Add error library.

3 files changed, 41 insertions, 0 deletions

diff --git a/error/CMakeLists.txt b/error/CMakeLists.txt
new file mode 100644
index 0000000..e47a1f9
--- /dev/null
+++ b/error/CMakeLists.txt
@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.0)
+
+project(error)
+
+add_library(error
+  src/error.c)
+
+target_include_directories(error PUBLIC
+  include)
+
+target_link_libraries(error
+  cstring)
+
+target_compile_options(error PRIVATE -Wall -Wextra)
diff --git a/error/include/error.h b/error/include/error.h
new file mode 100644
index 0000000..92c06ff
--- /dev/null
+++ b/error/include/error.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <cstring.h>
+#include <stdio.h>
+
+/// Get the last error.
+const char* get_error(void);
+
+extern xlstring gfx_error;
+
+/// Set the last error.
+#define set_error(...) \
+  gfx_error.length = snprintf(gfx_error.str, xlstring_size, __VA_ARGS__)
+
+/// Prepend an error to the last error.
+#define prepend_error(...)                                        \
+  {                                                               \
+    xlstring head;                                                \
+    head.length = snprintf(head.str, xlstring_size, __VA_ARGS__); \
+    xlstring_append(&head, xlstring_make(": "));                  \
+    gfx_error = xlstring_concat(head, gfx_error);                 \
+  }
diff --git a/error/src/error.c b/error/src/error.c
new file mode 100644
index 0000000..ccd850d
--- /dev/null
+++ b/error/src/error.c
@@ -0,0 +1,5 @@
+#include "error.h"
+
+xlstring gfx_error;
+
+const char* get_error(void) { return xlstring_cstr(&gfx_error); }