Initial checkin of the LLVM source-level debugger. This is still not finished,

by any stretch of the imagination, but it is pretty cool and works :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10685 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 116 insertions, 0 deletions

diff --git a/lib/Debugger/SourceFile.cpp b/lib/Debugger/SourceFile.cpp
new file mode 100644
index 0000000000..2eb3b5750b
--- /dev/null
+++ b/lib/Debugger/SourceFile.cpp
@@ -0,0 +1,116 @@
+//===-- SourceFile.cpp - SourceFile implementation for the debugger -------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+// 
+// This file implements the SourceFile class for the LLVM debugger.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Debugger/SourceFile.h"
+#include "Support/SlowOperationInformer.h"
+#include "Support/FileUtilities.h"
+#include <iostream>
+#include <cerrno>
+#include <fcntl.h>
+#include <unistd.h>
+using namespace llvm;
+
+/// readFile - Load Filename into FileStart and FileEnd.
+///
+void SourceFile::readFile() {
+  ssize_t FileSize = getFileSize(Filename);
+  if (FileSize != -1) {
+    FDHandle FD(open(Filename.c_str(), O_RDONLY));
+    if (FD != -1) {
+      char *FilePos = new char[FileSize];
+      FileStart = FilePos;
+
+      // If this takes a long time, inform the user what we are doing.
+      SlowOperationInformer SOI("loading source file '" + Filename + "'");
+
+      try {
+        // Read in the whole buffer.
+        unsigned Amount = FileSize;
+        while (Amount) {
+          unsigned AmountToRead = 512*1024;
+          if (Amount < AmountToRead) AmountToRead = Amount;
+          ssize_t ReadAmount = read(FD, FilePos, AmountToRead);
+          if (ReadAmount < 0 && errno == EINTR)
+            continue;
+          else if (ReadAmount <= 0) {
+            // Couldn't read whole file just free memory and continue.
+            throw "Error reading file '" + Filename + "'!";
+          }
+          Amount -= ReadAmount;
+          FilePos += ReadAmount;
+          
+          SOI.progress(FileSize-Amount, FileSize);
+        }
+
+      } catch (const std::string &Msg) {
+        std::cout << Msg << "\n";
+        // If the user cancels the operation, clean up after ourselves.
+        delete [] FileStart;
+        FileStart = 0;
+        return;
+      }
+      
+      FileEnd = FileStart+FileSize;
+    }
+  }
+}
+
+/// calculateLineOffsets - Compute the LineOffset vector for the current file.
+///
+void SourceFile::calculateLineOffsets() const {
+  assert(LineOffset.empty() && "Line offsets already computed!");
+  const char *BufPtr = FileStart;
+  do {
+    LineOffset.push_back(BufPtr-FileStart);
+
+    // Scan until we get to a newline.
+    while (BufPtr != FileEnd && *BufPtr != '\n' && *BufPtr != '\r')
+      ++BufPtr;
+
+    if (BufPtr != FileEnd) {
+      ++BufPtr;               // Skip over the \n or \r
+      if (BufPtr[-1] == '\r' && BufPtr != FileEnd && BufPtr[0] == '\n')
+        ++BufPtr;   // Skip over dos/windows style \r\n's
+    }
+  } while (BufPtr != FileEnd);
+}
+
+
+/// getSourceLine - Given a line number, return the start and end of the line
+/// in the file.  If the line number is invalid, or if the file could not be
+/// loaded, null pointers are returned for the start and end of the file. Note
+/// that line numbers start with 0, not 1.
+void SourceFile::getSourceLine(unsigned LineNo, const char *&LineStart,
+                               const char *&LineEnd) const {
+  LineStart = LineEnd = 0;
+  if (FileStart == 0) return;  // Couldn't load file, return null pointers
+  if (LineOffset.empty()) calculateLineOffsets();
+
+  // Asking for an out-of-range line number?
+  if (LineNo >= LineOffset.size()) return;
+
+  // Otherwise, they are asking for a valid line, which we can fulfill.
+  LineStart = FileStart+LineOffset[LineNo];
+
+  if (LineNo+1 < LineOffset.size())
+    LineEnd = FileStart+LineOffset[LineNo+1];
+  else
+    LineEnd = FileEnd;
+
+  // If the line ended with a newline, strip it off.
+  while (LineEnd != LineStart && (LineEnd[-1] == '\n' || LineEnd[-1] == '\r'))
+    --LineEnd;
+
+  assert(LineEnd >= LineStart && "We somehow got our pointers swizzled!");
+}
+