[clang] 4953213 - Make AST reading work better with LLVM_APPEND_VC_REV=NO

[Nico Weber via cfe-commits]

Author: Nico Weber
Date: 2020-01-27T22:08:37-05:00
New Revision: 49532137d087d8053789d18540c5e7916b91ef30

URL: https://github.com/llvm/llvm-project/commit/49532137d087d8053789d18540c5e7916b91ef30
DIFF: https://github.com/llvm/llvm-project/commit/49532137d087d8053789d18540c5e7916b91ef30.diff

LOG: Make AST reading work better with LLVM_APPEND_VC_REV=NO

With LLVM_APPEND_VC_REV=NO, Modules/merge-lifetime-extended-temporary.cpp
would fail if it ran before a0f50d731639350c7a7 (which changed
the serialization format) and then after, for these reasons:

1. With LLVM_APPEND_VC_REV=NO, the module hash before and after the
   change was the same.

2. Modules/merge-lifetime-extended-temporary.cpp is the only test
   we have that uses -fmodule-cache-path=%t that
   a) actually writes to the cache path
   b) doesn't do `rm -rf %t` at the top of the test

So the old run would write a module file, and then the new run would
try to load it, but the serialized format changed.

Do several things to fix this:

1. Include clang::serialization::VERSION_MAJOR/VERSION_MINOR in
   the module hash, so that when the AST format changes (...and
   we remember to bump these), we use a different module cache dir.
2. Bump VERSION_MAJOR, since a0f50d731639350c7a7 changed the
   on-disk format in a way that a gch file written before that change
   can't be read after that change.
3. Add `rm -rf %t` to all tests that pass -fmodule-cache-path=%t.
   This is unnecessary from a correctness PoV after 1 and 2,
   but makes it so that we don't amass many cache dirs over time.
   (Arguably, it also makes it so that the test suite doesn't catch
   when we change the serialization format but don't bump
   clang::serialization::VERSION_MAJOR/VERSION_MINOR; oh well.)

Differential Revision: https://reviews.llvm.org/D73202

Added: 
    

Modified: 
    clang/include/clang/Serialization/ASTBitCodes.h
    clang/lib/Frontend/CompilerInvocation.cpp
    clang/test/Modules/diagnostics.modulemap
    clang/test/Modules/exception-spec.cpp
    clang/test/Modules/merge-lifetime-extended-temporary.cpp
    clang/test/Modules/objc-method-redecl.m
    clang/test/Modules/using-decl-inheritance.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
index 44a12c875da7..83af4d15e27b 100644
--- a/clang/include/clang/Serialization/ASTBitCodes.h
+++ b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -41,7 +41,7 @@ namespace serialization {
     /// Version 4 of AST files also requires that the version control branch and
     /// revision match exactly, since there is no backward compatibility of
     /// AST files at this time.
-    const unsigned VERSION_MAJOR = 8;
+    const unsigned VERSION_MAJOR = 9;
 
     /// AST file minor version number supported by this version of
     /// Clang.

diff  --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index eb1c50f68a03..b3733a221090 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -41,6 +41,7 @@
 #include "clang/Lex/HeaderSearchOptions.h"
 #include "clang/Lex/PreprocessorOptions.h"
 #include "clang/Sema/CodeCompleteOptions.h"
+#include "clang/Serialization/ASTBitCodes.h"
 #include "clang/Serialization/ModuleFileExtension.h"
 #include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
 #include "llvm/ADT/APInt.h"
@@ -3635,6 +3636,11 @@ std::string CompilerInvocation::getModuleHash() const {
   // CityHash, but this will do for now.
   hash_code code = hash_value(getClangFullRepositoryVersion());
 
+  // Also include the serialization version, in case LLVM_APPEND_VC_REV is off
+  // and getClangFullRepositoryVersion() doesn't include git revision.
+  code = hash_combine(code, serialization::VERSION_MAJOR,
+                      serialization::VERSION_MINOR);
+
   // Extend the signature with the language options
 #define LANGOPT(Name, Bits, Default, Description) \
    code = hash_combine(code, LangOpts->Name);

diff  --git a/clang/test/Modules/diagnostics.modulemap b/clang/test/Modules/diagnostics.modulemap
index 865892b53b28..01aa0b66a406 100644
--- a/clang/test/Modules/diagnostics.modulemap
+++ b/clang/test/Modules/diagnostics.modulemap
@@ -1,3 +1,4 @@
+// RUN: rm -rf %t
 // RUN: not %clang_cc1 -fmodules -fmodules-cache-path=%t -fmodule-map-file=%S/Inputs/diagnostics-aux.modulemap -fmodule-map-file=%s -fsyntax-only -x c++ /dev/null 2>&1 | FileCheck %s --implicit-check-not error:
 
 // CHECK: In file included from {{.*}}diagnostics-aux.modulemap:3:

diff  --git a/clang/test/Modules/exception-spec.cpp b/clang/test/Modules/exception-spec.cpp
index 083cd950f7c5..a1fcc2238ad3 100644
--- a/clang/test/Modules/exception-spec.cpp
+++ b/clang/test/Modules/exception-spec.cpp
@@ -1,3 +1,4 @@
+// RUN: rm -rf %t
 // RUN: %clang_cc1 -x c++ -std=c++17 -fmodules -fmodules-local-submodule-visibility -fmodules-cache-path=%t %s -verify
 
 // expected-no-diagnostics

diff  --git a/clang/test/Modules/merge-lifetime-extended-temporary.cpp b/clang/test/Modules/merge-lifetime-extended-temporary.cpp
index 36db948b2c4e..632af01426b2 100644
--- a/clang/test/Modules/merge-lifetime-extended-temporary.cpp
+++ b/clang/test/Modules/merge-lifetime-extended-temporary.cpp
@@ -1,3 +1,4 @@
+// RUN: rm -rf %t
 // RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -x c++ -I%S/Inputs/merge-lifetime-extended-temporary -verify -std=c++11 %s -DORDER=1
 // RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -x c++ -I%S/Inputs/merge-lifetime-extended-temporary -verify -std=c++11 %s -DORDER=2
 

diff  --git a/clang/test/Modules/objc-method-redecl.m b/clang/test/Modules/objc-method-redecl.m
index f7acda5450d6..b4f0c86904a8 100644
--- a/clang/test/Modules/objc-method-redecl.m
+++ b/clang/test/Modules/objc-method-redecl.m
@@ -1,3 +1,4 @@
+// RUN: rm -rf %t
 // RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -x objective-c-header -emit-pch %S/Inputs/objc-method-redecl.h -o %t.pch -Wno-objc-root-class
 // RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -x objective-c -include-pch %t.pch %s -verify -Wno-objc-root-class
 // expected-no-diagnostics

diff  --git a/clang/test/Modules/using-decl-inheritance.cpp b/clang/test/Modules/using-decl-inheritance.cpp
index eba9636b75ef..168893127cee 100644
--- a/clang/test/Modules/using-decl-inheritance.cpp
+++ b/clang/test/Modules/using-decl-inheritance.cpp
@@ -1,3 +1,4 @@
+// RUN: rm -rf %t
 // RUN: %clang_cc1 -x c++ -fmodules -fmodules-local-submodule-visibility -fmodules-cache-path=%t %s -verify
 // RUN: %clang_cc1 -x c++ -fmodules -fmodules-cache-path=%t %s -verify