llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-debuginfo Author: Jeremy Morse (jmorse) <details> <summary>Changes</summary> Clang can chose which sort of source-file hash is attached to a DIFile metadata node. However, whenever hashing is possible, we /always/ attach a hash. This patch permits users who want DWARF5 but don't want the file hashes to opt out, by adding a "none" option to the -gsrc-hash option that skips hash computation. The option supports abnormal build processes where source-files are functionally identical between build time and debug time, but aren't byte-for-byte identical. Long story short, in various downstream builds we sometimes adjust things like version-strings and copyright notices in files after builds have taken place, and then distribute binaries + source to developers. This has no effect on the debugging experience as line-numbers don't change, but it does lead to a visual-studio pop-up alerting developers that some source files don't match the original build files. Obviously this isn't a perfect arrangement, and the pop-up is correct. This patch is an non-invasive way of opting out of this facility for builds where byte-for-byte identicalness can't be achieved. --- Full diff: https://github.com/llvm/llvm-project/pull/148657.diff 4 Files Affected: - (modified) clang/include/clang/Basic/CodeGenOptions.h (+1) - (modified) clang/include/clang/Driver/Options.td (+2-2) - (modified) clang/lib/CodeGen/CGDebugInfo.cpp (+2) - (modified) clang/test/CodeGen/debug-info-file-checksum.c (+3) ``````````diff diff --git a/clang/include/clang/Basic/CodeGenOptions.h b/clang/include/clang/Basic/CodeGenOptions.h index fe634d221b424..f6c61f202890e 100644 --- a/clang/include/clang/Basic/CodeGenOptions.h +++ b/clang/include/clang/Basic/CodeGenOptions.h @@ -115,6 +115,7 @@ class CodeGenOptions : public CodeGenOptionsBase { DSH_MD5, DSH_SHA1, DSH_SHA256, + DSH_NONE, }; // This field stores one of the allowed values for the option diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 54c71b066f9d4..504ba0e84f289 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -4681,8 +4681,8 @@ def gsimple_template_names_EQ Values<"simple,mangled">, Visibility<[CC1Option]>; def gsrc_hash_EQ : Joined<["-"], "gsrc-hash=">, Group<g_flags_Group>, Visibility<[CC1Option]>, - Values<"md5,sha1,sha256">, - NormalizedValues<["DSH_MD5", "DSH_SHA1", "DSH_SHA256"]>, + Values<"md5,sha1,sha256,none">, + NormalizedValues<["DSH_MD5", "DSH_SHA1", "DSH_SHA256", "DSH_NONE"]>, NormalizedValuesScope<"CodeGenOptions">, MarshallingInfoEnum<CodeGenOpts<"DebugSrcHash">, "DSH_MD5">; def gno_simple_template_names : Flag<["-"], "gno-simple-template-names">, diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index 8bf7d24d8551d..7b3345d9390ba 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -514,6 +514,8 @@ CGDebugInfo::computeChecksum(FileID FID, SmallString<64> &Checksum) const { case clang::CodeGenOptions::DSH_SHA256: llvm::toHex(llvm::SHA256::hash(Data), /*LowerCase=*/true, Checksum); return llvm::DIFile::CSK_SHA256; + case clang::CodeGenOptions::DSH_NONE: + return std::nullopt; } llvm_unreachable("Unhandled DebugSrcHashKind enum"); } diff --git a/clang/test/CodeGen/debug-info-file-checksum.c b/clang/test/CodeGen/debug-info-file-checksum.c index 2ca91d605d1c4..30138e74a3ebb 100644 --- a/clang/test/CodeGen/debug-info-file-checksum.c +++ b/clang/test/CodeGen/debug-info-file-checksum.c @@ -13,12 +13,15 @@ // RUN: | FileCheck --check-prefix=SHA256 %s // RUN: %clang -emit-llvm -S -g -gcodeview -x c %S/Inputs/debug-info-file-checksum.c -o - | FileCheck %s // RUN: %clang -emit-llvm -S -gdwarf-5 -x c %S/Inputs/debug-info-file-checksum.c -o - | FileCheck %s +// RUN: %clang -emit-llvm -S -gdwarf-5 -Xclang -gsrc-hash=md5 -x c %S/Inputs/debug-info-file-checksum.c -o - | FileCheck %s +// RUN: %clang -emit-llvm -S -gdwarf-5 -Xclang -gsrc-hash=none -x c %S/Inputs/debug-info-file-checksum.c -o - | FileCheck %s --check-prefix=NONE // Check that "checksum" is created correctly for the compiled file. // CHECK: !DIFile(filename:{{.*}}, directory:{{.*}}, checksumkind: CSK_MD5, checksum: "a3b7d27af071accdeccaa933fc603608") // SHA1: !DIFile(filename:{{.*}}, directory:{{.*}}, checksumkind: CSK_SHA1, checksum: "6f6eeaba705ad6db6fbb05c2cbcf3cbb3e374bcd") // SHA256: !DIFile(filename:{{.*}}, directory:{{.*}}, checksumkind: CSK_SHA256, checksum: "2d49b53859e57898a0f8c16ff1fa4d99306b8ec28d65cf7577109761f0d56197") +// NONE: !DIFile(filename:{{.*}}, directory:{{.*}}) // Ensure #line directives (in already pre-processed files) do not emit checksums // RUN: %clang -emit-llvm -S -g -gcodeview -x c %S/Inputs/debug-info-file-checksum-pre.cpp -o - | FileCheck %s --check-prefix NOCHECKSUM `````````` </details> https://github.com/llvm/llvm-project/pull/148657 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
