[Buildroot] [PATCH 1/1] package/webkitgtk: allow building with musl and uclibc

[Adrian Perez de Castro]

WebKitGTK 2.32.1 includes fixes for building with the Musl libc, which
also makes it possible to use uClibc as well, therefore arrange
dependencies to allow selecting the package any of the C libraries is in
use. This is done by making the dependencies be more granular, basically
following what the wpewebkit package does.

In order to make make it build against uClibc a small patch that has
been submitted to the upstream's Bugzilla is needed.

Signed-off-by: Adrian Perez de Castro <aperez at igalia.com>
---
 ...0001-Support-building-against-uClibc.patch | 76 +++++++++++++++++++
 package/webkitgtk/Config.in                   | 10 ++-
 2 files changed, 83 insertions(+), 3 deletions(-)
 create mode 100644 package/webkitgtk/0001-Support-building-against-uClibc.patch

diff --git a/package/webkitgtk/0001-Support-building-against-uClibc.patch b/package/webkitgtk/0001-Support-building-against-uClibc.patch
new file mode 100644
index 0000000000..cbed551d2d
--- /dev/null
+++ b/package/webkitgtk/0001-Support-building-against-uClibc.patch
@@ -0,0 +1,76 @@
+From 624d3b6a99778443e35fb260bef50a3969df9215 Mon Sep 17 00:00:00 2001
+From: Adrian Perez de Castro <aperez at igalia.com>
+Date: Wed, 26 May 2021 01:24:59 +0300
+Subject: [PATCH] Support building against uClibc
+ https://bugs.webkit.org/show_bug.cgi?id=226244
+
+Reviewed by NOBODY (OOPS!).
+
+Source/JavaScriptCore:
+
+* assembler/MacroAssemblerARM64.cpp:
+(getauxval): Provide a fallback implementation of getauxval() for
+systems which do not provide <sys/auxv.h>, like those using uClibc
+as their C library.
+
+Source/WTF:
+
+* wtf/PlatformRegisters.h: Use the <sys/ucontext.h> header instead of
+<ucontext.h>, which is enough to gain access to the type definitions
+for CPU registers and is available on every libc. On the other hand,
+uClibc does not have <ucontext.h>, so this fixes the build in that
+case.
+
+Signed-off-by: Adrian Perez de Castro <aperez at igalia.com>
+[Upstream status: https://bugs.webkit.org/show_bug.cgi?id=226244]
+---
+ .../assembler/MacroAssemblerARM64.cpp          | 18 ++++++++++++++++++
+ Source/WTF/wtf/PlatformRegisters.h             |  2 +-
+ 2 files changed, 19 insertions(+), 1 deletion(-)
+
+diff --git a/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp b/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp
+index 9e5c5147ea0..d20e632d825 100644
+--- a/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp
++++ b/Source/JavaScriptCore/assembler/MacroAssemblerARM64.cpp
+@@ -34,7 +34,25 @@
+ 
+ #if OS(LINUX)
+ #include <asm/hwcap.h>
++#if __has_include(<sys/auxv.h>)
+ #include <sys/auxv.h>
++#else
++#include <linux/auxvec.h>
++// Provide an implementation for C libraries which do not ship one.
++static unsigned long getauxval(unsigned long type)
++{
++    char** env = environ;
++    while (*env++) { /* no-op */ }
++
++    for (auto* auxv = reinterpret_cast<unsigned long*>(env); *auxv != AT_NULL; auxv += 2) {
++        if (*auxv == type)
++            return auxv[1];
++    }
++
++    errno = ENOENT;
++    return 0;
++}
++#endif
+ #endif
+ 
+ namespace JSC {
+diff --git a/Source/WTF/wtf/PlatformRegisters.h b/Source/WTF/wtf/PlatformRegisters.h
+index d26ef985169..e7f15b7eb62 100644
+--- a/Source/WTF/wtf/PlatformRegisters.h
++++ b/Source/WTF/wtf/PlatformRegisters.h
+@@ -35,7 +35,7 @@
+ #elif OS(WINDOWS)
+ #include <windows.h>
+ #else
+-#include <ucontext.h>
++#include <sys/ucontext.h>
+ #endif
+ 
+ namespace WTF {
+-- 
+2.31.1
+
diff --git a/package/webkitgtk/Config.in b/package/webkitgtk/Config.in
index a05161d052..425bf81e4e 100644
--- a/package/webkitgtk/Config.in
+++ b/package/webkitgtk/Config.in
@@ -12,20 +12,24 @@ config BR2_PACKAGE_WEBKITGTK_ARCH_SUPPORTS
 	depends on BR2_TOOLCHAIN_HAS_SYNC_4
 	depends on BR2_PACKAGE_LIBGPG_ERROR_ARCH_SUPPORTS # libgcrypt
 
-comment "webkitgtk needs libgtk3 and a glibc toolchain w/ C++, gcc >= 7, host gcc >= 4.9"
+comment "webkitgtk needs libgtk3 and a toolchain w/ C++, wchar, threads, dynamic library, gcc >= 7, host gcc >= 4.9"
 	depends on BR2_PACKAGE_WEBKITGTK_ARCH_SUPPORTS
+	depends on !BR2_BINFMT_FLAT
 	depends on !BR2_PACKAGE_LIBGTK3 || !BR2_INSTALL_LIBSTDCPP || \
-		!BR2_TOOLCHAIN_USES_GLIBC || \
+		!BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS || BR2_STATIC_LIBS || \
 		!BR2_TOOLCHAIN_GCC_AT_LEAST_7 || \
 		!BR2_HOST_GCC_AT_LEAST_4_9
 	depends on BR2_USE_MMU
 
 config BR2_PACKAGE_WEBKITGTK
 	bool "webkitgtk"
+	depends on !BR2_STATIC_LIBS # wayland
+	depends on !BR2_BINFMT_FLAT # icu
 	depends on BR2_HOST_GCC_AT_LEAST_4_9 # icu
 	depends on BR2_INSTALL_LIBSTDCPP
+	depends on BR2_TOOLCHAIN_HAS_THREADS # wayland, icu, libsoup
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_7
-	depends on BR2_TOOLCHAIN_USES_GLIBC
+	depends on BR2_USE_WCHAR # icu, libsoup
 	depends on BR2_PACKAGE_LIBGTK3
 	depends on BR2_PACKAGE_WEBKITGTK_ARCH_SUPPORTS
 	select BR2_PACKAGE_CAIRO
-- 
2.31.1