From 1d8ecdce28d7e268e9db8f1a963567375837291c Mon Sep 17 00:00:00 2001
From: Ilya Kurdyukov <jpegqs@gmail.com>
Date: Sat, 8 Jan 2022 21:29:38 +0700
Subject: [PATCH] kicad-6.0.0 e2k support

---
 thirdparty/libcontext/libcontext.cpp | 69 ++++++++++++++++++++++++++++
 thirdparty/libcontext/libcontext.h   |  8 ++++
 2 files changed, 77 insertions(+)

diff --git a/thirdparty/libcontext/libcontext.cpp b/thirdparty/libcontext/libcontext.cpp
index 44a969d..0194db2 100644
--- a/thirdparty/libcontext/libcontext.cpp
+++ b/thirdparty/libcontext/libcontext.cpp
@@ -1520,6 +1520,75 @@ void LIBCONTEXT_CALL_CONVENTION release_fcontext( fcontext_t ctx )
 };
 #endif
 
+#elif defined(LIBCONTEXT_USE_UCONTEXT)
+#include <cassert>
+#include <ucontext.h>
+
+namespace libcontext {
+extern "C" {
+
+struct LIBCONTEXT_CTX
+{
+    intptr_t args;
+    void (* fn)( intptr_t );
+    ucontext_t ctx;
+};
+
+intptr_t jump_fcontext( fcontext_t* ofc, fcontext_t nfc,
+        intptr_t vp, bool preserve_fpu )
+{
+    LIBCONTEXT_CTX caller, *callee = (LIBCONTEXT_CTX*) nfc;
+
+    *ofc = (fcontext_t) &caller;
+    callee->args = vp;
+    int swapcontext_ret = swapcontext( &caller.ctx, &callee->ctx );
+    assert( swapcontext_ret >= 0 );
+    return caller.args;
+}
+
+static void fcontext_start( LIBCONTEXT_CTX* callee )
+{
+    callee->fn( callee->args );
+    assert( false );
+}
+
+fcontext_t make_fcontext( void* sp, size_t size,
+        void (* fn)( intptr_t ) )
+{
+    assert( size > sizeof(LIBCONTEXT_CTX) + (1 << 14) );
+    sp = (char*)sp - size;
+    int align = (~(uintptr_t)sp + 1) & 31;
+    size = (size - align) & ~31;
+    sp = (char*)sp + align;
+    size -= sizeof(LIBCONTEXT_CTX);
+    LIBCONTEXT_CTX* callee = (LIBCONTEXT_CTX*)( (char*)sp + size );
+    callee->fn = fn;
+
+    int getcontext_ret = getcontext( &callee->ctx );
+    assert( getcontext_ret >= 0 );
+    callee->ctx.uc_stack.ss_sp = sp;
+    callee->ctx.uc_stack.ss_size = size;
+    callee->ctx.uc_stack.ss_flags = 0;
+    callee->ctx.uc_link = nullptr;
+#ifdef __e2k__
+    int makecontext_ret = makecontext_e2k( &callee->ctx, (void(*)())fcontext_start, 1, callee );
+    assert( makecontext_ret >= 0 );
+#else
+    makecontext( &callee->ctx, (void(*)())fcontext_start, 1, callee );
+#endif
+    return (fcontext_t) callee;
+}
+
+void release_fcontext( fcontext_t fc ) {
+#ifdef __e2k__
+    LIBCONTEXT_CTX* callee = (LIBCONTEXT_CTX*) fc;
+    freecontext_e2k( &callee->ctx );
+#endif
+}
+
+}    // extern "C"
+}    // namespace
+
 #else // defined(LIBCONTEXT_USE_WINFIBER) && (defined(LIBCONTEXT_PLATFORM_msvc_x86_64) || defined(LIBCONTEXT_PLATFORM_msvc_i386))
 
 #ifdef __cplusplus
diff --git a/thirdparty/libcontext/libcontext.h b/thirdparty/libcontext/libcontext.h
index 8214142..d2ff05a 100644
--- a/thirdparty/libcontext/libcontext.h
+++ b/thirdparty/libcontext/libcontext.h
@@ -28,6 +28,7 @@
 
     #define LIBCONTEXT_COMPILER_gcc
 
+    #ifndef LIBCONTEXT_USE_UCONTEXT
     #if defined(__linux__) || defined(__FreeBSD__)
     #if defined(__x86_64__) || defined(__amd64__)
         #define LIBCONTEXT_PLATFORM_linux_x86_64
@@ -81,6 +82,13 @@
         #define LIBCONTEXT_CALL_CONVENTION
     #endif
     #endif
+    #endif
+
+    #ifndef LIBCONTEXT_CALL_CONVENTION
+        #undef LIBCONTEXT_USE_UCONTEXT
+        #define LIBCONTEXT_USE_UCONTEXT
+        #define LIBCONTEXT_CALL_CONVENTION
+    #endif
 #elif defined (_MSC_VER )
 
 #if defined( LIBCONTEXT_USE_WINFIBER )
-- 
2.17.1