Move local variable declarations in a structure.

All local variables are created in an array declared in the top of the C functions.

diff --git a/src/compiling/compiling_global.nit b/src/compiling/compiling_global.nit
index 0b65a66..15f8376 100644 (file)
--- a/src/compiling/compiling_global.nit
+++ b/src/compiling/compiling_global.nit
@@ -872,6 +872,7 @@ redef class MMLocalClass
                                end
                        end
                        v.add_instr("return OBJ2VAL(obj);")
+                       v.cfc.generate_var_decls
                        ctx_old.append(v.ctx)
                        v.ctx = ctx_old
                        v.unindent

diff --git a/src/compiling/compiling_methods.nit b/src/compiling/compiling_methods.nit
index 1fc6574..af1e848 100644 (file)
--- a/src/compiling/compiling_methods.nit
+++ b/src/compiling/compiling_methods.nit
@@ -39,9 +39,6 @@ redef class CompilerVisitor
                if s[0] == ' ' then
                        return s
                end
-               if s == cfc.variable(cfc._variable_index-1) then
-                       return s
-               end
                var v = cfc.get_var
                add_assignment(v, s)
                return v
@@ -146,7 +143,12 @@ class CFunctionContext
        attr _variable_index_max: Int = 0
 
        # Association between nit variable and the corrsponding c variable
-       readable attr _varnames: Map[Variable, String] = new HashMap[Variable, String]
+       attr _varnames: Map[Variable, String] = new HashMap[Variable, String]
+
+       meth varname(v: Variable): String
+       do
+               return _varnames[v]
+       end
 
        # Return the next available variable
        meth get_var: String
@@ -154,19 +156,24 @@ class CFunctionContext
                var v = variable(_variable_index)
                _variable_index = _variable_index + 1
                if _variable_index > _variable_index_max then
-                       visitor.add_decl("val_t {v};")
                        _variable_index_max = _variable_index 
                end
                return v
        end
 
+       meth register_variable(v: Variable): String
+       do
+               var s = get_var
+               _varnames[v] = "variable[{_variable_index-1}]"
+               return s
+       end
+
        # Return the ith variable
        protected meth variable(i: Int): String
        do
-               return "variable{i}"
+               return "variable[{i}]"
        end
 
-
        # Mark the variable available
        meth free_var(v: String)
        do
@@ -176,6 +183,17 @@ class CFunctionContext
                end
        end
 
+       # Generate the local variable declarations
+       # To use at the end of the C function once all variables are known
+       meth generate_var_decls
+       do
+               if _variable_index_max > 0 then
+                       visitor.add_decl("val_t variable[{_variable_index_max}];")
+               else
+                       visitor.add_decl("val_t *variable = NULL;")
+               end
+       end
+
        init(v: CompilerVisitor) do _visitor = v
 end
 
@@ -352,6 +370,8 @@ redef class MMSrcMethod
                        v.add_instr("return {s};")
                end
 
+               v.cfc.generate_var_decls
+
                ctx_old.append(v.ctx)
                v.ctx = ctx_old
                v.unindent
@@ -449,8 +469,7 @@ redef class AConcreteMethPropdef
                        var sig = n_signature
                        assert sig isa ASignature
                        for ap in sig.n_params do
-                               var cname = v.cfc.get_var
-                               v.cfc.varnames[ap.variable] = cname
+                               var cname = v.cfc.register_variable(ap.variable)
                                var orig_type = orig_sig[ap.position]
                                if not orig_type < ap.variable.stype then
                                        # FIXME: do not test always
@@ -739,13 +758,12 @@ end
 redef class AVardeclExpr
        redef meth prepare_compile_stmt(v)
        do
-               var cname = v.cfc.get_var
-               v.cfc.varnames[variable] = cname
+               v.cfc.register_variable(variable)
        end
 
        redef meth compile_stmt(v)
        do
-               var cname = v.cfc.varnames[variable]
+               var cname = v.cfc.varname(variable)
                if n_expr == null then
                        var t = variable.stype
                        v.add_assignment(cname, "{t.default_cvalue} /*decl variable {variable.name}*/")
@@ -918,7 +936,8 @@ redef class AForVardeclExpr
                v.cfc.free_var(ok)
                var e = prop3.compile_call(v, [iter])
                e = v.ensure_var(e)
-               v.cfc.varnames[variable] = e
+               var cname = v.cfc.register_variable(variable)
+               v.add_assignment(cname, e)
                var par = parent
                assert par isa AForExpr
                var n_block = par.n_block
@@ -949,7 +968,7 @@ end
 redef class AVarExpr
        redef meth compile_expr(v)
        do
-               return " {v.cfc.varnames[variable]} /*{variable.name}*/"
+               return " {v.cfc.varname(variable)} /*{variable.name}*/"
        end
 end
 
@@ -957,17 +976,17 @@ redef class AVarAssignExpr
        redef meth compile_stmt(v)
        do
                var e = v.compile_expr(n_value)
-               v.add_assignment(v.cfc.varnames[variable], "{e} /*{variable.name}=*/")
+               v.add_assignment(v.cfc.varname(variable), "{e} /*{variable.name}=*/")
        end
 end
 
 redef class AVarReassignExpr
        redef meth compile_stmt(v)
        do
-               var e1 = v.cfc.varnames[variable]
+               var e1 = v.cfc.varname(variable)
                var e2 = v.compile_expr(n_value)
                var e3 = assign_method.compile_call(v, [e1, e2])
-               v.add_assignment(v.cfc.varnames[variable], "{e3} /*{variable.name}*/")
+               v.add_assignment(v.cfc.varname(variable), "{e3} /*{variable.name}*/")
        end
 end
 
@@ -1322,15 +1341,15 @@ redef class AOnceExpr
        do
                var i = v.new_number
                var cvar = v.cfc.get_var
-               v.add_decl("static val_t once_value_{cvar}_{i}; static int once_bool_{cvar}_{i};")
-               v.add_instr("if (once_bool_{cvar}_{i}) {cvar} = once_value_{cvar}_{i};")
+               v.add_decl("static val_t once_value_{i}; static int once_bool_{i}; /* Once value for {cvar}*/")
+               v.add_instr("if (once_bool_{i}) {cvar} = once_value_{i};")
                v.add_instr("else \{")
                v.indent
                v.cfc.free_var(cvar)
                var e = v.compile_expr(n_expr)
                v.add_assignment(cvar, e)
-               v.add_instr("once_value_{cvar}_{i} = {cvar};")
-               v.add_instr("once_bool_{cvar}_{i} = true;")
+               v.add_instr("once_value_{i} = {cvar};")
+               v.add_instr("once_bool_{i} = true;")
                v.unindent
                v.add_instr("}")
                return cvar