[Modules] Make -module-file-info print macro names in deterministic order #161332
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@llvm/pr-subscribers-clang @llvm/pr-subscribers-clang-modules Author: Hans Wennborg (zmodem) ChangesDevelopers reported non-deterministic output from Making the output deterministic also simplifies the test. This is a follow-up to 360c5fe Full diff: https://github.com/llvm/llvm-project/pull/161332.diff 2 Files Affected:
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 7424958d46612..d7d56b8166350 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -971,14 +971,17 @@ void DumpModuleInfoAction::ExecuteAction() {
// Emit the macro definitions in the module file so that we can know how
// much definitions in the module file quickly.
// TODO: Emit the macro definition bodies completely.
- if (auto FilteredMacros = llvm::make_filter_range(
- R->getPreprocessor().macros(),
- [](const auto &Macro) { return Macro.first->isFromAST(); });
- !FilteredMacros.empty()) {
- Out << " Macro Definitions:\n";
- for (/*<IdentifierInfo *, MacroState> pair*/ const auto &Macro :
- FilteredMacros)
- Out << " " << Macro.first->getName() << "\n";
+ {
+ std::vector<StringRef> MacroNames;
+ for (const auto &M : R->getPreprocessor().macros()) {
+ if (M.first->isFromAST())
+ MacroNames.push_back(M.first->getName());
+ }
+ llvm::sort(MacroNames);
+ if (!MacroNames.empty())
+ Out << " Macro Definitions:\n";
+ for (StringRef Name : MacroNames)
+ Out << " " << Name << "\n";
}
// Now let's print out any modules we did not see as part of the Primary.
diff --git a/clang/test/Modules/cxx20-module-file-info-macros.cpp b/clang/test/Modules/cxx20-module-file-info-macros.cpp
index 3b67e9b9acd41..431c967fbbccd 100644
--- a/clang/test/Modules/cxx20-module-file-info-macros.cpp
+++ b/clang/test/Modules/cxx20-module-file-info-macros.cpp
@@ -36,28 +36,28 @@
#define REDEFINE
// CHECK: Macro Definitions:
-// CHECK-DAG: REDEFINE
-// CHECK-DAG: FUNC_Macro
-// CHECK-DAG: CONSTANT
-// CHECK-DAG: FOO
+// CHECK: CONSTANT
+// CHECK: FOO
+// CHECK: FUNC_Macro
+// CHECK: REDEFINE
// CHECK-NEXT: ===
//--- include_foo.h
#include "foo.h"
#undef REDEFINE
// CHECK: Macro Definitions:
-// CHECK-DAG: CONSTANT
-// CHECK-DAG: FUNC_Macro
-// CHECK-DAG: FOO
+// CHECK: CONSTANT
+// CHECK: FOO
+// CHECK: FUNC_Macro
// CHECK-NEXT: ===
//--- import_foo.h
import "foo.h";
#undef REDEFINE
// CHECK: Macro Definitions:
-// CHECK-DAG: CONSTANT
-// CHECK-DAG: FUNC_Macro
-// CHECK-DAG: FOO
+// CHECK: CONSTANT
+// CHECK: FOO
+// CHECK: FUNC_Macro
// CHECK-NEXT: ===
//--- named_module.cppm
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ChuanqiXu9
approved these changes
Sep 30, 2025
This is where it came up: https://crbug.com/448270644 |
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Got it. And if the pcm are non determinism, it is super bad. It will be pretty appreciated to fix it. Such problems generally come from DenseMap |
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/163/builds/27340 Here is the relevant piece of the build log for the reference |
mahesh-attarde
pushed a commit
to mahesh-attarde/llvm-project
that referenced
this pull request
Oct 3, 2025
…rder (llvm#161332) Developers reported non-deterministic output from `-module-file-info`, thinking this reflected non-determinism in the .pcm files themselves. However, it turned out it was the printing that was non-deterministic: ``` $ cat /tmp/a.h #define FOO 1 #define BAR 2 $ build/bin/clang -cc1 -std=c++20 -x c++ -emit-header-unit /tmp/a.h -o /tmp/a.pcm $ build/bin/clang -cc1 -module-file-info /tmp/a.pcm | grep -A2 Definitions Macro Definitions: FOO BAR $ build/bin/clang -cc1 -module-file-info /tmp/a.pcm | grep -A2 Definitions Macro Definitions: BAR FOO ``` Making the output deterministic also simplifies the test. This is a follow-up to 360c5fe
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Developers reported non-deterministic output from
-module-file-info, thinking this reflected non-determinism in the .pcm files themselves. However, it turned out it was the printing that was non-deterministic:Making the output deterministic also simplifies the test.
This is a follow-up to 360c5fe