Provide the same ABI regardless of NDEBUG

For projects depending on LLVM, I find it very useful to combine a
release-no-asserts build of LLVM with a debug+asserts build of the dependent
project.  The motivation is that when developing a dependent project, you are
debugging that project itself, not LLVM.  In my usecase, a significant part of
the runtime is spent in LLVM optimization passes, so I would like to build LLVM
without assertions to get the best performance from this combination.

Currently, `lib/Support/Debug.cpp` changes the set of symbols it provides
depending on NDEBUG, while `include/llvm/Support/Debug.h` requires extra
symbols when NDEBUG is not defined.  Thus, it is not possible to enable
assertions in an external project that uses facilities of `Debug.h`.

This patch changes `Debug.cpp` and `Valgrind.cpp` to always define the symbols
that other code may depend on when #including LLVM headers without NDEBUG.

http://reviews.llvm.org/D7662

llvm-svn: 229819

1 files changed, 37 insertions, 28 deletions

diff --git a/llvm/lib/Support/Debug.cpp b/llvm/lib/Support/Debug.cpp
index cb86ea6a600..9c58ae8cc9f 100644
--- a/llvm/lib/Support/Debug.cpp
+++ b/llvm/lib/Support/Debug.cpp
@@ -29,11 +29,47 @@
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/circular_raw_ostream.h"
 
+#undef isCurrentDebugType
+#undef setCurrentDebugType
+
 using namespace llvm;
 
+// Even though LLVM might be built with NDEBUG, define symbols that the code
+// built without NDEBUG can depend on via the llvm/Support/Debug.h header.
+namespace llvm {
+/// Exported boolean set by the -debug option.
+bool DebugFlag = false;
+
+static ManagedStatic<std::vector<std::string>> CurrentDebugType;
+
+/// Return true if the specified string is the debug type
+/// specified on the command line, or if none was specified on the command line
+/// with the -debug-only=X option.
+bool isCurrentDebugType(const char *DebugType) {
+  if (CurrentDebugType->empty())
+    return true;
+  // see if DebugType is in list. Note: do not use find() as that forces us to
+  // unnecessarily create an std::string instance.
+  for (auto d : *CurrentDebugType) {
+    if (d == DebugType)
+      return true;
+  }
+  return false;
+}
+
+/// Set the current debug type, as if the -debug-only=X
+/// option were specified.  Note that DebugFlag also needs to be set to true for
+/// debug output to be produced.
+///
+void setCurrentDebugType(const char *Type) {
+  CurrentDebugType->clear();
+  CurrentDebugType->push_back(Type);
+}
+
+} // namespace llvm
+
 // All Debug.h functionality is a no-op in NDEBUG mode.
 #ifndef NDEBUG
-bool llvm::DebugFlag;  // DebugFlag - Exported boolean set by the -debug option
 
 // -debug - Command line option to enable the DEBUG statements in the passes.
 // This flag may only be enabled in debug builds.
@@ -51,8 +87,6 @@ DebugBufferSize("debug-buffer-size",
                 cl::Hidden,
                 cl::init(0));
 
-static ManagedStatic<std::vector<std::string> > CurrentDebugType;
-
 namespace {
 
 struct DebugOnlyOpt {
@@ -84,31 +118,6 @@ static void debug_user_sig_handler(void *Cookie) {
   dbgout->flushBufferWithBanner();
 }
 
-// isCurrentDebugType - Return true if the specified string is the debug type
-// specified on the command line, or if none was specified on the command line
-// with the -debug-only=X option.
-//
-bool llvm::isCurrentDebugType(const char *DebugType) {
-  if (CurrentDebugType->empty())
-    return true;
-  // see if DebugType is in list. Note: do not use find() as that forces us to
-  // unnecessarily create an std::string instance.
-  for (auto d : *CurrentDebugType) {
-    if (d == DebugType)
-      return true;
-  }
-  return false;
-}
-
-/// setCurrentDebugType - Set the current debug type, as if the -debug-only=X
-/// option were specified.  Note that DebugFlag also needs to be set to true for
-/// debug output to be produced.
-///
-void llvm::setCurrentDebugType(const char *Type) {
-  CurrentDebugType->clear();
-  CurrentDebugType->push_back(Type);
-}
-
 /// dbgs - Return a circular-buffered debug stream.
 raw_ostream &llvm::dbgs() {
   // Do one-time initialization in a thread-safe way.