Switch to clang and improve cpprt

README.md

@@ -31,7 +31,7 @@ Popcorn uses the `waf` build tool, which is included in the repo. The other
 requirements are:
 
 * python (to run waf)
-* gcc
+* clang
 * nasm
 
 After cloning, run `waf configure`. Then you can run `waf build` to build the

src/boot/wscript

@@ -11,7 +11,7 @@ def configure(ctx):
         'EFI_DEBUG=0',
         'EFI_DEBUG_CLEAR_MEMORY=0',
     ])
-    ctx.env.append_value('CFLAGS_EFI', ['-fPIC', '-fshort-wchar', '-Wa,--no-warn'])
+    ctx.env.append_value('CFLAGS_EFI', ['-fPIC', '-fshort-wchar'])
     ctx.env.append_value('LINKFLAGS_EFI', [
         '-shared',
         '-T', lds_path,

src/kernel/cpprt.cpp

@@ -1,3 +1,37 @@
+#include "kutil/assert.h"
+
+using __exit_func = void (*)(void *);
+
 extern "C" {
-	void __cxa_pure_virtual() { while(1); }
+	void *__dso_handle __attribute__ ((__weak__));
+	int __cxa_atexit(__exit_func, void *, void *);
+	void __cxa_pure_virtual();
+}
+
+
+struct __exit_func_entry
+{
+	__exit_func func;
+	void *obj;
+	void *dso;
+};
+
+static int __num_exit_funcs = 0;
+static const int __max_exit_funcs = 64;
+__exit_func_entry __exit_funcs[__max_exit_funcs];
+
+int
+__cxa_atexit(__exit_func f, void *o, void *dso)
+{
+	int i = __num_exit_funcs++;
+	if (i >= __max_exit_funcs) return -1;
+	__exit_funcs[i].func = f;
+	__exit_funcs[i].obj = o;
+	__exit_funcs[i].dso = dso;
+	return 0;
+}
+
+void __cxa_pure_virtual()
+{
+	kassert(0, "Pure virtual function call");
 }

src/kernel/kalloc.cpp

@@ -4,7 +4,8 @@ kutil::memory_manager g_kernel_memory_manager;
 
 void * kalloc(size_t length)				{ return g_kernel_memory_manager.allocate(length); }
 void kfree(void *p)							{ g_kernel_memory_manager.free(p); }
+
 void * operator new (size_t n)				{ return g_kernel_memory_manager.allocate(n); }
 void * operator new[] (size_t n)			{ return g_kernel_memory_manager.allocate(n); }
-void operator delete (void *p)  { return g_kernel_memory_manager.free(p); }
+void operator delete (void *p) noexcept		{ return g_kernel_memory_manager.free(p); }
-void operator delete[] (void *p){ return g_kernel_memory_manager.free(p); }
+void operator delete[] (void *p) noexcept	{ return g_kernel_memory_manager.free(p); }

src/kernel/main.cpp

@@ -23,8 +23,7 @@ extern "C" {
 	void *__bss_start, *__bss_end;
 }
 
-extern [[noreturn]] void
+extern void __kernel_assert(const char *, unsigned, const char *);
-__kernel_assert(const char *file, unsigned line, const char *message);
 
 void
 init_console(const popcorn_data *header)
@@ -55,7 +54,7 @@ init_console(const popcorn_data *header)
 	log::enable(logs::memory, log::level::debug);
 }
 
-void do_error_3() { int x = 1 / 0; }
+void do_error_3() { volatile int x = 1; volatile int y = 0; volatile int z = x / y; }
 void do_error_2() { do_error_3(); }
 void do_error_1() { do_error_2(); }
 

src/kernel/memory_bootstrap.cpp

@@ -357,7 +357,7 @@ find_efi_free_aligned_pages(const void *memory_map, size_t map_length, size_t de
 static unsigned
 check_needs_page_ident(page_table *table, unsigned index, page_table **free_pages)
 {
-	if (table->entries[index] & 0x1 == 1) return 0;
+	if ((table->entries[index] & 0x1) == 1) return 0;
 
 	kassert(*free_pages, "check_needs_page_ident needed to allocate but had no free pages");
 
@@ -404,6 +404,7 @@ page_in_ident(
 	}
 
 	kassert(0, "Ran to end of page_in_ident");
+	return 0; // Cannot reach
 }
 
 void

src/kernel/page_manager.cpp

@@ -263,6 +263,7 @@ page_manager::get_block()
 		return block;
 	} else {
 		kassert(0, "NYI: page_manager::get_block() needed to allocate.");
+		return nullptr;
 	}
 }
 
@@ -431,7 +432,7 @@ page_manager::unmap_pages(addr_t address, size_t count)
 void
 page_manager::check_needs_page(page_table *table, unsigned index)
 {
-	if (table->entries[index] & 0x1 == 1) return;
+	if ((table->entries[index] & 0x1) == 1) return;
 
 	page_table *new_table = get_table_page();
 	for (int i=0; i<512; ++i) new_table->entries[i] = 0;
@@ -527,7 +528,7 @@ page_table::dump(int level, uint64_t offset)
 		uint64_t ent = entries[i];
 		if (ent == 0) continue;
 
-		if (ent & 0x1 == 0) {
+		if ((ent & 0x1) == 0) {
 			log::info(logs::memory, "  %3d: %lx   NOT PRESENT", i, ent);
 			continue;
 		}

src/modules/kutil/assert.h

@@ -15,4 +15,4 @@ extern assert_callback __kernel_assert_p;
 } // namespace kutil
 
 
-#define kassert(stmt, message)  if(!(stmt)) { ::kutil::__kernel_assert_p(__FILE__, __LINE__, (message)); } else {}
+#define kassert(stmt, message)  do { if(!(stmt)) { ::kutil::__kernel_assert_p(__FILE__, __LINE__, (message)); }} while(0);

wscript

@@ -9,7 +9,7 @@ class TestContext(BuildContext):
 
 
 def options(opt):
-    opt.load("nasm gcc g++")
+    opt.load("nasm clang clang++")
 
     opt.add_option(
             '--arch',
@@ -36,7 +36,7 @@ def configure(ctx):
     ctx.find_program("ld", var="LINK_CC")
     ctx.env.LINK_CXX = ctx.env.LINK_CC
 
-    ctx.load("nasm gcc g++")
+    ctx.load("nasm clang clang++")
     ctx.find_program("objcopy", var="objcopy")
     ctx.find_program("objdump", var="objdump")
     ctx.find_program("mcopy", var="mcopy")
@@ -158,7 +158,7 @@ def configure(ctx):
     ##
     from waflib.ConfigSet import ConfigSet
     ctx.setenv('tests', env=ConfigSet())
-    ctx.load("g++")
+    ctx.load("clang++")
 
     ctx.env.append_value('INCLUDES', [
         join(ctx.path.abspath(), "src", "include"),