From 354e15012e234bfd950847e8e74dcb2e65b058d3 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Fri, 25 Mar 2016 02:09:49 -0400
Subject: [PATCH] Add a va_list printFormat

---
 src/Attributes.hh         |  3 ++-
 src/Console.hh            |  8 +++++--
 src/ConsolePrintFormat.cc | 45 ++++++++++++++++++++++-----------------
 3 files changed, 34 insertions(+), 22 deletions(-)

diff --git a/src/Attributes.hh b/src/Attributes.hh
index 07f3594..4eb037d 100644
--- a/src/Attributes.hh
+++ b/src/Attributes.hh
@@ -13,6 +13,7 @@
 #define __ATTRIBUTES_HH__
 
 #define PACKED __attribute__((packed))
-#define NORETURN __attribute((noreturn))
+#define NORETURN __attribute__((noreturn))
+#define PRINTF(formatArg, variableArgStart) __attribute__((format (printf, formatArg, variableArgStart)))
 
 #endif /* __ATTRIBUTES_HH__ */
diff --git a/src/Console.hh b/src/Console.hh
index ba17b76..647e661 100644
--- a/src/Console.hh
+++ b/src/Console.hh
@@ -9,8 +9,11 @@
 #ifndef __CONSOLE_HH__
 #define __CONSOLE_HH__
 
+#include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
+#include "Attributes.hh"
+
 
 namespace kernel {
 
@@ -62,8 +65,9 @@ struct Console
      * Write a format string to the current cursor position. Returns the number
      * of characters printed.
      */
-    int printFormat(const char *format, ...)
-        __attribute__((format (printf, 2, 3)));
+    int printFormat(const char *format, ...) PRINTF(2, 3);
+    int printFormat(const char *format, va_list args);
+
 
     void setColor(Color fg, Color bg);
 
diff --git a/src/ConsolePrintFormat.cc b/src/ConsolePrintFormat.cc
index ea9490e..637ba49 100644
--- a/src/ConsolePrintFormat.cc
+++ b/src/ConsolePrintFormat.cc
@@ -185,8 +185,8 @@ is_specifier(char c)
 namespace kernel {
 
 int
-Console::printFormat(const char* fmt,
-                     ...)
+Console::printFormat(const char* format,
+                     va_list args)
 {
     enum {
         Default = 0,
@@ -195,13 +195,10 @@ Console::printFormat(const char* fmt,
         Size
     } state = Default;
 
-    va_list vl;
-    va_start(vl, fmt);
-
     int nchars = 0;
     Spec spec;
 
-    for (const char* p = fmt; *p != 0; p++) {
+    for (const char* p = format; *p != 0; p++) {
         switch (state) {
             case Default:
                 if (*p == '%') {
@@ -273,19 +270,19 @@ Console::printFormat(const char* fmt,
             case 'i':
                 switch (spec.size) {
                     case Spec::Size::Normal:
-                        spec.value.d = va_arg(vl, int);
+                        spec.value.d = va_arg(args, int);
                         break;
                     case Spec::Size::DoubleShort:
-                        spec.value.hhd = (signed char)va_arg(vl, int);
+                        spec.value.hhd = (signed char)va_arg(args, int);
                         break;
                     case Spec::Size::Short:
-                        spec.value.hd = (short int)va_arg(vl, int);
+                        spec.value.hd = (short int)va_arg(args, int);
                         break;
                     case Spec::Size::Long:
-                        spec.value.ld = va_arg(vl, long int);
+                        spec.value.ld = va_arg(args, long int);
                         break;
                     case Spec::Size::DoubleLong:
-                        spec.value.lld = va_arg(vl, long long int);
+                        spec.value.lld = va_arg(args, long long int);
                         break;
                 }
                 spec.type = Spec::Type::Int;
@@ -296,29 +293,29 @@ Console::printFormat(const char* fmt,
             case 'x':
                 switch (spec.size) {
                     case Spec::Size::Normal:
-                        spec.value.x = va_arg(vl, unsigned int);
+                        spec.value.x = va_arg(args, unsigned int);
                         break;
                     case Spec::Size::DoubleShort:
-                        spec.value.hhx = (unsigned char)va_arg(vl, unsigned int);
+                        spec.value.hhx = (unsigned char)va_arg(args, unsigned int);
                         break;
                     case Spec::Size::Short:
-                        spec.value.hx = (unsigned short int)va_arg(vl, unsigned int);
+                        spec.value.hx = (unsigned short int)va_arg(args, unsigned int);
                         break;
                     case Spec::Size::Long:
-                        spec.value.lx = va_arg(vl, unsigned long int);
+                        spec.value.lx = va_arg(args, unsigned long int);
                         break;
                     case Spec::Size::DoubleLong:
-                        spec.value.llx = va_arg(vl, unsigned long long int);
+                        spec.value.llx = va_arg(args, unsigned long long int);
                         break;
                 }
                 spec.type = Spec::Type::Hex;
                 break;
             case 'c':
-                spec.value.c = va_arg(vl, int);
+                spec.value.c = va_arg(args, int);
                 spec.type = Spec::Type::Char;
                 break;
             case 's':
-                spec.value.s = va_arg(vl, char*);
+                spec.value.s = va_arg(args, char*);
                 spec.type = Spec::Type::String;
                 break;
         }
@@ -326,8 +323,18 @@ Console::printFormat(const char* fmt,
         continue;
     }
 
-    va_end(vl);
+    return nchars;
+}
 
+
+int
+Console::printFormat(const char* format,
+                     ...)
+{
+    va_list args;
+    va_start(args, format);
+    int nchars = printFormat(format, args);
+    va_end(args);
     return nchars;
 }