out of PassManager.cpp and into Core.cpp with the rest of the C binding code.

llvm-svn: 110494

llvm-svn: 108520

llvm-svn: 101342

feature, either build the JIT in debug mode to enable it by default or pass
-jit-emit-debug to lli.

Right now, the only debug information that this communicates to GDB is call
frame information, since it's already being generated to support exceptions in
the JIT.  Eventually, when DWARF generation isn't tied so tightly to AsmPrinter,
it will be easy to push that information to GDB through this interface.

Here's a step-by-step breakdown of how the feature works:

- The JIT generates the machine code and DWARF call frame info
  (.eh_frame/.debug_frame) for a function into memory.
- The JIT copies that info into an in-memory ELF file with a symbol for the
  function.
- The JIT creates a code entry pointing to the ELF buffer and adds it to a
  linked list hanging off of a global descriptor at a special symbol that GDB
  knows about.
- The JIT calls a function marked noinline that GDB knows about and has put an
  internal breakpoint in.
- GDB catches the breakpoint and reads the global descriptor to look for new
  code.
- When sees there is new code, it reads the ELF from the inferior's memory and
  adds it to itself as an object file.
- The JIT continues, and the next time we stop the program, we are able to
  produce a proper backtrace.

Consider running the following program through the JIT:

#include <stdio.h>
void baz(short z) {
  long w = z + 1;
  printf("%d, %x\n", w, *((int*)NULL));  // SEGFAULT here
}
void bar(short y) {
  int z = y + 1;
  baz(z);
}
void foo(char x) {
  short y = x + 1;
  bar(y);
}
int main(int argc, char** argv) {
  char x = 1;
  foo(x);
}

Here is a backtrace before this patch:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x2aaaabdfbd10 (LWP 25476)]
0x00002aaaabe7d1a8 in ?? ()
(gdb) bt
#0  0x00002aaaabe7d1a8 in ?? ()
#1  0x0000000000000003 in ?? ()
#2  0x0000000000000004 in ?? ()
#3  0x00032aaaabe7cfd0 in ?? ()
#4  0x00002aaaabe7d12c in ?? ()
#5  0x00022aaa00000003 in ?? ()
#6  0x00002aaaabe7d0aa in ?? ()
#7  0x01000002abe7cff0 in ?? ()
#8  0x00002aaaabe7d02c in ?? ()
#9  0x0100000000000001 in ?? ()
#10 0x00000000014388e0 in ?? ()
#11 0x00007fff00000001 in ?? ()
#12 0x0000000000b870a2 in llvm::JIT::runFunction (this=0x1405b70,
F=0x14024e0, ArgValues=@0x7fffffffe050)
   at /home/rnk/llvm-gdb/lib/ExecutionEngine/JIT/JIT.cpp:395
#13 0x0000000000baa4c5 in llvm::ExecutionEngine::runFunctionAsMain
(this=0x1405b70, Fn=0x14024e0, argv=@0x13f06f8, envp=0x7fffffffe3b0)
   at /home/rnk/llvm-gdb/lib/ExecutionEngine/ExecutionEngine.cpp:377
#14 0x00000000007ebd52 in main (argc=2, argv=0x7fffffffe398,
envp=0x7fffffffe3b0) at /home/rnk/llvm-gdb/tools/lli/lli.cpp:208

And a backtrace after this patch:
Program received signal SIGSEGV, Segmentation fault.
0x00002aaaabe7d1a8 in baz ()
(gdb) bt
#0  0x00002aaaabe7d1a8 in baz ()
#1  0x00002aaaabe7d12c in bar ()
#2  0x00002aaaabe7d0aa in foo ()
#3  0x00002aaaabe7d02c in main ()
#4  0x0000000000b870a2 in llvm::JIT::runFunction (this=0x1405b70,
F=0x14024e0, ArgValues=...)
   at /home/rnk/llvm-gdb/lib/ExecutionEngine/JIT/JIT.cpp:395
#5  0x0000000000baa4c5 in llvm::ExecutionEngine::runFunctionAsMain
(this=0x1405b70, Fn=0x14024e0, argv=..., envp=0x7fffffffe3c0)
   at /home/rnk/llvm-gdb/lib/ExecutionEngine/ExecutionEngine.cpp:377
#6  0x00000000007ebd52 in main (argc=2, argv=0x7fffffffe3a8,
envp=0x7fffffffe3c0) at /home/rnk/llvm-gdb/tools/lli/lli.cpp:208

llvm-svn: 82418

llvm-svn: 79777

llvm-svn: 79763

Use MCSectionELF methods as much as possible, removing some
ELFWriter methods which are now unused

llvm-svn: 78940

add support for PtrToInt, Add, Mul.

llvm-svn: 78552

Handle large integers, x86_fp80, ConstantAggregateZero, and two more ConstantExpr:
GetElementPtr and IntToPtr
Set SHF_MERGE bit for mergeable strings
Avoid zero initialized strings to be classified as a bss symbol
Don't allow common symbols to be classified as STB_WEAK
Add a constant to be used as a global value offset in data relocations 

llvm-svn: 78476

a dirty hack and isn't need anymore since the last x86 code emitter patch)
- Add a target-dependent modifier to addend calculation
- Use R_X86_64_32S relocation for X86::reloc_absolute_word_sext
- Use getELFSectionFlags whenever possible
- fix getTextSection to use TLOF and emit the right text section 
- Handle global emission for static ctors, dtors and Type::PointerTyID
- Some minor fixes

llvm-svn: 78176

initialize method, which can be called when an MCContext is available.

llvm-svn: 77687

llvm-svn: 77238

llvm-svn: 77232

instead and drive things based off of that.

llvm-svn: 77184

global declared symbols are initialized with references from other global
symbols.

llvm-svn: 76540

are referenced, ignore the relocation entry and patch the relocatable field with
the computed symbol offset directly

llvm-svn: 76414

Use R_X86_64_32S to handle Jump Table Index relocation entries. Hide TAI usage inside getSection* functions

llvm-svn: 76347

Use proper relocation type to build relocations for JumpTables (rodata
sections).

llvm-svn: 76326

llvm-svn: 75898

we care more about random access than insertion/deletion of elements.

llvm-svn: 75828

llvm-svn: 75537

llvm-svn: 75454

llvm-svn: 74821

llvm-svn: 74760

llvm-svn: 74718

Add section symbols to the symbol table

llvm-svn: 74170

Only pad when the section size > 0 and move the code that deals
with globals initializers to a place we know for sure the global
is initialized.

llvm-svn: 73944

llvm-svn: 73895

Support for .text relocations, implementing TargetELFWriter overloaded methods for x86/x86_64.
Use a map to track global values to their symbol table indexes
Code cleanup and small fixes

llvm-svn: 73894

Introduce new BinaryObject (blob) class, ELF Writer modified to use it. BinaryObject.h by Aaron Gray

llvm-svn: 73333

Emission for globals, using the correct data sections
Function alignment can be computed for each target using TargetELFWriterInfo
Some small fixes

llvm-svn: 73201

relocation sections.

llvm-svn: 73038

llvm-svn: 72982

MachO Writer. This will change with the arrival of ObjectCodeEmitter and
BinaryObject

llvm-svn: 72906

llvm-svn: 55092

adding <map> to many files that actually do need it.

llvm-svn: 48667

llvm-svn: 45418

Almost all occurrences of "bytecode" in the sources have been eliminated.

llvm-svn: 37913

llvm-svn: 36662

Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.

llvm-svn: 36652