Check if the compiler supports C99 and better check for some math functions.

Add a configuration check that says we would like to use C99 if the
compiler supports it. Also change the lround(), nan(), fmin() and
fmax() checks to look in the default libraries as well as the math
library.

Update the iverilog-vpi sh script to correctly quote CC since it
may now have two words (gcc -std=gnu99).

Add a missing int for main in draw_tt.c.
(cherry picked from commit ed7e9f8be5)

configure.in

@@ -11,6 +11,7 @@ AC_CONFIG_HEADER(tgt-vhdl/vhdl_config.h)
 AC_CANONICAL_HOST
 dnl Checks for programs.
 AC_PROG_CC
+AC_PROG_CC_C99
 AC_PROG_CXX
 AC_PROG_RANLIB
 AC_CHECK_TOOL(STRIP, strip, true)
@@ -156,7 +157,15 @@ AC_SUBST(file64_support)
 
 # Check that these functions exist. They are mostly C99
 # functions that older compilers may not yet support.
-AC_CHECK_FUNCS(lround nan fmin fmax fopen64)
+AC_CHECK_FUNCS(fopen64)
+# The following math functions may be defined in the math library so look
+# in the default libraries first and then look in -lm for them. On some
+# systems we may need to use the compiler in C99 mode to get a definition.
+# We requested C99 mode earlier with AC_PROG_CC_C99.
+AC_SEARCH_LIBS([lround], [m], [AC_DEFINE([HAVE_LROUND], [1])])
+AC_SEARCH_LIBS([nan], [m], [AC_DEFINE([HAVE_NAN], [1])])
+AC_SEARCH_LIBS([fmin], [m], [AC_DEFINE([HAVE_FMIN], [1])])
+AC_SEARCH_LIBS([fmax], [m], [AC_DEFINE([HAVE_FMAX], [1])])
 
 # Linker option used when compiling the target
 AX_LD_RDYNAMIC

iverilog-vpi.sh

@@ -19,7 +19,7 @@
 #
 
 # These are the variables used for compiling files
-CC=@IVCC@
+CC="@IVCC@"
 CXX=@IVCXX@
 CFLAGS="@PIC@ @IVCFLAGS@ -I@INCLUDEDIR@"
 

vvp/draw_tt.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001-2008 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -117,7 +117,7 @@ static void draw_oct_table()
       printf("};\n");
 }
 
-main()
+int main()
 {
       draw_hex_table();
       draw_oct_table();