lto: Clean up C libLTO interfaces pertaining to linker flags.

[pcc]

Summary

Specifically, remove the dependent library interface and replace the existing
linker option interface with a new one that returns a single list of flags.

[ygao]

LGTM. Thanks!

include/llvm-c/lto.h

 
 /**
  * @defgroup LLVMCLTO LTO
  * @ingroup LLVMC
  *
  * @{
  */
 
-#define LTO_API_VERSION 15
+#define LTO_API_VERSION 16
 
 /**
  * \since prior to LTO_API_VERSION=3
  */
 typedef enum {
     LTO_SYMBOL_ALIGNMENT_MASK              = 0x0000001F, /* log2 of alignment */
     LTO_SYMBOL_PERMISSIONS_MASK            = 0x000000E0,
     LTO_SYMBOL_PERMISSIONS_CODE            = 0x000000A0,

  *
  * \since prior to LTO_API_VERSION=3
  */
 extern lto_symbol_attributes
 lto_module_get_symbol_attribute(lto_module_t mod, unsigned int index);
 
 
 /**
- * Returns the number of dependent libraries in the object module.
+ * Returns the module's linker options.
  *
- * Deprecated. Now returns an empty list.
- *
- * \since LTO_API_VERSION=8
- */
-extern unsigned int
-lto_module_get_num_deplibs(lto_module_t mod);
-
-
-/**
- * Returns the ith dependent library in the module.
- *
- * Deprecated. Now always returns null.
- *
- * \since LTO_API_VERSION=8
- */
-extern const char*
-lto_module_get_deplib(lto_module_t mod, unsigned int index);
-
-
-/**
- * Returns the number of linker options in the object module.
- *
- * Each linker option may consist of multiple flags. It is the linker's
- * responsibility to split the flags using a platform-specific mechanism.
- *
- * \since LTO_API_VERSION=8
- */
-extern unsigned int
-lto_module_get_num_linkeropts(lto_module_t mod);
-
-
-/**
- * Returns the ith linker option in the module.
- *
- * Each linker option may consist of multiple flags. It is the linker's
+ * The linker options may consist of multiple flags. It is the linker's
  * responsibility to split the flags using a platform-specific mechanism.
  *
- * \since LTO_API_VERSION=8
+ * \since LTO_API_VERSION=16
  */
 extern const char*
-lto_module_get_linkeropt(lto_module_t mod, unsigned int index);
+lto_module_get_linkeropts(lto_module_t mod);
 
 
 /**
  * Diagnostic severity.
  *
  * \since LTO_API_VERSION=7
  */
 typedef enum {

tools/lto/lto.cpp

const char* lto_module_get_symbol_name(lto_module_t mod, unsigned int index) {
   return unwrap(mod)->getSymbolName(index);
 }
 
 lto_symbol_attributes lto_module_get_symbol_attribute(lto_module_t mod,
                                                       unsigned int index) {
   return unwrap(mod)->getSymbolAttributes(index);
 }
 
-unsigned int lto_module_get_num_deplibs(lto_module_t mod) {
-  return 0;
-}
-
-const char* lto_module_get_deplib(lto_module_t mod, unsigned int index) {
-  return nullptr;
-}
-
-unsigned int lto_module_get_num_linkeropts(lto_module_t mod) {
-  return 1;
-}
-
-const char* lto_module_get_linkeropt(lto_module_t mod, unsigned int index) {
-  if (index != 0)
-    return nullptr;
+const char* lto_module_get_linkeropts(lto_module_t mod) {
   return unwrap(mod)->getLinkerOpts();
 }
 
 void lto_codegen_set_diagnostic_handler(lto_code_gen_t cg,
                                         lto_diagnostic_handler_t diag_handler,
                                         void *ctxt) {
   unwrap(cg)->setDiagnosticHandler(diag_handler, ctxt);
 }

tools/lto/lto.exports

 lto_get_error_message
 lto_get_version
 lto_initialize_disassembler
 lto_module_create
 lto_module_create_from_fd
 lto_module_create_from_fd_at_offset
 lto_module_create_from_memory
 lto_module_create_from_memory_with_path
 lto_module_create_in_local_context
 lto_module_create_in_codegen_context
-lto_module_get_deplib
-lto_module_get_linkeropt
-lto_module_get_num_deplibs
-lto_module_get_num_linkeropts
+lto_module_get_linkeropts
 lto_module_get_num_symbols
 lto_module_get_symbol_attribute
 lto_module_get_symbol_name
 lto_module_get_target_triple
 lto_module_set_target_triple
 lto_module_is_object_file
 lto_module_is_object_file_for_target
 lto_module_is_object_file_in_memory