Unify asprintf/vasprintf implementations and make them truly portable by using vsnprintf (swiftlang#39314)

Author: kubamracek

include/swift/Runtime/Portability.h

@@ -29,36 +29,41 @@ size_t _swift_strlcpy(char *dst, const char *src, size_t maxlen);
 SWIFT_RUNTIME_ATTRIBUTE_ALWAYS_INLINE
 #endif
 #ifdef __clang__
-__attribute((__format__(__printf__, 2, 3)))
+__attribute((__format__(__printf__, 2, 0)))
 #endif
 inline static int
-swift_asprintf(char **strp, const char *fmt, ...) {
-  va_list args;
-  va_start(args, fmt);
-#if defined(_WIN32)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wuninitialized"
-  int len = _vscprintf(fmt, args);
-#pragma GCC diagnostic pop
-  if (len < 0) {
-    va_end(args);
+swift_vasprintf(char **strp, const char *fmt, va_list args) {
+  va_list args_for_len;
+  va_copy(args_for_len, args);
+  int len = vsnprintf(nullptr, 0, fmt, args_for_len);
+  va_end(args_for_len);
+
+  if (len < 0)
     return -1;
-  }
-  char *buffer = static_cast<char *>(malloc(len + 1));
-  if (!buffer) {
-    va_end(args);
+  char *buffer = reinterpret_cast<char *>(malloc(len + 1));
+  if (!buffer)
     return -1;
-  }
   int result = vsprintf(buffer, fmt, args);
   if (result < 0) {
-    va_end(args);
     free(buffer);
     return -1;
   }
   *strp = buffer;
-#else
-  int result = vasprintf(strp, fmt, args);
+  return result;
+}
+
+// Skip the attribute when included by the compiler.
+#ifdef SWIFT_RUNTIME_ATTRIBUTE_ALWAYS_INLINE
+SWIFT_RUNTIME_ATTRIBUTE_ALWAYS_INLINE
+#endif
+#ifdef __clang__
+__attribute((__format__(__printf__, 2, 3)))
 #endif
+inline static int
+swift_asprintf(char **strp, const char *fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  int result = swift_vasprintf(strp, fmt, args);
   va_end(args);
   return result;
 }

lib/SwiftDemangle/MangleHack.cpp

@@ -18,50 +18,25 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/SwiftDemangle/MangleHack.h"
+#include "swift/Runtime/Portability.h"
 #include "swift/Strings.h"
 #include <cassert>
 #include <cstdarg>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 
-#if defined(_WIN32)
-static int vasprintf(char **strp, const char *fmt, va_list ap) {
-  int len = _vscprintf(fmt, ap);
-  if (len < 0)
-    return len;
-  char *buffer = static_cast<char *>(malloc(len + 1));
-  if (buffer == nullptr)
-    return -1;
-  int result = vsprintf(buffer, fmt, ap);
-  if (result < 0) {
-    free(buffer);
-    return -1;
-  }
-  *strp = buffer;
-  return result;
-}
-
-static int asprintf(char **strp, const char *fmt, ...) {
-  va_list args;
-  va_start(args, fmt);
-  int result = vasprintf(strp, fmt, args);
-  va_end(args);
-  return result;
-}
-#endif
-
 const char *
 _swift_mangleSimpleClass(const char *module, const char *class_) {
   size_t moduleLength = strlen(module);
   size_t classLength = strlen(class_);
   char *value = nullptr;
   if (swift::STDLIB_NAME == llvm::StringRef(module)) {
-    int result = asprintf(&value, "_TtCs%zu%s", classLength, class_);
+    int result = swift_asprintf(&value, "_TtCs%zu%s", classLength, class_);
     assert(result > 0);
     (void)result;
   } else {
-    int result = asprintf(&value, "_TtC%zu%s%zu%s", moduleLength, module,
+    int result = swift_asprintf(&value, "_TtC%zu%s%zu%s", moduleLength, module,
                           classLength, class_);
     assert(result > 0);
     (void)result;
@@ -76,11 +51,11 @@ _swift_mangleSimpleProtocol(const char *module, const char *protocol) {
   size_t protocolLength = strlen(protocol);
   char *value = nullptr;
   if (swift::STDLIB_NAME == llvm::StringRef(module)) {
-    int result = asprintf(&value, "_TtPs%zu%s_", protocolLength, protocol);
+    int result = swift_asprintf(&value, "_TtPs%zu%s_", protocolLength, protocol);
     assert(result > 0);
     (void)result;
   } else {
-    int result = asprintf(&value, "_TtP%zu%s%zu%s_", moduleLength, module,
+    int result = swift_asprintf(&value, "_TtP%zu%s%zu%s_", moduleLength, module,
                           protocolLength, protocol);
     assert(result > 0);
     (void)result;

stdlib/public/runtime/Errors.cpp

@@ -39,6 +39,7 @@
 #include "ImageInspection.h"
 #include "swift/Runtime/Debug.h"
 #include "swift/Runtime/Mutex.h"
+#include "swift/Runtime/Portability.h"
 #include "swift/Demangling/Demangle.h"
 #include "llvm/ADT/StringRef.h"
 
@@ -288,7 +289,7 @@ reportOnCrash(uint32_t flags, const char *message)
   char *oldMessage = (char *)CRGetCrashLogMessage();
   char *newMessage;
   if (oldMessage) {
-    asprintf(&newMessage, "%s%s", oldMessage, message);
+    swift_asprintf(&newMessage, "%s%s", oldMessage, message);
     if (malloc_size(oldMessage)) free(oldMessage);
   } else {
     newMessage = strdup(message);
@@ -367,26 +368,6 @@ void swift::swift_reportError(uint32_t flags,
   reportOnCrash(flags, message);
 }
 
-static int swift_vasprintf(char **strp, const char *fmt, va_list ap) {
-#if defined(_WIN32)
-  int len = _vscprintf(fmt, ap);
-  if (len < 0)
-    return -1;
-  char *buffer = reinterpret_cast<char *>(malloc(len + 1));
-  if (!buffer)
-    return -1;
-  int result = vsprintf(buffer, fmt, ap);
-  if (result < 0) {
-    free(buffer);
-    return -1;
-  }
-  *strp = buffer;
-  return result;
-#else
-  return vasprintf(strp, fmt, ap);
-#endif
-}
-
 // Report a fatal error to system console, stderr, and crash logs, then abort.
 SWIFT_NORETURN void swift::fatalError(uint32_t flags, const char *format, ...) {
   va_list args;

stdlib/public/runtime/ReflectionMirror.cpp

@@ -43,27 +43,6 @@
 #include <stdarg.h>
 
 namespace {
-int asprintf(char **strp, const char *fmt, ...) {
-  va_list argp0, argp1;
-
-  va_start(argp0, fmt);
-  va_copy(argp1, argp0);
-
-  int length = _vscprintf(fmt, argp0);
-
-  *strp = reinterpret_cast<char *>(malloc(length + 1));
-  if (*strp == nullptr)
-    return -1;
-
-  length = _vsnprintf(*strp, length, fmt, argp1);
-  (*strp)[length] = '\0';
-
-  va_end(argp0);
-  va_end(argp1);
-
-  return length;
-}
-
 char *strndup(const char *s, size_t n) {
   size_t length = std::min(strlen(s), n);
 
@@ -289,7 +268,7 @@ struct TupleImpl : ReflectionMirrorImpl {
     if (!hasLabel) {
       // The name is the stringized element number '.0'.
       char *str;
-      asprintf(&str, ".%" PRIdPTR, i);
+      swift_asprintf(&str, ".%" PRIdPTR, i);
       *outName = str;
     }
 

stdlib/public/runtime/SwiftObject.mm

@@ -1553,13 +1553,13 @@ void swift_objc_swift3ImplicitObjCEntrypoint(id self, SEL selector,
     filenameLength = INT_MAX;
 
   char *message, *nullTerminatedFilename;
-  asprintf(&message,
+  swift_asprintf(&message,
            "implicit Objective-C entrypoint %c[%s %s] is deprecated and will "
            "be removed in Swift 4",
            isInstanceMethod ? '-' : '+',
            class_getName([self class]),
            sel_getName(selector));
-  asprintf(&nullTerminatedFilename, "%*s", (int)filenameLength, filename);
+  swift_asprintf(&nullTerminatedFilename, "%*s", (int)filenameLength, filename);
 
   RuntimeErrorDetails::FixIt fixit = {
     .filename = nullTerminatedFilename,

stdlib/public/stubs/OptionalBridgingHelper.mm

@@ -17,6 +17,7 @@
 #include "swift/Runtime/Metadata.h"
 #include "swift/Runtime/Mutex.h"
 #include "swift/Runtime/ObjCBridge.h"
+#include "swift/Runtime/Portability.h"
 #include <vector>
 #import <Foundation/Foundation.h>
 #import <CoreFoundation/CoreFoundation.h>
@@ -39,13 +40,10 @@ @interface __SwiftNull : NSObject {
 
 @implementation __SwiftNull : NSObject
 
-//   int
- // asprintf(char **ret, const char *format, ...);
-
 - (id)description {
   char *str = NULL;
   const char *clsName = class_getName([self class]);
-  int fmtResult = asprintf(&str, "<%s %p depth = %u>", clsName,
+  int fmtResult = swift_asprintf(&str, "<%s %p depth = %u>", clsName,
                                                        (void*)self,
                                                        self->depth);
   (void)fmtResult;