rustc: Stop using LLVMGetSectionName

src/librustc/lib/llvm.rs

@@ -1438,8 +1438,6 @@ pub mod llvm {
                                           -> Bool;
         /** Moves the section iterator to point to the next section. */
         pub fn LLVMMoveToNextSection(SI: SectionIteratorRef);
-        /** Returns the current section name. */
-        pub fn LLVMGetSectionName(SI: SectionIteratorRef) -> *c_char;
         /** Returns the current section size. */
         pub fn LLVMGetSectionSize(SI: SectionIteratorRef) -> c_ulonglong;
         /** Returns the current section contents as a string buffer. */
@@ -1784,6 +1782,9 @@ pub mod llvm {
 
         pub fn LLVMRustSetDLLExportStorageClass(V: ValueRef);
         pub fn LLVMVersionMinor() -> c_int;
+
+        pub fn LLVMRustGetSectionName(SI: SectionIteratorRef,
+                                      data: *mut *c_char) -> c_int;
     }
 }
 

src/librustc/metadata/loader.rs

@@ -29,9 +29,10 @@ use std::cast;
 use std::cmp;
 use std::io;
 use std::os::consts::{macos, freebsd, linux, android, win32};
+use std::ptr;
 use std::rc::Rc;
-use std::str;
 use std::slice;
+use std::str;
 
 use collections::{HashMap, HashSet};
 use flate;
@@ -439,8 +440,9 @@ fn get_metadata_section_imp(os: Os, filename: &Path) -> Result<MetadataBlob, ~st
         };
         let si = mk_section_iter(of.llof);
         while llvm::LLVMIsSectionIteratorAtEnd(of.llof, si.llsi) == False {
-            let name_buf = llvm::LLVMGetSectionName(si.llsi);
-            let name = str::raw::from_c_str(name_buf);
+            let mut name_buf = ptr::null();
+            let name_len = llvm::LLVMRustGetSectionName(si.llsi, &mut name_buf);
+            let name = str::raw::from_buf_len(name_buf as *u8, name_len as uint);
             debug!("get_metadata_section: name {}", name);
             if read_meta_section_name(os) == name {
                 let cbuf = llvm::LLVMGetSectionContents(si.llsi);

src/rustllvm/RustWrapper.cpp

@@ -10,6 +10,7 @@
 
 #include "rustllvm.h"
 #include "llvm/Object/Archive.h"
+#include "llvm/Object/ObjectFile.h"
 
 //===----------------------------------------------------------------------===
 //
@@ -679,3 +680,27 @@ extern "C" int
 LLVMVersionMinor() {
     return LLVM_VERSION_MINOR;
 }
+
+// Note that the two following functions look quite similar to the
+// LLVMGetSectionName function. Sadly, it appears that this function only
+// returns a char* pointer, which isn't guaranteed to be null-terminated. The
+// function provided by LLVM doesn't return the length, so we've created our own
+// function which returns the length as well as the data pointer.
+//
+// For an example of this not returning a null terminated string, see
+// lib/Object/COFFObjectFile.cpp in the getSectionName function. One of the
+// branches explicitly creates a StringRef without a null terminator, and then
+// that's returned.
+
+inline section_iterator *unwrap(LLVMSectionIteratorRef SI) {
+    return reinterpret_cast<section_iterator*>(SI);
+}
+
+extern "C" int
+LLVMRustGetSectionName(LLVMSectionIteratorRef SI, const char **ptr) {
+    StringRef ret;
+    if (error_code ec = (*unwrap(SI))->getName(ret))
+      report_fatal_error(ec.message());
+    *ptr = ret.data();
+    return ret.size();
+}