ensure enums are the size of ints

git-svn-id: https://protobuf-c.googlecode.com/svn/trunk@329 00440858-1255-0410-a3e6-75ea37f81c3a

ChangeLog

@@ -16,6 +16,7 @@
       - use a small constant-size hash-table instead of alloca() for
         detecting required fields, and it also prevents us from using too
 	much stack, etc.  (Related to Issue #60)
+      - add a macro to ensure enums are the size of ints. (Issue #69)
 
 0.15:
       - make protobuf_c_message_init() into a function (Issue #49, daveb)

TODO

@@ -10,6 +10,9 @@
   be static??
 - dispatch-within-dispatch protection needed (ie assert that you can't
   recursively invoke the main-loop)
+- uh not sure i like the hash-based situation for required values.
+  perhaps we need a message-descriptor flag to help out. (Could always use
+  different hashes and sizes)
 
 --------------------
 --- NEEDED TESTS ---

src/google/protobuf-c/protobuf-c-private.h

@@ -39,6 +39,15 @@
  */
 
 
+/* A little enum helper macro:  this will ensure that your
+   enum's size is sizeof(int).  In protobuf, it need not
+   be larger than 32-bits.
+ 
+   This is written assuming it is appended to a list w/o a tail comma. */
+#ifndef _PROTOBUF_C_FORCE_ENUM_TO_BE_INT_SIZE
+  #define _PROTOBUF_C_FORCE_ENUM_TO_BE_INT_SIZE(enum_name) \
+    , _##enum_name##_IS_INT_SIZE = INT_MAX
+#endif
 
 /* === needs to be declared for the PROTOBUF_C_BUFFER_SIMPLE_INIT macro === */
 

src/google/protobuf/compiler/c/c_enum.cc

@@ -44,6 +44,7 @@ void EnumGenerator::GenerateDefinition(io::Printer* printer) {
   map<string, string> vars;
   vars["classname"] = FullNameToC(descriptor_->full_name());
   vars["shortname"] = descriptor_->name();
+  vars["uc_name"] = FullNameToUpper(descriptor_->full_name());
 
   printer->Print(vars, "typedef enum _$classname$ {\n");
   printer->Indent();
@@ -53,10 +54,10 @@ void EnumGenerator::GenerateDefinition(io::Printer* printer) {
 
 
   vars["opt_comma"] = ",";
+  vars["prefix"] = FullNameToUpper(descriptor_->full_name()) + "__";
   for (int i = 0; i < descriptor_->value_count(); i++) {
     vars["name"] = descriptor_->value(i)->name();
     vars["number"] = SimpleItoa(descriptor_->value(i)->number());
-    vars["prefix"] = FullNameToUpper(descriptor_->full_name()) + "__";
     if (i + 1 == descriptor_->value_count())
       vars["opt_comma"] = "";
 
@@ -70,6 +71,7 @@ void EnumGenerator::GenerateDefinition(io::Printer* printer) {
     }
   }
 
+  printer->Print(vars, "  _PROTOBUF_C_FORCE_ENUM_TO_BE_INT_SIZE($uc_name$)\n");
   printer->Outdent();
   printer->Print(vars, "} $classname$;\n");
 }