[LLVM-C] Add Accessors For A Module's Source File Name

[CodaFi]

Summary

Also unblocks some cleanup in the echo-test.

[whitequark]

lib/IR/Core.cpp

240

Shouldn't the result be returned in a newly allocated buffer here?

[CodaFi]

lib/IR/Core.cpp

240

The lifetime of the string for the source file name is tied to the module itself - just like the string for the module identifier. Non-owning references seem like the norm in the wrappers.

[deadalnix]

tools/llvm-c-test/echo.cpp

938

There should be some module that actually check this code ran properly by having a filename defined in there.

[CodaFi]

Added source_filename to the echo test

include/llvm-c/Core.h

  */
 void LLVMSetModuleIdentifier(LLVMModuleRef M, const char *Ident, size_t Len);
 
+/**
+ * Obtain the module's original source file name.
+ *
+ * @param M Module to obtain the name of
+ * @param Len Out parameter which holds the length of the returned string
+ * @return The original source file name of M
+ * @see Module::getSourceFileName()
+ */
+const char *LLVMGetSourceFileName(LLVMModuleRef M, size_t *Len);
+
+/**
+ * Set the original source file name of a module to a string Name with length
+ * Len.
+ *
+ * @param M The module to set the source file name of
+ * @param Name The string to set M's source file name to
+ * @param Len Length of Name
+ * @see Module::setSourceFileName()
+ */
+void LLVMSetSourceFileName(LLVMModuleRef M, const char *Name, size_t Len);
+
 /**
  * Obtain the data layout for a module.
  *

lib/IR/Core.cpp

   unwrap(M)->setModuleIdentifier(StringRef(Ident, Len));
 }
 
+const char *LLVMGetSourceFileName(LLVMModuleRef M, size_t *Len) {
+  auto &Str = unwrap(M)->getSourceFileName();
+  *Len = Str.length();
+  return Str.c_str();
+}
+
+void LLVMSetSourceFileName(LLVMModuleRef M, const char *Name, size_t Len) {
+  unwrap(M)->setSourceFileName(StringRef(Name, Len));
+}
 
 /*--.. Data layout .........................................................--*/
 const char *LLVMGetDataLayoutStr(LLVMModuleRef M) {

test/Bindings/llvm-c/echo.ll

 ; RUN: llvm-as < %s | llvm-c-test --echo > %t.echo
 ; RUN: diff -w %t.orig %t.echo
 
+source_filename = "/test/Bindings/echo.ll"
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.11.0"
 

tools/llvm-c-test/echo.cpp

   LLVMEnablePrettyStackTrace();
 
   LLVMModuleRef Src = llvm_load_module(false, true);
-  size_t Len;
-  const char *ModuleName = LLVMGetModuleIdentifier(Src, &Len);
+  size_t SourceFileLen;
+  const char *SourceFileName = LLVMGetSourceFileName(Src, &SourceFileLen);
+  size_t ModuleIdentLen;
+  const char *ModuleName = LLVMGetModuleIdentifier(Src, &ModuleIdentLen);
   LLVMContextRef Ctx = LLVMContextCreate();
   LLVMModuleRef M = LLVMModuleCreateWithNameInContext(ModuleName, Ctx);
 
-  // This whole switcharound is done because the C API has no way to
-  // set the source_filename
-  LLVMSetModuleIdentifier(M, "", 0);
-  LLVMGetModuleIdentifier(M, &Len);
-  if (Len != 0)
-      report_fatal_error("LLVM{Set,Get}ModuleIdentifier failed");
-  LLVMSetModuleIdentifier(M, ModuleName, strlen(ModuleName));
+  LLVMSetSourceFileName(M, SourceFileName, SourceFileLen);
+  LLVMSetModuleIdentifier(M, ModuleName, ModuleIdentLen);
 
   LLVMSetTarget(M, LLVMGetTarget(Src));
   LLVMSetModuleDataLayout(M, LLVMGetModuleDataLayout(Src));