indexize Math.* properly. fixes issue 29

Author: kripken

src/library.js

@@ -599,7 +599,7 @@ var Library = {
     return ret;
   },
 
-  abs: 'Math.abs',
+  abs: 'Math.abs', // XXX should be integer?
 
   atoi: function(s) {
     return Math.floor(Number(Pointer_stringify(s)));

src/parseTools.js

@@ -692,14 +692,21 @@ function makeGetValue(ptr, pos, type, noNeedFirst, unsigned) {
   }
 }
 
-function indexizeFunctions(value) { // TODO: Also check for externals
+function indexizeFunctions(value) {
   if (value in Functions.currFunctions) {
     return Functions.getIndex(value);
   }
   if (value && value[0] && value[0] == '_') {
     var rootIdent = LibraryManager.getRootIdent(value.slice(1));
-    if (rootIdent && typeof Library[rootIdent] === 'function') {
+    if (!rootIdent) return value;
+    if (typeof Library[rootIdent] === 'function') {
       return Functions.getIndex('_' + rootIdent);
+    } else if (rootIdent.substr(0, 5) === 'Math.') {
+      // Library[..] can be a string, in which case we apply that string. There is one
+      // case where this can be a function: Math.*, since we try to optimize those as much
+      // as possible. In other words, we don't want to have a wrapper function(x) return Math.sqrt(x).
+      // If other functions are deemed important as well, we will need to add them here.
+      return Functions.getIndex(rootIdent);
     }
   }
   return value;

tests/runner.py

@@ -1097,6 +1097,21 @@ def test_funcptr(self):
         '''
         self.do_test(src, '*26,26,90,90,26,90*\n*1,0,0,1*\n*goodbye!*')
 
+    def test_mathfuncptr(self):
+        src = '''
+          #include <math.h>
+          #include <stdio.h>
+
+          int
+          main(void) {
+           float (*fn)(float) = &sqrtf;
+           float (*fn2)(float) = &fabsf;
+           printf("fn2(-5) = %d, fn(10) = %f\\n", (int)fn2(-5), fn(10));
+           return 0;
+          }
+          '''
+        self.do_test(src, 'fn2(-5) = 5, fn(10) = 3.16')
+
     def test_emptyclass(self):
         src = '''
         #include <stdio.h>