PNaCl ABI checker: Disallow "section", "thread_local" and "gc" attributes

 * Disallow "section" on functions and global variables.
 * Disallow "thread_local" on global variables.
 * Disallow "gc" on functions.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=2837
BUG= https://code.google.com/p/nativeclient/issues/detail?id=3126
TEST=test/NaCl/PNaClABI/global-attributes.ll + PNaCl toolchain trybots

Review URL: https://codereview.chromium.org/14063007

2 files changed, 56 insertions, 0 deletions

diff --git a/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp b/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp
index 23699860b0..d98868f53c 100644
--- a/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp
+++ b/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp
@@ -112,6 +112,15 @@ bool PNaClABIVerifyModule::runOnModule(Module &M) {
             " has disallowed linkage type: " <<
             linkageName(MI->getLinkage()) << "\n";
     }
+
+    if (MI->hasSection()) {
+      Reporter->addError() << "Variable " << MI->getName() <<
+          " has disallowed \"section\" attribute\n";
+    }
+    if (MI->isThreadLocal()) {
+      Reporter->addError() << "Variable " << MI->getName() <<
+          " has disallowed \"thread_local\" attribute\n";
+    }
   }
   // No aliases allowed for now.
   for (Module::alias_iterator MI = M.alias_begin(),
@@ -136,6 +145,15 @@ bool PNaClABIVerifyModule::runOnModule(Module &M) {
             PNaClABITypeChecker::getTypeName(PT) << "\n";
       }
     }
+
+    if (MI->hasSection()) {
+      Reporter->addError() << "Function " << MI->getName() <<
+          " has disallowed \"section\" attribute\n";
+    }
+    if (MI->hasGC()) {
+      Reporter->addError() << "Function " << MI->getName() <<
+          " has disallowed \"gc\" attribute\n";
+    }
   }
 
   // Check named metadata nodes
diff --git a/test/NaCl/PNaClABI/global-attributes.ll b/test/NaCl/PNaClABI/global-attributes.ll
new file mode 100644
index 0000000000..255e1f8a02
--- /dev/null
+++ b/test/NaCl/PNaClABI/global-attributes.ll
@@ -0,0 +1,38 @@
+; RUN: pnacl-abicheck < %s | FileCheck %s
+
+; Global variable attributes
+
+; CHECK: Variable var_with_section has disallowed "section" attribute
+@var_with_section = global i32 99, section ".some_section"
+
+; PNaCl programs can depend on data alignments in general, so we allow
+; "align" on global variables.
+; CHECK-NOT: var_with_alignment
+@var_with_alignment = global i32 99, align 8
+
+; TLS variables must be expanded out by ExpandTls.
+; CHECK-NEXT: Variable tls_var has disallowed "thread_local" attribute
+@tls_var = thread_local global i32 99
+
+
+; Function attributes
+
+; CHECK-NEXT: Function func_with_section has disallowed "section" attribute
+define void @func_with_section() section ".some_section" {
+  ret void
+}
+
+; TODO(mseaborn): PNaCl programs don't know what alignment is
+; reasonable for a function, so we should disallow this.
+; CHECK-NOT: func_with_alignment
+define void @func_with_alignment() align 1 {
+  ret void
+}
+
+; CHECK-NEXT: Function func_with_gc has disallowed "gc" attribute
+define void @func_with_gc() gc "my_gc_func" {
+  ret void
+}
+
+; CHECK-NOT: disallowed
+; If another check is added, there should be a check-not in between each check