Add support for C++17 hexadecimal floating literals

CHANGES.current

@@ -7,6 +7,9 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.0.0 (in progress)
 ===========================
 
+2019-02-13: ZackerySpytz
+            #1469 Add support for C++17 hexadecimal floating literals.
+
 2019-02-11: wsfulton
             [OCaml] #1437 OCaml has been give the 'Experimental' language status. The examples work
             and most of the test-suite is also working, so it is quite close to being a 'Supported' language.

Doc/Manual/CPlusPlus17.html

@@ -16,6 +16,7 @@
 <ul>
 <li><a href="#CPlusPlus17_nested_namespaces">Nested namespace definitions</a>
 <li><a href="#CPlusPlus17_u8_char_literals">UTF-8 character literals</a>
+<li><a href="#CPlusPlus17_hexadecimal_floating_literals">Hexadecimal floating literals</a>
 </ul>
 <li><a href="#CPlusPlus17_standard_library_changes">Standard library changes</a>
 </ul>
@@ -87,6 +88,20 @@ char a = u8'a';
 </pre>
 </div>
 
+<H3><a name="CPlusPlus17_hexadecimal_floating_literals">9.2.3 Hexadecimal floating literals</a></H3>
+
+
+<p>
+C++17 added hexadecimal floating literals.
+For example:
+</p>
+
+<div class="code">
+<pre>
+double f = 0xF.68p2;
+</pre>
+</div>
+
 <H2><a name="CPlusPlus17_standard_library_changes">9.3 Standard library changes</a></H2>
 
 

Doc/Manual/Contents.html

@@ -365,6 +365,7 @@
 <ul>
 <li><a href="CPlusPlus17.html#CPlusPlus17_nested_namespaces">Nested namespace definitions</a>
 <li><a href="CPlusPlus17.html#CPlusPlus17_u8_char_literals">UTF-8 character literals</a>
+<li><a href="CPlusPlus17.html#CPlusPlus17_hexadecimal_floating_literals">Hexadecimal floating literals</a>
 </ul>
 <li><a href="CPlusPlus17.html#CPlusPlus17_standard_library_changes">Standard library changes</a>
 </ul>

Examples/test-suite/common.mk

@@ -163,6 +163,7 @@ CPP_TEST_CASES += \
 	cpp_static \
 	cpp_typedef \
 	cpp14_binary_integer_literals \
+	cpp17_hex_floating_literals \
 	cpp17_nested_namespaces \
 	cpp17_nspace_nested_namespaces \
 	cpp17_u8_char_literals \

Examples/test-suite/cpp17_hex_floating_literals.i

@@ -0,0 +1,43 @@
+%module cpp17_hex_floating_literals
+
+// Tests are designed so that code compiles with C++98 compilers
+
+%{
+#if __cplusplus >= 201703L
+#define CPP17 1
+#endif
+%}
+
+double f1 = 0x.0p1;
+double f2 = 0x0.p1;
+double f3 = 0x0.0p-1;
+double f4 = 0xf.p-1;
+double f5 = 0xA.0p1;
+double f6 = 0x0.10P+10;
+double f7 = 0xb2F.p2;
+float f8 = 0x1234AP1F;
+float f9 = 0x45A1.D1A2p+10f;
+
+%{
+#if defined(CPP17)
+double f1 = 0x.0p1;
+double f2 = 0x0.p1;
+double f3 = 0x0.0p-1;
+double f4 = 0xf.p-1;
+double f5 = 0xA.0p1;
+double f6 = 0x0.10P+10;
+double f7 = 0xb2F.p2;
+float f8 = 0x1234AP1F;
+float f9 = 0x45A1.D1A2p+10f;
+#else
+double f1 = 0.;
+double f2 = 0.;
+double f3 = 0.;
+double f4 = 7.5;
+double f5 = 20.;
+double f6 = 64.;
+double f7 = 11452.;
+float f8 = 149140.f;
+float f9 = 18253638.f;
+#endif
+%}

Examples/test-suite/python/cpp17_hex_floating_literals_runme.py

@@ -0,0 +1,28 @@
+from cpp17_hex_floating_literals import *
+
+if cvar.f1 != 0.:
+    raise RuntimeError
+
+if cvar.f2 != 0.:
+    raise RuntimeError
+
+if cvar.f3 != 0.:
+    raise RuntimeError
+
+if cvar.f4 != 7.5:
+    raise RuntimeError
+
+if cvar.f5 != 20.:
+    raise RuntimeError
+
+if cvar.f6 != 64.:
+    raise RuntimeError
+
+if cvar.f7 != 11452.:
+    raise RuntimeError
+
+if cvar.f8 != 149140.:
+    raise RuntimeError
+
+if cvar.f9 != 18253638.:
+    raise RuntimeError

Source/Swig/scanner.c

@@ -1196,6 +1196,10 @@ static int look(Scanner *s) {
 	return SWIG_TOKEN_INT;
       if (isxdigit(c))
 	state = 85;
+      else if (c == '.') /* hexadecimal float */
+	state = 860;
+      else if ((c == 'p') || (c == 'P')) /* hexadecimal float */
+	state = 820;
       else if ((c == 'l') || (c == 'L')) {
 	state = 87;
       } else if ((c == 'u') || (c == 'U')) {
@@ -1220,7 +1224,22 @@ static int look(Scanner *s) {
 	return SWIG_TOKEN_INT;
       }
       break;
-
+    case 860:
+      /* hexadecimal float */
+      if ((c = nextchar(s)) == 0) {
+	Swig_error(cparse_file, cparse_start_line, "Hexadecimal floating literals require an exponent\n");
+	return SWIG_TOKEN_ERROR;
+      }
+      if (isxdigit(c))
+	state = 860;
+      else if ((c == 'p') || (c == 'P'))
+	state = 820;
+      else {
+	retract(s, 2);
+	Swig_error(cparse_file, cparse_start_line, "Hexadecimal floating literals require an exponent\n");
+	return SWIG_TOKEN_ERROR;
+      }
+      break;
     case 86:
       /* Rest of floating point number */