[clang][analyzer] Support 'tello' and 'fseeko' in the StreamChecker

[benshi001]

No description provided.

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-static-analyzer-1

Author: Ben Shi (benshi001)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/77580.diff

3 Files Affected:

• (modified) clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp (+4)
• (modified) clang/test/Analysis/Inputs/system-header-simulator.h (+3)
• (modified) clang/test/Analysis/stream-error.c (+82)

diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index fbfa101257d5e1..f6e6f3122f3aa7 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -268,8 +268,12 @@ class StreamChecker : public Checker<check::PreCall, eval::Call,
         std::bind(&StreamChecker::evalUngetc, _1, _2, _3, _4), 1}},
       {{{"fseek"}, 3},
        {&StreamChecker::preFseek, &StreamChecker::evalFseek, 0}},
+      {{{"fseeko"}, 3},
+       {&StreamChecker::preFseek, &StreamChecker::evalFseek, 0}},
       {{{"ftell"}, 1},
        {&StreamChecker::preDefault, &StreamChecker::evalFtell, 0}},
+      {{{"ftello"}, 1},
+       {&StreamChecker::preDefault, &StreamChecker::evalFtell, 0}},
       {{{"fflush"}, 1},
        {&StreamChecker::preFflush, &StreamChecker::evalFflush, 0}},
       {{{"rewind"}, 1},
diff --git a/clang/test/Analysis/Inputs/system-header-simulator.h b/clang/test/Analysis/Inputs/system-header-simulator.h
index caae59c38a4c8e..cd7ac616bcc67f 100644
--- a/clang/test/Analysis/Inputs/system-header-simulator.h
+++ b/clang/test/Analysis/Inputs/system-header-simulator.h
@@ -13,6 +13,7 @@ typedef __typeof(sizeof(int)) size_t;
 typedef long long __int64_t;
 typedef __int64_t __darwin_off_t;
 typedef __darwin_off_t fpos_t;
+typedef int off_t;
 
 typedef struct _FILE FILE;
 #define SEEK_SET 0 /* Seek from beginning of file. */
@@ -55,7 +56,9 @@ int fputc(int ch, FILE *stream);
 int fputs(const char *restrict s, FILE *restrict stream);
 int ungetc(int c, FILE *stream);
 int fseek(FILE *__stream, long int __off, int __whence);
+int fseeko(FILE *__stream, off_t __off, int __whence);
 long int ftell(FILE *__stream);
+off_t ftello(FILE *__stream);
 void rewind(FILE *__stream);
 int fgetpos(FILE *restrict stream, fpos_t *restrict pos);
 int fsetpos(FILE *stream, const fpos_t *pos);
diff --git a/clang/test/Analysis/stream-error.c b/clang/test/Analysis/stream-error.c
index c038348e799d29..1b14fc2eee2003 100644
--- a/clang/test/Analysis/stream-error.c
+++ b/clang/test/Analysis/stream-error.c
@@ -295,6 +295,37 @@ void error_fseek(void) {
   fclose(F);
 }
 
+void error_fseeko(void) {
+  FILE *F = fopen("file", "r");
+  if (!F)
+    return;
+  int rc = fseeko(F, 1, SEEK_SET);
+  if (rc) {
+    int IsFEof = feof(F), IsFError = ferror(F);
+    // Get feof or ferror or no error.
+    clang_analyzer_eval(IsFEof || IsFError);
+    // expected-warning@-1 {{FALSE}}
+    // expected-warning@-2 {{TRUE}}
+    clang_analyzer_eval(IsFEof && IsFError); // expected-warning {{FALSE}}
+    // Error flags should not change.
+    if (IsFEof)
+      clang_analyzer_eval(feof(F)); // expected-warning {{TRUE}}
+    else
+      clang_analyzer_eval(feof(F)); // expected-warning {{FALSE}}
+    if (IsFError)
+      clang_analyzer_eval(ferror(F)); // expected-warning {{TRUE}}
+    else
+      clang_analyzer_eval(ferror(F)); // expected-warning {{FALSE}}
+  } else {
+    clang_analyzer_eval(feof(F));   // expected-warning {{FALSE}}
+    clang_analyzer_eval(ferror(F)); // expected-warning {{FALSE}}
+    // Error flags should not change.
+    clang_analyzer_eval(feof(F));   // expected-warning {{FALSE}}
+    clang_analyzer_eval(ferror(F)); // expected-warning {{FALSE}}
+  }
+  fclose(F);
+}
+
 void error_fseek_0(void) {
   FILE *F = fopen("file", "r");
   if (!F)
@@ -324,6 +355,57 @@ void error_fseek_0(void) {
   fclose(F);
 }
 
+void error_fseeko_0(void) {
+  FILE *F = fopen("file", "r");
+  if (!F)
+    return;
+  int rc = fseeko(F, 0, SEEK_SET);
+  if (rc) {
+    int IsFEof = feof(F), IsFError = ferror(F);
+    // Get ferror or no error, but not feof.
+    clang_analyzer_eval(IsFError);
+    // expected-warning@-1 {{FALSE}}
+    // expected-warning@-2 {{TRUE}}
+    clang_analyzer_eval(IsFEof);
+    // expected-warning@-1 {{FALSE}}
+    // Error flags should not change.
+    clang_analyzer_eval(feof(F)); // expected-warning {{FALSE}}
+    if (IsFError)
+      clang_analyzer_eval(ferror(F)); // expected-warning {{TRUE}}
+    else
+      clang_analyzer_eval(ferror(F)); // expected-warning {{FALSE}}
+  } else {
+    clang_analyzer_eval(feof(F));   // expected-warning {{FALSE}}
+    clang_analyzer_eval(ferror(F)); // expected-warning {{FALSE}}
+    // Error flags should not change.
+    clang_analyzer_eval(feof(F));   // expected-warning {{FALSE}}
+    clang_analyzer_eval(ferror(F)); // expected-warning {{FALSE}}
+  }
+  fclose(F);
+}
+
+void error_ftell(void) {
+  FILE *F = fopen("file", "r");
+  if (!F)
+    return;
+  long Ret = ftell(F);
+  if (!(Ret >= 0)) {
+    clang_analyzer_eval(Ret == -1L); // expected-warning {{TRUE}}
+  }
+  fclose(F);
+}
+
+void error_ftello(void) {
+  FILE *F = fopen("file", "r");
+  if (!F)
+    return;
+  off_t Ret = ftello(F);
+  if (!(Ret == -1)) {
+    clang_analyzer_eval(Ret >= 0);   // expected-warning {{TRUE}}
+  }
+  fclose(F);
+}
+
 void error_fflush_after_fclose(void) {
   FILE *F = tmpfile();
   int Ret;

[balazske]

It is better to replace in code of evalFtell the C.getASTContext().LongTy with Call.getResultType() (occurs 2 times), this is more exact if off_t is defined to something else than long.

[benshi001]

It is better to replace in code of evalFtell the C.getASTContext().LongTy with Call.getResultType() (occurs 2 times), this is more exact if off_t is defined to something else than long.

This has been fixed. Thanks!