firefox: remove hard clang dependency

Firefox compiles with gcc - remove the hardcoded clang dependency.

New patches

freebl-ignore-unused-arguments-during-configure.patch:
A component is trying to remove some gcc warnings. OE adds
-Wformat-security by default, but the component also adds -Wno-format, which
cancels it out, but generates a warning (which is turned into an error):

cc1plus: error: '-Wformat-security' ignored without '-Wformat' [-Werror=format-security]

To avoid this, the patch adds also -Wno-format-security explicitly.

msgpack-enforce-endian-functionality.patch:
Using gcc, the msgpack third party application can't determine the endianness
of risc-v arch (at least not for qemuriscv64), failing the build. This issue
has been fixed upstream a while ago, but not pulled into Firefox yet. This
patch is a backport of that commit.

llama.cpp-unknown-type-name-__fp16.patch:
On 32-bit arm fp16 isn't defined by default. Added a patch taken from
https://stackoverflow.com/questions/31242106/fp16-type-undefined-in-gnu-arm-c

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>

Author: OldManYellsAtCloud

meta-firefox/recipes-browser/firefox/firefox-latest/llama.cpp-unknown-type-name-__fp16.patch

@@ -0,0 +1,21 @@
+Fixes error on 32-bit arm:
+
+E [...]/third_party/llama.cpp/ggml/src/ggml-cpu/simd-mappings.h:45:9: error: unknown type name '__fp16'; did you mean '__bf16'?
+
+Solution taken from
+https://stackoverflow.com/questions/31242106/fp16-type-undefined-in-gnu-arm-c
+
+Upstream-Status: Pending
+Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
+
+--- ./third_party/llama.cpp/moz.build.orig	2026-05-30 08:47:27.294716362 +0200
++++ ./third_party/llama.cpp/moz.build	2026-05-30 08:20:07.478595605 +0200
+@@ -45,6 +45,8 @@
+ elif CONFIG['TARGET_CPU'] == 'aarch64':
+     SOURCES += files['ARM64_SOURCES']
+ elif CONFIG['TARGET_CPU'] == 'arm':
++    CXXFLAGS += ["-mfp16-format=ieee"]
++    CFLAGS += ["-mfp16-format=ieee"]
+     SOURCES += files['ARM_SOURCES']
+ else:
+     DEFINES["GGML_CPU_GENERIC"] = 1

meta-firefox/recipes-browser/firefox/firefox.inc

@@ -54,7 +54,6 @@ SRC_URI += "https://ftp.mozilla.org/pub/firefox/releases/${PV}/source/firefox-${
            file://0001-Add-option-to-disable-arm-hw-crypto-engine.patch \
            file://0001-Fix-conflicting-types-for-once_flag-and-call_once-wi.patch \
            file://fix-glibc-2.43-compilation.patch \
-           file://freebl-ignore-unused-arguments-during-configure.patch \
            file://debian-hacks/Add-another-preferences-directory-for-applications-p.patch \
            file://debian-hacks/Avoid-using-vmrs-vmsr-on-armel.patch \
            file://debian-hacks/Avoid-wrong-sessionstore-data-to-keep-windows-out-of.patch \
@@ -73,6 +72,10 @@ SRC_URI += "https://ftp.mozilla.org/pub/firefox/releases/${PV}/source/firefox-${
            file://prefs/Set-DPI-to-system-settings.patch \
            "
 
+SRC_URI:append:toolchain-gcc = " file://fix-gcc-compilation.patch"
+SRC_URI:append:toolchain-clang = " file://freebl-ignore-unused-arguments-during-configure.patch"
+SRC_URI:append:riscv64:toolchain-gcc = " file://msgpack-enforce-endian-functionality.patch"
+
 SRCREV_FORMAT = "default"
 
 # Add a config file to enable GPU acceleration by default.
@@ -92,8 +95,6 @@ SRC_URI += "${@bb.utils.contains('PACKAGECONFIG', 'forbid-multiple-compositors',
             file://fixes/0001-Enable-to-suppress-multiple-compositors.patch \
            ', '', d)}"
 
-TOOLCHAIN:pn-firefox = "clang"
-
 DISABLE_STATIC = ""
 
 PACKAGECONFIG ??= "${@bb.utils.contains("DISTRO_FEATURES", "alsa", "alsa", "", d)} \

meta-firefox/recipes-browser/firefox/firefox/fix-gcc-compilation.patch

@@ -0,0 +1,21 @@
+By default, OE sets "-Wformat-security" in the CFLAGS variable.
+One particular module in the Firefox tree is trying to disable all
+such warnings, however it doesn't disable the -Wformat-security
+flag in particular, and due to this, compilation fails with the
+following error:
+
+cc1plus: error: '-Wformat-security' ignored without '-Wformat' [-Werror=format-security]
+
+Add this missing warning removal to the list of ignored warnings.
+
+Upstream-Status: Inappropriate [oe-specific]
+Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
+
+--- ./js/src/xsum/moz.build.orig	2026-05-29 10:18:14.888226193 +0200
++++ ./js/src/xsum/moz.build	2026-05-29 10:18:29.490810894 +0200
+@@ -17,4 +17,4 @@
+ ]
+ 
+ # Suppress warnings in third-party code.
+-SOURCES['xsum.cpp'].flags += ['-Wno-implicit-fallthrough', '-Wno-format', '-Wno-unused-value']
++SOURCES['xsum.cpp'].flags += ['-Wno-implicit-fallthrough', '-Wno-format', '-Wno-unused-value', '-Wno-format-security']

meta-firefox/recipes-browser/firefox/firefox/freebl-ignore-unused-arguments-during-configure.patch

@@ -1,4 +1,4 @@
-Clang sends warnings about unsued command line arguments to stderr during configuring
+Clang sends warnings about unused command line arguments to stderr during configuring
 freebl (which is enabled for targets without hw crypto support). Gyp only checks
 if there is anything on stderr, but not the content - it throws an error like this:
 

meta-firefox/recipes-browser/firefox/firefox/msgpack-enforce-endian-functionality.patch

@@ -0,0 +1,39 @@
+From f6ddc9b85adaa58f6426544e2bd1bd16e0aecd70 Mon Sep 17 00:00:00 2001
+From: Takatoshi Kondo <redboltz@gmail.com>
+Date: Sat, 8 Sep 2018 20:06:00 +0900
+Subject: [PATCH] Added enforcing endian functionality.
+
+Fixes error with gcc@riscv:
+third_party/msgpack/include/msgpack/sysdep.h:146:5: error: #error msgpack-c supports only big endian and little endian
+
+Upstream-Status: Backport [https://github.com/msgpack/msgpack-c/commit/f6ddc9b85adaa58f6426544e2bd1bd16e0aecd70]
+Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
+
+---
+ include/msgpack/sysdep.h | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/include/msgpack/sysdep.h b/include/msgpack/sysdep.h
+index 569ae4cdf..b430956b4 100644
+--- a/third_party/msgpack/include/msgpack/sysdep.h
++++ b/third_party/msgpack/include/msgpack/sysdep.h
+@@ -10,8 +10,6 @@
+ #ifndef MSGPACK_SYSDEP_H
+ #define MSGPACK_SYSDEP_H
+ 
+-#include <msgpack/predef.h>
+-
+ #include <stdlib.h>
+ #include <stddef.h>
+ 
+@@ -86,6 +84,10 @@
+ 
+ #endif
+ 
++#if !defined(MSGPACK_ENDIAN_LITTLE_BYTE) && !defined(MSGPACK_ENDIAN_BIG_BYTE)
++#include <msgpack/predef/other/endian.h>
++#endif // !defined(MSGPACK_ENDIAN_LITTLE_BYTE) && !defined(MSGPACK_ENDIAN_BIG_BYTE)
++
+ #if MSGPACK_ENDIAN_LITTLE_BYTE
+ 
+ #   if defined(unix) || defined(__unix) || defined(__APPLE__) || defined(__OpenBSD__)

meta-firefox/recipes-browser/firefox/firefox_151.0.2.bb

@@ -13,6 +13,8 @@ SRC_URI:append:libc-musl = " \
     file://fix-undeclared-identifier__NR_riscv_hwprobe.patch \
     "
 
+SRC_URI:append:toolchain-gcc:arm = " file://llama.cpp-unknown-type-name-__fp16.patch"
+
 SRC_URI[sha256sum] = "63c4267799f2618dd7ac5997d0306bbcf2a5306caaca0056795bc6c61d00f8c8"
 
 PACKAGECONFIG[legacy-appdir] = ""