[flang-commits] [flang] [flang] Fix references to destroyed objects (PR #111582)
Peter Klausler via flang-commits
flang-commits at lists.llvm.org
Tue Oct 8 13:43:38 PDT 2024
https://github.com/klausler updated https://github.com/llvm/llvm-project/pull/111582
>From 28d5082a947ff3410d64d6a9a729073e2219812c Mon Sep 17 00:00:00 2001
From: Peter Klausler <pklausler at nvidia.com>
Date: Tue, 8 Oct 2024 13:12:10 -0700
Subject: [PATCH] [flang] Fix references to destroyed objects
ProgramTree instances are created as the value of a local
variable in the Pre(const parser::ProgramUnit &) member function
in name resolution. But references to these ProgramTree instances
can persist in SubprogramNameDetails symbol table entries that
might survive that function call's lifetime, and lead to trouble
later when (e.g.) expression semantics needs to deal with a
possible forward reference in a function reference in an expression
being processed later in expression checking.
So put those ProgramTree instances into a longer-lived linked
list within the SemanticsContext.
Might fix some weird crashes reported on big-endian targets
(AIX & Solaris).
---
flang/{lib => include/flang}/Semantics/program-tree.h | 4 ++--
flang/include/flang/Semantics/semantics.h | 7 ++++++-
flang/lib/Semantics/program-tree.cpp | 8 ++++----
flang/lib/Semantics/resolve-names.cpp | 5 +++--
flang/lib/Semantics/semantics.cpp | 4 ++++
5 files changed, 19 insertions(+), 9 deletions(-)
rename flang/{lib => include/flang}/Semantics/program-tree.h (97%)
diff --git a/flang/lib/Semantics/program-tree.h b/flang/include/flang/Semantics/program-tree.h
similarity index 97%
rename from flang/lib/Semantics/program-tree.h
rename to flang/include/flang/Semantics/program-tree.h
index ab00261a964a13..1c89e6c175b964 100644
--- a/flang/lib/Semantics/program-tree.h
+++ b/flang/include/flang/Semantics/program-tree.h
@@ -9,8 +9,8 @@
#ifndef FORTRAN_SEMANTICS_PROGRAM_TREE_H_
#define FORTRAN_SEMANTICS_PROGRAM_TREE_H_
+#include "symbol.h"
#include "flang/Parser/parse-tree.h"
-#include "flang/Semantics/symbol.h"
#include <list>
#include <variant>
@@ -35,7 +35,7 @@ class ProgramTree {
std::list<common::Reference<const parser::GenericSpec>>;
// Build the ProgramTree rooted at one of these program units.
- static ProgramTree Build(const parser::ProgramUnit &, SemanticsContext &);
+ static ProgramTree &Build(const parser::ProgramUnit &, SemanticsContext &);
static std::optional<ProgramTree> Build(
const parser::MainProgram &, SemanticsContext &);
static std::optional<ProgramTree> Build(
diff --git a/flang/include/flang/Semantics/semantics.h b/flang/include/flang/Semantics/semantics.h
index 606afbe288c38d..c981d86fbd94cb 100644
--- a/flang/include/flang/Semantics/semantics.h
+++ b/flang/include/flang/Semantics/semantics.h
@@ -9,6 +9,8 @@
#ifndef FORTRAN_SEMANTICS_SEMANTICS_H_
#define FORTRAN_SEMANTICS_SEMANTICS_H_
+#include "module-dependences.h"
+#include "program-tree.h"
#include "scope.h"
#include "symbol.h"
#include "flang/Common/Fortran-features.h"
@@ -17,7 +19,6 @@
#include "flang/Evaluate/intrinsics.h"
#include "flang/Evaluate/target.h"
#include "flang/Parser/message.h"
-#include "flang/Semantics/module-dependences.h"
#include <iosfwd>
#include <set>
#include <string>
@@ -280,6 +281,9 @@ class SemanticsContext {
void DumpSymbols(llvm::raw_ostream &);
+ // Top-level ProgramTrees are owned by the SemanticsContext for persistence.
+ ProgramTree &SaveProgramTree(ProgramTree &&);
+
private:
struct ScopeIndexComparator {
bool operator()(parser::CharBlock, parser::CharBlock) const;
@@ -331,6 +335,7 @@ class SemanticsContext {
ModuleDependences moduleDependences_;
std::map<const Symbol *, SourceName> moduleFileOutputRenamings_;
UnorderedSymbolSet isDefined_;
+ std::list<ProgramTree> programTrees_;
};
class Semantics {
diff --git a/flang/lib/Semantics/program-tree.cpp b/flang/lib/Semantics/program-tree.cpp
index 250f5801b39e1a..86085e78803a23 100644
--- a/flang/lib/Semantics/program-tree.cpp
+++ b/flang/lib/Semantics/program-tree.cpp
@@ -6,7 +6,7 @@
//
//===----------------------------------------------------------------------===//
-#include "program-tree.h"
+#include "flang/Semantics/program-tree.h"
#include "flang/Common/idioms.h"
#include "flang/Parser/char-block.h"
#include "flang/Semantics/scope.h"
@@ -130,13 +130,13 @@ static ProgramTree BuildModuleTree(
return node;
}
-ProgramTree ProgramTree::Build(
+ProgramTree &ProgramTree::Build(
const parser::ProgramUnit &x, SemanticsContext &context) {
return common::visit(
- [&](const auto &y) {
+ [&](const auto &y) -> ProgramTree & {
auto node{Build(y.value(), context)};
CHECK(node.has_value());
- return std::move(*node);
+ return context.SaveProgramTree(std::move(*node));
},
x.u);
}
diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
index e5e03f644f1b00..f1ce0b415ebe9c 100644
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -10,7 +10,6 @@
#include "definable.h"
#include "mod-file.h"
#include "pointer-assignment.h"
-#include "program-tree.h"
#include "resolve-directives.h"
#include "resolve-names-utils.h"
#include "rewrite-parse-tree.h"
@@ -32,6 +31,7 @@
#include "flang/Parser/tools.h"
#include "flang/Semantics/attr.h"
#include "flang/Semantics/expression.h"
+#include "flang/Semantics/program-tree.h"
#include "flang/Semantics/scope.h"
#include "flang/Semantics/semantics.h"
#include "flang/Semantics/symbol.h"
@@ -2490,6 +2490,7 @@ Symbol &ScopeHandler::CopySymbol(const SourceName &name, const Symbol &symbol) {
}
// Look for name only in scope, not in enclosing scopes.
+
Symbol *ScopeHandler::FindInScope(
const Scope &scope, const parser::Name &name) {
return Resolve(name, FindInScope(scope, name.source));
@@ -9120,7 +9121,7 @@ bool ResolveNamesVisitor::Pre(const parser::ProgramUnit &x) {
ResolveAccParts(context(), x, &topScope_);
return false;
}
- auto root{ProgramTree::Build(x, context())};
+ ProgramTree &root{ProgramTree::Build(x, context())};
SetScope(topScope_);
ResolveSpecificationParts(root);
FinishSpecificationParts(root);
diff --git a/flang/lib/Semantics/semantics.cpp b/flang/lib/Semantics/semantics.cpp
index 637088ff0171c0..58dc1f218b56f4 100644
--- a/flang/lib/Semantics/semantics.cpp
+++ b/flang/lib/Semantics/semantics.cpp
@@ -663,6 +663,10 @@ void SemanticsContext::DumpSymbols(llvm::raw_ostream &os) {
DoDumpSymbols(os, globalScope());
}
+ProgramTree &SemanticsContext::SaveProgramTree(ProgramTree &&tree) {
+ return programTrees_.emplace_back(std::move(tree));
+}
+
void Semantics::DumpSymbols(llvm::raw_ostream &os) { context_.DumpSymbols(os); }
void Semantics::DumpSymbolsSources(llvm::raw_ostream &os) const {
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