Remove FileSpec::ReadFileContents.

This functionality is subsumed by DataBufferLLVM, which is
also more efficient since it will try to mmap.  However, we
don't yet support mmaping writable private sections, and in
some cases we were using ReadFileContents and then modifying
the buffer.  To address that I've added a flag to the
DataBufferLLVM methods that allow you to map privately, which
disables the mmaping path entirely.  Eventually we should teach
DataBufferLLVM to use mmap with writable private, but that is
orthogonal to this effort.

Differential Revision: https://reviews.llvm.org/D30622

llvm-svn: 297095

9 files changed, 47 insertions, 34 deletions

diff --git a/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp b/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp
index d1f1a3bb12b..a4bd1c99855 100644
--- a/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp
@@ -39,6 +39,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/Thread.h"
 #include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Error.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/RegularExpression.h"
@@ -2536,7 +2537,7 @@ bool RenderScriptRuntime::LoadAllocation(Stream &strm, const uint32_t alloc_id,
   }
 
   // Read file into data buffer
-  DataBufferSP data_sp(file.ReadFileContents());
+  auto data_sp = DataBufferLLVM::CreateFromPath(file.GetPath());
 
   // Cast start of buffer to FileHeader and use pointer to read metadata
   void *file_buf = data_sp->GetBytes();
@@ -3074,7 +3075,7 @@ bool RSModuleDescriptor::ParseRSInfo() {
   const addr_t size = info_sym->GetByteSize();
   const FileSpec fs = m_module->GetFileSpec();
 
-  const DataBufferSP buffer = fs.ReadFileContents(addr, size);
+  auto buffer = DataBufferLLVM::CreateSliceFromPath(fs.GetPath(), size, addr);
   if (!buffer)
     return false;
 
diff --git a/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp b/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
index 2113876e6c1..b74da330017 100644
--- a/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
+++ b/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
@@ -314,7 +314,7 @@ ObjectContainer *ObjectContainerBSDArchive::CreateInstance(
       // file gets updated by a new build while this .a file is being used for
       // debugging
       DataBufferSP archive_data_sp =
-          DataBufferLLVM::CreateFromPath(file->GetPath(), length, file_offset);
+          DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
       if (!archive_data_sp)
         return nullptr;
 
@@ -469,7 +469,7 @@ size_t ObjectContainerBSDArchive::GetModuleSpecifications(
   if (!archive_sp) {
     set_archive_arch = true;
     data_sp =
-        DataBufferLLVM::CreateFromPath(file.GetPath(), file_size, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file.GetPath(), file_size, file_offset);
     if (data_sp) {
       data.SetData(data_sp, 0, data_sp->GetByteSize());
       archive_sp = Archive::ParseAndCacheArchiveForFile(
diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 8a4734bd337..10213f572b8 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -388,7 +388,7 @@ ObjectFile *ObjectFileELF::CreateInstance(const lldb::ModuleSP &module_sp,
                                           lldb::offset_t length) {
   if (!data_sp) {
     data_sp =
-        DataBufferLLVM::CreateFromPath(file->GetPath(), length, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -406,7 +406,7 @@ ObjectFile *ObjectFileELF::CreateInstance(const lldb::ModuleSP &module_sp,
   // Update the data to contain the entire file if it doesn't already
   if (data_sp->GetByteSize() < length) {
     data_sp =
-        DataBufferLLVM::CreateFromPath(file->GetPath(), length, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -665,7 +665,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
           size_t section_header_end = header.e_shoff + header.e_shentsize;
           if (header.HasHeaderExtension() &&
             section_header_end > data_sp->GetByteSize()) {
-            data_sp = DataBufferLLVM::CreateFromPath(
+            data_sp = DataBufferLLVM::CreateSliceFromPath(
                 file.GetPath(), section_header_end, file_offset);
             if (data_sp) {
               data.SetData(data_sp);
@@ -679,7 +679,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
           section_header_end =
               header.e_shoff + header.e_shnum * header.e_shentsize;
           if (section_header_end > data_sp->GetByteSize()) {
-            data_sp = DataBufferLLVM::CreateFromPath(
+            data_sp = DataBufferLLVM::CreateSliceFromPath(
                 file.GetPath(), section_header_end, file_offset);
             if (data_sp)
               data.SetData(data_sp);
@@ -724,7 +724,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
                 size_t program_headers_end =
                     header.e_phoff + header.e_phnum * header.e_phentsize;
                 if (program_headers_end > data_sp->GetByteSize()) {
-                  data_sp = DataBufferLLVM::CreateFromPath(
+                  data_sp = DataBufferLLVM::CreateSliceFromPath(
                       file.GetPath(), program_headers_end, file_offset);
                   if (data_sp)
                     data.SetData(data_sp);
@@ -740,7 +740,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
                 }
 
                 if (segment_data_end > data_sp->GetByteSize()) {
-                  data_sp = DataBufferLLVM::CreateFromPath(
+                  data_sp = DataBufferLLVM::CreateSliceFromPath(
                       file.GetPath(), segment_data_end, file_offset);
                   if (data_sp)
                     data.SetData(data_sp);
@@ -750,7 +750,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
                     CalculateELFNotesSegmentsCRC32(program_headers, data);
               } else {
                 // Need to map entire file into memory to calculate the crc.
-                data_sp = DataBufferLLVM::CreateFromPath(file.GetPath(), -1,
+                data_sp = DataBufferLLVM::CreateSliceFromPath(file.GetPath(), -1,
                                                          file_offset);
                 if (data_sp) {
                   data.SetData(data_sp);
diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index 5901a1b4935..a6d5a85e2d4 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -860,7 +860,7 @@ ObjectFile *ObjectFileMachO::CreateInstance(const lldb::ModuleSP &module_sp,
                                             lldb::offset_t length) {
   if (!data_sp) {
     data_sp =
-        DataBufferLLVM::CreateFromPath(file->GetPath(), length, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -872,7 +872,7 @@ ObjectFile *ObjectFileMachO::CreateInstance(const lldb::ModuleSP &module_sp,
   // Update the data to contain the entire file if it doesn't already
   if (data_sp->GetByteSize() < length) {
     data_sp =
-        DataBufferLLVM::CreateFromPath(file->GetPath(), length, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -911,7 +911,8 @@ size_t ObjectFileMachO::GetModuleSpecifications(
       size_t header_and_load_cmds =
           header.sizeofcmds + MachHeaderSizeFromMagic(header.magic);
       if (header_and_load_cmds >= data_sp->GetByteSize()) {
-        data_sp = file.ReadFileContents(file_offset, header_and_load_cmds);
+        data_sp = DataBufferLLVM::CreateSliceFromPath(
+            file.GetPath(), header_and_load_cmds, file_offset);
         data.SetData(data_sp);
         data_offset = MachHeaderSizeFromMagic(header.magic);
       }
@@ -1123,8 +1124,8 @@ bool ObjectFileMachO::ParseHeader() {
                   ReadMemory(process_sp, m_memory_addr, header_and_lc_size);
             } else {
               // Read in all only the load command data from the file on disk
-              data_sp =
-                  m_file.ReadFileContents(m_file_offset, header_and_lc_size);
+              data_sp = DataBufferLLVM::CreateSliceFromPath(
+                  m_file.GetPath(), header_and_lc_size, m_file_offset);
               if (data_sp->GetByteSize() != header_and_lc_size)
                 return false;
             }
@@ -2095,7 +2096,7 @@ UUID ObjectFileMachO::GetSharedCacheUUID(FileSpec dyld_shared_cache,
                                          const ByteOrder byte_order,
                                          const uint32_t addr_byte_size) {
   UUID dsc_uuid;
-  DataBufferSP DscData = DataBufferLLVM::CreateFromPath(
+  DataBufferSP DscData = DataBufferLLVM::CreateSliceFromPath(
       dyld_shared_cache.GetPath(),
       sizeof(struct lldb_copy_dyld_cache_header_v1), 0);
   if (!DscData)
@@ -2703,7 +2704,7 @@ size_t ObjectFileMachO::ParseSymtab() {
 
       // Process the dyld shared cache header to find the unmapped symbols
 
-      DataBufferSP dsc_data_sp = DataBufferLLVM::CreateFromPath(
+      DataBufferSP dsc_data_sp = DataBufferLLVM::CreateSliceFromPath(
           dsc_filespec.GetPath(), sizeof(struct lldb_copy_dyld_cache_header_v1),
           0);
       if (!dsc_uuid.IsValid()) {
@@ -2738,7 +2739,7 @@ size_t ObjectFileMachO::ParseSymtab() {
             mappingOffset >= sizeof(struct lldb_copy_dyld_cache_header_v1)) {
 
           DataBufferSP dsc_mapping_info_data_sp =
-              DataBufferLLVM::CreateFromPath(
+              DataBufferLLVM::CreateSliceFromPath(
                   dsc_filespec.GetPath(),
                   sizeof(struct lldb_copy_dyld_cache_mapping_info),
                   mappingOffset);
@@ -2765,7 +2766,7 @@ size_t ObjectFileMachO::ParseSymtab() {
           if (localSymbolsOffset && localSymbolsSize) {
             // Map the local symbols
             DataBufferSP dsc_local_symbols_data_sp =
-                DataBufferLLVM::CreateFromPath(dsc_filespec.GetPath(),
+                DataBufferLLVM::CreateSliceFromPath(dsc_filespec.GetPath(),
                                                localSymbolsSize,
                                                localSymbolsOffset);
 
diff --git a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
index b9577b5d1f2..df665129ae2 100644
--- a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
+++ b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
@@ -68,7 +68,7 @@ ObjectFile *ObjectFilePECOFF::CreateInstance(const lldb::ModuleSP &module_sp,
                                              lldb::offset_t length) {
   if (!data_sp) {
     data_sp =
-        DataBufferLLVM::CreateFromPath(file->GetPath(), length, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -80,7 +80,7 @@ ObjectFile *ObjectFilePECOFF::CreateInstance(const lldb::ModuleSP &module_sp,
   // Update the data to contain the entire file if it doesn't already
   if (data_sp->GetByteSize() < length) {
     data_sp =
-        DataBufferLLVM::CreateFromPath(file->GetPath(), length, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
     if (!data_sp)
       return nullptr;
   }
@@ -430,7 +430,10 @@ bool ObjectFilePECOFF::ParseCOFFOptionalHeader(lldb::offset_t *offset_ptr) {
 
 DataExtractor ObjectFilePECOFF::ReadImageData(uint32_t offset, size_t size) {
   if (m_file) {
-    DataBufferSP buffer_sp(m_file.ReadFileContents(offset, size));
+    // A bit of a hack, but we intend to write to this buffer, so we can't 
+    // mmap it.
+    auto buffer_sp =
+        DataBufferLLVM::CreateSliceFromPath(m_file.GetPath(), size, offset, true);
     return DataExtractor(buffer_sp, GetByteOrder(), GetAddressByteSize());
   }
   ProcessSP process_sp(m_process_wp.lock());
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
index b1937efe553..75311078f74 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
@@ -37,6 +37,7 @@
 #include "lldb/Symbol/SymbolVendor.h"
 #include "lldb/Target/Process.h"
 #include "lldb/Target/Target.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Error.h"
 #include "lldb/Utility/Log.h"
 #include "llvm/ADT/STLExtras.h"
@@ -1154,13 +1155,16 @@ const char *PlatformDarwin::GetDeveloperDirectory() {
         xcode_dir_path.append(xcode_select_prefix_dir);
       xcode_dir_path.append("/usr/share/xcode-select/xcode_dir_path");
       temp_file_spec.SetFile(xcode_dir_path, false);
-      size_t bytes_read = temp_file_spec.ReadFileContents(
-          0, developer_dir_path, sizeof(developer_dir_path), NULL);
-      if (bytes_read > 0) {
-        developer_dir_path[bytes_read] = '\0';
-        while (developer_dir_path[bytes_read - 1] == '\r' ||
-               developer_dir_path[bytes_read - 1] == '\n')
-          developer_dir_path[--bytes_read] = '\0';
+      auto dir_buffer =
+          DataBufferLLVM::CreateFromPath(temp_file_spec.GetPath(), true);
+      if (dir_buffer && dir_buffer->GetByteSize() > 0) {
+        llvm::StringRef path_ref(dir_buffer->GetChars());
+        // Trim tailing newlines and make sure there is enough room for a null
+        // terminator.
+        path_ref =
+            path_ref.rtrim("\r\n").take_front(sizeof(developer_dir_path) - 1);
+        ::memcpy(developer_dir_path, path_ref.data(), path_ref.size());
+        developer_dir_path[path_ref.size()] = '\0';
         developer_dir_path_valid = true;
       }
     }
diff --git a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
index adb199ef166..99c1b7d3733 100644
--- a/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
+++ b/lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
@@ -24,6 +24,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/UnixSignals.h"
 #include "lldb/Utility/DataBufferHeap.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 
 #include "llvm/Support/ELF.h"
@@ -61,7 +62,8 @@ lldb::ProcessSP ProcessElfCore::CreateInstance(lldb::TargetSP target_sp,
     // to ignore possible presence of the header extension.
     const size_t header_size = sizeof(llvm::ELF::Elf64_Ehdr);
 
-    lldb::DataBufferSP data_sp(crash_file->ReadFileContents(0, header_size));
+    auto data_sp =
+        DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), header_size, 0);
     if (data_sp && data_sp->GetByteSize() == header_size &&
         elf::ELFHeader::MagicBytesMatch(data_sp->GetBytes())) {
       elf::ELFHeader elf_header;
diff --git a/lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp b/lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp
index 9941c632f3a..665fcd169b0 100644
--- a/lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp
+++ b/lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp
@@ -30,6 +30,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/Thread.h"
 #include "lldb/Utility/DataBuffer.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 
 // Project includes
@@ -66,7 +67,8 @@ lldb::ProcessSP ProcessMachCore::CreateInstance(lldb::TargetSP target_sp,
   lldb::ProcessSP process_sp;
   if (crash_file) {
     const size_t header_size = sizeof(llvm::MachO::mach_header);
-    lldb::DataBufferSP data_sp(crash_file->ReadFileContents(0, header_size));
+    auto data_sp =
+        DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), header_size, 0);
     if (data_sp && data_sp->GetByteSize() == header_size) {
       DataExtractor data(data_sp, lldb::eByteOrderLittle, 4);
 
diff --git a/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp b/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
index 352e33b1f36..f3f4664ad6e 100644
--- a/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
+++ b/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
@@ -53,7 +53,7 @@ lldb::ProcessSP ProcessMinidump::CreateInstance(lldb::TargetSP target_sp,
   // Read enough data for the Minidump header
   constexpr size_t header_size = sizeof(MinidumpHeader);
   auto DataPtr =
-      DataBufferLLVM::CreateFromPath(crash_file->GetPath(), header_size, 0);
+      DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), header_size, 0);
   if (!DataPtr)
     return nullptr;
 
@@ -65,7 +65,7 @@ lldb::ProcessSP ProcessMinidump::CreateInstance(lldb::TargetSP target_sp,
   if (header == nullptr)
     return nullptr;
 
-  auto AllData = DataBufferLLVM::CreateFromPath(crash_file->GetPath(), -1, 0);
+  auto AllData = DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), -1, 0);
   if (!AllData)
     return nullptr;