From: Chris Lattner <sabre@nondot.org>
Date: Sat, 19 Feb 2011 22:28:58 +0000 (+0000)
Subject: implement a tiny amount of codegen support for gnu array range
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e0fd832b076eb5a1e4a4549687af0dbf2ad57181;p=clang

implement a tiny amount of codegen support for gnu array range
designators: allowing codegen when the element initializer is a
constant or something else without a side effect.  This unblocks
enough to let process.c in the linux kernel build, PR9257.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@126056 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index b0749484f5..b9a6a5713b 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -1593,14 +1593,19 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
   } else {
     assert(D->isArrayRangeDesignator() && "Need array-range designator");
 
-
     DesignatedStartIndex =
       DIE->getArrayRangeStart(*D)->EvaluateAsInt(SemaRef.Context);
     DesignatedEndIndex =
       DIE->getArrayRangeEnd(*D)->EvaluateAsInt(SemaRef.Context);
     IndexExpr = DIE->getArrayRangeEnd(*D);
 
-    if (DesignatedStartIndex.getZExtValue() !=DesignatedEndIndex.getZExtValue())
+    // Codegen can't handle evaluating array range designators that have side
+    // effects, because we replicate the AST value for each initialized element.
+    // As such, set the sawArrayRangeDesignator() bit if we initialize multiple
+    // elements with something that has a side effect, so codegen can emit an
+    // "error unsupported" error instead of miscompiling the app.
+    if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
+        DIE->getInit()->HasSideEffects(SemaRef.Context))
       FullyStructuredList->sawArrayRangeDesignator();
   }
 
diff --git a/test/CodeGen/init.c b/test/CodeGen/init.c
index ccb04f343c..0f94729a94 100644
--- a/test/CodeGen/init.c
+++ b/test/CodeGen/init.c
@@ -100,3 +100,18 @@ int test10(int X) {
   // CHECK-NOT: store i32 0
   // CHECK: call void @bar
 }
+
+
+// PR9257
+struct test11S {
+  int A[10];
+};
+void test11(struct test11S *P) {
+  *P = (struct test11S) { .A = { [0 ... 3] = 4 } };
+  // CHECK: @test11
+  // CHECK: store i32 4
+  // CHECK: store i32 4
+  // CHECK: store i32 4
+  // CHECK: store i32 4
+  // CHECK: ret void
+}