[LTO API] split lto_codegen_compile to lto_codegen_optimize and

lto_codegen_compile_optimized. Also add lto_api_version.

Before this commit, we can only dump the optimized bitcode after running
lto_codegen_compile, but it includes some impacts of running codegen passes,
one example is StackProtector pass. We will get assertion failure when running
llc on the optimized bitcode, because StackProtector is effectively run twice.

After splitting lto_codegen_compile, the linker can choose to dump the bitcode
before running lto_codegen_compile_optimized.

lto_api_version is added so ld64 can check for runtime-availability of the new
API.

rdar://19565500

llvm-svn: 228000

1 files changed, 38 insertions, 1 deletions

diff --git a/llvm/include/llvm-c/lto.h b/llvm/include/llvm-c/lto.h
index 3f30d6d535d..3aaf818e3df 100644
--- a/llvm/include/llvm-c/lto.h
+++ b/llvm/include/llvm-c/lto.h
@@ -40,7 +40,7 @@ typedef bool lto_bool_t;
  * @{
  */
 
-#define LTO_API_VERSION 11
+#define LTO_API_VERSION 12
 
 /**
  * \since prior to LTO_API_VERSION=3
@@ -464,6 +464,8 @@ lto_codegen_write_merged_modules(lto_code_gen_t cg, const char* path);
 
 /**
  * Generates code for all added modules into one native object file.
+ * This calls lto_codegen_optimize then lto_codegen_compile_optimized.
+ *
  * On success returns a pointer to a generated mach-o/ELF buffer and
  * length set to the buffer size.  The buffer is owned by the
  * lto_code_gen_t and will be freed when lto_codegen_dispose()
@@ -477,6 +479,9 @@ lto_codegen_compile(lto_code_gen_t cg, size_t* length);
 
 /**
  * Generates code for all added modules into one native object file.
+ * This calls lto_codegen_optimize then lto_codegen_compile_optimized (instead
+ * of returning a generated mach-o/ELF buffer, it writes to a file).
+ *
  * The name of the file is written to name. Returns true on error.
  *
  * \since LTO_API_VERSION=5
@@ -484,6 +489,38 @@ lto_codegen_compile(lto_code_gen_t cg, size_t* length);
 extern lto_bool_t
 lto_codegen_compile_to_file(lto_code_gen_t cg, const char** name);
 
+/**
+ * Runs optimization for the merged module. Returns true on error.
+ *
+ * \since LTO_API_VERSION=12
+ */
+extern lto_bool_t
+lto_codegen_optimize(lto_code_gen_t cg);
+
+/**
+ * Generates code for the optimized merged module into one native object file.
+ * It will not run any IR optimizations on the merged module.
+ *
+ * On success returns a pointer to a generated mach-o/ELF buffer and length set
+ * to the buffer size.  The buffer is owned by the lto_code_gen_t and will be
+ * freed when lto_codegen_dispose() is called, or
+ * lto_codegen_compile_optimized() is called again. On failure, returns NULL
+ * (check lto_get_error_message() for details).
+ *
+ * \since LTO_API_VERSION=12
+ */
+extern const void*
+lto_codegen_compile_optimized(lto_code_gen_t cg, size_t* length);
+
+/**
+ * Returns the runtime API version.
+ *
+ * \since LTO_API_VERSION=12
+ */
+extern unsigned int
+lto_api_version() {
+  return LTO_API_VERSION;
+}
 
 /**
  * Sets options to help debug codegen bugs.