cmake: Fix relative path regression in -C

Since commit 4ca0526f8a (cmake: Pass -S and -B into PreLoad.cmake and -C
scripts, 2019-08-20, v3.16.0-rc1~195^2) the value of `CMAKE_SOURCE_DIR`
is the source directory rather than the current working directory.
This was correct on its own, but the place storing that value is also
used as the base for relative paths specified on the command line.
The latter should of course be relative to the current working
directory.

The fix is to switch to use a full path internally, unless a full path
is already specified.  Add tests for the behaviour of `-C` under these
four circumstances:

    {with -S, without -S} x {full path, relative path}

Fixes: #19827

13 files changed, 40 insertions, 10 deletions

diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index 50f47af..f63a264 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -423,6 +423,8 @@ bool cmake::SetCacheArgs(const std::vector<std::string>& args)
         }
       }
       std::cout << "loading initial cache file " << path << "\n";
+      // Resolve script path specified on command line relative to $PWD.
+      path = cmSystemTools::CollapseFullPath(path);
       this->ReadListFile(args, path);
     } else if (arg.find("-P", 0) == 0) {
       i++;
diff --git a/Tests/RunCMake/CommandLine/C-no-file-stderr.txt b/Tests/RunCMake/CommandLine/C-no-file-stderr.txt
index 2a4ee64..b65a349 100644
--- a/Tests/RunCMake/CommandLine/C-no-file-stderr.txt
+++ b/Tests/RunCMake/CommandLine/C-no-file-stderr.txt
@@ -1,3 +1,3 @@
-^CMake Error: Error processing file: nosuchcachefile.txt
+^CMake Error: Error processing file: .*/Tests/RunCMake/CommandLine/C-no-file-build/nosuchcachefile.txt
 CMake Error: The source directory ".*/Tests/RunCMake/CommandLine/C-no-file-build" does not appear to contain CMakeLists.txt.
 Specify --help for usage, or press the help button on the CMake GUI.$
diff --git a/Tests/RunCMake/CommandLine/C_basic-stderr.txt b/Tests/RunCMake/CommandLine/C_basic-stderr.txt
new file mode 100644
index 0000000..62d0cd5
--- /dev/null
+++ b/Tests/RunCMake/CommandLine/C_basic-stderr.txt
@@ -0,0 +1,4 @@
+initial-cache.txt: CMAKE_SOURCE_DIR: .*/Tests/RunCMake/CommandLine
+initial-cache.txt: CMAKE_BINARY_DIR: .*/Tests/RunCMake/CommandLine/C_basic-build
+CMakeLists.txt: INITIAL_SOURCE_DIR: .*/Tests/RunCMake/CommandLine
+CMakeLists.txt: INITIAL_BINARY_DIR: .*/Tests/RunCMake/CommandLine/C_basic-build
diff --git a/Tests/RunCMake/CommandLine/C_basic-stdout.txt b/Tests/RunCMake/CommandLine/C_basic-stdout.txt
new file mode 100644
index 0000000..74a938e
--- /dev/null
+++ b/Tests/RunCMake/CommandLine/C_basic-stdout.txt
@@ -0,0 +1 @@
+loading initial cache file ../C_basic_initial-cache.txt
diff --git a/Tests/RunCMake/CommandLine/C_basic.cmake b/Tests/RunCMake/CommandLine/C_basic.cmake
new file mode 100644
index 0000000..1a56593
--- /dev/null
+++ b/Tests/RunCMake/CommandLine/C_basic.cmake
@@ -0,0 +1,2 @@
+message("CMakeLists.txt: INITIAL_SOURCE_DIR: ${INITIAL_SOURCE_DIR}")
+message("CMakeLists.txt: INITIAL_BINARY_DIR: ${INITIAL_BINARY_DIR}")
diff --git a/Tests/RunCMake/CommandLine/C_basic_fullpath-stderr.txt b/Tests/RunCMake/CommandLine/C_basic_fullpath-stderr.txt
new file mode 100644
index 0000000..f382a01
--- /dev/null
+++ b/Tests/RunCMake/CommandLine/C_basic_fullpath-stderr.txt
@@ -0,0 +1,4 @@
+initial-cache.txt: CMAKE_SOURCE_DIR: .*/Tests/RunCMake/CommandLine
+initial-cache.txt: CMAKE_BINARY_DIR: .*/Tests/RunCMake/CommandLine/C_basic_fullpath-build
+CMakeLists.txt: INITIAL_SOURCE_DIR: .*/Tests/RunCMake/CommandLine
+CMakeLists.txt: INITIAL_BINARY_DIR: .*/Tests/RunCMake/CommandLine/C_basic_fullpath-build
diff --git a/Tests/RunCMake/CommandLine/C_basic_fullpath-stdout.txt b/Tests/RunCMake/CommandLine/C_basic_fullpath-stdout.txt
new file mode 100644
index 0000000..32724f5
--- /dev/null
+++ b/Tests/RunCMake/CommandLine/C_basic_fullpath-stdout.txt
@@ -0,0 +1 @@
+loading initial cache file .*/Tests/RunCMake/CommandLine/C_basic_initial-cache.txt
diff --git a/Tests/RunCMake/CommandLine/C_basic_fullpath.cmake b/Tests/RunCMake/CommandLine/C_basic_fullpath.cmake
new file mode 100644
index 0000000..1a56593
--- /dev/null
+++ b/Tests/RunCMake/CommandLine/C_basic_fullpath.cmake
@@ -0,0 +1,2 @@
+message("CMakeLists.txt: INITIAL_SOURCE_DIR: ${INITIAL_SOURCE_DIR}")
+message("CMakeLists.txt: INITIAL_BINARY_DIR: ${INITIAL_BINARY_DIR}")
diff --git a/Tests/RunCMake/CommandLine/C_basic_initial-cache.txt b/Tests/RunCMake/CommandLine/C_basic_initial-cache.txt
new file mode 100644
index 0000000..e7a8ac9
--- /dev/null
+++ b/Tests/RunCMake/CommandLine/C_basic_initial-cache.txt
@@ -0,0 +1,5 @@
+set(INITIAL_SOURCE_DIR "${CMAKE_SOURCE_DIR}" CACHE PATH "defined in initial.cmake")
+set(INITIAL_BINARY_DIR "${CMAKE_BINARY_DIR}" CACHE PATH "defined in initial.cmake")
+
+message("initial-cache.txt: CMAKE_SOURCE_DIR: ${CMAKE_SOURCE_DIR}")
+message("initial-cache.txt: CMAKE_BINARY_DIR: ${CMAKE_BINARY_DIR}")
diff --git a/Tests/RunCMake/CommandLine/C_buildsrcdir-stderr.txt b/Tests/RunCMake/CommandLine/C_buildsrcdir-stderr.txt
index 0d8f72e..4720a6f 100644
--- a/Tests/RunCMake/CommandLine/C_buildsrcdir-stderr.txt
+++ b/Tests/RunCMake/CommandLine/C_buildsrcdir-stderr.txt
@@ -1,8 +1,8 @@
 initial-cache.txt: CMAKE_SOURCE_DIR: .*/C_buildsrcdir/src
-initial-cache.txt: CMAKE_BINARY_DIR: .*/C_buildsrcdir-build/DummyBuildDir
+initial-cache.txt: CMAKE_BINARY_DIR: .*/ExplicitDirs-build/DummyBuildDir
 PreLoad.cmake: CMAKE_SOURCE_DIR: .*/C_buildsrcdir/src
-PreLoad.cmake: CMAKE_BINARY_DIR: .*/C_buildsrcdir-build/DummyBuildDir
+PreLoad.cmake: CMAKE_BINARY_DIR: .*/ExplicitDirs-build/DummyBuildDir
 CMakeLists.txt: INITIAL_SOURCE_DIR: .*/C_buildsrcdir/src
-CMakeLists.txt: INITIAL_BINARY_DIR: .*/C_buildsrcdir-build/DummyBuildDir
+CMakeLists.txt: INITIAL_BINARY_DIR: .*/ExplicitDirs-build/DummyBuildDir
 CMakeLists.txt: PRELOAD_SOURCE_DIR: .*/C_buildsrcdir/src
-CMakeLists.txt: PRELOAD_BINARY_DIR: .*/C_buildsrcdir-build/DummyBuildDir
+CMakeLists.txt: PRELOAD_BINARY_DIR: .*/ExplicitDirs-build/DummyBuildDir
diff --git a/Tests/RunCMake/CommandLine/C_buildsrcdir-stdout.txt b/Tests/RunCMake/CommandLine/C_buildsrcdir-stdout.txt
index c69b11e..862cfeb 100644
--- a/Tests/RunCMake/CommandLine/C_buildsrcdir-stdout.txt
+++ b/Tests/RunCMake/CommandLine/C_buildsrcdir-stdout.txt
@@ -1,2 +1,2 @@
-loading initial cache file .*/C_buildsrcdir/initial-cache.txt
+loading initial cache file .*initial-cache.txt
 .*
diff --git a/Tests/RunCMake/CommandLine/Cno-file-stderr.txt b/Tests/RunCMake/CommandLine/Cno-file-stderr.txt
index 67a2032..416686c 100644
--- a/Tests/RunCMake/CommandLine/Cno-file-stderr.txt
+++ b/Tests/RunCMake/CommandLine/Cno-file-stderr.txt
@@ -1,3 +1,3 @@
-^CMake Error: Error processing file: nosuchcachefile.txt
+^CMake Error: Error processing file: .*/Tests/RunCMake/CommandLine/Cno-file-build/nosuchcachefile.txt
 CMake Error: The source directory ".*/Tests/RunCMake/CommandLine/Cno-file-build" does not appear to contain CMakeLists.txt.
 Specify --help for usage, or press the help button on the CMake GUI.$
diff --git a/Tests/RunCMake/CommandLine/RunCMakeTest.cmake b/Tests/RunCMake/CommandLine/RunCMakeTest.cmake
index efd1cc2..b608d33 100644
--- a/Tests/RunCMake/CommandLine/RunCMakeTest.cmake
+++ b/Tests/RunCMake/CommandLine/RunCMakeTest.cmake
@@ -110,6 +110,14 @@ project(ExplicitDirsMissing LANGUAGES NONE)
   file(REMOVE_RECURSE "${binary_dir}")
   run_cmake_with_options(B-S -B${binary_dir} -S${source_dir})
 
+  message("copied to ${RunCMake_TEST_BINARY_DIR}/initial-cache.txt")
+  file(COPY ${RunCMake_SOURCE_DIR}/C_buildsrcdir/initial-cache.txt DESTINATION ${RunCMake_TEST_BINARY_DIR})
+
+  # CMAKE_BINARY_DIR should be determined by -B if specified, and CMAKE_SOURCE_DIR determined by -S if specified.
+  # Path to initial-cache.txt is relative to the $PWD, which is normally set to ${RunCMake_TEST_BINARY_DIR}.
+  run_cmake_with_options(C_buildsrcdir -B DummyBuildDir -S ${RunCMake_SOURCE_DIR}/C_buildsrcdir/src -C initial-cache.txt)
+  # Test that full path works, too.
+  run_cmake_with_options(C_buildsrcdir -B DummyBuildDir -S ${RunCMake_SOURCE_DIR}/C_buildsrcdir/src -C ${RunCMake_TEST_BINARY_DIR}/initial-cache.txt)
 endfunction()
 run_ExplicitDirs()
 
@@ -406,9 +414,10 @@ run_cmake_command(P_working-dir ${CMAKE_COMMAND} -DEXPECTED_WORKING_DIR=${RunCMa
 # Tests the values of CMAKE_BINARY_DIR CMAKE_CURRENT_BINARY_DIR CMAKE_SOURCE_DIR CMAKE_CURRENT_SOURCE_DIR.
 run_cmake_command(P_working-dir ${CMAKE_COMMAND} -DEXPECTED_WORKING_DIR=${RunCMake_BINARY_DIR}/P_working-dir-build -P ${RunCMake_SOURCE_DIR}/P_working-dir.cmake -S something_else -B something_else_1)
 
-# CMAKE_BINARY_DIR should be determined by -B if specified, and CMAKE_SOURCE_DIR determined by -S if specified.
-run_cmake_with_options(C_buildsrcdir -B DummyBuildDir -S ${RunCMake_SOURCE_DIR}/C_buildsrcdir/src -C ${RunCMake_SOURCE_DIR}/C_buildsrcdir/initial-cache.txt)
-
+# Place an initial cache where C_basic will find it when passed the relative path "..".
+file(COPY ${RunCMake_SOURCE_DIR}/C_basic_initial-cache.txt DESTINATION ${RunCMake_BINARY_DIR})
+run_cmake_with_options(C_basic -C ../C_basic_initial-cache.txt)
+run_cmake_with_options(C_basic_fullpath -C ${RunCMake_BINARY_DIR}/C_basic_initial-cache.txt)
 
 set(RunCMake_TEST_OPTIONS
   "-DFOO=-DBAR:BOOL=BAZ")