[TLI] Add support for pvalloc() (#144949)

While pvalloc() is a legacy POSIX function, it remains widely available
in common C libraries like glibc.

Model pvalloc() in TargetLibraryInfo, allowing LLVM to correctly infer
its attributes.

Author: melver

llvm/include/llvm/Analysis/TargetLibraryInfo.def

@@ -2046,6 +2046,11 @@ TLI_DEFINE_ENUM_INTERNAL(puts)
 TLI_DEFINE_STRING_INTERNAL("puts")
 TLI_DEFINE_SIG_INTERNAL(Int, Ptr)
 
+/// void *pvalloc(size_t size);
+TLI_DEFINE_ENUM_INTERNAL(pvalloc)
+TLI_DEFINE_STRING_INTERNAL("pvalloc")
+TLI_DEFINE_SIG_INTERNAL(Ptr, SizeT)
+
 /// ssize_t pwrite(int fildes, const void *buf, size_t nbyte, off_t offset);
 TLI_DEFINE_ENUM_INTERNAL(pwrite)
 TLI_DEFINE_STRING_INTERNAL("pwrite")

llvm/lib/Analysis/TargetLibraryInfo.cpp

@@ -814,6 +814,7 @@ static void initializeLibCalls(TargetLibraryInfoImpl &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc_pclose);
     TLI.setUnavailable(LibFunc_popen);
     TLI.setUnavailable(LibFunc_pread);
+    TLI.setUnavailable(LibFunc_pvalloc);
     TLI.setUnavailable(LibFunc_pwrite);
     TLI.setUnavailable(LibFunc_read);
     TLI.setUnavailable(LibFunc_readlink);

llvm/lib/Transforms/Utils/BuildLibCalls.cpp

@@ -514,10 +514,12 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
   case LibFunc_valloc:
   case LibFunc_malloc:
   case LibFunc_vec_malloc:
+    Changed |= setAllocSize(F, 0, std::nullopt);
+    [[fallthrough]];
+  case LibFunc_pvalloc:
     Changed |= setAllocFamily(F, TheLibFunc == LibFunc_vec_malloc ? "vec_malloc"
                                                                   : "malloc");
     Changed |= setAllocKind(F, AllocFnKind::Alloc | AllocFnKind::Uninitialized);
-    Changed |= setAllocSize(F, 0, std::nullopt);
     Changed |= setOnlyAccessesInaccessibleMemory(F);
     Changed |= setRetAndArgsNoUndef(F);
     Changed |= setDoesNotThrow(F);

llvm/test/Transforms/InferFunctionAttrs/annotate.ll

@@ -812,6 +812,9 @@ declare i32 @putchar_unlocked(i32)
 ; CHECK: declare noundef i32 @puts(ptr noundef readonly captures(none)) [[NOFREE_NOUNWIND]]
 declare i32 @puts(ptr)
 
+; CHECK: declare noalias noundef ptr @pvalloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND_ALLOCUNINIT_FAMILY_MALLOC:#[0-9]+]]
+declare ptr @pvalloc(i64)
+
 ; CHECK: declare noundef i64 @pwrite(i32 noundef, ptr noundef readonly captures(none), i64 noundef, i64 noundef) [[NOFREE]]
 declare i64 @pwrite(i32, ptr, i64, i64)
 
@@ -1195,6 +1198,7 @@ declare void @memset_pattern16(ptr, ptr, i64)
 ; CHECK-DAG: attributes [[NOFREE_NOUNWIND_READONLY]] = { nofree nounwind memory(read) }
 ; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGMEMONLY_NOUNWIND_WILLRETURN_ALLOCKIND_FREE_FAMILY_MALLOC]] = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND_ALLOCUNINIT_ALLOCSIZE0_FAMILY_MALLOC]] = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" }
+; CHECK-DAG: attributes [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND_ALLOCUNINIT_FAMILY_MALLOC]] = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") memory(inaccessiblemem: readwrite) "alloc-family"="malloc" }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN]] = { mustprogress nocallback nofree nounwind willreturn memory(argmem: read) }
 ; CHECK-DAG: attributes [[NOFREE]] = { nofree }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND]] = { nocallback nofree nounwind memory(argmem: readwrite) }

llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml

@@ -54,10 +54,10 @@
 ## the exact count first; the two directives should add up to that.
 ## Yes, this means additions to TLI will fail this test, but the argument
 ## to -COUNT can't be an expression.
-# AVAIL: TLI knows 523 symbols, 289 available
+# AVAIL: TLI knows 524 symbols, 289 available
 # AVAIL-COUNT-289: {{^}} available
 # AVAIL-NOT:       {{^}} available
-# UNAVAIL-COUNT-234: not available
+# UNAVAIL-COUNT-235: not available
 # UNAVAIL-NOT:       not available
 
 ## This is a large file so it's worth telling lit to stop here.

llvm/unittests/Analysis/TargetLibraryInfoTest.cpp

@@ -315,6 +315,7 @@ TEST_F(TargetLibraryInfoTest, ValidProto) {
       "declare i32 @putchar(i32)\n"
       "declare i32 @putchar_unlocked(i32)\n"
       "declare i32 @puts(i8*)\n"
+      "declare i8* @pvalloc(i64)\n"
       "declare void @qsort(i8*, i64, i64, i32 (i8*, i8*)*)\n"
       "declare i64 @readlink(i8*, i8*, i64)\n"
       "declare i8* @realloc(i8*, i64)\n"