Remove an overly aggressive assert in r298491 and leave a comment

explaining why we have to ignore errors here even though in other parts
of codegen we can be more strict with builtins.

Also add a test case based on the code in a TSan test that found this
issue.

llvm-svn: 298494

2 files changed, 19 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index b9090b413c6..e56fe2c1c1d 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1813,7 +1813,11 @@ void CodeGenModule::ConstructAttributeList(
     ASTContext::GetBuiltinTypeError Error;
     getContext().GetBuiltinType(BuiltinID, Error, nullptr,
                                 &OverrideNonnullReturn, &OverrideNonnullArgs);
-    assert(Error == ASTContext::GE_None && "Should not codegen an error");
+    // Note that we can't check the 'Error' here as there may be errors that
+    // have been diagnosed and reported to the programmer as warnings but
+    // repaired in the AST such as for implicit declarations of builtin
+    // functions. None of those impact our usage of this to analyze attributes
+    // for the builtins.
   }
 
   bool HasOptnone = false;
diff --git a/clang/test/CodeGen/function-attributes.c b/clang/test/CodeGen/function-attributes.c
index 2139f6fe654..49f47bf74d4 100644
--- a/clang/test/CodeGen/function-attributes.c
+++ b/clang/test/CodeGen/function-attributes.c
@@ -108,6 +108,20 @@ void f20(void) {
   _setjmp(0);
 }
 
+// Bogus declarations that will end up with bad types when detecting builtins,
+// but that we will still process when considering whether to add attributes.
+struct __jmp_buf_tag;
+extern int __sigsetjmp(struct __jmp_buf_tag *__env, int __savemask);
+
+// CHECK-LABEL: define void @f21()
+// CHECK: {
+// CHECK: call i32 @__sigsetjmp(%{{.*}}* null, i32 0)
+// CHECK: [[RT_CALL]]
+// CHECK: ret void
+void f21(void) {
+  __sigsetjmp(0, 0);
+}
+
 // CHECK: attributes [[NUW]] = { nounwind optsize{{.*}} }
 // CHECK: attributes [[AI]] = { alwaysinline nounwind optsize{{.*}} }
 // CHECK: attributes [[NUW_OS_RN]] = { nounwind optsize readnone{{.*}} }