FetchContent: Enforce FETCHCONTENT_FULLY_DISCONNECTED requirements

FETCHCONTENT_FULLY_DISCONNECTED should only be set to true if
each dependency's source directory has already been populated.
Previously, this wasn't being checked, but now it is (subject to a new
policy).

13 files changed, 83 insertions, 0 deletions

diff --git a/Tests/RunCMake/CMP0170/CMP0170-NEW-result.txt b/Tests/RunCMake/CMP0170/CMP0170-NEW-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-NEW-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/CMP0170/CMP0170-NEW-stderr.txt b/Tests/RunCMake/CMP0170/CMP0170-NEW-stderr.txt
new file mode 100644
index 0000000..f786bd6
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-NEW-stderr.txt
@@ -0,0 +1,14 @@
+CMake Error at .*/Modules/FetchContent\.cmake:[0-9]+ \(message\):
+  FETCHCONTENT_FULLY_DISCONNECTED is set to true, which requires the source
+  directory for dependency t1 to already be populated\.  This generally means
+  it must not be set to true the first time CMake is run in a build
+  directory\.  The following source directory should already be populated, but
+  it doesn't exist:[
+]+    .*/Tests/RunCMake/CMP0170/IdoNotExist[
+]+  Policy CMP0170 controls enforcement of this requirement\.
+Call Stack \(most recent call first\):
+  .*/Modules/FetchContent\.cmake:[0-9]+:EVAL:1 \(__FetchContent_Populate\)
+  .*/Modules/FetchContent\.cmake:[0-9]+ \(cmake_language\)
+  CMP0170\.cmake:[0-9]+ \(FetchContent_Populate\)
+  CMP0170-NEW\.cmake:[0-9]+ \(include\)
+  CMakeLists\.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/CMP0170/CMP0170-NEW-stdout.txt b/Tests/RunCMake/CMP0170/CMP0170-NEW-stdout.txt
new file mode 100644
index 0000000..2dc34a6
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-NEW-stdout.txt
@@ -0,0 +1,2 @@
+-- Starting population
+-- Configuring incomplete, errors occurred!
diff --git a/Tests/RunCMake/CMP0170/CMP0170-NEW.cmake b/Tests/RunCMake/CMP0170/CMP0170-NEW.cmake
new file mode 100644
index 0000000..60b386a
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-NEW.cmake
@@ -0,0 +1,2 @@
+cmake_policy(SET CMP0170 NEW)
+include(CMP0170.cmake)
diff --git a/Tests/RunCMake/CMP0170/CMP0170-OLD-stdout.txt b/Tests/RunCMake/CMP0170/CMP0170-OLD-stdout.txt
new file mode 100644
index 0000000..82c260b
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-OLD-stdout.txt
@@ -0,0 +1,3 @@
+-- Starting population
+-- Configuring done \([0-9]+\.[0-9]s\)
+-- Generating done \([0-9]+\.[0-9]s\)
diff --git a/Tests/RunCMake/CMP0170/CMP0170-OLD.cmake b/Tests/RunCMake/CMP0170/CMP0170-OLD.cmake
new file mode 100644
index 0000000..812cca0
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-OLD.cmake
@@ -0,0 +1,2 @@
+cmake_policy(SET CMP0170 OLD)
+include(CMP0170.cmake)
diff --git a/Tests/RunCMake/CMP0170/CMP0170-WARN-stderr.txt b/Tests/RunCMake/CMP0170/CMP0170-WARN-stderr.txt
new file mode 100644
index 0000000..1253abd
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-WARN-stderr.txt
@@ -0,0 +1,28 @@
+CMake Warning at .*/Modules/FetchContent\.cmake:[0-9]+ \(message\):
+  FETCHCONTENT_FULLY_DISCONNECTED is set to true, which requires the source
+  directory for dependency t1 to already be populated\.  This generally means
+  it must not be set to true the first time CMake is run in a build
+  directory\.  The following source directory should already be populated, but
+  it doesn't exist:[
+]+    .*/Tests/RunCMake/CMP0170/IdoNotExist[
+]+  Policy CMP0170 controls enforcement of this requirement\.
+Call Stack \(most recent call first\):
+  .*/Modules/FetchContent\.cmake:[0-9]+:EVAL:1 \(__FetchContent_Populate\)
+  .*/Modules/FetchContent\.cmake:[0-9]+ \(cmake_language\)
+  CMP0170\.cmake:[0-9]+ \(FetchContent_Populate\)
+  CMP0170-WARN\.cmake:[0-9]+ \(include\)
+  CMakeLists\.txt:[0-9]+ \(include\)
+[
+]+CMake Warning at .*/Modules/FetchContent\.cmake:[0-9]+ \(message\):
+  FETCHCONTENT_FULLY_DISCONNECTED is set to true, which requires the source
+  directory for dependency t2 to already be populated\.  This generally means
+  it must not be set to true the first time CMake is run in a build
+  directory\.  The following source directory should already be populated, but
+  it doesn't exist:[
+]+    .*/Tests/RunCMake/CMP0170/IdoNotExist[
+]+  Policy CMP0170 controls enforcement of this requirement\.
+Call Stack \(most recent call first\):
+  .*/Modules/FetchContent\.cmake:[0-9]+ \(__FetchContent_Populate\)
+  CMP0170\.cmake:[0-9]+ \(FetchContent_MakeAvailable\)
+  CMP0170-WARN\.cmake:[0-9]+ \(include\)
+  CMakeLists\.txt:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/CMP0170/CMP0170-WARN-stdout.txt b/Tests/RunCMake/CMP0170/CMP0170-WARN-stdout.txt
new file mode 100644
index 0000000..82c260b
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-WARN-stdout.txt
@@ -0,0 +1,3 @@
+-- Starting population
+-- Configuring done \([0-9]+\.[0-9]s\)
+-- Generating done \([0-9]+\.[0-9]s\)
diff --git a/Tests/RunCMake/CMP0170/CMP0170-WARN.cmake b/Tests/RunCMake/CMP0170/CMP0170-WARN.cmake
new file mode 100644
index 0000000..1754c24
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170-WARN.cmake
@@ -0,0 +1 @@
+include(CMP0170.cmake)
diff --git a/Tests/RunCMake/CMP0170/CMP0170.cmake b/Tests/RunCMake/CMP0170/CMP0170.cmake
new file mode 100644
index 0000000..4e63e25
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMP0170.cmake
@@ -0,0 +1,18 @@
+cmake_policy(SET CMP0168 NEW)  # Faster, don't need to test with sub-build
+cmake_policy(SET CMP0169 OLD)  # So we can test FetchContent_Populate() directly
+
+set(FETCHCONTENT_FULLY_DISCONNECTED TRUE)
+
+include(FetchContent)
+
+message(STATUS "Starting population")
+
+FetchContent_Declare(t1
+  SOURCE_DIR "${CMAKE_CURRENT_LIST_DIR}/IdoNotExist"
+)
+FetchContent_Populate(t1)
+
+FetchContent_Declare(t2
+  SOURCE_DIR "${CMAKE_CURRENT_LIST_DIR}/IdoNotExist"
+)
+FetchContent_MakeAvailable(t2)
diff --git a/Tests/RunCMake/CMP0170/CMakeLists.txt b/Tests/RunCMake/CMP0170/CMakeLists.txt
new file mode 100644
index 0000000..94e43ba
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/CMakeLists.txt
@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 3.29)
+project(${RunCMake_TEST} NONE)
+include(${RunCMake_TEST}.cmake)
diff --git a/Tests/RunCMake/CMP0170/RunCMakeTest.cmake b/Tests/RunCMake/CMP0170/RunCMakeTest.cmake
new file mode 100644
index 0000000..0ba64e3
--- /dev/null
+++ b/Tests/RunCMake/CMP0170/RunCMakeTest.cmake
@@ -0,0 +1,5 @@
+include(RunCMake)
+
+run_cmake(CMP0170-WARN)
+run_cmake(CMP0170-OLD)
+run_cmake(CMP0170-NEW)
diff --git a/Tests/RunCMake/CMakeLists.txt b/Tests/RunCMake/CMakeLists.txt
index 8c047d0..5c1e5f6 100644
--- a/Tests/RunCMake/CMakeLists.txt
+++ b/Tests/RunCMake/CMakeLists.txt
@@ -176,6 +176,7 @@ add_RunCMake_test(CMP0160)
 add_RunCMake_test(CMP0163)
 add_RunCMake_test(CMP0165)
 add_RunCMake_test(CMP0169)
+add_RunCMake_test(CMP0170)
 
 # The test for Policy 65 requires the use of the
 # CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS variable, which both the VS and Xcode