[libc][uefi] fix error, exit, and io OSUtil support compilation

Author: RossComputerGuy

libc/src/__support/OSUtil/uefi/CMakeLists.txt

@@ -10,6 +10,7 @@ add_object_library(
   DEPENDS
     libc.include.errno
     libc.include.limits
+    libc.include.uefi
     libc.src.__support.common
     libc.src.__support.CPP.string_view
 )

libc/src/__support/OSUtil/uefi/error.cpp

@@ -15,9 +15,9 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-static const struct {
+static constexpr struct errno_efi_status_entry {
   EFI_STATUS status;
-  int errno;
+  int errno_value;
 } uefi_status_errno_map[] = {
     {EFI_SUCCESS, 0},
     {ERROR_BIT | EFI_LOAD_ERROR, EINVAL},
@@ -65,20 +65,20 @@ static constexpr size_t uefi_status_errno_map_length =
 
 int uefi_status_to_errno(EFI_STATUS status) {
   for (size_t i = 0; i < uefi_status_errno_map_length; i++) {
-    if (uefi_status_errno_map[i].status == status) {
-      return uefi_status_errno_map[i].errno;
-    }
+    const struct errno_efi_status_entry *entry = &uefi_status_errno_map[i];
+    if (entry->status == status)
+      return entry->errno_value;
   }
 
   // Unknown type
   __builtin_unreachable();
 }
 
-EFI_STATUS errno_to_uefi_status(int errno) {
+EFI_STATUS errno_to_uefi_status(int errno_value) {
   for (size_t i = 0; i < uefi_status_errno_map_length; i++) {
-    if (uefi_status_errno_map[i].errno == errno) {
-      return uefi_status_errno_map[i].status;
-    }
+    const struct errno_efi_status_entry *entry = &uefi_status_errno_map[i];
+    if (entry->errno_value == errno_value)
+      return entry->status;
   }
 
   // Unknown type

libc/src/__support/OSUtil/uefi/exit.cpp

@@ -7,14 +7,15 @@
 //===-----------------------------------------------------------------===//
 
 #include "src/__support/OSUtil/exit.h"
-#include "include/Uefi.h"
+#include "Uefi.h"
 #include "src/__support/macros/config.h"
 
 namespace LIBC_NAMESPACE_DECL {
 namespace internal {
 
 [[noreturn]] void exit(int status) {
-  efi_system_table->BootServices->Exit(efi_image_handle, status, 0, nullptr);
+  __llvm_libc_efi_system_table->BootServices->Exit(__llvm_libc_efi_image_handle,
+                                                   status, 0, nullptr);
   __builtin_unreachable();
 }
 

libc/src/__support/OSUtil/uefi/io.cpp

@@ -8,28 +8,34 @@
 
 #include "io.h"
 
+#include "Uefi.h"
 #include "src/__support/CPP/string_view.h"
 #include "src/__support/macros/config.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
-ssize_t read_from_stdin(char *buf, size_t size) { return 0; }
+ssize_t read_from_stdin([[gnu::unused]] char *buf,
+                        [[gnu::unused]] size_t size) {
+  return 0;
+}
 
 void write_to_stdout(cpp::string_view msg) {
   // TODO: use mbstowcs once implemented
   for (size_t i = 0; i < msg.size(); i++) {
     char16_t e[2] = {msg[i], 0};
-    efi_system_table->ConOut->OutputString(
-        efi_system_table->ConOut, reinterpret_cast<const char16_t *>(&e));
+    __llvm_libc_efi_system_table->ConOut->OutputString(
+        __llvm_libc_efi_system_table->ConOut,
+        reinterpret_cast<const char16_t *>(&e));
   }
 }
 
 void write_to_stderr(cpp::string_view msg) {
   // TODO: use mbstowcs once implemented
   for (size_t i = 0; i < msg.size(); i++) {
     char16_t e[2] = {msg[i], 0};
-    efi_system_table->StdErr->OutputString(
-        efi_system_table->StdErr, reinterpret_cast<const char16_t *>(&e));
+    __llvm_libc_efi_system_table->StdErr->OutputString(
+        __llvm_libc_efi_system_table->StdErr,
+        reinterpret_cast<const char16_t *>(&e));
   }
 }