From c4615e0363baf5fb90257cdc0009485a22396ce2 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Wed, 30 May 2018 21:18:03 -0400
Subject: [PATCH] add binary literals

---
 src/parser/parser.l | 29 +++++++++++++++++++++++++++++
 tests/t005.cxl      |  8 ++++++++
 tests/t005.x        |  1 +
 3 files changed, 38 insertions(+)
 create mode 100644 tests/t005.cxl
 create mode 100644 tests/t005.x

diff --git a/src/parser/parser.l b/src/parser/parser.l
index 235767b..7060c96 100644
--- a/src/parser/parser.l
+++ b/src/parser/parser.l
@@ -22,6 +22,7 @@ static std::string * build_string = nullptr;
 static size_t current_line = 1u;
 static std::string * current_file = nullptr;
 void handle_loc(const char * input);
+static const char hex_digit[] = "0123456789ABCDEF";
 
 %}
 
@@ -136,6 +137,34 @@ L?'\\x[0-9A-Fa-f]{2}'   return CHAR_CONST;
 L?'\\[0-7]{1,3}'        return CHAR_CONST;
 [0-9]+[uU]?[lL]?[lL]?                return INT_CONST;
 0[xX][0-9a-fA-F]+([uU][lL]?[lL]?)?   return INT_CONST;
+0[bB][01]+([uU][lL]?[lL]?)? {
+    size_t end = 3u;
+    while (yytext[end] == '0' || yytext[end] == '1')
+    {
+        end++;
+    }
+    std::string * hex_str = new std::string("0x");
+    size_t n_bits_to_nibble = ((end - 2u + 3u) % 4u) + 1u;
+    int nibble_value = 0;
+    for (size_t i = 2u; i < end; i++)
+    {
+        nibble_value <<= 1u;
+        nibble_value += yytext[i] - '0';
+        if (n_bits_to_nibble == 1)
+        {
+            *hex_str += hex_digit[nibble_value];
+            n_bits_to_nibble = 4;
+            nibble_value = 0;
+        }
+        else
+        {
+            n_bits_to_nibble--;
+        }
+    }
+    *hex_str += yytext[end];
+    (*yylval)->token.text = hex_str;
+    return INT_CONST;
+}
 ([0-9]+\.[0-9]*|\.[0-9]+)([eE][-+]?[0-9]+)?[fFlL]?     return FLOAT_CONST;
 
 L?\" {
diff --git a/tests/t005.cxl b/tests/t005.cxl
new file mode 100644
index 0000000..2b04a13
--- /dev/null
+++ b/tests/t005.cxl
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main(int argc, char * argv[])
+{
+    printf("%d;", 0b01u | 0b10u);
+    printf("%d;", 0x100 - 0b100000000);
+    printf("\n");
+}
diff --git a/tests/t005.x b/tests/t005.x
new file mode 100644
index 0000000..edd8d81
--- /dev/null
+++ b/tests/t005.x
@@ -0,0 +1 @@
+3;0;