[clang analysis] ExprMutationAnalyzer avoid infinite recursion for recursive forwarding reference #87954
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…ference Partialy fixes: llvm#60895
llvmbot
added
clang
|
@llvm/pr-subscribers-clang-tools-extra @llvm/pr-subscribers-clang Author: Congcong Cai (HerrCai0907) ChangesPartialy fixes: #60895 Full diff: https://github.com/llvm/llvm-project/pull/87954.diff 3 Files Affected:
diff --git a/clang/include/clang/Analysis/Analyses/ExprMutationAnalyzer.h b/clang/include/clang/Analysis/Analyses/ExprMutationAnalyzer.h
index 1ceef944fbc34e..af6106fe303afd 100644
--- a/clang/include/clang/Analysis/Analyses/ExprMutationAnalyzer.h
+++ b/clang/include/clang/Analysis/Analyses/ExprMutationAnalyzer.h
@@ -8,11 +8,10 @@
#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_EXPRMUTATIONANALYZER_H
#define LLVM_CLANG_ANALYSIS_ANALYSES_EXPRMUTATIONANALYZER_H
-#include <type_traits>
-
#include "clang/AST/AST.h"
#include "clang/ASTMatchers/ASTMatchers.h"
#include "llvm/ADT/DenseMap.h"
+#include <variant>
namespace clang {
@@ -22,8 +21,15 @@ class FunctionParmMutationAnalyzer;
/// a given statement.
class ExprMutationAnalyzer {
public:
+ friend class FunctionParmMutationAnalyzer;
+ struct Cache {
+ llvm::DenseMap<const FunctionDecl *,
+ std::unique_ptr<FunctionParmMutationAnalyzer>>
+ FuncParmAnalyzer;
+ };
+
ExprMutationAnalyzer(const Stmt &Stm, ASTContext &Context)
- : Stm(Stm), Context(Context) {}
+ : ExprMutationAnalyzer(Stm, Context, nullptr) {}
bool isMutated(const Expr *Exp) { return findMutation(Exp) != nullptr; }
bool isMutated(const Decl *Dec) { return findMutation(Dec) != nullptr; }
@@ -45,6 +51,19 @@ class ExprMutationAnalyzer {
using MutationFinder = const Stmt *(ExprMutationAnalyzer::*)(const Expr *);
using ResultMap = llvm::DenseMap<const Expr *, const Stmt *>;
+ ExprMutationAnalyzer(const Stmt &Stm, ASTContext &Context, Cache *ParentCache)
+ : Stm(Stm), Context(Context) {
+ if (ParentCache != nullptr) {
+ CrossAnalysisCache = ParentCache;
+ } else {
+ CrossAnalysisCache = std::make_unique<Cache>();
+ }
+ }
+ ExprMutationAnalyzer(const Stmt &Stm, ASTContext &Context,
+ std::unique_ptr<Cache> CrossAnalysisCache)
+ : Stm(Stm), Context(Context),
+ CrossAnalysisCache(std::move(CrossAnalysisCache)) {}
+
const Stmt *findMutationMemoized(const Expr *Exp,
llvm::ArrayRef<MutationFinder> Finders,
ResultMap &MemoizedResults);
@@ -67,11 +86,15 @@ class ExprMutationAnalyzer {
const Stmt *findReferenceMutation(const Expr *Exp);
const Stmt *findFunctionArgMutation(const Expr *Exp);
+ Cache *getCache() {
+ return std::holds_alternative<Cache *>(CrossAnalysisCache)
+ ? std::get<Cache *>(CrossAnalysisCache)
+ : std::get<std::unique_ptr<Cache>>(CrossAnalysisCache).get();
+ }
+
const Stmt &Stm;
ASTContext &Context;
- llvm::DenseMap<const FunctionDecl *,
- std::unique_ptr<FunctionParmMutationAnalyzer>>
- FuncParmAnalyzer;
+ std::variant<Cache *, std::unique_ptr<Cache>> CrossAnalysisCache;
ResultMap Results;
ResultMap PointeeResults;
};
@@ -80,7 +103,10 @@ class ExprMutationAnalyzer {
// params.
class FunctionParmMutationAnalyzer {
public:
- FunctionParmMutationAnalyzer(const FunctionDecl &Func, ASTContext &Context);
+ FunctionParmMutationAnalyzer(const FunctionDecl &Func, ASTContext &Context)
+ : FunctionParmMutationAnalyzer(Func, Context, nullptr) {}
+ FunctionParmMutationAnalyzer(const FunctionDecl &Func, ASTContext &Context,
+ ExprMutationAnalyzer::Cache *CrossAnalysisCache);
bool isMutated(const ParmVarDecl *Parm) {
return findMutation(Parm) != nullptr;
diff --git a/clang/lib/Analysis/ExprMutationAnalyzer.cpp b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
index bb042760d297a7..dba6f2a3c02112 100644
--- a/clang/lib/Analysis/ExprMutationAnalyzer.cpp
+++ b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
@@ -638,9 +638,10 @@ const Stmt *ExprMutationAnalyzer::findFunctionArgMutation(const Expr *Exp) {
if (!RefType->getPointeeType().getQualifiers() &&
RefType->getPointeeType()->getAs<TemplateTypeParmType>()) {
std::unique_ptr<FunctionParmMutationAnalyzer> &Analyzer =
- FuncParmAnalyzer[Func];
+ getCache()->FuncParmAnalyzer[Func];
if (!Analyzer)
- Analyzer.reset(new FunctionParmMutationAnalyzer(*Func, Context));
+ Analyzer.reset(
+ new FunctionParmMutationAnalyzer(*Func, Context, getCache()));
if (Analyzer->findMutation(Parm))
return Exp;
continue;
@@ -653,13 +654,15 @@ const Stmt *ExprMutationAnalyzer::findFunctionArgMutation(const Expr *Exp) {
}
FunctionParmMutationAnalyzer::FunctionParmMutationAnalyzer(
- const FunctionDecl &Func, ASTContext &Context)
- : BodyAnalyzer(*Func.getBody(), Context) {
+ const FunctionDecl &Func, ASTContext &Context,
+ ExprMutationAnalyzer::Cache *CrossAnalysisCache)
+ : BodyAnalyzer(*Func.getBody(), Context, CrossAnalysisCache) {
if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(&Func)) {
// CXXCtorInitializer might also mutate Param but they're not part of
// function body, check them eagerly here since they're typically trivial.
for (const CXXCtorInitializer *Init : Ctor->inits()) {
- ExprMutationAnalyzer InitAnalyzer(*Init->getInit(), Context);
+ ExprMutationAnalyzer InitAnalyzer(*Init->getInit(), Context,
+ CrossAnalysisCache);
for (const ParmVarDecl *Parm : Ctor->parameters()) {
if (Results.contains(Parm))
continue;
@@ -675,11 +678,14 @@ FunctionParmMutationAnalyzer::findMutation(const ParmVarDecl *Parm) {
const auto Memoized = Results.find(Parm);
if (Memoized != Results.end())
return Memoized->second;
-
+ // To handle call A -> call B -> call A. Assume parameters of A is not mutated
+ // before analyzing parameters of A. Then when analyzing the second "call A",
+ // FunctionParmMutationAnalyzer can use this memoized value to avoid infinite
+ // recursion.
+ Results[Parm] = nullptr;
if (const Stmt *S = BodyAnalyzer.findMutation(Parm))
return Results[Parm] = S;
-
- return Results[Parm] = nullptr;
+ return Results[Parm];
}
} // namespace clang
diff --git a/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp b/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
index f58ce4aebcbfc8..9c1dc1a76db63d 100644
--- a/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
+++ b/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
@@ -977,6 +977,36 @@ TEST(ExprMutationAnalyzerTest, FollowFuncArgModified) {
"void f() { int x; g(x); }");
Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("g(x)"));
+
+ AST = buildASTFromCode(
+ StdRemoveReference + StdForward +
+ "template <class T> void f1(T &&a);"
+ "template <class T> void f2(T &&a);"
+ "template <class T> void f1(T &&a) { f2<T>(std::forward<T>(a)); }"
+ "template <class T> void f2(T &&a) { f1<T>(std::forward<T>(a)); }"
+ "void f() { int x; f1(x); }");
+ Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+ EXPECT_FALSE(isMutated(Results, AST.get()));
+
+ AST = buildASTFromCode(
+ StdRemoveReference + StdForward +
+ "template <class T> void f1(T &&a);"
+ "template <class T> void f2(T &&a);"
+ "template <class T> void f1(T &&a) { f2<T>(std::forward<T>(a)); }"
+ "template <class T> void f2(T &&a) { f1<T>(std::forward<T>(a)); a++; }"
+ "void f() { int x; f1(x); }");
+ Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+ EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("f1(x)"));
+
+ AST = buildASTFromCode(
+ StdRemoveReference + StdForward +
+ "template <class T> void f1(T &&a);"
+ "template <class T> void f2(T &&a);"
+ "template <class T> void f1(T &&a) { f2<T>(std::forward<T>(a)); a++; }"
+ "template <class T> void f2(T &&a) { f1<T>(std::forward<T>(a)); }"
+ "void f() { int x; f1(x); }");
+ Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+ EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("f1(x)"));
}
TEST(ExprMutationAnalyzerTest, FollowFuncArgNotModified) {
|
HerrCai0907
changed the title
PiotrZSL
reviewed
Apr 8, 2024
bazuzi
pushed a commit
to bazuzi/llvm-project
that referenced
this pull request
Apr 15, 2024
…cursive forwarding reference (llvm#87954)
|
This broke the sanitizer bots, e.g. https://lab.llvm.org/buildbot/#/builders/239/builds/6587/steps/10/logs/stdio |
fmayer
added a commit
that referenced
this pull request
Apr 15, 2024
…n for recursive forwarding reference" (#88765) Reverts #87954 Broke sanitizer bots, e.g. https://lab.llvm.org/buildbot/#/builders/239/builds/6587/steps/10/logs/stdio
aniplcc
pushed a commit
to aniplcc/llvm-project
that referenced
this pull request
Apr 15, 2024
…cursive forwarding reference (llvm#87954)
aniplcc
pushed a commit
to aniplcc/llvm-project
that referenced
this pull request
Apr 15, 2024
…n for recursive forwarding reference" (llvm#88765) Reverts llvm#87954 Broke sanitizer bots, e.g. https://lab.llvm.org/buildbot/#/builders/239/builds/6587/steps/10/logs/stdio
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Partialy fixes: #60895