https://github.com/necto updated https://github.com/llvm/llvm-project/pull/196298
>From fc1e8b138b8f7a826eb2d79789cb44c518be727a Mon Sep 17 00:00:00 2001 From: Arseniy Zaostrovnykh <[email protected]> Date: Thu, 7 May 2026 14:01:31 +0200 Subject: [PATCH 1/2] Demonstrate CTU import failure when mtime is advanced --- clang/test/Analysis/ctu/reusable-pch.c | 42 ++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 clang/test/Analysis/ctu/reusable-pch.c diff --git a/clang/test/Analysis/ctu/reusable-pch.c b/clang/test/Analysis/ctu/reusable-pch.c new file mode 100644 index 0000000000000..6f42cd3c90097 --- /dev/null +++ b/clang/test/Analysis/ctu/reusable-pch.c @@ -0,0 +1,42 @@ +// RUN: rm -rf %t +// RUN: mkdir -p %t +// RUN: split-file %s %t + +// Step 1: Build PCH and defmap. +// RUN: %clang_cc1 -x c -emit-pch -o %t/other.c.ast %t/other.c +// RUN: %clang_extdef_map %t/other.c -- -c -x c > %t/externalDefMap.tmp.txt +// RUN: sed 's| .*other\.c| other.c.ast|' %t/externalDefMap.tmp.txt > %t/externalDefMap.txt + +// Step 2: Run CTU using the PCH - the division by zero is found via inlining. +// RUN: %clang_cc1 -analyze \ +// RUN: -analyzer-checker=core \ +// RUN: -analyzer-config experimental-enable-naive-ctu-analysis=true \ +// RUN: -analyzer-config ctu-dir=%t \ +// RUN: -verify %t/main.c + +// Step 3: Advance mtime of the source from which PCH was built. +// RUN: %python -c "import os, sys, time; os.utime(sys.argv[1], (time.time() + 120, time.time() + 120))" %t/other.c + +// Step 4: Run CTU using the now-stale PCH - it breaks. +// RUN: not %clang_cc1 -analyze \ +// RUN: -analyzer-checker=core \ +// RUN: -analyzer-config experimental-enable-naive-ctu-analysis=true \ +// RUN: -analyzer-config ctu-dir=%t \ +// RUN: %t/main.c 2>&1 | FileCheck --check-prefix=BREAKS %s + +// BREAKS: file '{{.*}}other.c' has been modified since the precompiled file '{{.*}}other.c.ast' was built + +//--- main.c +// Without CTU, always_zero() has an unknown return value so no bug is found. +// With CTU, always_zero() is inlined and its return value (0) is known, +// exposing the division by zero. + +int always_zero(void); + +void f(void) { + int x = always_zero(); + (void)(1 / x); // expected-warning{{Division by zero}} +} + +//--- other.c +int always_zero(void) { return 0; } >From 5aebb6266f50abda207076c459ca88fc600143b0 Mon Sep 17 00:00:00 2001 From: Arseniy Zaostrovnykh <[email protected]> Date: Thu, 7 May 2026 14:08:29 +0200 Subject: [PATCH 2/2] Forward ValidateASTInputFilesContent when importing AST dumps --- clang/lib/Frontend/ASTUnit.cpp | 7 ++++++- clang/test/Analysis/ctu/reusable-pch.c | 12 ++++++------ 2 files changed, 12 insertions(+), 7 deletions(-) diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp index 05ae1f348f920..df6f85560227f 100644 --- a/clang/lib/Frontend/ASTUnit.cpp +++ b/clang/lib/Frontend/ASTUnit.cpp @@ -780,11 +780,16 @@ std::unique_ptr<ASTUnit> ASTUnit::LoadFromASTFile( DisableValidationForModuleKind::None; if (::getenv("LIBCLANG_DISABLE_PCH_VALIDATION")) disableValid = DisableValidationForModuleKind::All; + bool ValidateASTInputFilesContent = HSOpts.ValidateASTInputFilesContent; + AST->Reader = llvm::makeIntrusiveRefCnt<ASTReader>( *AST->PP, *AST->ModCache, AST->Ctx.get(), PCHContainerRdr, *AST->CodeGenOpts, ArrayRef<std::shared_ptr<ModuleFileExtension>>(), /*isysroot=*/"", - /*DisableValidationKind=*/disableValid, AllowASTWithCompilerErrors); + /*DisableValidationKind=*/disableValid, AllowASTWithCompilerErrors, + /*AllowConfigurationMismatch=*/false, + /*ValidateSystemInputs=*/false, + /*ForceValidateUserInputs=*/true, ValidateASTInputFilesContent); // Attach the AST reader to the AST context as an external AST source, so that // declarations will be deserialized from the AST file as needed. diff --git a/clang/test/Analysis/ctu/reusable-pch.c b/clang/test/Analysis/ctu/reusable-pch.c index 6f42cd3c90097..988148692f02f 100644 --- a/clang/test/Analysis/ctu/reusable-pch.c +++ b/clang/test/Analysis/ctu/reusable-pch.c @@ -3,12 +3,13 @@ // RUN: split-file %s %t // Step 1: Build PCH and defmap. -// RUN: %clang_cc1 -x c -emit-pch -o %t/other.c.ast %t/other.c +// RUN: %clang_cc1 -x c -emit-pch -fvalidate-ast-input-files-content -o %t/other.c.ast %t/other.c // RUN: %clang_extdef_map %t/other.c -- -c -x c > %t/externalDefMap.tmp.txt // RUN: sed 's| .*other\.c| other.c.ast|' %t/externalDefMap.tmp.txt > %t/externalDefMap.txt // Step 2: Run CTU using the PCH - the division by zero is found via inlining. // RUN: %clang_cc1 -analyze \ +// RUN: -fvalidate-ast-input-files-content \ // RUN: -analyzer-checker=core \ // RUN: -analyzer-config experimental-enable-naive-ctu-analysis=true \ // RUN: -analyzer-config ctu-dir=%t \ @@ -17,14 +18,13 @@ // Step 3: Advance mtime of the source from which PCH was built. // RUN: %python -c "import os, sys, time; os.utime(sys.argv[1], (time.time() + 120, time.time() + 120))" %t/other.c -// Step 4: Run CTU using the now-stale PCH - it breaks. -// RUN: not %clang_cc1 -analyze \ +// Step 4: Run CTU using the "stale" PCH +// RUN: %clang_cc1 -analyze \ +// RUN: -fvalidate-ast-input-files-content \ // RUN: -analyzer-checker=core \ // RUN: -analyzer-config experimental-enable-naive-ctu-analysis=true \ // RUN: -analyzer-config ctu-dir=%t \ -// RUN: %t/main.c 2>&1 | FileCheck --check-prefix=BREAKS %s - -// BREAKS: file '{{.*}}other.c' has been modified since the precompiled file '{{.*}}other.c.ast' was built +// RUN: %t/main.c //--- main.c // Without CTU, always_zero() has an unknown return value so no bug is found. _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
