(test_shell_path [[/c/shell/path]])
+  elseif(CMAKE_GENERATOR STREQUAL "Unix Makefiles")
+    check(test_shell_path [[c:/shell/path]])
+  else()
+    check(test_shell_path [[c:\shell\path]])
+  endif()
+else()
+  check(test_shell_path [[/shell/path]])
+endif()
diff --git a/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH-result.txt b/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH-stderr.txt b/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH-stderr.txt
new file mode 100644
index 0000000..8d3c4cc
--- /dev/null
+++ b/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH-stderr.txt
@@ -0,0 +1,17 @@
+CMake Error at BadSHELL_PATH.cmake:[0-9]+ \(add_custom_target\):
+  Error evaluating generator expression:
+
+    \$<SHELL_PATH:>
+
+  "" is not an absolute path.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
++
+CMake Error at BadSHELL_PATH.cmake:[0-9]+ \(add_custom_target\):
+  Error evaluating generator expression:
+
+    \$<SHELL_PATH:Relative/Path>
+
+  "Relative/Path" is not an absolute path.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
diff --git a/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH.cmake b/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH.cmake
new file mode 100644
index 0000000..5eff7bc
--- /dev/null
+++ b/Tests/RunCMake/GeneratorExpression/BadSHELL_PATH.cmake
@@ -0,0 +1,4 @@
+add_custom_target(check ALL COMMAND check
+  $<SHELL_PATH:>
+  $<SHELL_PATH:Relative/Path>
+  VERBATIM)
diff --git a/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake b/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake
index 0679024..45175d8 100644
--- a/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake
+++ b/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake
@@ -10,6 +10,7 @@ run_cmake(BadTargetName)
 run_cmake(BadTargetTypeInterface)
 run_cmake(BadTargetTypeObject)
 run_cmake(BadInstallPrefix)
+run_cmake(BadSHELL_PATH)
 run_cmake(CMP0044-WARN)
 run_cmake(NonValidTarget-C_COMPILER_ID)
 run_cmake(NonValidTarget-CXX_COMPILER_ID)