Bug#1120656: deal.ii: FTBFS: Fix relocation R_LARCH_B26 overflow on loong64

[zhangdandan]

Source: deal.ii
Version: 9.6.2-4
Severity: normal
Tags: FTBFS patch
User: debian-loongarch at lists.debian.org
Usertags: loong64

Dear maintainers,

Compiling the deal.ii failed for loong64 in the Debian Package 
Auto-Building environment.
The error log is as follows,
```
......
[100%] Built target object_grid_release
/usr/bin/ld: 
dofs/CMakeFiles/object_dofs_debug.dir/dof_accessor_set.cc.o: relocation 
R_LARCH_B26 overflow 0xfffffffff7ff8a40
Dump relocate record:
stack top        relocation name        symbol
at 
dofs/CMakeFiles/object_dofs_debug.dir/dof_accessor_set.cc.o(.text._ZN6dealii8internal24process_by_interpolationILi2ELi3ELb0ENS_6VectorIfEEfEEvRKNS_15DoFCellAccessorIXT_EXT0_EXT1_EEERKNS2_IT3_EERT2_tRKSt8functionIFvS7_SB_SD_EE[_ZN6dealii8internal24process_by_interpolationILi2ELi3ELb0ENS_6VectorIfEEfEEvRKNS_15DoFCellAccessorIXT_EXT0_EXT1_EEERKNS2_IT3_EERT2_tRKSt8functionIFvS7_SB_SD_EE]+0x778):
...
0x0000000000000000 R_LARCH_B21    `.L9995'
......
```
The full build log can be found at 
https://buildd.debian.org/status/fetch.php?pkg=deal.ii&arch=loong64&ver=9.6.2-1&stamp=1740534269&raw=0.
Please consider the patch I attached.
Your opinions are welcome.

Best regards,
Dandan Zhang

-------------- next part --------------
diff -Nru deal.ii-9.6.2/debian/changelog deal.ii-9.6.2/debian/changelog
--- deal.ii-9.6.2/debian/changelog	2025-06-30 07:29:44.000000000 +0000
+++ deal.ii-9.6.2/debian/changelog	2025-11-11 19:16:05.000000000 +0000
@@ -1,3 +1,9 @@
+deal.ii (9.6.2-4+loong64) unstable; urgency=medium
+
+  * Fix relocation R_LARCH_B26 overflow for loong64.
+
+ -- Dandan Zhang <zhangdandan at loongson.cn>  Wed, 12 Nov 2025 03:16:05 +0800
+
 deal.ii (9.6.2-4) unstable; urgency=medium
 
   [ Matthias Maier ]
diff -Nru deal.ii-9.6.2/debian/rules deal.ii-9.6.2/debian/rules
--- deal.ii-9.6.2/debian/rules	2025-06-29 19:26:43.000000000 +0000
+++ deal.ii-9.6.2/debian/rules	2025-11-11 19:16:05.000000000 +0000
@@ -3,6 +3,11 @@
 export PRTE_MCA_plm_ssh_agent=/bin/false
 export PRTE_MCA_rmaps_default_mapping_policy=:oversubscribe
 
+CONFIGURE_CXX_FLAGS=-DDEAL_II_CXX_FLAGS="-Wno-nonnull-compare -Wno-address"
+ifneq (,$(filter $(DEB_HOST_ARCH),loong64))
+CONFIGURE_CXX_FLAGS=-DDEAL_II_CXX_FLAGS="-Wno-nonnull-compare -Wno-address -mcmodel=medium"
+endif
+
 ifneq (,$(filter $(DEB_HOST_ARCH),ppc64el))
 CONFIGURE_LINKER_FLAGS=-DDEAL_II_LINKER_FLAGS="-Wl,-Bsymbolic-functions"
 endif
@@ -17,7 +22,7 @@
 #   symengine (https://github.com/sympy/symengine)
 override_dh_auto_configure:
 	dh_auto_configure -- \
-	-DDEAL_II_CXX_FLAGS="-Wno-nonnull-compare -Wno-address" \
+	$(CONFIGURE_CXX_FLAGS) \
 	$(CONFIGURE_LINKER_FLAGS) \
 	-DCMAKE_PREFIX_PATH="/usr/lib/$(DEB_HOST_MULTIARCH)/hdf5/openmpi;/usr/include/hdf5/openmpi" \
 	-DCMAKE_BUILD_TYPE=DebugRelease \