[ODRHash] Do not rely on Type* when computing the hash.

ODRHash aims to provide Cross-TU stable hashing. Making clang::Type pointer part of the hash connects (remotely) the ODRHash with the TU-specific ::Profile hasher. r332281 exposed the issue by changing the way the ASTContext different elaborated types if there is an owning tag. In that case, ODRHash stores two different types in its TypeMap which yields false ODR violation in modules. The current state of implementation shouldn't need the TypeMap concept anymore. Rip it out. Differential Revision: https://reviews.llvm.org/D48524 llvm-svn: 335853
llvm · Jun 28, 2018 · 61914d3 · 61914d3
1 parent 63feb16
commit 61914d3
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Showing 8 changed files with 46 additions and 10 deletions.
diff --git a/clang/include/clang/AST/ODRHash.h b/clang/include/clang/AST/ODRHash.h
@@ -40,7 +40,6 @@ class ODRHash {
   // Use DenseMaps to convert from DeclarationName and Type pointers
   // to an index value.
   llvm::DenseMap<DeclarationName, unsigned> DeclNameMap;
-  llvm::DenseMap<const Type*, unsigned> TypeMap;
 
   // Save space by processing bools at the end.
   llvm::SmallVector<bool, 128> Bools;

diff --git a/clang/lib/AST/ODRHash.cpp b/clang/lib/AST/ODRHash.cpp
@@ -180,7 +180,6 @@ void ODRHash::AddTemplateParameterList(const TemplateParameterList *TPL) {
 
 void ODRHash::clear() {
   DeclNameMap.clear();
-  TypeMap.clear();
   Bools.clear();
   ID.clear();
 }
@@ -770,14 +769,6 @@ class ODRTypeVisitor : public TypeVisitor<ODRTypeVisitor> {
 
 void ODRHash::AddType(const Type *T) {
   assert(T && "Expecting non-null pointer.");
-  auto Result = TypeMap.insert(std::make_pair(T, TypeMap.size()));
-  ID.AddInteger(Result.first->second);
-  // On first encounter of a Type pointer, process it.  Every time afterwards,
-  // only the index value is needed.
-  if (!Result.second) {
-    return;
-  }
-
   ODRTypeVisitor(ID, *this).Visit(T);
 }
 

diff --git a/clang/test/Modules/Inputs/odr_hash-elaborated-types/first.h b/clang/test/Modules/Inputs/odr_hash-elaborated-types/first.h
@@ -0,0 +1,6 @@
+#ifndef FIRST
+#define FIRST
+
+#include "textual_time.h"
+
+#endif
diff --git a/clang/test/Modules/Inputs/odr_hash-elaborated-types/module.modulemap b/clang/test/Modules/Inputs/odr_hash-elaborated-types/module.modulemap
@@ -0,0 +1,5 @@
+module M {
+  module first { header "first.h" export *}
+  module second { header "second.h" export *}
+  export *
+}
diff --git a/clang/test/Modules/Inputs/odr_hash-elaborated-types/second.h b/clang/test/Modules/Inputs/odr_hash-elaborated-types/second.h
@@ -0,0 +1,6 @@
+#ifndef SECOND
+#define SECOND
+
+#include "textual_stat.h"
+
+#endif
diff --git a/clang/test/Modules/Inputs/odr_hash-elaborated-types/textual_stat.h b/clang/test/Modules/Inputs/odr_hash-elaborated-types/textual_stat.h
@@ -0,0 +1,11 @@
+#ifndef _SYS_STAT_H
+#define _SYS_STAT_H
+
+#include "textual_time.h"
+
+struct stat {
+  struct timespec st_atim;
+  struct timespec st_mtim;
+};
+
+#endif
diff --git a/clang/test/Modules/Inputs/odr_hash-elaborated-types/textual_time.h b/clang/test/Modules/Inputs/odr_hash-elaborated-types/textual_time.h
@@ -0,0 +1,6 @@
+#ifndef _TIME_H
+#define _TIME_H
+
+struct timespec { };
+
+#endif
diff --git a/clang/test/Modules/odr_hash-elaborated-types.cpp b/clang/test/Modules/odr_hash-elaborated-types.cpp
@@ -0,0 +1,12 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -std=c++1z -I%S/Inputs/odr_hash-elaborated-types -verify %s
+// RUN: %clang_cc1 -std=c++1z -fmodules -fmodules-local-submodule-visibility -fmodule-map-file=%S/Inputs/odr_hash-elaborated-types/module.modulemap -fmodules-cache-path=%t -x c++ -I%S/Inputs/odr_hash-elaborated-types -verify %s
+
+#include "textual_stat.h"
+
+#include "first.h"
+#include "second.h"
+
+void use() { struct stat value; }
+
+// expected-no-diagnostics