Reland [Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types (#149613)

The checks for the 'z' and 't' format specifiers added in the original
PR #143653 had some issues and were overly strict, causing some build
failures and were consequently reverted at
https://github.com/llvm/llvm-project/commit/4c85bf2fe8042c855c9dd5be4b02191e9d071ffd.

In the latest commit
https://github.com/llvm/llvm-project/pull/149613/commits/27c58629ec76a703fde9c0b99b170573170b4a7a,
I relaxed the checks for the 'z' and 't' format specifiers, so warnings
are now only issued when they are used with mismatched types.

The original intent of these checks was to diagnose code that assumes
the underlying type of `size_t` is `unsigned` or `unsigned long`, for
example:

```c
printf("%zu", 1ul); // Not portable, but not an error when size_t is unsigned long
```  

However, it produced a significant number of false positives. This was
partly because Clang does not treat the `typedef` `size_t` and
`__size_t` as having a common "sugar" type, and partly because a large
amount of existing code either assumes `unsigned` (or `unsigned long`)
is `size_t`, or they define the equivalent of size_t in their own way
(such as
sanitizer_internal_defs.h).https://github.com/llvm/llvm-project/blob/2e67dcfdcd023df2f06e0823eeea23990ce41534/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h#L203

1 files changed, 44 insertions, 36 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
index 1c748f9..52b3d1e 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
@@ -1666,7 +1666,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
   const QualType IntTy = ACtx.IntTy;
   const QualType UnsignedIntTy = ACtx.UnsignedIntTy;
   const QualType LongTy = ACtx.LongTy;
-  const QualType SizeTy = ACtx.getSizeType();
+  const QualType SizeTyCanonTy = ACtx.getCanonicalSizeType();
 
   const QualType VoidPtrTy = getPointerTy(VoidTy); // void *
   const QualType IntPtrTy = getPointerTy(IntTy);   // int *
@@ -1684,14 +1684,14 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
   const QualType ConstWchar_tPtrTy =
       getPointerTy(getConstTy(WCharTy)); // const wchar_t *
   const QualType ConstVoidPtrRestrictTy = getRestrictTy(ConstVoidPtrTy);
-  const QualType SizePtrTy = getPointerTy(SizeTy);
+  const QualType SizePtrTy = getPointerTy(SizeTyCanonTy);
   const QualType SizePtrRestrictTy = getRestrictTy(SizePtrTy);
 
   const RangeInt IntMax = BVF.getMaxValue(IntTy)->getLimitedValue();
   const RangeInt UnsignedIntMax =
       BVF.getMaxValue(UnsignedIntTy)->getLimitedValue();
   const RangeInt LongMax = BVF.getMaxValue(LongTy)->getLimitedValue();
-  const RangeInt SizeMax = BVF.getMaxValue(SizeTy)->getLimitedValue();
+  const RangeInt SizeMax = BVF.getMaxValue(SizeTyCanonTy)->getLimitedValue();
 
   // Set UCharRangeMax to min of int or uchar maximum value.
   // The C standard states that the arguments of functions like isalpha must
@@ -2057,18 +2057,19 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
 
   // size_t fread(void *restrict ptr, size_t size, size_t nitems,
   //              FILE *restrict stream);
-  addToFunctionSummaryMap(
-      "fread",
-      Signature(ArgTypes{VoidPtrRestrictTy, SizeTy, SizeTy, FilePtrRestrictTy},
-                RetType{SizeTy}),
-      FreadSummary);
+  addToFunctionSummaryMap("fread",
+                          Signature(ArgTypes{VoidPtrRestrictTy, SizeTyCanonTy,
+                                             SizeTyCanonTy, FilePtrRestrictTy},
+                                    RetType{SizeTyCanonTy}),
+                          FreadSummary);
   // size_t fwrite(const void *restrict ptr, size_t size, size_t nitems,
   //               FILE *restrict stream);
-  addToFunctionSummaryMap("fwrite",
-                          Signature(ArgTypes{ConstVoidPtrRestrictTy, SizeTy,
-                                             SizeTy, FilePtrRestrictTy},
-                                    RetType{SizeTy}),
-                          FreadSummary);
+  addToFunctionSummaryMap(
+      "fwrite",
+      Signature(ArgTypes{ConstVoidPtrRestrictTy, SizeTyCanonTy, SizeTyCanonTy,
+                         FilePtrRestrictTy},
+                RetType{SizeTyCanonTy}),
+      FreadSummary);
 
   std::optional<QualType> Ssize_tTy = lookupTy("ssize_t");
   std::optional<RangeInt> Ssize_tMax = getMaxValue(Ssize_tTy);
@@ -2083,12 +2084,14 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
   // should handle them together with the rest of the POSIX functions.
   // ssize_t read(int fildes, void *buf, size_t nbyte);
   addToFunctionSummaryMap(
-      "read", Signature(ArgTypes{IntTy, VoidPtrTy, SizeTy}, RetType{Ssize_tTy}),
+      "read",
+      Signature(ArgTypes{IntTy, VoidPtrTy, SizeTyCanonTy}, RetType{Ssize_tTy}),
       ReadSummary);
   // ssize_t write(int fildes, const void *buf, size_t nbyte);
   addToFunctionSummaryMap(
       "write",
-      Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTy}, RetType{Ssize_tTy}),
+      Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTyCanonTy},
+                RetType{Ssize_tTy}),
       ReadSummary);
 
   auto GetLineSummary =
@@ -2618,7 +2621,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     // char *strndup(const char *s, size_t n);
     addToFunctionSummaryMap(
         "strndup",
-        Signature(ArgTypes{ConstCharPtrTy, SizeTy}, RetType{CharPtrTy}),
+        Signature(ArgTypes{ConstCharPtrTy, SizeTyCanonTy}, RetType{CharPtrTy}),
         Summary(NoEvalCall)
             .ArgConstraint(NotNull(ArgNo(0)))
             .ArgConstraint(
@@ -2649,7 +2652,8 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
 
     // char *getcwd(char *buf, size_t size);
     addToFunctionSummaryMap(
-        "getcwd", Signature(ArgTypes{CharPtrTy, SizeTy}, RetType{CharPtrTy}),
+        "getcwd",
+        Signature(ArgTypes{CharPtrTy, SizeTyCanonTy}, RetType{CharPtrTy}),
         Summary(NoEvalCall)
             .Case({NotNull(0),
                    ArgumentCondition(1, WithinRange, Range(1, SizeMax)),
@@ -2957,8 +2961,9 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     // FIXME: Improve for errno modeling.
     addToFunctionSummaryMap(
         "mmap",
-        Signature(ArgTypes{VoidPtrTy, SizeTy, IntTy, IntTy, IntTy, Off_tTy},
-                  RetType{VoidPtrTy}),
+        Signature(
+            ArgTypes{VoidPtrTy, SizeTyCanonTy, IntTy, IntTy, IntTy, Off_tTy},
+            RetType{VoidPtrTy}),
         Summary(NoEvalCall)
             .ArgConstraint(ArgumentCondition(1, WithinRange, Range(1, SizeMax)))
             .ArgConstraint(
@@ -2970,8 +2975,9 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     // FIXME: Improve for errno modeling.
     addToFunctionSummaryMap(
         "mmap64",
-        Signature(ArgTypes{VoidPtrTy, SizeTy, IntTy, IntTy, IntTy, Off64_tTy},
-                  RetType{VoidPtrTy}),
+        Signature(
+            ArgTypes{VoidPtrTy, SizeTyCanonTy, IntTy, IntTy, IntTy, Off64_tTy},
+            RetType{VoidPtrTy}),
         Summary(NoEvalCall)
             .ArgConstraint(ArgumentCondition(1, WithinRange, Range(1, SizeMax)))
             .ArgConstraint(
@@ -3002,8 +3008,9 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     //                  size_t bufsize);
     addToFunctionSummaryMap(
         "readlink",
-        Signature(ArgTypes{ConstCharPtrRestrictTy, CharPtrRestrictTy, SizeTy},
-                  RetType{Ssize_tTy}),
+        Signature(
+            ArgTypes{ConstCharPtrRestrictTy, CharPtrRestrictTy, SizeTyCanonTy},
+            RetType{Ssize_tTy}),
         Summary(NoEvalCall)
             .Case({ArgumentCondition(2, WithinRange, Range(1, IntMax)),
                    ReturnValueCondition(LessThanOrEq, ArgNo(2)),
@@ -3025,9 +3032,9 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     //                    char *restrict buf, size_t bufsize);
     addToFunctionSummaryMap(
         "readlinkat",
-        Signature(
-            ArgTypes{IntTy, ConstCharPtrRestrictTy, CharPtrRestrictTy, SizeTy},
-            RetType{Ssize_tTy}),
+        Signature(ArgTypes{IntTy, ConstCharPtrRestrictTy, CharPtrRestrictTy,
+                           SizeTyCanonTy},
+                  RetType{Ssize_tTy}),
         Summary(NoEvalCall)
             .Case({ArgumentCondition(3, WithinRange, Range(1, IntMax)),
                    ReturnValueCondition(LessThanOrEq, ArgNo(3)),
@@ -3268,14 +3275,14 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
             //                  size_t length,
             //                  int flags, struct sockaddr *restrict address,
             //                  socklen_t *restrict address_len);
-            Signature(ArgTypes{IntTy, VoidPtrRestrictTy, SizeTy, IntTy,
+            Signature(ArgTypes{IntTy, VoidPtrRestrictTy, SizeTyCanonTy, IntTy,
                                StructSockaddrPtrRestrictTy,
                                Socklen_tPtrRestrictTy},
                       RetType{Ssize_tTy}),
             Recvfrom))
       addToFunctionSummaryMap(
           "recvfrom",
-          Signature(ArgTypes{IntTy, VoidPtrRestrictTy, SizeTy, IntTy,
+          Signature(ArgTypes{IntTy, VoidPtrRestrictTy, SizeTyCanonTy, IntTy,
                              Irrelevant, Socklen_tPtrRestrictTy},
                     RetType{Ssize_tTy}),
           Recvfrom);
@@ -3297,14 +3304,14 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
             // ssize_t sendto(int socket, const void *message, size_t length,
             //                int flags, const struct sockaddr *dest_addr,
             //                socklen_t dest_len);
-            Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTy, IntTy,
+            Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTyCanonTy, IntTy,
                                ConstStructSockaddrPtrTy, Socklen_tTy},
                       RetType{Ssize_tTy}),
             Sendto))
       addToFunctionSummaryMap(
           "sendto",
-          Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTy, IntTy, Irrelevant,
-                             Socklen_tTy},
+          Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTyCanonTy, IntTy,
+                             Irrelevant, Socklen_tTy},
                     RetType{Ssize_tTy}),
           Sendto);
 
@@ -3320,7 +3327,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     // ssize_t recv(int sockfd, void *buf, size_t len, int flags);
     addToFunctionSummaryMap(
         "recv",
-        Signature(ArgTypes{IntTy, VoidPtrTy, SizeTy, IntTy},
+        Signature(ArgTypes{IntTy, VoidPtrTy, SizeTyCanonTy, IntTy},
                   RetType{Ssize_tTy}),
         Summary(NoEvalCall)
             .Case({ReturnValueCondition(LessThanOrEq, ArgNo(2)),
@@ -3395,7 +3402,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     // ssize_t send(int sockfd, const void *buf, size_t len, int flags);
     addToFunctionSummaryMap(
         "send",
-        Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTy, IntTy},
+        Signature(ArgTypes{IntTy, ConstVoidPtrTy, SizeTyCanonTy, IntTy},
                   RetType{Ssize_tTy}),
         Summary(NoEvalCall)
             .Case({ReturnValueCondition(LessThanOrEq, ArgNo(2)),
@@ -3683,7 +3690,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     // int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize);
     addToFunctionSummaryMap(
         {"pthread_attr_setstacksize", "pthread_attr_setguardsize"},
-        Signature(ArgTypes{Pthread_attr_tPtrTy, SizeTy}, RetType{IntTy}),
+        Signature(ArgTypes{Pthread_attr_tPtrTy, SizeTyCanonTy}, RetType{IntTy}),
         Summary(NoEvalCall)
             .ArgConstraint(NotNull(ArgNo(0)))
             .ArgConstraint(
@@ -3888,13 +3895,14 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
             .ArgConstraint(NotNull(ArgNo(1))));
     addToFunctionSummaryMap(
         "__buf_size_arg_constraint",
-        Signature(ArgTypes{ConstVoidPtrTy, SizeTy}, RetType{IntTy}),
+        Signature(ArgTypes{ConstVoidPtrTy, SizeTyCanonTy}, RetType{IntTy}),
         Summary(EvalCallAsPure)
             .ArgConstraint(
                 BufferSize(/*Buffer=*/ArgNo(0), /*BufSize=*/ArgNo(1))));
     addToFunctionSummaryMap(
         "__buf_size_arg_constraint_mul",
-        Signature(ArgTypes{ConstVoidPtrTy, SizeTy, SizeTy}, RetType{IntTy}),
+        Signature(ArgTypes{ConstVoidPtrTy, SizeTyCanonTy, SizeTyCanonTy},
+                  RetType{IntTy}),
         Summary(EvalCallAsPure)
             .ArgConstraint(BufferSize(/*Buffer=*/ArgNo(0), /*BufSize=*/ArgNo(1),
                                       /*BufSizeMultiplier=*/ArgNo(2))));