giflib
Author: Ludovic HENRY <ludovic.henry@qti.qualcomm.com>
Date: 2026-06-17
Scope: RISC-V (riscv64/linux) support status for giflib
Audience: Technical leadership, resource allocation strategy
Verification policy: Every claim is cross-referenced to a primary upstream source. Items that could not be verified against a second source are marked [NEEDS VERIFICATION].
1. Project Overview
giflib is a pure-C library for reading and writing GIF image files. It implements the GIF87a and GIF89a formats and provides the canonical C API used by downstream multimedia and graphics consumers. It is not a compute-intensive library: GIF is a lossless, palette-based format with no floating-point math in its critical path.
Governance: No foundation affiliation. The project is individually maintained, hosted on SourceForge. The current lead maintainer is Eric S. Raymond (ESR), who returned to the project in April 2012 at the request of the prior maintainer, Toshio Kuratomi. Original author: Gershon Elber. There is no corporate sponsor; the project solicits individual donations via ESR’s Patreon.
License: MIT.
Community stance on new ports: Not applicable. giflib contains no architecture-specific code, no assembly, and no SIMD. It compiles on any architecture supported by a C99-capable compiler. The project explicitly discourages redesign. No upstream action is ever required for a new architecture port.
Note on the referenced repository: The repository identifier qrb/giflib on GitHub returns HTTP 404 and does not exist. The canonical upstream is SourceForge. GitHub mirrors (rcancro/giflib, mirrorer/giflib) exist as read-only forks with no active development, no open issues, and no CI.
2. Port History and Upstreaming Timeline
| Date | Event | Source |
|---|---|---|
| No specific date | giflib ships as architecture-agnostic C; riscv64 support is implicit from day one of distro packaging | SourceForge source tree |
| Current | Debian sid giflib 6.1.3-1 status “Installed” on riscv64 builder rv-osuosl-05 | Debian buildd |
| Current | Ubuntu 24.04 Noble ships giflib-tools 5.2.2-1ubuntu1 listing riscv64 as a supported architecture | Ubuntu packages |
| 2025-04-09 | Alpine Linux edge ships giflib-5.2.2-r1 for riscv64 | Alpine packages |
No porting work was ever required. There are no riscv64-specific commits in the upstream source, in either active GitHub mirror, or in any Debian patch series. The Debian patch set for giflib 6.1.3-1 contains four patches (integer overflow hardening, signed overflow in gifbuild.c, a buffer overrun fix, a race condition on install); none is architecture-specific.
Key contributors for riscv64: None. Distro packagers built the package without modification.
Fully upstream: Yes, trivially – there is nothing to upstream.
3. Upstream Support Tier
giflib has no formal tier policy. The project has no CI, no test matrix, and no concept of supported versus unsupported architectures. Every architecture that can compile C99 is equally supported.
Evidence:
- No upstream CI exists. The SourceForge project provides no GitHub Actions, no Buildbot, and no automated test infrastructure.
- There are no architecture-specific release-blocking criteria.
- No official upstream binary releases exist; distribution packaging is the sole delivery mechanism.
Comparison table:
| Property | amd64 | arm64 | riscv64 |
|---|---|---|---|
| Upstream CI | None | None | None |
| Release-blocking tests | None | None | None |
| Official upstream binaries | No | No | No |
| Distro packages available | Yes | Yes | Yes |
| Build status (Debian sid) | Installed | Installed | Installed |
riscv64 is at parity with amd64 and arm64. The absence of upstream CI is uniform across all architectures, not a riscv64-specific gap.
4. Technical Architecture and RISC-V-Specific Subsystems
giflib’s source tree consists of portable C files: dgif_lib.c (decode), egif_lib.c (encode), quantize.c (color quantization), and a set of command-line utilities. The complete tree contains:
- 0 assembly (
.S) files - 0
arch/orarch/riscv/directories - 0 SIMD dispatch infrastructure
- 0 RVV intrinsics (
vfloat32m1_t,vsetvl, etc.) - 0
#ifdef __riscvconditional compilation guards - 0 JIT backends
- 0 cryptographic operations
Component table:
| Component | amd64 | arm64 | riscv64 | Notes |
|---|---|---|---|---|
| GIF decode (dgif_lib.c) | scalar C | scalar C | scalar C | Identical across all architectures |
| GIF encode (egif_lib.c) | scalar C | scalar C | scalar C | Identical across all architectures |
| Color quantization (quantize.c) | scalar C | scalar C | scalar C | Identical across all architectures |
| SIMD/vectorized paths | None | None | None | Not applicable |
| Assembly files | None | None | None | Not applicable |
| JIT backend | None | None | None | Not applicable |
No ISA extensions are used or required on any platform.
5. Build System, Cross-Compilation, and Toolchain
Build system: Hand-written GNU Makefile. No CMake, no autoconf, no pkg-config.
Key Makefile variables:
CC ?= gcc
CFLAGS += -std=gnu99 -fPIC -Wall $(OFLAGS)
OFLAGS = -O2
UNAME:=$(shell uname) # Linux vs Darwin branching only
Platform detection is limited to distinguishing Linux (.so) from macOS (.dylib). There are no CROSS_COMPILE, -march, -mabi, ARCH, or other cross-compilation variables.
Native build:
make
make install PREFIX=/usr
riscv64 cross-build:
make CC=riscv64-linux-gnu-gcc \
CFLAGS="-std=gnu99 -fPIC -Wall -O2" \
PREFIX=/usr \
LIBDIR=/usr/lib/riscv64-linux-gnu
make check
The Debian debian/rules demonstrates the canonical approach used in production:
override_dh_auto_build:
dh_auto_build -- OFLAGS="$(CPPFLAGS) $(CFLAGS) $(LDFLAGS)" \
PREFIX=/usr \
LIBDIR=/usr/lib/$(DEB_TARGET_MULTIARCH)
Toolchain requirements: C99 compiler. Any GCC >= 4.x or Clang supporting -std=gnu99 and <stdint.h> is sufficient. No minimum version is documented upstream. No architecture-specific flags are required or beneficial.
QEMU: Not documented upstream. Debian’s build infrastructure uses QEMU user-mode emulation transparently for cross-testing on riscv64, but this is invisible to giflib’s own build system.
Known build failures: None on riscv64. The only known build failure is on x32 (a -fPIC relocation issue specific to the x32 ABI, unrelated to riscv64).
Build documentation files: build.adoc (in source tarball). No BUILDING.md, INSTALL, CMakeLists.txt, or cross-compilation guide exists.
6. Feature Coverage and Gap Analysis vs arm64 and amd64
There are no functional gaps between riscv64, arm64, and amd64 for giflib. The library is architecture-agnostic and all three targets execute identical code paths.
Feature matrix:
| Feature | amd64 | arm64 | riscv64 | Gap |
|---|---|---|---|---|
| GIF decode | Full | Full | Full | None |
| GIF encode | Full | Full | Full | None |
| Color quantization | Full | Full | Full | None |
| 32-bit color support | Full | Full | Full | None |
| Extensions (GIF89a) | Full | Full | Full | None |
| SIMD acceleration | None | None | None | None (N/A) |
| Vectorized quantization | None | None | None | None (N/A) |
Performance gaps: No SIMD optimization exists for any architecture, so there is no riscv64-specific performance deficit. GIF quantization (the only computationally non-trivial operation) runs as scalar C on all targets.
Security hardening gaps: None identified. CVE-2026-23868 (double-free) and CVE-2026-26740 (buffer overflow) are both fixed in giflib 6.1.3-1, which is the version shipping in Debian sid for riscv64.
Floating-point semantics: Not applicable. giflib performs no floating-point operations in its decode or encode paths.
7. CI/CD Infrastructure
No upstream CI exists for giflib on any architecture.
qrb/giflibon GitHub does not exist (HTTP 404).mirrorer/giflibandrcancro/giflibGitHub mirrors contain no.github/workflowsdirectory and no CI configuration.- The SourceForge canonical project has no automated CI.
riscv64 build validation is performed exclusively by downstream distribution CI (Debian buildd, Ubuntu Launchpad).
RISE runners: None. RISE has no involvement with giflib.
CI comparison table:
| CI | amd64 | arm64 | riscv64 |
|---|---|---|---|
| Upstream CI | None | None | None |
| Debian buildd | Yes | Yes | Yes (rv-osuosl-05) |
| Ubuntu Launchpad | Yes | Yes | Yes |
| Alpine build | Yes | Yes | Yes |
The absence of upstream CI is uniform. riscv64 is not disadvantaged relative to other architectures.
8. Distribution and Release Status
giflib has no official upstream binary releases. All binary delivery is through Linux distribution packaging.
Distribution package status:
| Distribution | Version | riscv64 Status | Notes |
|---|---|---|---|
| Debian sid | 6.1.3-1 | Installed | Built on rv-osuosl-05 |
| Debian crossqa | 6.1.3-1 and 5.2.2-1 | ok (cross-build) | amd64 host to riscv64 target |
| Ubuntu 24.04 Noble | 5.2.2-1ubuntu1 | Available | universe section, giflib-tools |
| Alpine Linux edge | 5.2.2-r1 | Available | Built 2025-04-09 |
| Arch Linux RISC-V | Unknown | Implicitly available [NEEDS VERIFICATION] | Not on blacklist or broken status list; upstream Arch extra repo carries giflib |
Package sizes: The riscv64 Debian package (libgif7) has an installed size of approximately 475 kB versus amd64’s 162 kB. This difference is attributable to ELF format overhead on riscv64, not functional differences.
What a user must do: Install the distro package. For Debian/Ubuntu: apt install libgif-dev. No patches, no special flags, no workarounds required.
PyPI: Not applicable. giflib is a C library with no Python package on PyPI (HTTP 404 confirmed).
RISE wheel builder: Not applicable. giflib is not a Python wheel.
9. Dependencies
| Name | Role | riscv64 Build | riscv64 Test | riscv64 Release | Blocking Issues |
|---|---|---|---|---|---|
| libc (glibc/musl) | C runtime, POSIX I/O, malloc/free | Pass | Pass | Released | None. Only standard POSIX interfaces used. No SIMD, no JIT. |
| libm | Math library (linked as -lm) | Pass | Pass | Released | None. Used only for basic floating-point in quantize.c. |
| reallocarray(3) | Memory allocator helper | Pass | Pass | Released | Bundled fallback openbsd-reallocarray.c compiles in when the platform libc lacks it; no riscv64 gap. |
| GCC or Clang | Build toolchain | Pass | Pass | Released | Standard toolchain. riscv64 GCC and Clang both support -std=gnu99 -fPIC -O2 without issue. |
| xmlto | DocBook to man/HTML (docs only) | Pass | N/A | Released | Documentation-only build dependency. Not linked into the library. |
giflib has no JIT backends, no SIMD intrinsics, no cryptography, and no compression engine. Its dependency chain bottoms out at libc and libm, both fully supported on riscv64.
Reverse dependencies that consume libgif (for example, libsdl2-image, Skia in Android) carry their own riscv64 status separately and are outside the scope of this report.
11. Known Bugs and Active Issues
The following open bugs are tracked on the SourceForge giflib tracker. None are RISC-V-specific.
| ID | Title | Status | Severity | Notes |
|---|---|---|---|---|
| 202 | Heap buffer overflow in GifQuantizeBuffer via integer overflow |
Open | High | Opened 2026-05-17. Not architecture-specific. |
| 201 | Heap buffer overflow in EGifGCBToSavedExtension on malformed GCE |
Open | High | Opened 2026-05-15. Not architecture-specific. |
| 198 | EGifPutScreenDesc pointer-reuse causes double-free |
Open | High | Opened 2026-04-20. CVE-2026-23868. Fixed in 6.1.3-1 (Debian sid). |
| 189 | giflib 6.1.1 missing symbol | Open | Medium | Opened 2026-02-19. Not architecture-specific. |
Open patches: Four open patches on SourceForge address integer overflow hardening, signed overflow in gifbuild.c, a buffer overrun fix, and a race condition on install. None is architecture-specific.
Correctness bugs on riscv64: None known. No riscv64-specific issues have been filed in any tracked source.
12. Objections and Upstream Blockers
There are no objections, technical blockers, or organizational blockers to riscv64 support for giflib.
- The project has no concept of supported versus unsupported architectures.
- No maintainer has stated any objection to riscv64.
- No architecture-conditional code exists that could block riscv64.
- Distro packages build and ship without modification.
Upstream acceptance probability for any riscv64-specific contribution: not applicable – there is nothing to contribute.
13. Investment Analysis
giflib is already fully functional on riscv64 with zero investment. The analysis below quantifies remaining work for completeness.
13.1 Functional Enablement
No work required. giflib is fully functional on riscv64 through implicit C portability. Debian sid and Ubuntu 24.04 both ship working riscv64 packages without patches.
13.2 Performance Optimization
giflib has no SIMD implementation for any architecture (including amd64 and arm64). Color quantization in quantize.c is a candidate for RVV vectorization but given that giflib is not a performance-critical library in any identified use case, and no comparable optimization exists for amd64 (no SSE/AVX implementation), there is no competitive gap to close.
13.3 CI/CD Infrastructure
No upstream CI exists for any architecture. Adding riscv64 CI would first require establishing CI at all. Given the project’s minimal maintenance posture and ESR’s stated preference against redesign, upstream CI adoption is unlikely.
13.4 Ecosystem Enablement
Not applicable. giflib is a standalone C library. Its consumers (multimedia decoders, graphics toolkits) are separate projects with their own riscv64 status.
13.5 Summary Table
| Area | Work Item | Effort (person-weeks) | Owner | Priority |
|---|---|---|---|---|
| Functional | None required | 0 | N/A | N/A |
| Performance | RVV vectorization of quantize.c | 1-2 | Contributor | Low |
| CI/CD | Upstream CI does not exist for any arch; adding riscv64 CI would require establishing CI first | 1 | Contributor | Low |
| Ecosystem | None required | 0 | N/A | N/A |
Overall investment recommendation: Zero investment required for functional riscv64 support. The optional performance work (RVV quantization) has negligible impact on real workloads. CI investment would benefit all architectures equally but faces low adoption probability from an individually-maintained project with no corporate backing.
14. Updates
No updates yet – initial report dated 2026-06-17.
15. References
- giflib project homepage (SourceForge)
- giflib SourceForge source tree (master)
- giflib SourceForge bug tracker
- giflib SourceForge patch tracker
- rcancro/giflib GitHub mirror
- mirrorer/giflib GitHub mirror
- Debian buildd status for giflib
- Debian packages – libgif-dev riscv64 sid
- Debian crossqa giflib
- Debian Salsa giflib debian/rules
- Debian patch tracker giflib 6.1.3-1
- Ubuntu 24.04 Noble package search – giflib
- Alpine Linux packages – giflib riscv64
- RISE Project homepage
- RISE Project blog