1 files changed, 22 insertions, 14 deletions
diff --git a/mesalib/src/glsl/s_expression.cpp b/mesalib/src/glsl/s_expression.cpp
index e704a3be2..57de9d334 100644
--- a/mesalib/src/glsl/s_expression.cpp
+++ b/mesalib/src/glsl/s_expression.cpp
@@ -23,6 +23,7 @@
  */
 
 #include <assert.h>
+#include <limits>
 #include "s_expression.h"
 
 s_symbol::s_symbol(const char *str, size_t n)
@@ -64,21 +65,28 @@ read_atom(void *ctx, const char *&src, char *&symbol_buffer)
    if (n == 0)
       return NULL; // no atom
 
-   // Check if the atom is a number.
-   char *float_end = NULL;
-   double f = glsl_strtod(src, &float_end);
-   if (float_end != src) {
-      char *int_end = NULL;
-      int i = strtol(src, &int_end, 10);
-      // If strtod matched more characters, it must have a decimal part
-      if (float_end > int_end)
-	 expr = new(ctx) s_float(f);
-      else
-	 expr = new(ctx) s_int(i);
+   // Check for the special symbol '+INF', which means +Infinity.  Note: C99
+   // requires strtod to parse '+INF' as +Infinity, but we still support some
+   // non-C99-compliant compilers (e.g. MSVC).
+   if (n == 4 && strncmp(src, "+INF", 4) == 0) {
+      expr = new(ctx) s_float(std::numeric_limits<float>::infinity());
    } else {
-      // Not a number; return a symbol.
-      symbol_buffer[n] = '\0';
-      expr = new(ctx) s_symbol(symbol_buffer, n);
+      // Check if the atom is a number.
+      char *float_end = NULL;
+      double f = glsl_strtod(src, &float_end);
+      if (float_end != src) {
+         char *int_end = NULL;
+         int i = strtol(src, &int_end, 10);
+         // If strtod matched more characters, it must have a decimal part
+         if (float_end > int_end)
+            expr = new(ctx) s_float(f);
+         else
+            expr = new(ctx) s_int(i);
+      } else {
+         // Not a number; return a symbol.
+         symbol_buffer[n] = '\0';
+         expr = new(ctx) s_symbol(symbol_buffer, n);
+      }
    }
 
    src += n;