Bug 1690167 - Change VsprintfLiteral/SprintfLiteral to rely on PrintfTarget. r=nika,Gankra,firefox-build-system-reviewers,mhentges

Instead of snprintf.

Because some standalone code uses those functions directly or indirectly,
and PrintfTarget lives in mozglue, they now need to depend on mozglue
instead of mfbt. Except logalloc/replay, which cherry-picks what it
uses, and the updater, for which we keep using vsnprintf.

Differential Revision: https://phabricator.services.mozilla.com/D103730

media/gmp-clearkey/0.1/moz.build

@@ -7,7 +7,7 @@
 with Files("**"):
     BUG_COMPONENT = ("Core", "Audio/Video: GMP")
 
-SharedLibrary("clearkey")
+GeckoSharedLibrary("clearkey", linkage=None)
 
 FINAL_TARGET = "dist/bin/gmp-clearkey/0.1"
 

memory/replace/logalloc/replay/moz.build

@@ -44,7 +44,19 @@ if CONFIG["MOZ_DMD"] or CONFIG["MOZ_PHC"]:
             "/mozglue/misc/StackWalk.h",
         ]
 
-if not CONFIG["MOZ_REPLACE_MALLOC_STATIC"]:
+if CONFIG["MOZ_REPLACE_MALLOC_STATIC"]:
+    UNIFIED_SOURCES += [
+        "/mfbt/double-conversion/double-conversion/bignum-dtoa.cc",
+        "/mfbt/double-conversion/double-conversion/bignum.cc",
+        "/mfbt/double-conversion/double-conversion/cached-powers.cc",
+        "/mfbt/double-conversion/double-conversion/double-to-string.cc",
+        "/mfbt/double-conversion/double-conversion/fast-dtoa.cc",
+        "/mfbt/double-conversion/double-conversion/fixed-dtoa.cc",
+        "/mfbt/double-conversion/double-conversion/string-to-double.cc",
+        "/mfbt/double-conversion/double-conversion/strtod.cc",
+        "/mozglue/misc/Printf.cpp",
+    ]
+else:
     SOURCES += [
         "../FdPrintf.cpp",
     ]

mfbt/tests/moz.build

@@ -91,9 +91,6 @@ if not CONFIG["MOZ_ASAN"]:
         ]
     )
 
-# Since we link directly with MFBT object files, define IMPL_MFBT
-DEFINES["IMPL_MFBT"] = True
-
 DisableStlWrapping()
 
 if CONFIG["CC_TYPE"] == "clang-cl":
@@ -103,7 +100,7 @@ if CONFIG["CC_TYPE"] == "clang-cl":
     ]
 
 USE_LIBS += [
-    "mfbt",
+    "mozglue",
 ]
 
 if CONFIG["CC_TYPE"] in ("clang", "gcc"):

mozglue/misc/Printf.h

@@ -88,6 +88,8 @@ class PrintfTarget {
   bool MFBT_API appendIntOct(uint64_t);
   bool MFBT_API appendIntHex(uint64_t);
 
+  inline size_t emitted() { return mEmitted; }
+
  protected:
   MFBT_API PrintfTarget();
   virtual ~PrintfTarget() = default;

mozglue/misc/Sprintf.h

@@ -11,19 +11,60 @@
 
 #include <stdio.h>
 #include <stdarg.h>
+#include <algorithm>
 
 #include "mozilla/Assertions.h"
 #include "mozilla/Attributes.h"
+#include "mozilla/Printf.h"
 
 #ifdef __cplusplus
 
+#  ifndef SPRINTF_H_USES_VSNPRINTF
+namespace mozilla {
+namespace detail {
+
+struct MOZ_STACK_CLASS SprintfAppend final : public mozilla::PrintfTarget {
+  template <size_t N>
+  explicit SprintfAppend(char (&aBuf)[N]) : mBuf(aBuf), mBufLen(N) {}
+
+  bool append(const char* aStr, size_t aLen) override {
+    if (aLen == 0) {
+      return true;
+    }
+    // Don't copy more than what's left to use.
+    size_t copy = std::min(mBufLen, aLen);
+    if (copy > 0) {
+      memcpy(mBuf, aStr, copy);
+      mBuf += copy;
+      mBufLen -= copy;
+    }
+    return true;
+  }
+
+ private:
+  char* mBuf;
+  size_t mBufLen;
+};
+
+}  // namespace detail
+}  // namespace mozilla
+#  endif  // SPRINTF_H_USES_VSNPRINTF
+
 template <size_t N>
 MOZ_FORMAT_PRINTF(2, 0)
 int VsprintfLiteral(char (&buffer)[N], const char* format, va_list args) {
   MOZ_ASSERT(format != buffer);
+#  ifdef SPRINTF_H_USES_VSNPRINTF
   int result = vsnprintf(buffer, N, format, args);
   buffer[N - 1] = '\0';
   return result;
+#  else
+  mozilla::detail::SprintfAppend ss(buffer);
+  ss.vprint(format, args);
+  size_t len = ss.emitted();
+  buffer[std::min(len, N - 1)] = '\0';
+  return len;
+#  endif
 }
 
 template <size_t N>

toolkit/mozapps/update/updater/updater-common.build

@@ -85,6 +85,7 @@ if CONFIG["MOZ_TSAN"]:
         "TsanOptions.cpp",
     ]
 
+DEFINES["SPRINTF_H_USES_VSNPRINTF"] = True
 DEFINES["NS_NO_XPCOM"] = True
 DisableStlWrapping()
 for var in ("MAR_CHANNEL_ID", "MOZ_APP_VERSION"):

xpcom/tests/moz.build

@@ -24,7 +24,7 @@ test_progs = [
 ]
 SimplePrograms(test_progs)
 
-USE_LIBS += ["mfbt"]
+USE_LIBS += ["mozglue"]
 
 XPCSHELL_TESTS_MANIFESTS += ["unit/xpcshell.ini"]