When grepping for LDC specific code look for "LDC" and "LLVM" upper and lower case. dmd2 specific code is "DMDV2"

File tour

LDC is built from files in subdirectories dmd, gen, and ir.

• dmd/mars.c holds the main() function.
• gen/toobj.cpp holds Module::genobjfile(). This is the main plug into the llvm backend.
• gen/irstate declares IRState, an instance of which is created in Module::genobjfile() and available as gIR. Most codegen happens through that instance.
• gen/dvalue holds DValue and derivaties, which basically contain a D type and LLVM value
• gen/statements.cpp has codegen for most statements
• gen/toir.cpp has codegen for most expressions
• gen/llvmhelpers has codegen helpers, like DtoAssign
• gen/tollvm has LLVM utilities, like DtoType which converts D types to LLVM types
• gen/todebug produce, explain how debugging with llvm works: http://llvm.org/docs/SourceLevelDebugging.html

The other directories contain:

• bin/ - This is where the compiled ldc binary resides, also holds ldc.conf/ini.
• lib/ - The runtime library .so and .a files live in here.
• runtime/ - Scripts for building Tango runtime and Tango patch
• runtime/internal - LDC specific part of runtime
• tango/ - Tango checkout.
• lphobos/ - Phobos runtime. Unused for a long time, recently reactivated by downs.
• tests/ - Mini tests and DStress tests
• demos/ - Rarely used.

Debugging help

• To enable assertions in LDC, you need to have LLVM compiled with --enable-assertions
• add -DDEBUG to the CPP_FLAGS in "ccmake ." to enable DEBUG sections in LDC
• Set CMAKE_BUILD_TYPE to Debug in cmake to get a debug build of LDC. (works?)
• Use ->toChars() on instances of DMDFE classes and ->dump() on LLVM values and types.