Incorporate shimming into the irt

src/untrusted/irt/irt_interfaces.c

Index: src/untrusted/irt/irt_interfaces.c
===================================================================
--- src/untrusted/irt/irt_interfaces.c	(revision 9381)
+++ src/untrusted/irt/irt_interfaces.c	(working copy)
@@ -30,6 +30,7 @@
   { NACL_IRT_BLOCKHOOK_v0_1, &nacl_irt_blockhook, sizeof(nacl_irt_blockhook) },
   { NACL_IRT_RESOURCE_OPEN_v0_1, &nacl_irt_resource_open,
       sizeof(nacl_irt_resource_open) },
+/* @IGNORE_LINES_FOR_CODE_HYGIENE[1] */
 #ifdef IRT_PPAPI
   { NACL_IRT_PPAPIHOOK_v0_1, &nacl_irt_ppapihook, sizeof(nacl_irt_ppapihook) },
   { NACL_IRT_RANDOM_v0_1, &nacl_irt_random, sizeof(nacl_irt_random) },
@@ -39,10 +40,28 @@
     sizeof(nacl_irt_dev_exception_handling) },
 };
 
+/* controls whether cc shim'ed tables should be used */
+int g_use_cc_shim = 0;
+
 size_t nacl_irt_interface(const char *interface_ident,
-                          void *table, size_t tablesize) {
-  int i;
-  for (i = 0; i < NACL_ARRAY_SIZE(irt_interfaces); ++i) {
+                          void *table,
+                          size_t tablesize) {
+  /*
+   * fast track for a few hooks indicated by a leading '@'
+   * Other things that could be added here:
+   *   * irt verbosity control
+   *   * irt strict mode (abort on failure)
+   *   * etc.
+   */
+  if (interface_ident[0] == '@') {

[Roland McGrath, 2012/08/06 23:32:24]

I don't see any defensible rationale for this kludgery.
Just add a new interface that parallels nacl_irt_ppapihook.
The speculated "other things" can be functions available in some new
nacl_irt_control interface if they ever get added.

[Robert Muth (chromium), 2012/08/07 14:45:40]

added a new interface but this will likely complicate the switch for pnacl from
linktime shims to irt shims.

+    if (0 == strcmp(interface_ident, "@nacl-cc-shim-mode")) {
+      g_use_cc_shim = 1;
+    }
+    /* TODO(robertm): add better error/success handling */
+    return 0;
+  }
+
+  for (int i = 0; i < NACL_ARRAY_SIZE(irt_interfaces); ++i) {
     if (0 == strcmp(interface_ident, irt_interfaces[i].name)) {
       const size_t size = irt_interfaces[i].size;
       if (size <= tablesize) {