Add warning capabilities in LLVM.

The patch adds a new LLVMContext::diagnose that can be used to communicate to
the front-end, if any, that something of interest happened.
The diagnostics are supported by a new abstraction, the DiagnosticInfo class.
The base class contains the following information:
- The kind of the report: What this is about.
- The severity of the report: How bad this is.

This patch also adds 2 classes:
- DiagnosticInfoInlineAsm: For inline asm reporting. Basically, this diagnostic
will be used to switch to the new diagnostic API for LLVMContext::emitError.
- DiagnosticStackSize: For stack size reporting. Comes as a replacement of the
hard coded warning in PEI.

This patch also features dynamic diagnostic identifiers. In other words plugins
can use this infrastructure for their own diagnostics (for more details, see
getNextAvailablePluginDiagnosticKind).

This patch introduces a new DiagnosticHandlerTy and a new DiagnosticContext in
the LLVMContext that should be set by the front-end to be able to map these
diagnostics in its own system.

http://llvm-reviews.chandlerc.com/D2376
<rdar://problem/15515174>

llvm-svn: 197438

1 files changed, 54 insertions, 0 deletions

diff --git a/llvm/lib/Support/DiagnosticInfo.cpp b/llvm/lib/Support/DiagnosticInfo.cpp
new file mode 100644
index 00000000000..0ce0d90a42f
--- /dev/null
+++ b/llvm/lib/Support/DiagnosticInfo.cpp
@@ -0,0 +1,54 @@
+//===- llvm/Support/DiagnosticInfo.cpp - Diagnostic Definitions -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the different classes involved in low level diagnostics.
+//
+// Diagnostics reporting is still done as part of the LLVMContext.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/Support/Atomic.h"
+#include "llvm/Support/DiagnosticInfo.h"
+#include "llvm/Support/DiagnosticPrinter.h"
+
+#include <string>
+
+using namespace llvm;
+
+int getNextAvailablePluginDiagnosticKind() {
+  static sys::cas_flag PluginKindID = DK_FirstPluginKind;
+  return (int)sys::AtomicIncrement(&PluginKindID);
+}
+
+DiagnosticInfoInlineAsm::DiagnosticInfoInlineAsm(const Instruction &I,
+                                                 const Twine &MsgStr,
+                                                 DiagnosticSeverity Severity)
+    : DiagnosticInfo(DK_InlineAsm, Severity), LocCookie(0), MsgStr(MsgStr),
+      Instr(&I) {
+  if (const MDNode *SrcLoc = I.getMetadata("srcloc")) {
+    if (SrcLoc->getNumOperands() != 0)
+      if (const ConstantInt *CI = dyn_cast<ConstantInt>(SrcLoc->getOperand(0)))
+        LocCookie = CI->getZExtValue();
+  }
+}
+
+void DiagnosticInfoInlineAsm::print(DiagnosticPrinter &DP) const {
+  DP << getMsgStr();
+  if (getLocCookie())
+    DP << " at line " << getLocCookie();
+}
+
+void DiagnosticInfoStackSize::print(DiagnosticPrinter &DP) const {
+  DP << "stack size limit exceeded (" << getStackSize() << ") in "
+     << getFunction();
+}