From be1b22538a60e52987d238bb11f93043682b6e9a Mon Sep 17 00:00:00 2001
From: Alyssa Ross <hi@alyssa.is>
Date: Wed, 24 Jun 2020 17:58:30 +0000
Subject: [PATCH] cmake: only set output paths with multiple outputs

This brings cmake inline with the behaviour used for configure
scripts, defined in multiple-outputs.sh.  It's important because
that setup hook will only set shareDocName if multiple outputs are in
use (and setOutputFlags hasn't been disabled).  So previously,
CMAKE_INSTALL_DOCDIR would be set to $out/share/doc for single-output
derivations, instead of $out/share/doc/$shareDocName, which would
result in collisions.

Since this hook now uses the setOutputFlags variable, I had to remove
the empty assignment of it added in
a714284d8b7d2dac3ed2c76670f290fe332da00c.

Fixes: https://github.com/NixOS/nixpkgs/issues/82304
---
 .../tools/build-managers/cmake/setup-hook.sh  | 30 +++++++++++--------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/pkgs/development/tools/build-managers/cmake/setup-hook.sh b/pkgs/development/tools/build-managers/cmake/setup-hook.sh
index 87bbefa6bbfaec2..b343e1f91fceb7d 100755
--- a/pkgs/development/tools/build-managers/cmake/setup-hook.sh
+++ b/pkgs/development/tools/build-managers/cmake/setup-hook.sh
@@ -68,19 +68,24 @@ cmakeConfigurePhase() {
     # nix/store directory.
     cmakeFlags="-DCMAKE_INSTALL_NAME_DIR=${!outputLib}/lib $cmakeFlags"
 
-    # This ensures correct paths with multiple output derivations
-    # It requires the project to use variables from GNUInstallDirs module
-    # https://cmake.org/cmake/help/latest/module/GNUInstallDirs.html
-    cmakeFlags="-DCMAKE_INSTALL_BINDIR=${!outputBin}/bin $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_SBINDIR=${!outputBin}/sbin $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_INCLUDEDIR=${!outputInclude}/include $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_OLDINCLUDEDIR=${!outputInclude}/include $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_MANDIR=${!outputMan}/share/man $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_INFODIR=${!outputInfo}/share/info $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_DOCDIR=${!outputDoc}/share/doc/${shareDocName} $cmakeFlags"
+    if [ "$outputs" != "out" -a -n "${setOutputFlags-1}" ]; then
+        # This ensures correct paths with multiple output derivations
+        # It requires the project to use variables from GNUInstallDirs module
+        # https://cmake.org/cmake/help/latest/module/GNUInstallDirs.html
+        cmakeFlags="-DCMAKE_INSTALL_BINDIR=${!outputBin}/bin $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_SBINDIR=${!outputBin}/sbin $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_INCLUDEDIR=${!outputInclude}/include $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_OLDINCLUDEDIR=${!outputInclude}/include $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_MANDIR=${!outputMan}/share/man $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_INFODIR=${!outputInfo}/share/info $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_DOCDIR=${!outputDoc}/share/doc/${shareDocName} $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_LIBEXECDIR=${!outputLib}/libexec $cmakeFlags"
+        cmakeFlags="-DCMAKE_INSTALL_LOCALEDIR=${!outputLib}/share/locale $cmakeFlags"
+    fi
+
+    # This output flag must always be set, unlike the others, because
+    # otherwise we end up with lib64.
     cmakeFlags="-DCMAKE_INSTALL_LIBDIR=${!outputLib}/lib $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_LIBEXECDIR=${!outputLib}/libexec $cmakeFlags"
-    cmakeFlags="-DCMAKE_INSTALL_LOCALEDIR=${!outputLib}/share/locale $cmakeFlags"
 
     # Don’t build tests when doCheck = false
     if [ -z "${doCheck-}" ]; then
@@ -115,7 +120,6 @@ cmakeConfigurePhase() {
 }
 
 if [ -z "${dontUseCmakeConfigure-}" -a -z "${configurePhase-}" ]; then
-    setOutputFlags=
     configurePhase=cmakeConfigurePhase
 fi