Duncan P. N. Exon Smith 60fa28882e Modules: Use hash of PCM content for SIGNATURE
Change ASTFileSignature from a random 32-bit number to the hash of the
PCM content.

  - Move definition ASTFileSignature to Basic/Module.h so Module and
    ASTSourceDescriptor can use it.

  - Change the signature from uint64_t to std::array<uint32_t,5>.

  - Stop using (saving/reading) the size and modification time of PCM
    files when there is a valid SIGNATURE.

  - Add UNHASHED_CONTROL_BLOCK, and use it to store the SIGNATURE record
    and other records that shouldn't affect the hash.  Because implicit
    modules reuses the same file for multiple levels of -Werror, this
    includes DIAGNOSTIC_OPTIONS and DIAG_PRAGMA_MAPPINGS.

This helps to solve a PCH + implicit Modules dependency issue: PCH files
are handled by the external build system, whereas implicit modules are
handled by internal compiler build system.  This prevents invalidating a
PCH when the compiler overwrites a PCM file with the same content
(modulo the diagnostic differences).

Design and original patch by Manman Ren!

llvm-svn: 297655
2017-03-13 18:45:08 +00:00

44 lines
2.2 KiB
Objective-C

// RUN: rm -rf %t
// Build Module and set its timestamp
// RUN: echo '@import Module;' | %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs -x objective-c -
// RUN: touch -m -a -t 201101010000 %t/Module.pcm
// RUN: cp %t/Module.pcm %t/Module.pcm.saved
// RUN: wc -c %t/Module.pcm > %t/Module.size.saved
// Build DependsOnModule
// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs %s
// RUN: diff %t/Module.pcm %t/Module.pcm.saved
// RUN: cp %t/DependsOnModule.pcm %t/DependsOnModule.pcm.saved
// Rebuild Module, reset its timestamp, and verify its size hasn't changed
// RUN: rm %t/Module.pcm
// RUN: echo '@import Module;' | %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs -x objective-c -
// RUN: touch -m -a -t 201101010000 %t/Module.pcm
// RUN: wc -c %t/Module.pcm > %t/Module.size
// RUN: diff %t/Module.size %t/Module.size.saved
// RUN: cp %t/Module.pcm %t/Module.pcm.saved.2
// The signature is the hash of the PCM content, we will not rebuild rebuild DependsOnModule.
// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs %s
// RUN: diff %t/Module.pcm %t/Module.pcm.saved.2
// RUN: diff %t/DependsOnModule.pcm %t/DependsOnModule.pcm.saved
// Rebuild Module, reset its timestamp, and verify its size hasn't changed
// RUN: rm %t/Module.pcm
// RUN: echo '@import Module;' | %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs -x objective-c -
// RUN: touch -m -a -t 201101010000 %t/Module.pcm
// RUN: wc -c %t/Module.pcm > %t/Module.size
// RUN: diff %t/Module.size %t/Module.size.saved
// RUN: cp %t/Module.pcm %t/Module.pcm.saved.2
// Verify again with Module pre-imported.
// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs %s
// RUN: diff %t/Module.pcm %t/Module.pcm.saved.2
// RUN: diff %t/DependsOnModule.pcm %t/DependsOnModule.pcm.saved
#ifdef PREIMPORT
@import Module;
#endif
@import DependsOnModule;