From: Aaron Ballman <aaron@aaronballman.com>
Date: Fri, 1 Aug 2014 13:49:00 +0000 (+0000)
Subject: The GNU-style aligned attribute has an optional expression, but the generated pretty... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=18dfa9d42e05217a0c17ad051788b705996cefb4;p=clang

The GNU-style aligned attribute has an optional expression, but the generated pretty printing logic was unaware of this. Fixed the pretty printing logic, and added a test to ensure it no longer asserts.

Added a FIXME to the code about eliding the parenthesis when pretty printing such a construct.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214513 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/test/Sema/ast-print.c b/test/Sema/ast-print.c
index 382f0d3896..8ac4960b11 100644
--- a/test/Sema/ast-print.c
+++ b/test/Sema/ast-print.c
@@ -39,3 +39,6 @@ int rvarr(int n, int a[restrict static n]) {
   return a[2];
 }
 
+typedef struct {
+  int f;
+} T __attribute__ ((__aligned__));
diff --git a/utils/TableGen/ClangAttrEmitter.cpp b/utils/TableGen/ClangAttrEmitter.cpp
index 0f0f89e55c..45e9e02508 100644
--- a/utils/TableGen/ClangAttrEmitter.cpp
+++ b/utils/TableGen/ClangAttrEmitter.cpp
@@ -486,9 +486,10 @@ namespace {
     }
     void writeValue(raw_ostream &OS) const override {
       OS << "\";\n";
-      OS << "    assert(is" << getLowerName() << "Expr && " << getLowerName()
-         << "Expr != nullptr);\n";
-      OS << "    " << getLowerName() << "Expr->printPretty(OS, 0, Policy);\n";
+      // The aligned attribute argument expression is optional.
+      OS << "    if (is" << getLowerName() << "Expr && "
+         << getLowerName() << "Expr)\n";
+      OS << "      " << getLowerName() << "Expr->printPretty(OS, 0, Policy);\n";
       OS << "    OS << \"";
     }
     void writeDump(raw_ostream &OS) const override {
@@ -1120,6 +1121,11 @@ writePrettyPrintFunction(Record &R,
       continue;
     }
 
+    // FIXME: always printing the parenthesis isn't the correct behavior for
+    // attributes which have optional arguments that were not provided. For
+    // instance: __attribute__((aligned)) will be pretty printed as
+    // __attribute__((aligned())). The logic should check whether there is only
+    // a single argument, and if it is optional, whether it has been provided.
     if (!Args.empty())
       OS << "(";
     if (Spelling == "availability") {