Re: [PATCH 3/4] cmake: add a preparatory work-around to accommodate `vcpkg`

Hi Danh,

On Sun, 28 Mar 2021, Đoàn Trần Công Danh wrote:

On 2021-03-27 23:06:24+0000, Johannes Schindelin via GitGitGadget [off-list ref] wrote:

quoted

From: Johannes Schindelin <redacted>

We are about to add support for installing the `.dll` files of Git's
dependencies (such as libcurl) in the CMake configuration. The `vcpkg`
ecosystem from which we get said dependencies makes that relatively
easy: simply turn on `X_VCPKG_APPLOCAL_DEPS_INSTALL`.

However, current `vcpkg` introduces a limitation if one does that:
While it is totally cool with CMake to specify multiple targets within
one invocation of `install(TARGETS ...) (at least according to
https://cmake.org/cmake/help/latest/command/install.html#command:install),
`vcpkg`'s parser insists on a single target per `install(TARGETS ...)`
invocation.

Well, that's easily accomplished: Let's feed the targets individually to
the `install(TARGETS ...)` function in a `foreach()` look.

This also has the advantage that we do not have to manually cull off the
two entries from the `${PROGRAMS_BUILT}` array before scheduling the
remainder to be installed into `libexec/git-core`. Instead, we iterate
through the array and decide for each entry where it wants to go.

Signed-off-by: Johannes Schindelin <redacted>
---
 contrib/buildsystems/CMakeLists.txt | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index da2811ae3aad..a166be0eb1b8 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt

@@ -811,15 +811,19 @@ list(TRANSFORM git_shell_scripts PREPEND "${CMAKE_BINARY_DIR}/")
 list(TRANSFORM git_perl_scripts PREPEND "${CMAKE_BINARY_DIR}/")

 #install
-install(TARGETS git git-shell
+foreach(program ${PROGRAMS_BUILT})
+if(${program} STREQUAL git OR ${program} STREQUAL git-shell)

Please don't use `${}` around variable inside `if()`, and quote the
string. CMake has a quirk with the `${}` inside if (expanded variable
will be treated as a variable if it is defined, or string otherwise).
Unquoted string will be seen as a variable if it's defined, string
otherwise. IOW, suggested command:

	if (program STREQUAL "git" OR program STREQUAL "git-shell")

We also have another problem with quoted arguments could be interpreted
as variable or keyword if CMP0054 policy not enabled, too.
I think it's better to have it enabled, but it's not in the scope of
this patch.

 https://cmake.org/cmake/help/latest/policy/CMP0054.html

Thank you for this information! I've sent out v2 based on your suggestion.

Thanks,
Dscho