[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/balazske closed https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/balazske updated
https://github.com/llvm/llvm-project/pull/79470
From 70eeae8170a782b93b546b81ac913e1b8eacd28e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?=
Date: Thu, 22 Feb 2024 10:18:06 +0100
Subject: [PATCH 1/2] [clang][analyzer] Fix argument invalidations in
StreamChecker.
Specific arguments passed to stream handling functions are changed by the
function,
this means these should be invalidated ("escaped") by the analyzer.
This change adds the argument invalidation (in specific cases) to the checker.
---
.../StaticAnalyzer/Checkers/StreamChecker.cpp | 39 ++-
1 file changed, 38 insertions(+), 1 deletion(-)
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index a070f451694a3b..65bdc4cac30940 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -21,6 +21,7 @@
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
+#include "llvm/ADT/Sequence.h"
#include
#include
@@ -629,6 +630,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef escapeArgs(ProgramStateRef State, CheckerContext &C,
+ const CallEvent &Call,
+ ArrayRef EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
+ return State;
+}
+
//===--===//
// Methods of StreamChecker.
//===--===//
@@ -819,6 +835,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && !E.isStreamEof())
+State = escapeArgs(State, C, Call, {0});
+
// Generate a transition for the success state.
// If we know the state to be FEOF at fread, do not add a success state.
if (!IsFread || !E.isStreamEof()) {
@@ -863,6 +884,9 @@ void StreamChecker::evalFgetx(const FnDescription *Desc,
const CallEvent &Call,
return;
if (!E.isStreamEof()) {
+// If there was already EOF, assume that read buffer is not changed.
+// Otherwise it may change at success or failure.
+State = escapeArgs(State, C, Call, {0});
if (SingleChar) {
// Generate a transition for the success state of `fgetc`.
NonLoc RetVal = makeRetVal(C, E.CE).castAs();
@@ -1011,6 +1035,14 @@ void StreamChecker::evalFscanf(const FnDescription
*Desc, const CallEvent &Call,
State->BindExpr(E.CE, C.getLocationContext(), RetVal);
StateNotFailed =
E.assumeBinOpNN(StateNotFailed, BO_GE, RetVal, E.getZeroVal(Call));
+if (!StateNotFailed)
+ return;
+
+SmallVector EscArgs;
+for (auto EscArg : llvm::seq(2u, Call.getNumArgs()))
+ EscArgs.push_back(EscArg);
+StateNotFailed = escapeArgs(StateNotFailed, C, Call, EscArgs);
+
if (StateNotFailed)
C.addTransition(StateNotFailed);
}
@@ -1073,8 +1105,12 @@ void StreamChecker::evalGetdelim(const FnDescription
*Desc,
// return -1.
// If an error occurs, the function shall return -1 and set 'errno'.
- // Add transition for the successful state.
if (!E.isStreamEof()) {
+// Escape buffer and size (may change by the call).
+// May happen even at error (partial read?).
+State = escapeArgs(State, C, Call, {0, 1});
+
+// Add transition for the successful state.
NonLoc RetVal = makeRetVal(C, E.CE).castAs();
ProgramStateRef StateNotFailed =
State->BindExpr(E.CE, C.getLocationContext(), RetVal);
@@ -1161,6 +1197,7 @@ void StreamChecker::evalFgetpos(const FnDescription *Desc,
ProgramStateRef StateNotFailed, StateFailed;
std::tie(StateFailed, StateNotFailed) = E.makeRetValAndAssumeDual(State, C);
+ StateNotFailed = escapeArgs(StateNotFailed, C, Call, {1});
// This function does not affect the stream state.
// Still we add success and failure state with the appropriate return value.
From deb62b2e2694e8a45eca1c6001b8d90dfb1b1d7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?=
Date: Fri, 23 Feb 2024 08:59:03 +0100
Subject: [PATCH 2/2] Add test file
---
clang/test/Analysis/stream-invalidate.c | 147
1 file changed, 147 inserti
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
alejandro-alvarez-sonarsource wrote:
Ok, let’s do that, and send this patch as a separate pr. @steakhal LGTM.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
balazske wrote:
This could be a future improvement (after this patch). I am not sure if this
works always correct, because it looks like that the `ElementCount` value at
`fread` is used but not the "size" argument (size of one element). It is
assumed that the specified element size is always the same as one array
element, but this can be different.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
alejandro-alvarez-sonarsource wrote:
Here it is:
https://gist.github.com/alejandro-alvarez-sonarsource/48edec4debc8912a6485f989b2a6f0db
I have rebased it on top of 4f12f47550eee85447c9ec37d27a20c6593d3d40 and run
check-clang to make sure I didn't break anything.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
alejandro-alvarez-sonarsource wrote:
It turns out I was comparing with our downstream copy of v17, where
`UpdateBufferRegionForFread` is defined.
So it can be done for the case of arrays. I have double-checked with the
original author and he agrees it can be upstreamed. Let me uplift the patch and
then I will share it with you.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
balazske wrote: I have rebased the branch to latest version of `StreamChecker`, no other changes were made to the patch. https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/balazske updated
https://github.com/llvm/llvm-project/pull/79470
From 70eeae8170a782b93b546b81ac913e1b8eacd28e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?=
Date: Thu, 22 Feb 2024 10:18:06 +0100
Subject: [PATCH] [clang][analyzer] Fix argument invalidations in
StreamChecker.
Specific arguments passed to stream handling functions are changed by the
function,
this means these should be invalidated ("escaped") by the analyzer.
This change adds the argument invalidation (in specific cases) to the checker.
---
.../StaticAnalyzer/Checkers/StreamChecker.cpp | 39 ++-
1 file changed, 38 insertions(+), 1 deletion(-)
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index a070f451694a3b..65bdc4cac30940 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -21,6 +21,7 @@
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
+#include "llvm/ADT/Sequence.h"
#include
#include
@@ -629,6 +630,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef escapeArgs(ProgramStateRef State, CheckerContext &C,
+ const CallEvent &Call,
+ ArrayRef EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
+ return State;
+}
+
//===--===//
// Methods of StreamChecker.
//===--===//
@@ -819,6 +835,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && !E.isStreamEof())
+State = escapeArgs(State, C, Call, {0});
+
// Generate a transition for the success state.
// If we know the state to be FEOF at fread, do not add a success state.
if (!IsFread || !E.isStreamEof()) {
@@ -863,6 +884,9 @@ void StreamChecker::evalFgetx(const FnDescription *Desc,
const CallEvent &Call,
return;
if (!E.isStreamEof()) {
+// If there was already EOF, assume that read buffer is not changed.
+// Otherwise it may change at success or failure.
+State = escapeArgs(State, C, Call, {0});
if (SingleChar) {
// Generate a transition for the success state of `fgetc`.
NonLoc RetVal = makeRetVal(C, E.CE).castAs();
@@ -1011,6 +1035,14 @@ void StreamChecker::evalFscanf(const FnDescription
*Desc, const CallEvent &Call,
State->BindExpr(E.CE, C.getLocationContext(), RetVal);
StateNotFailed =
E.assumeBinOpNN(StateNotFailed, BO_GE, RetVal, E.getZeroVal(Call));
+if (!StateNotFailed)
+ return;
+
+SmallVector EscArgs;
+for (auto EscArg : llvm::seq(2u, Call.getNumArgs()))
+ EscArgs.push_back(EscArg);
+StateNotFailed = escapeArgs(StateNotFailed, C, Call, EscArgs);
+
if (StateNotFailed)
C.addTransition(StateNotFailed);
}
@@ -1073,8 +1105,12 @@ void StreamChecker::evalGetdelim(const FnDescription
*Desc,
// return -1.
// If an error occurs, the function shall return -1 and set 'errno'.
- // Add transition for the successful state.
if (!E.isStreamEof()) {
+// Escape buffer and size (may change by the call).
+// May happen even at error (partial read?).
+State = escapeArgs(State, C, Call, {0, 1});
+
+// Add transition for the successful state.
NonLoc RetVal = makeRetVal(C, E.CE).castAs();
ProgramStateRef StateNotFailed =
State->BindExpr(E.CE, C.getLocationContext(), RetVal);
@@ -1161,6 +1197,7 @@ void StreamChecker::evalFgetpos(const FnDescription *Desc,
ProgramStateRef StateNotFailed, StateFailed;
std::tie(StateFailed, StateNotFailed) = E.makeRetValAndAssumeDual(State, C);
+ StateNotFailed = escapeArgs(StateNotFailed, C, Call, {1});
// This function does not affect the stream state.
// Still we add success and failure state with the appropriate return value.
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/balazske edited https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
balazske wrote:
The current solution invalidates the whole buffer (if I think correctly)
because the `SVal` of the buffer is passed to `invalidateRegions`. Is there a
solution to invalidate a partial buffer (of specific size)?
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/alejandro-alvarez-sonarsource edited https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/alejandro-alvarez-sonarsource edited https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
alejandro-alvarez-sonarsource wrote:
From what I can tell, the lambda `UpdateBufferRegionForFread` is already used
to take care of this in a more fine-grained manner. For instance:
```cpp
int buffer[10];
buffer[5] = 42;
if (1 == fread(buffer, sizeof(int), 5, fd)) {
assert(buffer[5] == 42);
}
```
Before this change, the assertion would pass, since lambda took `nmemb` into
account. With this change, the whole buffer is invalidated.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
=?utf-8?q?Balázs_Kéri?= Message-ID: In-Reply-To: https://github.com/steakhal approved this pull request. Thanks for resolving my comments. FYI if I forget about a PR (that I promise to come back on the next day) - feel free to ping it or explicitly push the "request review" button. Wait for my collage to also have a look, as I believe he might be in context to review this change. @alejandro-alvarez-sonarsource https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/balazske updated
https://github.com/llvm/llvm-project/pull/79470
From dbd9af4e77c34fcf6ce82f226f7dbf836033a8f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?=
Date: Thu, 25 Jan 2024 17:50:42 +0100
Subject: [PATCH 1/2] [clang][analyzer] Fix argument invalidations in
StreamChecker.
Specific arguments passed to stream handling functions are changed by the
function,
this means these should be invalidated ("escaped") by the analyzer.
This change adds the argument invalidation (in specific cases) to the checker.
---
.../StaticAnalyzer/Checkers/StreamChecker.cpp | 35 +
clang/test/Analysis/stream-invalidate.c | 133 ++
2 files changed, 168 insertions(+)
create mode 100644 clang/test/Analysis/stream-invalidate.c
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index 07727b339d967ae..166bd981a003af2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -21,6 +21,7 @@
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
+#include "llvm/ADT/Sequence.h"
#include
#include
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
+ return State;
+}
+
//===--===//
// Methods of StreamChecker.
//===--===//
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
+
// Generate a transition for the success state.
// If we know the state to be FEOF at fread, do not add a success state.
if (!IsFread || (OldSS->ErrorState != ErrorFEof)) {
@@ -824,6 +845,10 @@ void StreamChecker::evalFgetx(const FnDescription *Desc,
const CallEvent &Call,
// `fgets` returns the read buffer address on success, otherwise returns
NULL.
if (OldSS->ErrorState != ErrorFEof) {
+// If there was already EOF, assume that read buffer is not changed.
+// Otherwise it may change at success or failure.
+
+State = escapeArgs(State, C, Call, {0});
if (SingleChar) {
// Generate a transition for the success state of `fgetc`.
NonLoc RetVal = makeRetVal(C, CE).castAs();
@@ -1032,6 +1057,11 @@ void StreamChecker::evalFscanf(const FnDescription
*Desc, const CallEvent &Call,
return;
StateNotFailed = StateNotFailed->assume(*RetGeZero, true);
+SmallVector EscArgs;
+for (auto EscArg : llvm::seq(2u, Call.getNumArgs()))
+ EscArgs.push_back(EscArg);
+StateNotFailed = escapeArgs(StateNotFailed, C, Call, EscArgs);
+
C.addTransition(StateNotFailed);
}
@@ -1118,6 +1148,10 @@ void StreamChecker::evalGetdelim(const FnDescription
*Desc,
// Add transition for the successful state.
if (OldSS->ErrorState != ErrorFEof) {
+// Escape buffer and size (may change by the call).
+// May happen even at error (partial read?).
+State = escapeArgs(State, C, Call, {0, 1});
+
NonLoc RetVal = makeRetVal(C, CE).castAs();
ProgramStateRef StateNotFailed =
State->BindExpr(CE, C.getLocationContext(), RetVal);
@@ -1236,6 +1270,7 @@ void StreamChecker::evalFgetpos(const FnDescription *Desc,
ProgramStateRef StateNotFailed, StateFailed;
std::tie(StateFailed, StateNotFailed) =
C.getConstraintManager().assumeDual(State, RetVal);
+ StateNotFailed = escapeArgs(StateNotFailed, C, Call, {1});
// This function does not affect the stream state.
// Still we add success and failure state with the appropriate return value.
diff --git a/clang/test/Analysis/stream-invalidate.c
b/clang/test/Analysis/stream-invalidate.c
new file mode 100644
index 000..c5b7874f0ee8f6f
--- /dev/null
+++ b/clang/test/Analysis/stream-invalidate.c
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyze
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
steakhal wrote:
Yup, have a look at `RegionStoreManager::invalidateRegions`. Depending on the
nature of the call, invalidates system or every global variables.
We don't really care about it, so let's just not pass the `Call` here.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
balazske wrote:
If this change is made, a error shows up in **stream-errno.c** line 190
(unexpected warning: FALSE).
```
int Ret = fgetpos(F, &Pos);
if (Ret)
clang_analyzer_eval(errno != 0); // expected-warning{{TRUE}}
else
clang_analyzer_eval(errno == 0); // expected-warning{{TRUE}} we get FALSE
too
```
Probably the `errno` is invalidated somehow, this is likely to be caused by the
`Call` argument. Without these additional arguments to `invalidateRegions` the
test passes.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyzer-checker=debug.StreamTester \
+// RUN: -analyzer-checker=debug.ExprInspection
+
+#include "Inputs/system-header-simulator.h"
+
+void clang_analyzer_eval(int);
+void clang_analyzer_dump(int);
+void clang_analyzer_warnIfReached(void);
+void StreamTesterChecker_make_feof_stream(FILE *);
+void StreamTesterChecker_make_ferror_stream(FILE *);
+
+void test_fread(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fread(Buf, 1, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{conj_$}} Should not
preserve the previous value, thus should not be 10.
+ clang_analyzer_dump(Buf[2]); // expected-warning {{conj_$}}
+ if (feof(F)) {
balazske wrote:
At `ferror(F)` the next stream call should produce a "file position
indeterminate" warning (this is tested in another file) that stops the
analysis, buffer invalidation is not needed to be tested.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyzer-checker=debug.StreamTester \
+// RUN: -analyzer-checker=debug.ExprInspection
+
+#include "Inputs/system-header-simulator.h"
+
+void clang_analyzer_eval(int);
+void clang_analyzer_dump(int);
+void clang_analyzer_warnIfReached(void);
+void StreamTesterChecker_make_feof_stream(FILE *);
+void StreamTesterChecker_make_ferror_stream(FILE *);
+
+void test_fread(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fread(Buf, 1, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{conj_$}} Should not
preserve the previous value, thus should not be 10.
+ clang_analyzer_dump(Buf[2]); // expected-warning {{conj_$}}
+ if (feof(F)) {
steakhal wrote:
In this, and the in the rest of the test, could we have a branch for testing if
the api-call encountered an error?
E.g. when `ferror(F)==true`. On that path, we should still invalidate the
buffer.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
steakhal wrote:
```suggestion
State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
C.getLocationContext(),
/*CausesPointerEscape=*/false,
/*InvalidatedSymbols=*/nullptr, &Call);
```
I can't recall now what difference it makes to pass the `Call` to this API, but
given that we have one, why not?
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyzer-checker=debug.StreamTester \
+// RUN: -analyzer-checker=debug.ExprInspection
+
+#include "Inputs/system-header-simulator.h"
+
+void clang_analyzer_eval(int);
+void clang_analyzer_dump(int);
+void clang_analyzer_warnIfReached(void);
+void StreamTesterChecker_make_feof_stream(FILE *);
+void StreamTesterChecker_make_ferror_stream(FILE *);
+
+void test_fread(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fread(Buf, 1, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{conj_$}} Should not
preserve the previous value, thus should not be 10.
+ clang_analyzer_dump(Buf[2]); // expected-warning {{conj_$}}
+ if (feof(F)) {
+char Buf1[3] = {10, 10, 10};
+fread(Buf1, 1, 3, F); // expected-warning {{is in EOF state}}
+clang_analyzer_dump(Buf1[0]); // expected-warning {{10 S32b}}
+clang_analyzer_dump(Buf1[2]); // expected-warning {{10 S32b}}
+ }
+
+ fclose(F);
+}
+
+void test_fwrite(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fwrite(Buf, 1, 3, F);
+ // this check applies to succes and failure
steakhal wrote:
```suggestion
// This check applies to success and failure.
```
As per llvm style, capitalize and punctuate comments.
`sed "s/this check applies to succes and failure/This check applies to success
and failure."`
There was also a typo `sed "s/succes/success/g"` this file.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyzer-checker=debug.StreamTester \
+// RUN: -analyzer-checker=debug.ExprInspection
+
+#include "Inputs/system-header-simulator.h"
+
+void clang_analyzer_eval(int);
+void clang_analyzer_dump(int);
+void clang_analyzer_warnIfReached(void);
+void StreamTesterChecker_make_feof_stream(FILE *);
+void StreamTesterChecker_make_ferror_stream(FILE *);
+
+void test_fread(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fread(Buf, 1, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{conj_$}} Should not
preserve the previous value, thus should not be 10.
+ clang_analyzer_dump(Buf[2]); // expected-warning {{conj_$}}
+ if (feof(F)) {
+char Buf1[3] = {10, 10, 10};
+fread(Buf1, 1, 3, F); // expected-warning {{is in EOF state}}
+clang_analyzer_dump(Buf1[0]); // expected-warning {{10 S32b}}
+clang_analyzer_dump(Buf1[2]); // expected-warning {{10 S32b}}
+ }
+
+ fclose(F);
+}
+
+void test_fwrite(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fwrite(Buf, 1, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{10 S32b}}
+ clang_analyzer_dump(Buf[2]); // expected-warning {{10 S32b}}
+
+ fclose(F);
+}
+
+void test_fgets() {
+ FILE *F = tmpfile();
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fgets(Buf, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{conj_$}} Should not
preserve the previous value, thus should not be 10.
+ clang_analyzer_dump(Buf[2]); // expected-warning {{conj_$}}
+ if (feof(F)) {
+char Buf1[3] = {10, 10, 10};
+fgets(Buf1, 3, F); // expected-warning {{is in EOF state}}
+clang_analyzer_dump(Buf1[0]); // expected-warning {{10 S32b}}
+clang_analyzer_dump(Buf1[2]); // expected-warning {{10 S32b}}
+ }
+
+ fclose(F);
+}
+
+void test_fputs() {
+ FILE *F = tmpfile();
+ if (!F)
+return;
+
+ char *Buf = "aaa";
+ fputs(Buf, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{97 S32b}}
+ clang_analyzer_dump(Buf[2]); // expected-warning {{97 S32b}}
+ clang_analyzer_dump(Buf[3]); // expected-warning {{0 S32b}}
+
+ fclose(F);
+}
+
+void test_fscanf() {
+ FILE *F = tmpfile();
+ if (!F)
+return;
+
+ int a = 1;
+ unsigned b;
+ int Ret = fscanf(F, "%d %u", &a, &b);
+ if (Ret >= 0) {
+// FIXME: return value
+clang_analyzer_dump(a); // expected-warning {{conj_$}}
+clang_analyzer_dump(b); // expected-warning {{conj_$}}
+ } else {
+clang_analyzer_dump(a); // expected-warning {{1 S32b}}
+clang_analyzer_dump(b); // expected-warning {{uninitialized value}}
+ }
+ fclose(F);
+}
+
+void test_getdelim(char *P, size_t Sz) {
+ FILE *F = tmpfile();
+ if (!F)
+return;
+
+ char *P1 = P;
+ size_t Sz1 = Sz;
+ ssize_t Ret = getdelim(&P, &Sz, '\t', F);
+ clang_analyzer_eval(P == P1); // expected-warning {{FALSE}} \
+// expected-warning {{TRUE}}
+ clang_analyzer_eval(Sz == Sz1); // expected-warning {{FALSE}} \
+ // expected-warning {{TRUE}}
steakhal wrote:
I don't think this is too useful this way. We can't distinguish the failure and
success branches.
Lets have different branches depending on `Ret`, to make it clear.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
steakhal wrote:
```suggestion
escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
ArrayRef EscapingArgs) {
```
Views should be preferred for input parameters.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyzer-checker=debug.StreamTester \
+// RUN: -analyzer-checker=debug.ExprInspection
+
+#include "Inputs/system-header-simulator.h"
+
+void clang_analyzer_eval(int);
+void clang_analyzer_dump(int);
+void clang_analyzer_warnIfReached(void);
+void StreamTesterChecker_make_feof_stream(FILE *);
+void StreamTesterChecker_make_ferror_stream(FILE *);
+
+void test_fread(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fread(Buf, 1, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{conj_$}} Should not
preserve the previous value, thus should not be 10.
+ clang_analyzer_dump(Buf[2]); // expected-warning {{conj_$}}
+ if (feof(F)) {
+char Buf1[3] = {10, 10, 10};
+fread(Buf1, 1, 3, F); // expected-warning {{is in EOF state}}
+clang_analyzer_dump(Buf1[0]); // expected-warning {{10 S32b}}
+clang_analyzer_dump(Buf1[2]); // expected-warning {{10 S32b}}
+ }
+
+ fclose(F);
+}
+
+void test_fwrite(void) {
+ FILE *F = fopen("file", "r+");
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fwrite(Buf, 1, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{10 S32b}}
+ clang_analyzer_dump(Buf[2]); // expected-warning {{10 S32b}}
+
+ fclose(F);
+}
+
+void test_fgets() {
+ FILE *F = tmpfile();
+ if (!F)
+return;
+
+ char Buf[3] = {10, 10, 10};
+ fgets(Buf, 3, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{conj_$}} Should not
preserve the previous value, thus should not be 10.
+ clang_analyzer_dump(Buf[2]); // expected-warning {{conj_$}}
+ if (feof(F)) {
+char Buf1[3] = {10, 10, 10};
+fgets(Buf1, 3, F); // expected-warning {{is in EOF state}}
+clang_analyzer_dump(Buf1[0]); // expected-warning {{10 S32b}}
+clang_analyzer_dump(Buf1[2]); // expected-warning {{10 S32b}}
+ }
+
+ fclose(F);
+}
+
+void test_fputs() {
+ FILE *F = tmpfile();
+ if (!F)
+return;
+
+ char *Buf = "aaa";
+ fputs(Buf, F);
+ // this check applies to succes and failure
+ clang_analyzer_dump(Buf[0]); // expected-warning {{97 S32b}}
+ clang_analyzer_dump(Buf[2]); // expected-warning {{97 S32b}}
+ clang_analyzer_dump(Buf[3]); // expected-warning {{0 S32b}}
+
+ fclose(F);
+}
+
+void test_fscanf() {
+ FILE *F = tmpfile();
+ if (!F)
+return;
+
+ int a = 1;
+ unsigned b;
+ int Ret = fscanf(F, "%d %u", &a, &b);
+ if (Ret >= 0) {
+// FIXME: return value
+clang_analyzer_dump(a); // expected-warning {{conj_$}}
steakhal wrote:
```suggestion
clang_analyzer_dump(a); // expected-warning {{conj_$}}
clang_analyzer_eval(Ret > 2); // expected-warning {{FALSE}}
expected-warning {{TRUE}} FIXME: should be only FALSE.
```
Let's take the opportunity for adding an expected (but failing) assumption
here. May be fixed in the future.
https://github.com/llvm/llvm-project/pull/79470
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[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/steakhal commented: I like what you do in this patch. I only have a couple nits. That's it. Tomorrow, I'll check if there are any other APIs that we should test; but seems complete at first glance. https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/steakhal edited https://github.com/llvm/llvm-project/pull/79470 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
llvmbot wrote:
@llvm/pr-subscribers-clang-static-analyzer-1
Author: Balázs Kéri (balazske)
Changes
Specific arguments passed to stream handling functions are changed by the
function, this means these should be invalidated ("escaped") by the analyzer.
This change adds the argument invalidation (in specific cases) to the checker.
---
Full diff: https://github.com/llvm/llvm-project/pull/79470.diff
2 Files Affected:
- (modified) clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp (+35)
- (added) clang/test/Analysis/stream-invalidate.c (+133)
``diff
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index 07727b339d967ae..166bd981a003af2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -21,6 +21,7 @@
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
+#include "llvm/ADT/Sequence.h"
#include
#include
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
+ return State;
+}
+
//===--===//
// Methods of StreamChecker.
//===--===//
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
+
// Generate a transition for the success state.
// If we know the state to be FEOF at fread, do not add a success state.
if (!IsFread || (OldSS->ErrorState != ErrorFEof)) {
@@ -824,6 +845,10 @@ void StreamChecker::evalFgetx(const FnDescription *Desc,
const CallEvent &Call,
// `fgets` returns the read buffer address on success, otherwise returns
NULL.
if (OldSS->ErrorState != ErrorFEof) {
+// If there was already EOF, assume that read buffer is not changed.
+// Otherwise it may change at success or failure.
+
+State = escapeArgs(State, C, Call, {0});
if (SingleChar) {
// Generate a transition for the success state of `fgetc`.
NonLoc RetVal = makeRetVal(C, CE).castAs();
@@ -1032,6 +1057,11 @@ void StreamChecker::evalFscanf(const FnDescription
*Desc, const CallEvent &Call,
return;
StateNotFailed = StateNotFailed->assume(*RetGeZero, true);
+SmallVector EscArgs;
+for (auto EscArg : llvm::seq(2u, Call.getNumArgs()))
+ EscArgs.push_back(EscArg);
+StateNotFailed = escapeArgs(StateNotFailed, C, Call, EscArgs);
+
C.addTransition(StateNotFailed);
}
@@ -1118,6 +1148,10 @@ void StreamChecker::evalGetdelim(const FnDescription
*Desc,
// Add transition for the successful state.
if (OldSS->ErrorState != ErrorFEof) {
+// Escape buffer and size (may change by the call).
+// May happen even at error (partial read?).
+State = escapeArgs(State, C, Call, {0, 1});
+
NonLoc RetVal = makeRetVal(C, CE).castAs();
ProgramStateRef StateNotFailed =
State->BindExpr(CE, C.getLocationContext(), RetVal);
@@ -1236,6 +1270,7 @@ void StreamChecker::evalFgetpos(const FnDescription *Desc,
ProgramStateRef StateNotFailed, StateFailed;
std::tie(StateFailed, StateNotFailed) =
C.getConstraintManager().assumeDual(State, RetVal);
+ StateNotFailed = escapeArgs(StateNotFailed, C, Call, {1});
// This function does not affect the stream state.
// Still we add success and failure state with the appropriate return value.
diff --git a/clang/test/Analysis/stream-invalidate.c
b/clang/test/Analysis/stream-invalidate.c
new file mode 100644
index 000..c5b7874f0ee8f6f
--- /dev/null
+++ b/clang/test/Analysis/stream-invalidate.c
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyzer-checker=debug.StreamTester \
+// RUN: -analyzer-checker=debug.ExprInspection
+
+#include "Inputs/system-header-simulator.h"
+
+void clang_analyzer_eval(int);
+void clang_analyzer_dump(int);
+void clang_analyze
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
llvmbot wrote:
@llvm/pr-subscribers-clang
Author: Balázs Kéri (balazske)
Changes
Specific arguments passed to stream handling functions are changed by the
function, this means these should be invalidated ("escaped") by the analyzer.
This change adds the argument invalidation (in specific cases) to the checker.
---
Full diff: https://github.com/llvm/llvm-project/pull/79470.diff
2 Files Affected:
- (modified) clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp (+35)
- (added) clang/test/Analysis/stream-invalidate.c (+133)
``diff
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index 07727b339d967ae..166bd981a003af2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -21,6 +21,7 @@
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
+#include "llvm/ADT/Sequence.h"
#include
#include
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
+ return State;
+}
+
//===--===//
// Methods of StreamChecker.
//===--===//
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
+
// Generate a transition for the success state.
// If we know the state to be FEOF at fread, do not add a success state.
if (!IsFread || (OldSS->ErrorState != ErrorFEof)) {
@@ -824,6 +845,10 @@ void StreamChecker::evalFgetx(const FnDescription *Desc,
const CallEvent &Call,
// `fgets` returns the read buffer address on success, otherwise returns
NULL.
if (OldSS->ErrorState != ErrorFEof) {
+// If there was already EOF, assume that read buffer is not changed.
+// Otherwise it may change at success or failure.
+
+State = escapeArgs(State, C, Call, {0});
if (SingleChar) {
// Generate a transition for the success state of `fgetc`.
NonLoc RetVal = makeRetVal(C, CE).castAs();
@@ -1032,6 +1057,11 @@ void StreamChecker::evalFscanf(const FnDescription
*Desc, const CallEvent &Call,
return;
StateNotFailed = StateNotFailed->assume(*RetGeZero, true);
+SmallVector EscArgs;
+for (auto EscArg : llvm::seq(2u, Call.getNumArgs()))
+ EscArgs.push_back(EscArg);
+StateNotFailed = escapeArgs(StateNotFailed, C, Call, EscArgs);
+
C.addTransition(StateNotFailed);
}
@@ -1118,6 +1148,10 @@ void StreamChecker::evalGetdelim(const FnDescription
*Desc,
// Add transition for the successful state.
if (OldSS->ErrorState != ErrorFEof) {
+// Escape buffer and size (may change by the call).
+// May happen even at error (partial read?).
+State = escapeArgs(State, C, Call, {0, 1});
+
NonLoc RetVal = makeRetVal(C, CE).castAs();
ProgramStateRef StateNotFailed =
State->BindExpr(CE, C.getLocationContext(), RetVal);
@@ -1236,6 +1270,7 @@ void StreamChecker::evalFgetpos(const FnDescription *Desc,
ProgramStateRef StateNotFailed, StateFailed;
std::tie(StateFailed, StateNotFailed) =
C.getConstraintManager().assumeDual(State, RetVal);
+ StateNotFailed = escapeArgs(StateNotFailed, C, Call, {1});
// This function does not affect the stream state.
// Still we add success and failure state with the appropriate return value.
diff --git a/clang/test/Analysis/stream-invalidate.c
b/clang/test/Analysis/stream-invalidate.c
new file mode 100644
index 000..c5b7874f0ee8f6f
--- /dev/null
+++ b/clang/test/Analysis/stream-invalidate.c
@@ -0,0 +1,133 @@
+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN: -analyzer-checker=core \
+// RUN: -analyzer-checker=alpha.unix.Stream \
+// RUN: -analyzer-checker=debug.StreamTester \
+// RUN: -analyzer-checker=debug.ExprInspection
+
+#include "Inputs/system-header-simulator.h"
+
+void clang_analyzer_eval(int);
+void clang_analyzer_dump(int);
+void clang_analyzer_warnIfReached(vo
[clang] [clang][analyzer] Fix argument invalidations in StreamChecker. (PR #79470)
https://github.com/balazske created
https://github.com/llvm/llvm-project/pull/79470
Specific arguments passed to stream handling functions are changed by the
function, this means these should be invalidated ("escaped") by the analyzer.
This change adds the argument invalidation (in specific cases) to the checker.
From dbd9af4e77c34fcf6ce82f226f7dbf836033a8f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?=
Date: Thu, 25 Jan 2024 17:50:42 +0100
Subject: [PATCH] [clang][analyzer] Fix argument invalidations in
StreamChecker.
Specific arguments passed to stream handling functions are changed by the
function,
this means these should be invalidated ("escaped") by the analyzer.
This change adds the argument invalidation (in specific cases) to the checker.
---
.../StaticAnalyzer/Checkers/StreamChecker.cpp | 35 +
clang/test/Analysis/stream-invalidate.c | 133 ++
2 files changed, 168 insertions(+)
create mode 100644 clang/test/Analysis/stream-invalidate.c
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index 07727b339d967ae..166bd981a003af2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -21,6 +21,7 @@
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
+#include "llvm/ADT/Sequence.h"
#include
#include
@@ -544,6 +545,21 @@ const ExplodedNode
*StreamChecker::getAcquisitionSite(const ExplodedNode *N,
return nullptr;
}
+static ProgramStateRef
+escapeArgs(ProgramStateRef State, CheckerContext &C, const CallEvent &Call,
+ const SmallVector &EscapingArgs) {
+ const auto *CE = Call.getOriginExpr();
+
+ SmallVector EscapingVals;
+ EscapingVals.reserve(EscapingArgs.size());
+ for (auto EscArgIdx : EscapingArgs)
+EscapingVals.push_back(Call.getArgSVal(EscArgIdx));
+ State = State->invalidateRegions(EscapingVals, CE, C.blockCount(),
+ C.getLocationContext(),
+ /*CausesPointerEscape=*/false);
+ return State;
+}
+
//===--===//
// Methods of StreamChecker.
//===--===//
@@ -763,6 +779,11 @@ void StreamChecker::evalFreadFwrite(const FnDescription
*Desc,
return;
}
+ // At read, invalidate the buffer in any case of error or success,
+ // except if EOF was already present.
+ if (IsFread && (OldSS->ErrorState != ErrorFEof))
+State = escapeArgs(State, C, Call, {0});
+
// Generate a transition for the success state.
// If we know the state to be FEOF at fread, do not add a success state.
if (!IsFread || (OldSS->ErrorState != ErrorFEof)) {
@@ -824,6 +845,10 @@ void StreamChecker::evalFgetx(const FnDescription *Desc,
const CallEvent &Call,
// `fgets` returns the read buffer address on success, otherwise returns
NULL.
if (OldSS->ErrorState != ErrorFEof) {
+// If there was already EOF, assume that read buffer is not changed.
+// Otherwise it may change at success or failure.
+
+State = escapeArgs(State, C, Call, {0});
if (SingleChar) {
// Generate a transition for the success state of `fgetc`.
NonLoc RetVal = makeRetVal(C, CE).castAs();
@@ -1032,6 +1057,11 @@ void StreamChecker::evalFscanf(const FnDescription
*Desc, const CallEvent &Call,
return;
StateNotFailed = StateNotFailed->assume(*RetGeZero, true);
+SmallVector EscArgs;
+for (auto EscArg : llvm::seq(2u, Call.getNumArgs()))
+ EscArgs.push_back(EscArg);
+StateNotFailed = escapeArgs(StateNotFailed, C, Call, EscArgs);
+
C.addTransition(StateNotFailed);
}
@@ -1118,6 +1148,10 @@ void StreamChecker::evalGetdelim(const FnDescription
*Desc,
// Add transition for the successful state.
if (OldSS->ErrorState != ErrorFEof) {
+// Escape buffer and size (may change by the call).
+// May happen even at error (partial read?).
+State = escapeArgs(State, C, Call, {0, 1});
+
NonLoc RetVal = makeRetVal(C, CE).castAs();
ProgramStateRef StateNotFailed =
State->BindExpr(CE, C.getLocationContext(), RetVal);
@@ -1236,6 +1270,7 @@ void StreamChecker::evalFgetpos(const FnDescription *Desc,
ProgramStateRef StateNotFailed, StateFailed;
std::tie(StateFailed, StateNotFailed) =
C.getConstraintManager().assumeDual(State, RetVal);
+ StateNotFailed = escapeArgs(StateNotFailed, C, Call, {1});
// This function does not affect the stream state.
// Still we add success and failure state with the appropriate return value.
diff --git a/clang/test/Analysis/stream-invalidate.c
b/clang/test/Analysis/stream-invalidate.c
new file mode 100644
index 000..c5b
