Reduce some false-positive warnings from GCC to warnings with -Werror

This also works around some of the same warnings. These are known bugs
in GCC 11+ and GCC 13.x.

CMakeLists.txt

@@ -192,7 +192,7 @@ if (MSVC)
         # TODO: This is disabled for now because there a bunch of known
         # compiler warnings on Windows that we don't have good fixes for.
         #set(WERROR_FLAG "/WX")
-        #set(WERROR_FLAG "/WX")
+        #set(WNOERROR_FLAG "/WX:NO")
     endif ()
 
     # Always build binpac in static mode if building on Windows
@@ -202,6 +202,20 @@ else ()
     include(GNUInstallDirs)
     if (BUILD_WITH_WERROR)
         set(WERROR_FLAG "-Werror")
+        set(WNOERROR_FLAG "-Wno-error")
+
+        # With versions >=13.0 GCC gained `-Warray-bounds` which reports false
+        # positives, see e.g., https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111273.
+        if (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 13.0)
+            list(APPEND WERROR_FLAG "-Wno-error=array-bounds")
+        endif ()
+
+        # With versions >=11.0 GCC is returning false positives for -Wrestrict. See
+        # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100366. It's more prevalent
+        # building with -std=c++20.
+        if (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 11.0)
+            list(APPEND WERROR_FLAG "-Wno-error=restrict")
+        endif ()
     endif ()
 endif ()
 

src/CMakeLists.txt

@@ -41,18 +41,8 @@ set(BISON_FLAGS "--debug")
 
 if (MSVC)
     set(SIGN_COMPARE_FLAG "/wd4018")
-    if (BUILD_WITH_WERROR)
-        # TODO: This is disabled for now because there a bunch of known
-        # compiler warnings on Windows that we don't have good fixes for.
-        #set(WERROR_FLAG "/WX")
-        #set(WNOERROR_FLAG "/WX:NO")
-    endif ()
 else ()
     set(SIGN_COMPARE_FLAG "-Wno-sign-compare")
-    if (BUILD_WITH_WERROR)
-        set(WERROR_FLAG "-Werror")
-        set(WNOERROR_FLAG "-Wno-error")
-    endif ()
 endif ()
 
 # Rule parser/scanner

src/input/readers/ascii/Ascii.cc

@@ -121,15 +121,15 @@ bool Ascii::OpenFile() {
     fname = Info().source;
 
     if ( fname.front() != '/' && ! path_prefix.empty() ) {
-        string path = path_prefix;
+        std::size_t last = path_prefix.find_last_not_of('/');
-        std::size_t last = path.find_last_not_of('/');
 
+        string path;
         if ( last == string::npos ) // Nothing but slashes -- weird but ok...
             path = "/";
         else
-            path.erase(last + 1);
+            path = path_prefix.substr(0, last + 1);
 
-        fname = path + "/" + fname;
+        fname = util::fmt("%s/%s", path.c_str(), fname.c_str());
     }
 
     file.open(fname);

src/input/readers/binary/Binary.cc

@@ -95,15 +95,15 @@ bool Binary::DoInit(const ReaderInfo& info, int num_fields, const Field* const*
 
     // Handle path-prefixing. See similar logic in Ascii::OpenFile().
     if ( fname.front() != '/' && ! path_prefix.empty() ) {
-        string path = path_prefix;
+        std::size_t last = path_prefix.find_last_not_of('/');
-        std::size_t last = path.find_last_not_of('/');
 
+        string path;
         if ( last == string::npos ) // Nothing but slashes -- weird but ok...
             path = "/";
         else
-            path.erase(last + 1);
+            path = path_prefix.substr(0, last + 1);
 
-        fname = path + "/" + fname;
+        fname = util::fmt("%s/%s", path.c_str(), fname.c_str());
     }
 
     if ( ! OpenInput() )

src/script_opt/ZAM/Profile.cc

@@ -40,8 +40,10 @@ std::string ZAMLocInfo::Describe(bool include_lines) const {
 
         if ( include_lines ) {
             desc += ";" + func_name + ":" + std::to_string(loc->FirstLine());
-            if ( loc->LastLine() > loc->FirstLine() )
+            if ( loc->LastLine() > loc->FirstLine() ) {
-                desc += "-" + std::to_string(loc->LastLine());
+                desc.append("-");
+                desc.append(std::to_string(loc->LastLine()));
+            }
         }
     }
 

src/zeekygen/Target.cc

@@ -368,7 +368,9 @@ void PackageTarget::DoGenerate() const {
 
     for ( const auto& [pkg, info_vec] : pkg_manifest ) {
         string header = util::fmt("Package: %s", pkg->Name().c_str());
-        header += "\n" + string(header.size(), '=');
+        auto header_size = header.size();
+        header.append("\n");
+        header.append(string(header_size, '='));
 
         fprintf(file.f, "%s\n\n", header.c_str());