Merge branch 'fmorgner/abort' into 'feat_memory_manager'

Implement support for `std::terminate` via `::abort`

See merge request teachos/kernel!2

3 files changed, 44 insertions, 12 deletions

diff --git a/arch/x86_64/src/exception_handling/abort.cpp b/arch/x86_64/src/exception_handling/abort.cpp
new file mode 100644
index 0000000..dc40008
--- /dev/null
+++ b/arch/x86_64/src/exception_handling/abort.cpp
@@ -0,0 +1,17 @@
+#include "arch/exception_handling/panic.hpp"
+
+#include <cstdlib>
+
+namespace teachos::arch::exception_handling
+{
+
+  /**
+   * @brief Override for the newlib abort function.
+   *
+   * newlib defines @p ::abort as a weak symbol, thus allowing implementations to override it by simply providing a
+   * matching implementation. Since the default implemenatation calls a number of functions the kernel does not
+   * currently implement, @p ::abort gets overridden to simply panic.
+   */
+  extern "C" auto abort() -> void { panic("Terminate was called, possibly due to an unhandled exception"); }
+
+}  // namespace teachos::arch::exception_handling
\ No newline at end of file
diff --git a/arch/x86_64/src/exception_handling/assert.cpp b/arch/x86_64/src/exception_handling/assert.cpp
index b55da49..86696f8 100644
--- a/arch/x86_64/src/exception_handling/assert.cpp
+++ b/arch/x86_64/src/exception_handling/assert.cpp
@@ -1,4 +1,6 @@
-#include "arch/video/vga/text.hpp"
+#include "arch/exception_handling/assert.hpp"
+
+#include "arch/exception_handling/panic.hpp"
 
 namespace teachos::arch::exception_handling
 {
@@ -9,16 +11,6 @@ namespace teachos::arch::exception_handling
       return;
     }
 
-    video::vga::text::write("Assert failed: ", video::vga::text::common_attributes::green_on_black);
-    video::vga::text::write(message, video::vga::text::common_attributes::green_on_black);
-    for (;;)
-    {
-      // Trick the compiler into thinking the variable is changes at run time,
-      // to prevent the while loop being optimized away
-      // See
-      // https://stackoverflow.com/questions/9495856/how-to-prevent-g-from-optimizing-out-a-loop-controlled-by-a-variable-that-can
-      // for more information.
-      asm volatile("" : "+g"(condition));
-    }
+    panic("Assertion Violation: ", message);
   }
 }  // namespace teachos::arch::exception_handling
\ No newline at end of file
diff --git a/arch/x86_64/src/exception_handling/panic.cpp b/arch/x86_64/src/exception_handling/panic.cpp
new file mode 100644
index 0000000..56edfd5
--- /dev/null
+++ b/arch/x86_64/src/exception_handling/panic.cpp
@@ -0,0 +1,23 @@
+#include "arch/exception_handling/panic.hpp"
+
+#include "arch/kernel/halt.hpp"
+#include "arch/video/vga/text.hpp"
+
+namespace teachos::arch::exception_handling
+{
+
+  extern "C" char const message_prefix_panic[];
+
+  auto panic(char const * reason) -> void { panic(message_prefix_panic, reason); }
+
+  auto panic(char const * prefix, char const * reason) -> void
+  {
+    using video::vga::text::common_attributes::white_on_red;
+
+    video::vga::text::newline();
+    video::vga::text::write(prefix, white_on_red);
+    video::vga::text::write(reason, white_on_red);
+
+    kernel::halt();
+  };
+}  // namespace teachos::arch::exception_handling
\ No newline at end of file