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[clang][analyzer] Add missing stream related functions to StdCLibraryFunctionsChecker.
Some stream functions were recently added to StreamChecker that were not modeled by StdCLibraryFunctionsChecker. To ensure consistency these functions are added to the other checker too. Some of the related tests are re-organized.
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6 files changed

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-46
lines changed

6 files changed

+166
-46
lines changed

‎clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp

Lines changed: 71 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -2023,13 +2023,6 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
20232023
{{EOFv, EOFv}, {0, UCharRangeMax}},
20242024
"an unsigned char value or EOF")));
20252025

2026-
// The getc() family of functions that returns either a char or an EOF.
2027-
addToFunctionSummaryMap(
2028-
{"getc", "fgetc"}, Signature(ArgTypes{FilePtrTy}, RetType{IntTy}),
2029-
Summary(NoEvalCall)
2030-
.Case({ReturnValueCondition(WithinRange,
2031-
{{EOFv, EOFv}, {0, UCharRangeMax}})},
2032-
ErrnoIrrelevant));
20332026
addToFunctionSummaryMap(
20342027
"getchar", Signature(ArgTypes{}, RetType{IntTy}),
20352028
Summary(NoEvalCall)
@@ -2139,7 +2132,17 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
21392132
std::move(GetenvSummary));
21402133
}
21412134

2142-
if (ModelPOSIX) {
2135+
if (!ModelPOSIX) {
2136+
// Without POSIX use of 'errno' is not specified (in these cases).
2137+
// Add these functions without 'errno' checks.
2138+
addToFunctionSummaryMap(
2139+
{"getc", "fgetc"}, Signature(ArgTypes{FilePtrTy}, RetType{IntTy}),
2140+
Summary(NoEvalCall)
2141+
.Case({ReturnValueCondition(WithinRange,
2142+
{{EOFv, EOFv}, {0, UCharRangeMax}})},
2143+
ErrnoIrrelevant)
2144+
.ArgConstraint(NotNull(ArgNo(0))));
2145+
} else {
21432146
const auto ReturnsZeroOrMinusOne =
21442147
ConstraintSet{ReturnValueCondition(WithinRange, Range(-1, 0))};
21452148
const auto ReturnsZero =
@@ -2192,6 +2195,16 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
21922195
.ArgConstraint(NotNull(ArgNo(1)))
21932196
.ArgConstraint(NotNull(ArgNo(2))));
21942197

2198+
// FILE *fdopen(int fd, const char *mode);
2199+
addToFunctionSummaryMap(
2200+
"fdopen",
2201+
Signature(ArgTypes{IntTy, ConstCharPtrTy}, RetType{FilePtrTy}),
2202+
Summary(NoEvalCall)
2203+
.Case({NotNull(Ret)}, ErrnoMustNotBeChecked, GenericSuccessMsg)
2204+
.Case({IsNull(Ret)}, ErrnoNEZeroIrrelevant, GenericFailureMsg)
2205+
.ArgConstraint(ArgumentCondition(0, WithinRange, Range(0, IntMax)))
2206+
.ArgConstraint(NotNull(ArgNo(1))));
2207+
21952208
// int fclose(FILE *stream);
21962209
addToFunctionSummaryMap(
21972210
"fclose", Signature(ArgTypes{FilePtrTy}, RetType{IntTy}),
@@ -2201,6 +2214,56 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
22012214
ErrnoNEZeroIrrelevant, GenericFailureMsg)
22022215
.ArgConstraint(NotNull(ArgNo(0))));
22032216

2217+
// int fgetc(FILE *stream);
2218+
// 'getc' is the same as 'fgetc' but may be a macro
2219+
addToFunctionSummaryMap(
2220+
{"getc", "fgetc"}, Signature(ArgTypes{FilePtrTy}, RetType{IntTy}),
2221+
Summary(NoEvalCall)
2222+
.Case({ReturnValueCondition(WithinRange, {{0, UCharRangeMax}})},
2223+
ErrnoMustNotBeChecked, GenericSuccessMsg)
2224+
.Case({ReturnValueCondition(WithinRange, SingleValue(EOFv))},
2225+
ErrnoNEZeroIrrelevant, GenericFailureMsg)
2226+
.ArgConstraint(NotNull(ArgNo(0))));
2227+
2228+
// int fputc(int c, FILE *stream);
2229+
// 'putc' is the same as 'fputc' but may be a macro
2230+
addToFunctionSummaryMap(
2231+
{"putc", "fputc"},
2232+
Signature(ArgTypes{IntTy, FilePtrTy}, RetType{IntTy}),
2233+
Summary(NoEvalCall)
2234+
.Case({ReturnValueCondition(BO_EQ, ArgNo(0))},
2235+
ErrnoMustNotBeChecked, GenericSuccessMsg)
2236+
.Case({ReturnValueCondition(WithinRange, SingleValue(EOFv))},
2237+
ErrnoNEZeroIrrelevant, GenericFailureMsg)
2238+
.ArgConstraint(NotNull(ArgNo(1)))
2239+
.ArgConstraint(
2240+
ArgumentCondition(0, WithinRange, {{0, UCharRangeMax}})));
2241+
2242+
// char *fgets(char *restrict s, int n, FILE *restrict stream);
2243+
addToFunctionSummaryMap(
2244+
"fgets",
2245+
Signature(ArgTypes{CharPtrRestrictTy, IntTy, FilePtrRestrictTy},
2246+
RetType{CharPtrTy}),
2247+
Summary(NoEvalCall)
2248+
.Case({ReturnValueCondition(BO_EQ, ArgNo(0))},
2249+
ErrnoMustNotBeChecked, GenericSuccessMsg)
2250+
.Case({IsNull(Ret)}, ErrnoNEZeroIrrelevant, GenericFailureMsg)
2251+
.ArgConstraint(NotNull(ArgNo(0)))
2252+
.ArgConstraint(ArgumentCondition(1, WithinRange, Range(0, IntMax)))
2253+
.ArgConstraint(NotNull(ArgNo(2))));
2254+
2255+
// int fputs(const char *restrict s, FILE *restrict stream);
2256+
addToFunctionSummaryMap(
2257+
"fputs",
2258+
Signature(ArgTypes{ConstCharPtrRestrictTy, FilePtrRestrictTy},
2259+
RetType{IntTy}),
2260+
Summary(NoEvalCall)
2261+
.Case(ReturnsNonnegative, ErrnoMustNotBeChecked, GenericSuccessMsg)
2262+
.Case({ReturnValueCondition(WithinRange, SingleValue(EOFv))},
2263+
ErrnoNEZeroIrrelevant, GenericFailureMsg)
2264+
.ArgConstraint(NotNull(ArgNo(0)))
2265+
.ArgConstraint(NotNull(ArgNo(1))));
2266+
22042267
// int fseek(FILE *stream, long offset, int whence);
22052268
// FIXME: It can be possible to get the 'SEEK_' values (like EOFv) and use
22062269
// these for condition of arg 2.
@@ -2800,15 +2863,6 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
28002863
"pathconf", Signature(ArgTypes{ConstCharPtrTy, IntTy}, RetType{LongTy}),
28012864
Summary(NoEvalCall).ArgConstraint(NotNull(ArgNo(0))));
28022865

2803-
// FILE *fdopen(int fd, const char *mode);
2804-
// FIXME: Improve for errno modeling.
2805-
addToFunctionSummaryMap(
2806-
"fdopen",
2807-
Signature(ArgTypes{IntTy, ConstCharPtrTy}, RetType{FilePtrTy}),
2808-
Summary(NoEvalCall)
2809-
.ArgConstraint(ArgumentCondition(0, WithinRange, Range(0, IntMax)))
2810-
.ArgConstraint(NotNull(ArgNo(1))));
2811-
28122866
// void rewinddir(DIR *dir);
28132867
addToFunctionSummaryMap(
28142868
"rewinddir", Signature(ArgTypes{DirPtrTy}, RetType{VoidTy}),

‎clang/test/Analysis/std-c-library-functions.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -53,8 +53,6 @@
5353
// CHECK-NEXT: Loaded summary for: int toupper(int)
5454
// CHECK-NEXT: Loaded summary for: int tolower(int)
5555
// CHECK-NEXT: Loaded summary for: int toascii(int)
56-
// CHECK-NEXT: Loaded summary for: int getc(FILE *)
57-
// CHECK-NEXT: Loaded summary for: int fgetc(FILE *)
5856
// CHECK-NEXT: Loaded summary for: int getchar(void)
5957
// CHECK-NEXT: Loaded summary for: unsigned int fread(void *restrict, size_t, size_t, FILE *restrict)
6058
// CHECK-NEXT: Loaded summary for: unsigned int fwrite(const void *restrict, size_t, size_t, FILE *restrict)
@@ -63,6 +61,8 @@
6361
// CHECK-NEXT: Loaded summary for: ssize_t getline(char **restrict, size_t *restrict, FILE *restrict)
6462
// CHECK-NEXT: Loaded summary for: ssize_t getdelim(char **restrict, size_t *restrict, int, FILE *restrict)
6563
// CHECK-NEXT: Loaded summary for: char *getenv(const char *)
64+
// CHECK-NEXT: Loaded summary for: int getc(FILE *)
65+
// CHECK-NEXT: Loaded summary for: int fgetc(FILE *)
6666

6767
#include "Inputs/std-c-library-functions.h"
6868

‎clang/test/Analysis/stream-error.c

Lines changed: 0 additions & 26 deletions
Original file line numberDiff line numberDiff line change
@@ -308,32 +308,6 @@ void error_fseek_0(void) {
308308
fclose(F);
309309
}
310310

311-
void error_fflush_after_fclose(void) {
312-
FILE *F = tmpfile();
313-
int Ret;
314-
fflush(NULL); // no-warning
315-
if (!F)
316-
return;
317-
if ((Ret = fflush(F)) != 0)
318-
clang_analyzer_eval(Ret == EOF); // expected-warning {{TRUE}}
319-
fclose(F);
320-
fflush(F); // expected-warning {{Stream might be already closed}}
321-
}
322-
323-
void error_fflush_on_open_failed_stream(void) {
324-
FILE *F = tmpfile();
325-
if (!F) {
326-
fflush(F); // no-warning
327-
return;
328-
}
329-
fclose(F);
330-
}
331-
332-
void error_fflush_on_unknown_stream(FILE *F) {
333-
fflush(F); // no-warning
334-
fclose(F); // no-warning
335-
}
336-
337311
void error_fflush_on_non_null_stream_clear_error_states(void) {
338312
FILE *F0 = tmpfile(), *F1 = tmpfile();
339313
// `fflush` clears a non-EOF stream's error state.

‎clang/test/Analysis/stream-noopen.c

Lines changed: 68 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -57,6 +57,60 @@ void test_fwrite(FILE *F) {
5757
clang_analyzer_eval(ferror(F)); // expected-warning {{UNKNOWN}}
5858
}
5959

60+
void test_fgetc(FILE *F) {
61+
int Ret = fgetc(F);
62+
clang_analyzer_eval(F != NULL); // expected-warning {{TRUE}}
63+
if (Ret != EOF) {
64+
if (errno) {} // expected-warning {{undefined}}
65+
} else {
66+
clang_analyzer_eval(errno != 0); // expected-warning {{TRUE}}
67+
}
68+
clang_analyzer_eval(feof(F)); // expected-warning {{UNKNOWN}}
69+
clang_analyzer_eval(ferror(F)); // expected-warning {{UNKNOWN}}
70+
}
71+
72+
void test_fputc(FILE *F) {
73+
int Ret = fputc('a', F);
74+
clang_analyzer_eval(F != NULL); // expected-warning {{TRUE}}
75+
if (Ret != EOF) {
76+
clang_analyzer_eval(Ret == 'a'); // expected-warning {{TRUE}}
77+
if (errno) {} // expected-warning {{undefined}}
78+
} else {
79+
clang_analyzer_eval(errno != 0); // expected-warning {{TRUE}}
80+
}
81+
clang_analyzer_eval(feof(F)); // expected-warning {{UNKNOWN}}
82+
clang_analyzer_eval(ferror(F)); // expected-warning {{UNKNOWN}}
83+
}
84+
85+
void test_fgets(char *Buf, int N, FILE *F) {
86+
char *Ret = fgets(Buf, N, F);
87+
clang_analyzer_eval(F != NULL); // expected-warning {{TRUE}}
88+
clang_analyzer_eval(Buf != NULL); // expected-warning {{TRUE}}
89+
clang_analyzer_eval(N >= 0); // expected-warning {{TRUE}}
90+
if (Ret == Buf) {
91+
if (errno) {} // expected-warning {{undefined}}
92+
} else {
93+
clang_analyzer_eval(Ret == 0); // expected-warning {{TRUE}}
94+
clang_analyzer_eval(errno != 0); // expected-warning {{TRUE}}
95+
}
96+
clang_analyzer_eval(feof(F)); // expected-warning {{UNKNOWN}}
97+
clang_analyzer_eval(ferror(F)); // expected-warning {{UNKNOWN}}
98+
}
99+
100+
void test_fputs(char *Buf, FILE *F) {
101+
int Ret = fputs(Buf, F);
102+
clang_analyzer_eval(F != NULL); // expected-warning {{TRUE}}
103+
clang_analyzer_eval(Buf != NULL); // expected-warning {{TRUE}}
104+
if (Ret >= 0) {
105+
if (errno) {} // expected-warning {{undefined}}
106+
} else {
107+
clang_analyzer_eval(Ret == EOF); // expected-warning {{TRUE}}
108+
clang_analyzer_eval(errno != 0); // expected-warning {{TRUE}}
109+
}
110+
clang_analyzer_eval(feof(F)); // expected-warning {{UNKNOWN}}
111+
clang_analyzer_eval(ferror(F)); // expected-warning {{UNKNOWN}}
112+
}
113+
60114
void test_fclose(FILE *F) {
61115
int Ret = fclose(F);
62116
clang_analyzer_eval(F != NULL); // expected-warning {{TRUE}}
@@ -138,6 +192,20 @@ void test_rewind(FILE *F) {
138192
rewind(F);
139193
}
140194

195+
void test_fflush(FILE *F) {
196+
errno = 0;
197+
int Ret = fflush(F);
198+
clang_analyzer_eval(F != NULL); // expected-warning{{TRUE}}
199+
// expected-warning@-1{{FALSE}}
200+
if (Ret == EOF) {
201+
clang_analyzer_eval(errno != 0); // expected-warning{{TRUE}}
202+
} else {
203+
clang_analyzer_eval(Ret == 0); // expected-warning{{TRUE}}
204+
clang_analyzer_eval(errno == 0); // expected-warning{{TRUE}}
205+
// expected-warning@-1{{FALSE}}
206+
}
207+
}
208+
141209
void test_feof(FILE *F) {
142210
errno = 0;
143211
feof(F);

‎clang/test/Analysis/stream-note.c

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -56,6 +56,7 @@ void check_note_freopen(void) {
5656

5757
void check_note_fdopen(int fd) {
5858
FILE *F = fdopen(fd, "r"); // expected-note {{Stream opened here}}
59+
// stdargs-note@-1 {{'fdopen' is successful}}
5960
if (!F)
6061
// expected-note@-1 {{'F' is non-null}}
6162
// expected-note@-2 {{Taking false branch}}

‎clang/test/Analysis/stream.c

Lines changed: 24 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,9 @@
1-
// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.unix.Stream -verify %s
1+
// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.unix.Stream,debug.ExprInspection -verify %s
22

33
#include "Inputs/system-header-simulator.h"
44

5+
void clang_analyzer_eval(int);
6+
57
void check_fread(void) {
68
FILE *fp = tmpfile();
79
fread(0, 0, 0, fp); // expected-warning {{Stream pointer might be NULL}}
@@ -299,3 +301,24 @@ void check_leak_noreturn_2(void) {
299301
} // expected-warning {{Opened stream never closed. Potential resource leak}}
300302
// FIXME: This warning should be placed at the `return` above.
301303
// See https://reviews.llvm.org/D83120 about details.
304+
305+
void fflush_after_fclose(void) {
306+
FILE *F = tmpfile();
307+
int Ret;
308+
fflush(NULL); // no-warning
309+
if (!F)
310+
return;
311+
if ((Ret = fflush(F)) != 0)
312+
clang_analyzer_eval(Ret == EOF); // expected-warning {{TRUE}}
313+
fclose(F);
314+
fflush(F); // expected-warning {{Stream might be already closed}}
315+
}
316+
317+
void fflush_on_open_failed_stream(void) {
318+
FILE *F = tmpfile();
319+
if (!F) {
320+
fflush(F); // no-warning
321+
return;
322+
}
323+
fclose(F);
324+
}

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