[PATCH] D77809: [Analyzer] Include typedef statements in CFG build.

[Balázs Kéri via Phabricator via cfe-commits]

balazske updated this revision to Diff 257330.
balazske added a comment.

- Added tests.
- Updated a comment.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77809/new/

https://reviews.llvm.org/D77809

Files:
  clang/lib/Analysis/CFG.cpp
  clang/test/Analysis/cfg.cpp


Index: clang/test/Analysis/cfg.cpp
===================================================================
--- clang/test/Analysis/cfg.cpp
+++ clang/test/Analysis/cfg.cpp
@@ -568,6 +568,25 @@
   return 2;
 }
 
+// CHECK-LABEL: void vla_simple(int x)
+// CHECK: [B1]
+// CHECK-NEXT:   1: x
+// CHECK-NEXT:   2: [B1.1] (ImplicitCastExpr, LValueToRValue, int)
+// CHECK-NEXT:   3: int vla[x];
+void vla_simple(int x) {
+  int vla[x];
+}
+
+// CHECK-LABEL: void vla_typedef(int x)
+// CHECK: [B1]
+// CHECK-NEXT:   1: x
+// CHECK-NEXT:   2: [B1.1] (ImplicitCastExpr, LValueToRValue, int)
+// CHECK-NEXT:   3: VLA vla;
+void vla_typedef(int x) {
+  typedef int VLA[x];
+  VLA vla;
+}
+
 // CHECK-LABEL: template<> int *PR18472<int>()
 // CHECK: [B2 (ENTRY)]
 // CHECK-NEXT:   Succs (1): B1
Index: clang/lib/Analysis/CFG.cpp
===================================================================
--- clang/lib/Analysis/CFG.cpp
+++ clang/lib/Analysis/CFG.cpp
@@ -2839,11 +2839,24 @@
 /// DeclStmts and initializers in them.
 CFGBlock *CFGBuilder::VisitDeclSubExpr(DeclStmt *DS) {
   assert(DS->isSingleDecl() && "Can handle single declarations only.");
+
+  if (const auto *TDD = dyn_cast<TypedefDecl>(DS->getSingleDecl())) {
+    // If we encounter a VLA in typedef, then process its size expressions.
+    CFGBlock *LastBlock = Block;
+    for (const VariableArrayType *VA =
+             FindVA(TDD->getUnderlyingType().getTypePtr());
+         VA != nullptr; VA = FindVA(VA->getElementType().getTypePtr())) {
+      if (CFGBlock *newBlock = addStmt(VA->getSizeExpr()))
+        LastBlock = newBlock;
+    }
+    return LastBlock;
+  }
+
   VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl());
 
   if (!VD) {
-    // Of everything that can be declared in a DeclStmt, only VarDecls impact
-    // runtime semantics.
+    // Of everything that can be declared in a DeclStmt, only VarDecls and the
+    // exceptions above impact runtime semantics.
     return Block;
   }
 


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