address feedback from nikic and oli-obk https://github.com/rust-lang/rust/pull/113723/files

use slice memcpy rather than strcpy and write it on stdout

use println on failure

Co-authored-by: Oli Scherer <github35764891676564198441@oli-obk.de>

Author: khei4

compiler/rustc_codegen_llvm/src/lib.rs

@@ -46,6 +46,7 @@ use rustc_span::symbol::Symbol;
 
 use std::any::Any;
 use std::ffi::CStr;
+use std::io::Write;
 
 mod back {
     pub mod archive;
@@ -177,32 +178,30 @@ impl WriteBackendMethods for LlvmCodegenBackend {
     type ThinData = back::lto::ThinData;
     type ThinBuffer = back::lto::ThinBuffer;
     fn print_pass_timings(&self) {
-        let msg = unsafe {
-            let cstr = llvm::LLVMRustPrintPassTimings();
+        unsafe {
+            let mut size = 0;
+            let cstr = llvm::LLVMRustPrintPassTimings(&mut size as *mut usize);
             if cstr.is_null() {
-                "failed to get pass timings".into()
+                println!("failed to get pass timings");
             } else {
-                let timings = CStr::from_ptr(cstr).to_bytes();
-                let timings = String::from_utf8_lossy(timings).to_string();
+                let timings = std::slice::from_raw_parts(cstr as *const u8, size);
+                std::io::stdout().write_all(timings).unwrap();
                 libc::free(cstr as *mut _);
-                timings
             }
-        };
-        println!("{}", msg);
+        }
     }
     fn print_statistics(&self) {
-        let msg = unsafe {
-            let cstr = llvm::LLVMRustPrintStatistics();
+        unsafe {
+            let mut size = 0;
+            let cstr = llvm::LLVMRustPrintStatistics(&mut size as *mut usize);
             if cstr.is_null() {
-                "failed to get stats".into()
+                println!("failed to get pass stats");
             } else {
-                let stats = CStr::from_ptr(cstr).to_bytes();
-                let stats = String::from_utf8_lossy(stats).to_string();
+                let stats = std::slice::from_raw_parts(cstr as *const u8, size);
+                std::io::stdout().write_all(stats).unwrap();
                 libc::free(cstr as *mut _);
-                stats
             }
-        };
-        println!("{}", msg);
+        }
     }
     fn run_link(
         cgcx: &CodegenContext<Self>,

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1868,10 +1868,10 @@ extern "C" {
     pub fn LLVMRustGetLastError() -> *const c_char;
 
     /// Print the pass timings since static dtors aren't picking them up.
-    pub fn LLVMRustPrintPassTimings() -> *const c_char;
+    pub fn LLVMRustPrintPassTimings(size: *const size_t) -> *const c_char;
 
     /// Print the statistics since static dtors aren't picking them up.
-    pub fn LLVMRustPrintStatistics() -> *const c_char;
+    pub fn LLVMRustPrintStatistics(size: *const size_t) -> *const c_char;
 
     pub fn LLVMStructCreateNamed(C: &Context, Name: *const c_char) -> &Type;
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -112,23 +112,25 @@ extern "C" void LLVMRustSetNormalizedTarget(LLVMModuleRef M,
   unwrap(M)->setTargetTriple(Triple::normalize(Triple));
 }
 
-extern "C" const char *LLVMRustPrintPassTimings(void) {
+extern "C" const char *LLVMRustPrintPassTimings(size_t *Len) {
   std::string buf;
   raw_string_ostream SS(buf);
   TimerGroup::printAll(SS);
   SS.flush();
-  char* CStr = (char*) malloc((buf.length() + 1) * sizeof(char));
-  strcpy(CStr, buf.c_str());
+  *Len = buf.length();
+  char *CStr = (char *)malloc(*Len);
+  memcpy(CStr, buf.c_str(), *Len);
   return CStr;
 }
 
-extern "C" const char *LLVMRustPrintStatistics(void) {
+extern "C" const char *LLVMRustPrintStatistics(size_t *Len) {
   std::string buf;
   raw_string_ostream SS(buf);
   llvm::PrintStatistics(SS);
   SS.flush();
-  char* CStr = (char*) malloc((buf.length() + 1) * sizeof(char));
-  strcpy(CStr, buf.c_str());
+  *Len = buf.length();
+  char *CStr = (char *)malloc(*Len);
+  memcpy(CStr, buf.c_str(), *Len);
   return CStr;
 }