Fix compilation warnings and re-enable werror=yes on Travis

Fix -Wunused-variable, -Wunused-but-set-variable and -Wswitch warnings
raised by GCC 8 and 9.

Fix -Wunused-function, -Wunused-private-field and
-Wtautological-constant-out-of-range-compare raised by Clang.

Fix MSVC 2019 warning C4804 (unsafe use of type 'bool' in comparison
operation).

GCC -Wcpp warnings/Clang -W#warnings (`#warning`) are no longer raising
errors and will thus not abort compilation with `werror=yes`.

Treat glslang headers are system headers to avoid raising warnings.

Re-enables us to build with `werror=yes` on Linux and macOS, thus
catching warnings that would be introduced by new code.

Fixes #36132.

1 files changed, 7 insertions, 1 deletions

diff --git a/SConstruct b/SConstruct
index 2b368f7b19..fe6178d670 100644
--- a/SConstruct
+++ b/SConstruct
@@ -357,7 +357,8 @@ if selected_platform in platform_list:
                 env.Append(CCFLAGS=['-Walloc-zero',
                     '-Wduplicated-branches', '-Wduplicated-cond',
                     '-Wstringop-overflow=4', '-Wlogical-op'])
-                env.Append(CXXFLAGS=['-Wnoexcept', '-Wplacement-new=1'])
+                # -Wnoexcept was removed temporarily due to GH-36325.
+                env.Append(CXXFLAGS=['-Wplacement-new=1'])
                 version = methods.get_compiler_version(env)
                 if version != None and version[0] >= '9':
                     env.Append(CCFLAGS=['-Wattribute-alias=2'])
@@ -369,6 +370,11 @@ if selected_platform in platform_list:
             env.Append(CCFLAGS=['-w'])
         if (env["werror"]):
             env.Append(CCFLAGS=['-Werror'])
+            # FIXME: Temporary workaround after the Vulkan merge, remove once warnings are fixed.
+            if methods.using_gcc(env):
+                env.Append(CXXFLAGS=['-Wno-error=cpp'])
+            else:
+                env.Append(CXXFLAGS=['-Wno-error=#warnings'])
         else: # always enable those errors
             env.Append(CCFLAGS=['-Werror=return-type'])