[libc] Make more of the libc unit testing llvm independent

(WIP, hopefully I'll add more to this patch before submitting)

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D91665

libc/utils/UnitTest/CMakeLists.txt

@@ -2,7 +2,6 @@ add_llvm_library(
   LibcUnitTest
   Test.cpp
   Test.h
-  LINK_COMPONENTS Support
 )
 target_include_directories(LibcUnitTest PUBLIC ${LIBC_SOURCE_DIR})
 add_dependencies(LibcUnitTest libc.utils.CPP.standalone_cpp)

libc/utils/testutils/CMakeLists.txt

@@ -11,6 +11,4 @@ add_llvm_library(
   ExecuteFunction.h
   ${FDReaderFile}
   FDReader.h
-  LINK_COMPONENTS
-    Support
 )

libc/utils/testutils/ExecuteFunctionUnix.cpp

@@ -7,9 +7,10 @@
 //===----------------------------------------------------------------------===//
 
 #include "ExecuteFunction.h"
-#include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <cstdlib>
+#include <cstring>
+#include <iostream>
 #include <memory>
 #include <poll.h>
 #include <signal.h>
@@ -41,8 +42,8 @@ ProcessStatus invokeInSubprocess(FunctionCaller *Func, unsigned timeoutMS) {
     return ProcessStatus::Error("pipe(2) failed");
 
   // Don't copy the buffers into the child process and print twice.
-  llvm::outs().flush();
-  llvm::errs().flush();
+  std::cout.flush();
+  std::cerr.flush();
   pid_t Pid = ::fork();
   if (Pid == -1)
     return ProcessStatus::Error("fork(2) failed");

libc/utils/testutils/FDReaderUnix.cpp

@@ -7,17 +7,19 @@
 //===----------------------------------------------------------------------===//
 
 #include "FDReader.h"
-#include "llvm/Support/MemoryBuffer.h"
 #include <cassert>
 #include <cstring>
+#include <iostream>
 #include <unistd.h>
 
 namespace __llvm_libc {
 namespace testutils {
 
 FDReader::FDReader() {
-  if (::pipe(pipefd))
-    llvm::report_fatal_error("pipe(2) failed");
+  if (::pipe(pipefd)) {
+    std::cerr << "pipe(2) failed";
+    abort();
+  }
 }
 
 FDReader::~FDReader() {
@@ -26,15 +28,25 @@ FDReader::~FDReader() {
 }
 
 bool FDReader::matchWritten(const char *str) {
-  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> bufOrErr =
-      llvm::MemoryBuffer::getOpenFile(pipefd[0], "<pipe>",
-                                      /* FileSize (irrelevant) */ 0);
-  if (!bufOrErr) {
-    assert(0 && "Error reading from pipe");
-    return false;
+
+  ::close(pipefd[1]);
+
+  constexpr ssize_t ChunkSize = 4096 * 4;
+
+  char Buffer[ChunkSize];
+  std::string PipeStr;
+  std::string InputStr(str);
+
+  for (int BytesRead; (BytesRead = ::read(pipefd[0], Buffer, ChunkSize));) {
+    if (BytesRead > 0) {
+      PipeStr.insert(PipeStr.size(), Buffer, BytesRead);
+    } else {
+      assert(0 && "Error reading from pipe");
+      return false;
+    }
   }
-  const llvm::MemoryBuffer &buf = **bufOrErr;
-  return !std::strncmp(buf.getBufferStart(), str, buf.getBufferSize());
+
+  return PipeStr == InputStr;
 }
 
 } // namespace testutils

libc/utils/testutils/StreamWrapper.cpp

@@ -7,19 +7,19 @@
 //===----------------------------------------------------------------------===//
 
 #include "StreamWrapper.h"
-#include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <iostream>
 #include <memory>
 #include <string>
 
 namespace __llvm_libc {
 namespace testutils {
 
-StreamWrapper outs() { return {std::addressof(llvm::outs())}; }
+StreamWrapper outs() { return {std::addressof(std::cout)}; }
 
 template <typename T> StreamWrapper &StreamWrapper::operator<<(T t) {
   assert(OS);
-  llvm::raw_ostream &Stream = *reinterpret_cast<llvm::raw_ostream *>(OS);
+  std::ostream &Stream = *reinterpret_cast<std::ostream *>(OS);
   Stream << t;
   return *this;
 }