[clang] 894c224 - [clang][Driver] Don't ignore -gmodules .gch files (#77711)
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Tue Jan 16 15:32:47 PST 2024
Author: Michael Spencer
Date: 2024-01-16T15:32:43-08:00
New Revision: 894c22406f68af6574a62a40ec49e058344c324b
URL: https://github.com/llvm/llvm-project/commit/894c22406f68af6574a62a40ec49e058344c324b
DIFF: https://github.com/llvm/llvm-project/commit/894c22406f68af6574a62a40ec49e058344c324b.diff
LOG: [clang][Driver] Don't ignore -gmodules .gch files (#77711)
A previous commit (82f75ed) made clang ignore .gch files that were not
Clang AST files. This broke `-gmodules`, which embeds the Clang AST into
an object file containing debug info.
This changes the probing to detect any file format recognized by
`llvm::identify_magic()` as potentially containing a Clang AST.
Previous PR: https://github.com/llvm/llvm-project/pull/69204
Added:
Modified:
clang/lib/Driver/ToolChains/Clang.cpp
clang/test/PCH/gch-probe.c
llvm/include/llvm/BinaryFormat/Magic.h
llvm/lib/BinaryFormat/Magic.cpp
llvm/lib/Object/Binary.cpp
llvm/lib/Object/ObjectFile.cpp
Removed:
################################################################################
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 9edae3fec91a87..997ec2d491d02c 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -43,7 +43,9 @@
#include "clang/Driver/XRayArgs.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/BinaryFormat/Magic.h"
#include "llvm/Config/llvm-config.h"
+#include "llvm/Object/ObjectFile.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Compiler.h"
@@ -948,11 +950,21 @@ static void handleAMDGPUCodeObjectVersionOptions(const Driver &D,
}
}
-static bool hasClangPchSignature(const Driver &D, StringRef Path) {
- if (llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MemBuf =
- D.getVFS().getBufferForFile(Path))
- return (*MemBuf)->getBuffer().starts_with("CPCH");
- return false;
+static bool maybeHasClangPchSignature(const Driver &D, StringRef Path) {
+ llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MemBuf =
+ D.getVFS().getBufferForFile(Path);
+ if (!MemBuf)
+ return false;
+ llvm::file_magic Magic = llvm::identify_magic((*MemBuf)->getBuffer());
+ if (Magic == llvm::file_magic::unknown)
+ return false;
+ // Return true for both raw Clang AST files and object files which may
+ // contain a __clangast section.
+ if (Magic == llvm::file_magic::clang_ast)
+ return true;
+ Expected<std::unique_ptr<llvm::object::ObjectFile>> Obj =
+ llvm::object::ObjectFile::createObjectFile(**MemBuf, Magic);
+ return !Obj.takeError();
}
static bool gchProbe(const Driver &D, StringRef Path) {
@@ -964,14 +976,14 @@ static bool gchProbe(const Driver &D, StringRef Path) {
std::error_code EC;
for (llvm::vfs::directory_iterator DI = D.getVFS().dir_begin(Path, EC), DE;
!EC && DI != DE; DI = DI.increment(EC)) {
- if (hasClangPchSignature(D, DI->path()))
+ if (maybeHasClangPchSignature(D, DI->path()))
return true;
}
D.Diag(diag::warn_drv_pch_ignoring_gch_dir) << Path;
return false;
}
- if (hasClangPchSignature(D, Path))
+ if (maybeHasClangPchSignature(D, Path))
return true;
D.Diag(diag::warn_drv_pch_ignoring_gch_file) << Path;
return false;
diff --git a/clang/test/PCH/gch-probe.c b/clang/test/PCH/gch-probe.c
index 8b1e1fab5ad97b..0905c9baebdae0 100644
--- a/clang/test/PCH/gch-probe.c
+++ b/clang/test/PCH/gch-probe.c
@@ -2,6 +2,10 @@
// RUN: %clang -x c-header -c %s -o %t.h.gch
// RUN: %clang -fsyntax-only -include %t.h %s
+// -gmodules embeds the Clang AST file in an object file.
+// RUN: %clang -x c-header -c %s -gmodules -o %t.h.gch
+// RUN: %clang -fsyntax-only -include %t.h %s
+
// gch probing should ignore files which are not clang pch files.
// RUN: %clang -fsyntax-only -include %S/Inputs/gch-probe.h %s 2>&1 | FileCheck %s
// CHECK: warning: precompiled header '{{.*}}gch-probe.h.gch' was ignored because it is not a clang PCH file
diff --git a/llvm/include/llvm/BinaryFormat/Magic.h b/llvm/include/llvm/BinaryFormat/Magic.h
index c635a269576587..6978c066bda468 100644
--- a/llvm/include/llvm/BinaryFormat/Magic.h
+++ b/llvm/include/llvm/BinaryFormat/Magic.h
@@ -21,6 +21,7 @@ struct file_magic {
enum Impl {
unknown = 0, ///< Unrecognized file
bitcode, ///< Bitcode file
+ clang_ast, ///< Clang PCH or PCM
archive, ///< ar style archive file
elf, ///< ELF Unknown type
elf_relocatable, ///< ELF Relocatable object file
diff --git a/llvm/lib/BinaryFormat/Magic.cpp b/llvm/lib/BinaryFormat/Magic.cpp
index 45a0b7e11452b4..bd378337ed3338 100644
--- a/llvm/lib/BinaryFormat/Magic.cpp
+++ b/llvm/lib/BinaryFormat/Magic.cpp
@@ -98,6 +98,8 @@ file_magic llvm::identify_magic(StringRef Magic) {
case 'C':
if (startswith(Magic, "CCOB"))
return file_magic::offload_bundle_compressed;
+ if (startswith(Magic, "CPCH"))
+ return file_magic::clang_ast;
break;
case '!':
if (startswith(Magic, "!<arch>\n") || startswith(Magic, "!<thin>\n"))
diff --git a/llvm/lib/Object/Binary.cpp b/llvm/lib/Object/Binary.cpp
index 0b9d95485287dc..2dfae8ab5d3c64 100644
--- a/llvm/lib/Object/Binary.cpp
+++ b/llvm/lib/Object/Binary.cpp
@@ -84,6 +84,7 @@ Expected<std::unique_ptr<Binary>> object::createBinary(MemoryBufferRef Buffer,
// PDB does not support the Binary interface.
return errorCodeToError(object_error::invalid_file_type);
case file_magic::unknown:
+ case file_magic::clang_ast:
case file_magic::cuda_fatbinary:
case file_magic::coff_cl_gl_object:
case file_magic::dxcontainer_object:
diff --git a/llvm/lib/Object/ObjectFile.cpp b/llvm/lib/Object/ObjectFile.cpp
index c05eb0a0468e2b..6a226a3bbdbca3 100644
--- a/llvm/lib/Object/ObjectFile.cpp
+++ b/llvm/lib/Object/ObjectFile.cpp
@@ -155,6 +155,7 @@ ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type,
switch (Type) {
case file_magic::unknown:
case file_magic::bitcode:
+ case file_magic::clang_ast:
case file_magic::coff_cl_gl_object:
case file_magic::archive:
case file_magic::macho_universal_binary:
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