--- a/configure.in
+++ b/configure.in
@@ -1411,34 +1411,60 @@ if test "$GNU_CC"; then
             esac
         fi
     fi
 
     # Turn on gcc/clang warnings:
     # https://gcc.gnu.org/onlinedocs/gcc-4.4.0/gcc/Warning-Options.html
     #
     # -Wall - turn on a lot of warnings
+    # -Wchar-subscripts - catches array index using signed char
+    # -Wcomment - catches nested comments
     # -Wdeclaration-after-statement - MSVC doesn't like these
     # -Wempty-body - catches bugs, e.g. "if (c); foo();", few false positives
+    # -Wendif-labels - catches `#else FOO` and `#endif FOO` not in comment
+    # -Wenum-compare - catches comparison of different enum types
+    # -Wignored-qualifiers - catches returns types with qualifiers like const
+    # -Wimplicit-int - catches C variable declaration without a type
     # -Wint-to-pointer-cast - catches cast to pointer from integer of different size
+    # -Wmultichar - catches multicharacter integer constants like 'THIS'
+    # -Wnonnull - catches NULL used with functions arguments marked as non-null
     # -Wpointer-arith - catches pointer arithmetic using NULL or sizeof(void)
+    # -Wpointer-sign - catches mixing pointers to signed and unsigned types
+    # -Wpointer-to-int-cast - catches casts from pointer to different sized int
     # -Wreturn-type - catches missing returns, zero false positives
+    # -Wsequence-point - catches undefined order behavior like `a = a++`
     # -Wsign-compare - catches comparison of signed and unsigned types
+    # -Wtrigraphs - catches unlikely use of trigraphs
     # -Wtype-limits - catches overflow bugs, few false positives
+    # -Wunknown-pragmas - catches unexpected #pragma directives
     #
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wall"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wdeclaration-after-statement"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wempty-body"
-    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wpointer-arith"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wpointer-to-int-cast"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wsign-compare"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wtype-limits"
 
     # Treat some warnings as errors:
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=char-subscripts"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=comment"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=endif-labels"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=enum-compare"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=ignored-qualifiers"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=implicit-int"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=int-to-pointer-cast"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=multichar"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=nonnull"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=pointer-arith"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=pointer-sign"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=return-type"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=sequence-point"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=trigraphs"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=unknown-pragmas"
 
     # Turn off the following warnings that -Wall turns on:
     # -Wno-unused - lots of violations in third-party code
     #
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wno-unused"
 
     if test -z "$INTEL_CC" -a -z "$CLANG_CC"; then
        # Don't use -Wcast-align with ICC or clang
@@ -1484,32 +1510,46 @@ if test "$GNU_CXX"; then
     # FIXME: Let us build with strict aliasing. bug 414641.
     CXXFLAGS="$CXXFLAGS -fno-exceptions -fno-strict-aliasing"
 
     # Turn on gcc/clang warnings:
     # https://gcc.gnu.org/onlinedocs/gcc-4.4.0/gcc/Warning-Options.html
     #
     # -Wall - turn on a lot of warnings
     # -Wempty-body - catches bugs, e.g. "if (c); foo();", few false positives
+    # -Wendif-labels - catches `#else FOO` and `#endif FOO` not in comment
     # -Wint-to-pointer-cast - catches cast to pointer from integer of different size
+    # -Wmissing-braces - catches aggregate initializers missing nested braces
     # -Woverloaded-virtual - function declaration hides virtual function from base class
+    # -Wparentheses - catches `if (a=b)` and operator precedence bugs
     # -Wpointer-arith - catches pointer arithmetic using NULL or sizeof(void)
     # -Wreturn-type - catches missing returns, zero false positives
+    # -Wsequence-point - catches undefined order behavior like `a = a++`
     # -Wsign-compare - catches comparison of signed and unsigned types
+    # -Wtrigraphs - catches unlikely use of trigraphs
     # -Wtype-limits - catches overflow bugs, few false positives
+    # -Wunused-label - catches unused goto labels
+    # -Wwrite-strings - catches non-const char* pointers to string literals
     #
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wall"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wempty-body"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Woverloaded-virtual"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wpointer-arith"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wsign-compare"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wwrite-strings"
 
     # Treat some warnings as errors:
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=endif-labels"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=int-to-pointer-cast"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=missing-braces"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=parentheses"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=return-type"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=sequence-point"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=unused-label"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=trigraphs"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=type-limits"
 
     # Turn off the following warnings that -Wall turns on:
     # -Wno-invalid-offsetof - we use offsetof on non-POD types frequently
     # -Wno-inline-new-delete - we inline 'new' and 'delete' in mozalloc
     #   for performance reasons, and because GCC and clang accept it (though
     #   clang warns about it).
     #

--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -1163,34 +1163,72 @@ if test "$GNU_CC"; then
                   [NSPR_LDFLAGS="$NSPR_LDFLAGS -Wl,--build-id"],
                   AC_MSG_RESULT([no])
                   LDFLAGS=$_SAVE_LDFLAGS)
 
     # Turn on gcc/clang warnings:
     # https://gcc.gnu.org/onlinedocs/gcc-4.4.0/gcc/Warning-Options.html
     #
     # -Wall - turn on a lot of warnings
+    # -Waddress - catches suspicious uses of memory addresses
+    # -Wchar-subscripts - catches array index using signed char
+    # -Wcomment - catches nested comments
     # -Wdeclaration-after-statement - MSVC doesn't like these
     # -Wempty-body - catches bugs, e.g. "if (c); foo();", few false positives
+    # -Wendif-labels - catches `#else FOO` and `#endif FOO` not in comment
+    # -Wenum-compare - catches comparison of different enum types
+    # -Wignored-qualifiers - catches returns types with qualifiers like const
+    # -Wimplicit-function-declaration - catches missing C function prototypes
+    # -Wimplicit-int - catches C variable declaration without a type
     # -Wint-to-pointer-cast - catches cast to pointer from integer of different size
+    # -Wmissing-braces - catches aggregate initializers missing nested braces
+    # -Wmultichar - catches multicharacter integer constants like 'THIS'
+    # -Wnonnull - catches NULL used with functions arguments marked as non-null
+    # -Wparentheses - catches `if (a=b)` and operator precedence bugs
     # -Wpointer-arith - catches pointer arithmetic using NULL or sizeof(void)
+    # -Wpointer-sign - catches mixing pointers to signed and unsigned types
+    # -Wpointer-to-int-cast - catches casts from pointer to different sized int
     # -Wreturn-type - catches missing returns, zero false positives
+    # -Wsequence-point - catches undefined order behavior like `a = a++`
     # -Wsign-compare - catches comparison of signed and unsigned types
+    # -Wswitch - catches switches without all enum cases or default case
+    # -Wtrigraphs - catches unlikely use of trigraphs
     # -Wtype-limits - catches overflow bugs, few false positives
+    # -Wunknown-pragmas - catches unexpected #pragma directives
+    # -Wwrite-strings - catches non-const char* pointers to string literals
     #
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wall"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wdeclaration-after-statement"
-    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wempty-body"
-    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wpointer-arith"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wsign-compare"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wtype-limits"
 
     # Treat some warnings as errors:
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=address"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=char-subscripts"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=comment"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=empty-body"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=endif-labels"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=enum-compare"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=ignored-qualifiers"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=implicit-function-declaration"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=implicit-int"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=int-to-pointer-cast"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=missing-braces"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=multichar"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=nonnull"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=parentheses"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=pointer-arith"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=pointer-sign"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=pointer-to-int-cast"
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=return-type"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=sequence-point"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=switch"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=trigraphs"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=unknown-pragmas"
+    _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Werror=write-strings"
 
     # Turn off the following warnings that -Wall turns on:
     # -Wno-unused - lots of violations in third-party code
     #
     _WARNINGS_CFLAGS="${_WARNINGS_CFLAGS} -Wno-unused"
 
     if test -z "$INTEL_CC" -a -z "$CLANG_CC"; then
        # Don't use -Wcast-align with ICC or clang
@@ -1231,37 +1269,66 @@ else
     _DEFINES_CFLAGS='$(ACDEFINES) -D_JS_CONFDEFS_H_ -DMOZILLA_CLIENT'
 fi
 
 if test "$GNU_CXX"; then
     # Turn on gcc/clang warnings:
     # https://gcc.gnu.org/onlinedocs/gcc-4.4.0/gcc/Warning-Options.html
     #
     # -Wall - turn on a lot of warnings
+    # -Wchar-subscripts - catches array index using signed char
+    # -Wcomment - catches nested comments
     # -Wconversion-null - catches conversions between NULL and non-pointer types
     # -Wempty-body - catches bugs, e.g. "if (c); foo();", few false positives
+    # -Wendif-labels - catches `#else FOO` and `#endif FOO` not in comment
+    # -Wignored-qualifiers - catches returns types with qualifiers like const
     # -Wint-to-pointer-cast - catches cast to pointer from integer of different size
+    # -Wmissing-braces - catches aggregate initializers missing nested braces
     # -Woverloaded-virtual - function declaration hides virtual function from base class
+    # -Wparentheses - catches `if (a=b)` and operator precedence bugs
     # -Wpointer-arith - catches pointer arithmetic using NULL or sizeof(void)
+    # -Wpointer-to-int-cast - catches casts from pointer to different sized int
+    # -Wreorder - catches ctor initializer list not matching class definition order
     # -Wreturn-type - catches missing returns, zero false positives
+    # -Wsequence-point - catches undefined order behavior like `a = a++`
     # -Wsign-compare - catches comparison of signed and unsigned types
+    # -Wswitch - catches switches without all enum cases or default case
+    # -Wtrigraphs - catches unlikely use of trigraphs
     # -Wtype-limits - catches overflow bugs, few false positives
+    # -Wunknown-pragmas - catches unexpected #pragma directives
+    # -Wunused-label - catches unused goto labels
+    # -Wunused-value - catches unused expression results
+    # -Wwrite-strings - catches non-const char* pointers to string literals
     #
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wall"
-    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wempty-body"
-    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Woverloaded-virtual"
-    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wpointer-arith"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wignored-qualifiers"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wsign-compare"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wtype-limits"
 
     # Treat some warnings as errors:
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=char-subscripts"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=comment"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=empty-body"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=endif-labels"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=int-to-pointer-cast"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=missing-braces"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=overloaded-virtual"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=parentheses"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=pointer-arith"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=reorder"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=return-type"
-
-    MOZ_CXX_SUPPORTS_WARNING(-W, error=conversion-null, ac_cxx_has_werror_conversion_null)
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=sequence-point"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=switch"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=trigraphs"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=unknown-pragmas"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=unused-label"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=unused-value"
+    _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=write-strings"
+
+    MOZ_CXX_SUPPORTS_WARNING(-Werror=, conversion-null, ac_cxx_has_werror_conversion_null)
 
     # Turn off the following warnings that -Wall turns on:
     # -Wno-invalid-offsetof - we use offsetof on non-POD types frequently
     #
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wno-invalid-offsetof"
 
     if test -z "$INTEL_CXX" -a -z "$CLANG_CXX"; then
        # Don't use -Wcast-align with ICC or clang