[vala/wip/profile-posix] codegen: Support string comparision (POSIX)

[Rico Tzschichholz <ricotz src gnome org>]

commit a74d36c213e6e1b1cba001f392c655e9512c0bf9
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Mar 19 17:04:21 2018 +0100

    codegen: Support string comparision (POSIX)

 codegen/valaccodebasemodule.vala |   55 +++++++++++++++++++++++++++++++++++++-
 1 files changed, 54 insertions(+), 1 deletions(-)
---
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 23cce16..f0db8b1 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -5547,7 +5547,12 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
                                   || expr.operator == BinaryOperator.GREATER_THAN
                                   || expr.operator == BinaryOperator.LESS_THAN_OR_EQUAL
                                   || expr.operator == BinaryOperator.GREATER_THAN_OR_EQUAL) {
-                               var ccall = new CCodeFunctionCall (new CCodeIdentifier ("g_strcmp0"));
+                               CCodeFunctionCall ccall;
+                               if (context.profile == Profile.POSIX) {
+                                       ccall = new CCodeFunctionCall (new CCodeIdentifier 
(generate_cmp_wrapper (new CCodeIdentifier ("strcmp"))));
+                               } else {
+                                       ccall = new CCodeFunctionCall (new CCodeIdentifier ("g_strcmp0"));
+                               }
                                ccall.add_argument (cleft);
                                ccall.add_argument (cright);
                                cleft = ccall;
@@ -5646,6 +5651,54 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
                return array_contains_func;
        }
 
+       string generate_cmp_wrapper (CCodeIdentifier cmpid) {
+               // generate and call NULL-aware cmp function to reduce number
+               // of temporary variables and simplify code
+
+               string cmp0_func = "_%s0".printf (cmpid.name);
+
+               // g_strcmp0 is already NULL-safe
+               if (cmpid.name == "g_strcmp0") {
+                       cmp0_func = cmpid.name;
+               } else if (add_wrapper (cmp0_func)) {
+                       var cmp0_fun = new CCodeFunction (cmp0_func, "int");
+                       cmp0_fun.add_parameter (new CCodeParameter ("s1", "const void *"));
+                       cmp0_fun.add_parameter (new CCodeParameter ("s2", "const void *"));
+                       cmp0_fun.modifiers = CCodeModifiers.STATIC;
+
+                       push_function (cmp0_fun);
+
+                       // s1 != s2;
+                       var noteq = new CCodeBinaryExpression (CCodeBinaryOperator.INEQUALITY, new 
CCodeIdentifier ("s1"), new CCodeIdentifier ("s2"));
+
+                       // if (!s1) return -(s1 != s2);
+                       {
+                               var cexp = new CCodeUnaryExpression (CCodeUnaryOperator.LOGICAL_NEGATION, new 
CCodeIdentifier ("s1"));
+                               ccode.open_if (cexp);
+                               ccode.add_return (new CCodeUnaryExpression (CCodeUnaryOperator.MINUS, noteq));
+                               ccode.close ();
+                       }
+                       // if (!s2) return s1 != s2;
+                       {
+                               var cexp = new CCodeUnaryExpression (CCodeUnaryOperator.LOGICAL_NEGATION, new 
CCodeIdentifier ("s2"));
+                               ccode.open_if (cexp);
+                               ccode.add_return (noteq);
+                               ccode.close ();
+                       }
+                       // return strcmp (s1, s2);
+                       var cmp_call = new CCodeFunctionCall (cmpid);
+                       cmp_call.add_argument (new CCodeIdentifier ("s1"));
+                       cmp_call.add_argument (new CCodeIdentifier ("s2"));
+                       ccode.add_return (cmp_call);
+
+                       pop_function ();
+
+                       cfile.add_function (cmp0_fun);
+               }
+
+               return cmp0_func;
+       }
+
        public override void visit_type_check (TypeCheck expr) {
                generate_type_declaration (expr.type_reference, cfile);