Limit size of non-GlobalValue name

Otherwise, in some extreme test case, very long names are created and the
compiler consumes large amount of memory. Size limit is set to a relatively
high value not to disturb debugging.

Compiler flag -non-global-value-max-name-size=<value> can be used to customize
the size.

Differential Revision: https://reviews.llvm.org/D41296

llvm-svn: 321886

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
index 163c785f5d7..01b7aff0f15 100644
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -39,6 +39,10 @@
 
 using namespace llvm;
 
+static cl::opt<unsigned> NonGlobalValueMaxNameSize(
+    "non-global-value-max-name-size", cl::Hidden, cl::init(1024),
+    cl::desc("Maximum size for the name of non-global values."));
+
 //===----------------------------------------------------------------------===//
 //                                Value Class
 //===----------------------------------------------------------------------===//
@@ -244,6 +248,11 @@ void Value::setNameImpl(const Twine &NewName) {
   if (getName() == NameRef)
     return;
 
+  // Cap the size of non-GlobalValue names.
+  if (NameRef.size() > NonGlobalValueMaxNameSize && !isa<GlobalValue>(this))
+    NameRef =
+        NameRef.substr(0, std::max(1u, (unsigned)NonGlobalValueMaxNameSize));
+
   assert(!getType()->isVoidTy() && "Cannot assign a name to void values!");
 
   // Get the symbol table to update for this object.