[analyzer][CrossTU] Extend CTU to VarDecls with initializer

Summary:
The existing CTU mechanism imports `FunctionDecl`s where the definition is available in another TU. This patch extends that to VarDecls, to bind more constants.

- Add VarDecl importing functionality to CrossTranslationUnitContext
- Import Decls while traversing them in AnalysisConsumer
- Add VarDecls to CTU external mappings generator
- Name changes from "external function map" to "external definition map"

Reviewers: NoQ, dcoughlin, xazax.hun, george.karpenkov, martong

Reviewed By: xazax.hun

Subscribers: Charusso, baloghadamsoftware, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, george.karpenkov, mgorny, whisperity, szepet, rnkovacs, a.sidorin, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D46421

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@358968 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp b/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
index e2f6014fae..5c674923e0 100644
--- a/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
+++ b/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
@@ -342,6 +342,35 @@ public:
     return true;
   }
 
+  bool VisitVarDecl(VarDecl *VD) {
+    if (!Opts->IsNaiveCTUEnabled)
+      return true;
+
+    if (VD->hasExternalStorage() || VD->isStaticDataMember()) {
+      if (!cross_tu::containsConst(VD, *Ctx))
+        return true;
+    } else {
+      // Cannot be initialized in another TU.
+      return true;
+    }
+
+    if (VD->getAnyInitializer())
+      return true;
+
+    llvm::Expected<const VarDecl *> CTUDeclOrError =
+      CTU.getCrossTUDefinition(VD, Opts->CTUDir, Opts->CTUIndexName, 
+                               Opts->DisplayCTUProgress);
+
+    if (!CTUDeclOrError) {
+      handleAllErrors(CTUDeclOrError.takeError(),
+                      [&](const cross_tu::IndexError &IE) {
+                        CTU.emitCrossTUDiagnostics(IE);
+                      });
+    }
+
+    return true;
+  }
+
   bool VisitFunctionDecl(FunctionDecl *FD) {
     IdentifierInfo *II = FD->getIdentifier();
     if (II && II->getName().startswith("__inline"))