Merge ~liushuyu-011/ubuntu/+source/libgrokj2k:ubuntu/devel into ubuntu/+source/libgrokj2k:ubuntu/devel

[Zixing Liu]

This merge proposal fixes the FTBFS issue on armhf by switching the compiler to Clang/LLVM.

PPA build: https://launchpad.net/~liushuyu-011/+archive/ubuntu/misc/+sourcepub/16579758/+listing-archive-extra

[Lukas Märdian (slyon)]

Please note that there's an upstream fix that is supposedly fixing the armhf FTBFS:

* https://mentors.debian.net/package/libgrokj2k/
* https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1085165

[Dave Jones (waveform)]

Is this still the right way forward, given the patch posted on the Debian report? Reading through that report it seems there's also a new version potentially ready for inclusion in Debian, but pending upload.

[Andreas Hasenack (ahasenack)]

Since debian has also removed the package, and it had no delta, let's leave it be. If debian reintroduces the package, we can get it.

review: Disapprove

Unmerged commits

f04d595... by Zixing Liu on 2024-10-21

changelog

9300d6a... by Zixing Liu on 2024-10-21

d/rules: fix armhf SIMD errors by using Clang/LLVM to generate a fallback

code path for fp16 SIMD element-wise widening conversion

diff --git a/debian/changelog b/debian/changelog
index d6ae1f9..bb0f02e 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+libgrokj2k (10.0.5-1ubuntu1) plucky; urgency=medium
+
+  * d/rules: fix armhf SIMD errors by using Clang/LLVM to generate a fallback
+    fp16 code path (GCC does not support this as of GCC 15).
+
+ -- Zixing Liu <[e-mail]>  Mon, 21 Oct 2024 15:32:11 -0600
+
 libgrokj2k (10.0.5-1build5) plucky; urgency=medium
 
   * No-change rebuild for libperl soname.
diff --git a/debian/control b/debian/control
index 2b69295..a38edfa 100644
--- a/debian/control
+++ b/debian/control
@@ -12,6 +12,7 @@ Build-Depends: cmake (>= 3.16.0),
                libjpeg-dev,
                zlib1g-dev,
                libimage-exiftool-perl,
+               clang [armhf],
 Build-Depends-Indep: doxygen
 Standards-Version: 4.6.1.0
 Section: libs
diff --git a/debian/rules b/debian/rules
index 77be8b0..20a416c 100755
--- a/debian/rules
+++ b/debian/rules
@@ -6,6 +6,16 @@ DEB_HOST_MULTIARCH ?= $(shell dpkg-architecture -qDEB_HOST_MULTIARCH)
 # as per upstream request:
 export DEB_CXXFLAGS_MAINT_APPEND = -fvisibility=hidden
 
+ifeq (armhf,$(DEB_HOST_ARCH))
+# FP16 is an armv8.2 feature and GCC does not know how to generate fallback
+# code for FP16 Neon AdvSIMD operations, we use clang to do that
+  export CC=clang
+  export CXX=clang++
+# Downgrade DWARF version to make dwz happy
+  export DEB_CFLAGS_MAINT_APPEND+=-gdwarf-4
+  export DEB_CXXFLAGS_MAINT_APPEND+=-gdwarf-4
+endif
+
 %:
 	dh $@