c_gen: fix Decls in while statements

    while (Decl* d = init()) ..
should become:
    {
        Decl* d;
        while (d = init()) ..
    }

Author: bvdberg

generator/c_generator_stmt.c2

@@ -22,6 +22,21 @@ import string_buffer;
 import stdio;
 import string;
 
+fn void Generator.emitVarDecl(Generator* gen, VarDecl* vd, string_buffer.Buf* out, bool emit_init) {
+    Decl* d = cast<Decl*>(vd);
+    if (vd.hasLocalQualifier()) out.add("static ");
+    gen.emitTypePre(out, d.getType());
+    out.space();
+    out.add(d.getName());
+    gen.emitTypePost(out, d.getType());
+    d.setGenerated();
+    Expr* ie = vd.getInit();
+    if (ie && emit_init) {
+        out.add(" = ");
+        gen.emitExpr(out, ie);
+    }
+}
+
 fn void Generator.emitStmt(Generator* gen, Stmt* s, u32 indent, bool newline) {
     string_buffer.Buf* out = gen.out;
 
@@ -87,14 +102,21 @@ fn void Generator.emitStmt(Generator* gen, Stmt* s, u32 indent, bool newline) {
         Stmt* cond = w.getCond();
         bool is_decl = cond.isDecl();
         if (is_decl) {
-            // TODO leave out init part
-            gen.emitStmt(cond, 0, true);
-            out.indent(indent);
-            out.add("while (");
+            out.add("{\n");
+            indent++;
             DeclStmt* ds = cast<DeclStmt*>(cond);
             VarDecl* vd = ds.getDecl();
+            out.indent(indent);
+            gen.emitVarDecl(vd, out, false);
+            out.add(";\n");
+            out.indent(indent);
+            out.add("while (");
             out.add(vd.asDecl().getName());
-            // TODO also add init part
+            // add init part
+            out.add(" = ");
+            Expr* ie = vd.getInit();
+            assert(ie);
+            gen.emitExpr(out, ie);
         } else {
             out.add("while (");
             gen.emitStmt(cond, 0, false);
@@ -106,6 +128,11 @@ fn void Generator.emitStmt(Generator* gen, Stmt* s, u32 indent, bool newline) {
             out.add1(';');
         }
         out.newline();
+        if (is_decl) {
+            indent--;
+            out.indent(indent);
+            out.add("}\n");
+        }
         break;
     case For:
         ForStmt* f = cast<ForStmt*>(s);
@@ -174,18 +201,7 @@ fn void Generator.emitStmt(Generator* gen, Stmt* s, u32 indent, bool newline) {
     case Decl:
         DeclStmt* ds = cast<DeclStmt*>(s);
         VarDecl* vd = ds.getDecl();
-        Decl* d = cast<Decl*>(vd);
-        if (vd.hasLocalQualifier()) out.add("static ");
-        gen.emitTypePre(out, d.getType());
-        out.space();
-        out.add(d.getName());
-        gen.emitTypePost(out, d.getType());
-        d.setGenerated();
-        Expr* ie = vd.getInit();
-        if (ie) {
-            out.add(" = ");
-            gen.emitExpr(out, ie);
-        }
+        gen.emitVarDecl(vd, out, true);
         if (newline) out.add(";\n");
         break;
     case Asm:

test/c_generator/stmts/while_stmt_expr.c2t

@@ -29,8 +29,10 @@ int32_t main(int32_t argc, const char** argv)
         if ((argc == 2)) break;
     }
 
-    int32_t b = 10;
-    while (b) {
+    {
+        int32_t b;
+        while (b = 10) {
+        }
     }
 
     while (true) {