[clang] [clang][analyzer] Support `fputs` in the StreamChecker (PR #73335)
Ben Shi via cfe-commits
cfe-commits at lists.llvm.org
Fri Nov 24 06:53:38 PST 2023
https://github.com/benshi001 created https://github.com/llvm/llvm-project/pull/73335
None
>From c59788f4b918c5335efe7444b8d588878565cb26 Mon Sep 17 00:00:00 2001
From: Ben Shi <bennshi at tencent.com>
Date: Fri, 24 Nov 2023 22:51:27 +0800
Subject: [PATCH] [clang][analyzer] Support `fputs` in the StreamChecker
---
.../StaticAnalyzer/Checkers/StreamChecker.cpp | 61 +++++++++++++------
.../Analysis/Inputs/system-header-simulator.h | 1 +
clang/test/Analysis/stream-error.c | 18 ++++++
clang/test/Analysis/stream.c | 6 ++
4 files changed, 68 insertions(+), 18 deletions(-)
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index 8eca989d7bcdea4..0e85f1fd0655143 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -252,10 +252,16 @@ class StreamChecker : public Checker<check::PreCall, eval::Call,
std::bind(&StreamChecker::evalFreadFwrite, _1, _2, _3, _4, false), 3}},
{{{"fgetc"}, 1},
{std::bind(&StreamChecker::preReadWrite, _1, _2, _3, _4, true),
- std::bind(&StreamChecker::evalFgetcFputc, _1, _2, _3, _4, true), 0}},
+ std::bind(&StreamChecker::evalFgetxFputx, _1, _2, _3, _4, true, true),
+ 0}},
{{{"fputc"}, 2},
{std::bind(&StreamChecker::preReadWrite, _1, _2, _3, _4, false),
- std::bind(&StreamChecker::evalFgetcFputc, _1, _2, _3, _4, false), 1}},
+ std::bind(&StreamChecker::evalFgetxFputx, _1, _2, _3, _4, false, true),
+ 1}},
+ {{{"fputs"}, 2},
+ {std::bind(&StreamChecker::preReadWrite, _1, _2, _3, _4, false),
+ std::bind(&StreamChecker::evalFgetxFputx, _1, _2, _3, _4, false, false),
+ 1}},
{{{"fseek"}, 3},
{&StreamChecker::preFseek, &StreamChecker::evalFseek, 0}},
{{{"ftell"}, 1},
@@ -317,8 +323,8 @@ class StreamChecker : public Checker<check::PreCall, eval::Call,
void evalFreadFwrite(const FnDescription *Desc, const CallEvent &Call,
CheckerContext &C, bool IsFread) const;
- void evalFgetcFputc(const FnDescription *Desc, const CallEvent &Call,
- CheckerContext &C, bool IsRead) const;
+ void evalFgetxFputx(const FnDescription *Desc, const CallEvent &Call,
+ CheckerContext &C, bool IsRead, bool SingleChar) const;
void preFseek(const FnDescription *Desc, const CallEvent &Call,
CheckerContext &C) const;
@@ -754,9 +760,9 @@ void StreamChecker::evalFreadFwrite(const FnDescription *Desc,
C.addTransition(StateFailed);
}
-void StreamChecker::evalFgetcFputc(const FnDescription *Desc,
+void StreamChecker::evalFgetxFputx(const FnDescription *Desc,
const CallEvent &Call, CheckerContext &C,
- bool IsRead) const {
+ bool IsRead, bool SingleChar) const {
ProgramStateRef State = C.getState();
SymbolRef StreamSym = getStreamArg(Desc, Call).getAsSymbol();
if (!StreamSym)
@@ -774,26 +780,45 @@ void StreamChecker::evalFgetcFputc(const FnDescription *Desc,
// `fgetc` returns the read character on success, otherwise returns EOF.
// `fputc` returns the written character on success, otherwise returns EOF.
+ // `fputs` returns a non negative value on sucecess, otherwise returns EOF.
- // Generate a transition for the success state of fputc.
+ SValBuilder &SVB = C.getSValBuilder();
+ auto &ASTC = C.getASTContext();
if (!IsRead) {
- std::optional<NonLoc> PutVal = Call.getArgSVal(0).getAs<NonLoc>();
- if (!PutVal)
- return;
- ProgramStateRef StateNotFailed =
- State->BindExpr(CE, C.getLocationContext(), *PutVal);
- StateNotFailed =
- StateNotFailed->set<StreamMap>(StreamSym, StreamState::getOpened(Desc));
- C.addTransition(StateNotFailed);
+ // Generddate a transition for the success state of `fputc`.
+ if (SingleChar) {
+ std::optional<NonLoc> PutVal = Call.getArgSVal(0).getAs<NonLoc>();
+ if (!PutVal)
+ return;
+ ProgramStateRef StateNotFailed =
+ State->BindExpr(CE, C.getLocationContext(), *PutVal);
+ StateNotFailed = StateNotFailed->set<StreamMap>(
+ StreamSym, StreamState::getOpened(Desc));
+ C.addTransition(StateNotFailed);
+ }
+ // Generddate a transition for the success state of `fputs`.
+ else {
+ NonLoc RetVal = makeRetVal(C, CE).castAs<NonLoc>();
+ ProgramStateRef StateNotFailed =
+ State->BindExpr(CE, C.getLocationContext(), RetVal);
+ auto Cond =
+ SVB.evalBinOp(State, BO_GE, RetVal, SVB.makeZeroVal(ASTC.IntTy),
+ SVB.getConditionType())
+ .getAs<DefinedOrUnknownSVal>();
+ if (!Cond)
+ return;
+ StateNotFailed = StateNotFailed->assume(*Cond, true);
+ if (!StateNotFailed)
+ return;
+ C.addTransition(StateNotFailed);
+ }
}
- // Generate a transition for the success state of fgetc.
+ // Generate a transition for the success state of `fgetc`.
// If we know the state to be FEOF at fgetc, do not add a success state.
else if (OldSS->ErrorState != ErrorFEof) {
NonLoc RetVal = makeRetVal(C, CE).castAs<NonLoc>();
ProgramStateRef StateNotFailed =
State->BindExpr(CE, C.getLocationContext(), RetVal);
- SValBuilder &SVB = C.getSValBuilder();
- auto &ASTC = C.getASTContext();
// The returned 'unsigned char' of `fgetc` is converted to 'int',
// so we need to check if it is in range [0, 255].
auto CondLow =
diff --git a/clang/test/Analysis/Inputs/system-header-simulator.h b/clang/test/Analysis/Inputs/system-header-simulator.h
index fc57e8bdc3d30c3..351de8c132fecc7 100644
--- a/clang/test/Analysis/Inputs/system-header-simulator.h
+++ b/clang/test/Analysis/Inputs/system-header-simulator.h
@@ -50,6 +50,7 @@ size_t fread(void *restrict, size_t, size_t, FILE *restrict);
size_t fwrite(const void *restrict, size_t, size_t, FILE *restrict);
int fgetc(FILE *stream);
int fputc(int ch, FILE *stream);
+int fputs(const char *str, FILE *stream);
int fseek(FILE *__stream, long int __off, int __whence);
long int ftell(FILE *__stream);
void rewind(FILE *__stream);
diff --git a/clang/test/Analysis/stream-error.c b/clang/test/Analysis/stream-error.c
index 38e6b77b9bb5053..04e6b834fe9d4b5 100644
--- a/clang/test/Analysis/stream-error.c
+++ b/clang/test/Analysis/stream-error.c
@@ -141,6 +141,24 @@ void error_fputc(void) {
fputc('A', F); // expected-warning {{Stream might be already closed}}
}
+void error_fputs(void) {
+ FILE *F = tmpfile();
+ if (!F)
+ return;
+ int Ret = fputs("XYZ", F);
+ if (Ret >= 0) {
+ clang_analyzer_eval(feof(F) || ferror(F)); // expected-warning {{FALSE}}
+ fputs("QWD", F); // no-warning
+ } else {
+ clang_analyzer_eval(Ret == EOF); // expected-warning {{TRUE}}
+ clang_analyzer_eval(ferror(F)); // expected-warning {{TRUE}}
+ clang_analyzer_eval(feof(F)); // expected-warning {{FALSE}}
+ fputs("QWD", F); // expected-warning {{might be 'indeterminate'}}
+ }
+ fclose(F);
+ fputs("ABC", F); // expected-warning {{Stream might be already closed}}
+}
+
void freadwrite_zerosize(FILE *F) {
size_t Ret;
Ret = fwrite(0, 1, 0, F);
diff --git a/clang/test/Analysis/stream.c b/clang/test/Analysis/stream.c
index a7ee9982478bb96..b0f39af8eb2f3a3 100644
--- a/clang/test/Analysis/stream.c
+++ b/clang/test/Analysis/stream.c
@@ -26,6 +26,12 @@ void check_fputc(void) {
fclose(fp);
}
+void check_fputs(void) {
+ FILE *fp = tmpfile();
+ fputs("ABC", fp); // expected-warning {{Stream pointer might be NULL}}
+ fclose(fp);
+}
+
void check_fseek(void) {
FILE *fp = tmpfile();
fseek(fp, 0, 0); // expected-warning {{Stream pointer might be NULL}}
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