[Buildroot] [PATCH v3 1/1] package/pkg-generic.mk: fix absolute paths in per-package config files

[Adam Duskett]

Some packages (notably qmake packages) generate .cmake, .pc, and .pri files
with absolute paths. Unfortunately, doing so breaks per-package builds because
the paths in those files point outside the per-package sysroot for packages
that have rsynced those same files.

- Rename FIXUP_PYTHON_SYSCONFIGDATA to FIXUP_PER_PACKAGE_FILES in pkg-generic.mk
  to avoid more calls to ifeq ($(BR2_PER_PACKAGE_DIRECTORIES),y)

- Add a new step which searches for .cmake, .pc, and .pri files in a
  given per-package host and staging directory and replaces the old
  $(PER_PACKAGE_DIR) directory with the correct directory for the given package.

This simple fix allows qt5 submodule packages to build with per-package enabled.

Based off of Louis-Paul's earlier work found here:
https://lore.kernel.org/buildroot/a339f273-33f3-f232-eac4-6e50427abf6d@cordier.org/

And Yann Morin's feedback found here:
https://patchwork.ozlabs.org/project/buildroot/patch/20200217212350.29750-21-anaumann@ultratronik.de/

Signed-off-by: Adam Duskett <aduskett at gmail.com>
---
changes v2 -> v3:
  - Rename FIXUP_PYTHON_SYSCONFIGDATA to FIXUP_PER_PACKAGE_FILES in
    pkg-generic.mk (Yann)
  
  - Combine FIXUP_CONFIG_FILES_ABSOLUTE_PATHS with FIXUP_PER_PACKAGE_FILES (Yann)

changes v1 -> v2
  - Drop patches 2 and 3 and combine them into a single macro in pkg-generic.mk
  - Move the PRE_CONFIGURE_HOOK to inner-generic-package so it actually runs
  - Rename FIXUP_PC_FILES_ABSOLUTE_PATHS to FIXUP_CONFIG_FILES_ABSOLUTE_PATHS
  - Use $(HOST_DIR) instead of $(STAGING_DIR) to cover both stagin and host
    directories in a single step.

 package/pkg-generic.mk | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk
index 5626af1d87..65fe9baced 100644
--- a/package/pkg-generic.mk
+++ b/package/pkg-generic.mk
@@ -113,8 +113,16 @@ endif
 # fail.
 # So we just use HOST_DIR as a starting point, and filter on the two directories
 # of interest.
+#
+# When per-package is enabled, packages may generate files with absolute paths
+# that point to the packages per-package sysroot. However, this breaks
+# per-package isolation when the files are rsynced to a new package that depends
+# on the first package. because the hard-coded paths point to directories
+# outside the packages sysroot. Run sed on all .cmake, .pc, and .pri files in a
+# given packages sysroot containing the word "per-package" and replace the path
+# with the appropriate per-package directory.
 ifeq ($(BR2_PER_PACKAGE_DIRECTORIES),y)
-define FIXUP_PYTHON_SYSCONFIGDATA
+define FIXUP_PER_PACKAGE_FILES
 	$(Q)find $(HOST_DIR) \
 		\(    -path '$(HOST_DIR)/lib/python*' \
 		   -o -path '$(STAGING_DIR)/usr/lib/python*' \
@@ -124,6 +132,11 @@ define FIXUP_PYTHON_SYSCONFIGDATA
 		\) \
 	| xargs -0 --no-run-if-empty \
 		$(SED) 's:$(PER_PACKAGE_DIR)/[^/]\+/:$(PER_PACKAGE_DIR)/$($(PKG)_NAME)/:g'
+
+	$(Q)find $(HOST_DIR)/ -name "*.pc" -o -name "*.cmake" -o -name "*.pri" \
+		| xargs --no-run-if-empty \
+		$(SED) "s:$(PER_PACKAGE_DIR)/[^/]\+/:$(PER_PACKAGE_DIR)/$(NAME)/:g"
+
 endef
 endif
 
@@ -836,7 +849,7 @@ $(2)_EXTRACT_CMDS ?= \
 		$$(TAR_OPTIONS) -)
 
 # pre/post-steps hooks
-$(2)_POST_PREPARE_HOOKS += FIXUP_PYTHON_SYSCONFIGDATA
+$(2)_POST_PREPARE_HOOKS += FIXUP_PER_PACKAGE_FILES
 
 ifeq ($$($(2)_TYPE),target)
 ifneq ($$(HOST_$(2)_KCONFIG_VAR),)
-- 
2.33.1