use helper libs via QMAKE_USE

for that, qt_help_lib.prf gains the ability to write "external module
pri" files that contain suitable information for QMAKE_USE.

these files have a bunch of limitations:
- they are not installed, because a) they are not relocatable and b) the
  helper libs' headers are not installed, either
- it won't work with qmake -r, which is ok, as qt5 does not build with
  qmake -r anyway
- deps are not transitive, neither at build nor at use time

the freetype, harfbuzz-ng, pcre, and png helper libs have been adjusted
accordingly, and their uses replaced with QMAKE_USE instances. this also
allowed inlining the now trivial {harfbuzz,pcrc,png}_dependency.pri
files. freetype_dependency.pri remains due to its funkiness.

Change-Id: I16890eecb122e34ec49f3d3e68380d1ea71a198a
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

1 files changed, 0 insertions, 6 deletions

diff --git a/src/3rdparty/harfbuzz_dependency.pri b/src/3rdparty/harfbuzz_dependency.pri
deleted file mode 100644
index 5946f403c5..0000000000
--- a/src/3rdparty/harfbuzz_dependency.pri
+++ /dev/null
@@ -1,6 +0,0 @@
-qtConfig(system-harfbuzz) {
-    QMAKE_USE_PRIVATE += harfbuzz
-} else: qtConfig(harfbuzz) {
-    INCLUDEPATH += $$PWD/harfbuzz-ng/include
-    LIBS_PRIVATE += -L$$QT_BUILD_TREE/lib -lqtharfbuzzng$$qtPlatformTargetSuffix()
-}