BuildLibCalls: also set allocsize() attributes

[durin42]

Summary

This is part of being able to get rid of two more columns in
MemoryBuiltins.cpp's large table. We'll have two more changes before
we can finish the job.

[nikic]

llvm/lib/Transforms/Utils/BuildLibCalls.cpp

234

Remove braces for single-line if.

375

This is incorrect: allocsize is a lower bound on the allocation size, while the strndup argument is an upper bound. strndup may allocate less if it encounters a null byte earlier.

[durin42]

good catch on strndup, fixed

[nikic]

I'm missing the test update for calloc here.

[durin42]

In D119582#3435597, @nikic wrote:

I'm missing the test update for calloc here.

Whoops, fixed.

[nikic]

LGTM

llvm/lib/Transforms/Utils/BuildLibCalls.cpp

 
 static bool setAlignedAllocParam(Function &F, unsigned ArgNo) {
   if (F.hasParamAttribute(ArgNo, Attribute::AllocAlign))
     return false;
   F.addParamAttr(ArgNo, Attribute::AllocAlign);
   return true;
 }
 
+static bool setAllocSize(Function &F, unsigned ElemSizeArg,
+                         Optional<unsigned> NumElemsArg) {
+  if (F.hasFnAttribute(Attribute::AllocSize)) {
+    return false;
+  }
+  F.addFnAttr(Attribute::getWithAllocSizeArgs(F.getContext(), ElemSizeArg,
+                                              NumElemsArg));
+  return true;
+}
+
 bool llvm::inferLibFuncAttributes(Module *M, StringRef Name,
                                   const TargetLibraryInfo &TLI) {
   Function *F = M->getFunction(Name);
   if (!F)
     return false;
   return inferLibFuncAttributes(*F, TLI);
 }
 
case LibFunc_scanf:
     return Changed;
   case LibFunc_setbuf:
   case LibFunc_setvbuf:
     Changed |= setRetAndArgsNoUndef(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
     return Changed;
   case LibFunc_strndup:
+    Changed |= setAllocSize(F, 1, None);
     Changed |= setArgNoUndef(F, 1);
     LLVM_FALLTHROUGH;
   case LibFunc_strdup:
     Changed |= setOnlyAccessesInaccessibleMemOrArgMem(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setRetDoesNotAlias(F);
     Changed |= setWillReturn(F);
     Changed |= setDoesNotCapture(F, 0);
bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
   case LibFunc_system:
     // May throw; "system" is a valid pthread cancellation point.
     Changed |= setRetAndArgsNoUndef(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setOnlyReadsMemory(F, 0);
     return Changed;
   case LibFunc_aligned_alloc:
     Changed |= setAlignedAllocParam(F, 0);
+    Changed |= setAllocSize(F, 1, None);
     LLVM_FALLTHROUGH;
   case LibFunc_valloc:
   case LibFunc_malloc:
   case LibFunc_vec_malloc:
+    Changed |= setAllocSize(F, 0, None);
     Changed |= setOnlyAccessesInaccessibleMemory(F);
     Changed |= setRetAndArgsNoUndef(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setRetDoesNotAlias(F);
     Changed |= setWillReturn(F);
     return Changed;
   case LibFunc_memcmp:
     Changed |= setOnlyAccessesArgMemory(F);
case LibFunc_memcpy_chk:
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotAlias(F, 0);
     Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotAlias(F, 1);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
   case LibFunc_memalign:
+    Changed |= setAllocSize(F, 1, None);
     Changed |= setAlignedAllocParam(F, 0);
     Changed |= setOnlyAccessesInaccessibleMemory(F);
     Changed |= setRetNoUndef(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setRetDoesNotAlias(F);
     Changed |= setWillReturn(F);
     return Changed;
   case LibFunc_mkdir:
     Changed |= setRetAndArgsNoUndef(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setOnlyReadsMemory(F, 0);
     return Changed;
   case LibFunc_mktime:
     Changed |= setRetAndArgsNoUndef(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setWillReturn(F);
     Changed |= setDoesNotCapture(F, 0);
     return Changed;
   case LibFunc_realloc:
   case LibFunc_vec_realloc:
   case LibFunc_reallocf:
+    Changed |= setAllocSize(F, 1, None);
     Changed |= setOnlyAccessesInaccessibleMemOrArgMem(F);
     Changed |= setRetNoUndef(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setRetDoesNotAlias(F);
     Changed |= setWillReturn(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setArgNoUndef(F, 1);
     return Changed;
case LibFunc_bzero:
     Changed |= setDoesNotThrow(F);
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setWillReturn(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setOnlyWritesMemory(F, 0);
     return Changed;
   case LibFunc_calloc:
   case LibFunc_vec_calloc:
+    Changed |= setAllocSize(F, 0, 1);
     Changed |= setOnlyAccessesInaccessibleMemory(F);
     Changed |= setRetAndArgsNoUndef(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setRetDoesNotAlias(F);
     Changed |= setWillReturn(F);
     return Changed;
   case LibFunc_chmod:
   case LibFunc_chown:

llvm/test/Transforms/InferFunctionAttrs/annotate.ll

 declare x86_fp80 @logl(x86_fp80)
 
 ; CHECK: declare noundef i32 @lstat(i8* nocapture noundef readonly, %opaque* nocapture noundef) [[NOFREE_NOUNWIND]]
 declare i32 @lstat(i8*, %opaque*)
 
 ; CHECK-LINUX: declare noundef i32 @lstat64(i8* nocapture noundef readonly, %opaque* nocapture noundef) [[NOFREE_NOUNWIND]]
 declare i32 @lstat64(i8*, %opaque*)
 
-; CHECK: declare noalias noundef i8* @malloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
+; CHECK: declare noalias noundef i8* @malloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE:#[0-9]+]]
 declare i8* @malloc(i64)
 
 ; CHECK-LINUX: declare noalias noundef i8* @memalign(i64 allocalign, i64) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
 declare i8* @memalign(i64, i64)
 
 ; CHECK: declare i8* @memccpy(i8* noalias writeonly, i8* noalias nocapture readonly, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare i8* @memccpy(i8*, i8*, i32, i64)
 

 declare void @qsort(i8*, i64, i64, i32 (i8*, i8*)*)
 
 ; CHECK: declare noundef i64 @read(i32 noundef, i8* nocapture noundef, i64 noundef) [[NOFREE]]
 declare i64 @read(i32, i8*, i64)
 
 ; CHECK: declare noundef i64 @readlink(i8* nocapture noundef readonly, i8* nocapture noundef, i64 noundef) [[NOFREE_NOUNWIND]]
 declare i64 @readlink(i8*, i8*, i64)
 
-; CHECK: declare noalias noundef i8* @realloc(i8* nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN]]
+; CHECK: declare noalias noundef i8* @realloc(i8* nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCSIZE:#[0-9]+]]
 declare i8* @realloc(i8*, i64)
 
-; CHECK: declare noalias noundef i8* @reallocf(i8* nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN]]
+; CHECK: declare noalias noundef i8* @reallocf(i8* nocapture, i64 noundef) [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCSIZE]]
 declare i8* @reallocf(i8*, i64)
 
 ; CHECK: declare noundef i8* @realpath(i8* nocapture noundef readonly, i8* noundef) [[NOFREE_NOUNWIND]]
 declare i8* @realpath(i8*, i8*)
 
 ; CHECK: declare noundef i32 @remove(i8* nocapture noundef readonly) [[NOFREE_NOUNWIND]]
 declare i32 @remove(i8*)
 

 declare i8* @strncat(i8*, i8*, i64)
 
 ; CHECK: declare i32 @strncmp(i8* nocapture, i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i32 @strncmp(i8*, i8*, i64)
 
 ; CHECK: declare i8* @strncpy(i8* noalias returned writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare i8* @strncpy(i8*, i8*, i64)
 
-; CHECK: declare noalias i8* @strndup(i8* nocapture readonly, i64 noundef) [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN]]
+; CHECK: declare noalias i8* @strndup(i8* nocapture readonly, i64 noundef) [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE:#[0-9]+]]
 declare i8* @strndup(i8*, i64)
 
 ; CHECK: declare i64 @strnlen(i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN:#[0-9]+]]
 declare i64 @strnlen(i8*, i64)
 
 ; CHECK: declare i8* @strpbrk(i8*, i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN]]
 declare i8* @strpbrk(i8*, i8*)
 

 declare i32 @unsetenv(i8*)
 
 ; CHECK: declare noundef i32 @utime(i8* nocapture noundef readonly, %opaque* nocapture noundef readonly) [[NOFREE_NOUNWIND]]
 declare i32 @utime(i8*, %opaque*)
 
 ; CHECK: declare noundef i32 @utimes(i8* nocapture noundef readonly, %opaque* nocapture noundef readonly) [[NOFREE_NOUNWIND]]
 declare i32 @utimes(i8*, %opaque*)
 
-; CHECK: declare noalias noundef i8* @valloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
+; CHECK: declare noalias noundef i8* @valloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE]]
 declare i8* @valloc(i64)
 
 ; CHECK: declare noundef i32 @vfprintf(%opaque* nocapture noundef, i8* nocapture noundef readonly, %opaque* noundef) [[NOFREE_NOUNWIND]]
 declare i32 @vfprintf(%opaque*, i8*, %opaque*)
 
 ; CHECK: declare noundef i32 @vfscanf(%opaque* nocapture noundef, i8* nocapture noundef readonly, %opaque* noundef) [[NOFREE_NOUNWIND]]
 declare i32 @vfscanf(%opaque*, i8*, %opaque*)
 

 ; memset_pattern{4,8,16} aren't available everywhere.
 ; CHECK-DARWIN: declare void @memset_pattern4(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare void @memset_pattern4(i8*, i8*, i64)
 ; CHECK-DARWIN: declare void @memset_pattern8(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare void @memset_pattern8(i8*, i8*, i64)
 ; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare void @memset_pattern16(i8*, i8*, i64)
 
-
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_WILLRETURN]] = { mustprogress nofree nounwind willreturn }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_WILLRETURN_WRITEONLY]] = { mustprogress nofree nounwind willreturn writeonly }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND]] = { nofree nounwind }
-; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN]] = { inaccessiblememonly mustprogress nofree nounwind willreturn }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE]] = { inaccessiblememonly mustprogress nofree nounwind willreturn allocsize(0) }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_READONLY_WILLRETURN]] = { mustprogress nofree nounwind readonly willreturn }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]] = { argmemonly mustprogress nofree nounwind willreturn }
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_READONLY]] = { nofree nounwind readonly }
 ; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCSIZE]] = { inaccessiblemem_or_argmemonly mustprogress nounwind willreturn allocsize(1) }
 ; CHECK-DAG: attributes [[NOFREE_WILLRETURN]] = { mustprogress nofree willreturn }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN]] = { argmemonly mustprogress nofree nounwind readonly willreturn }
 ; CHECK-DAG: attributes [[NOFREE]] = { nofree }
 ; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN]]  = { inaccessiblemem_or_argmemonly mustprogress nofree nounwind willreturn }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCSIZE]]  = { inaccessiblemem_or_argmemonly mustprogress nofree nounwind willreturn allocsize(1) }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND]] = { argmemonly nofree nounwind }
 
 ; CHECK-NVPTX-DAG: attributes [[NOFREE_NOUNWIND_READNONE]] = { nofree nosync nounwind readnone }