[clang] Add wasm-opt warning (PR #100321)

[Quentin Michaud via cfe-commits]

https://github.com/mh4ck-Thales updated https://github.com/llvm/llvm-project/pull/100321

>From b812b9c2a7b92edf5dab739eadff0295c2a1f631 Mon Sep 17 00:00:00 2001
From: Quentin Michaud <quentin.michaud at thalesgroup.com>
Date: Wed, 24 Jul 2024 09:54:53 +0200
Subject: [PATCH 1/2] First draft of wasm-opt warning

---
 clang/lib/Driver/ToolChains/WebAssembly.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/clang/lib/Driver/ToolChains/WebAssembly.cpp b/clang/lib/Driver/ToolChains/WebAssembly.cpp
index 9aacda5fd5702f..dc49fde378a9a7 100644
--- a/clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ b/clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -180,6 +180,9 @@ void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     if (WasmOptPath == "wasm-opt") {
       WasmOptPath = {};
     }
+    if (WasmOptPath.empty()) {
+      printf("warning: wasm-opt not found but was requested\n");
+    }
   }
 
   if (!WasmOptPath.empty()) {

>From a798b1fd7a7a6c7b782584021e5c32e52c3abffc Mon Sep 17 00:00:00 2001
From: Quentin Michaud <quentin.michaud at thalesgroup.com>
Date: Thu, 29 Aug 2024 16:31:48 +0200
Subject: [PATCH 2/2] Add errors and warnings for when wasm-opt is missing or
 invoked but incompatible

---
 clang/include/clang/Basic/DiagnosticDriverKinds.td |  8 ++++++++
 clang/include/clang/Basic/DiagnosticGroups.td      |  2 ++
 clang/include/clang/Driver/Options.td              |  1 +
 clang/lib/Driver/ToolChains/WebAssembly.cpp        | 14 +++++++++++++-
 4 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
index ba90742fbdaabc..2a862edf8788c8 100644
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -826,4 +826,12 @@ def err_drv_triple_version_invalid : Error<
 
 def warn_missing_include_dirs : Warning<
   "no such include directory: '%0'">, InGroup<MissingIncludeDirs>, DefaultIgnore;
+
+def warn_wasm_opt_not_found : Warning<
+  "wasm-opt was not found, some optimizations were not applied">,
+  InGroup<WebAssemblyOptimization>;
+def err_wasm_opt_not_found_with_flag : Error<
+  "wasm-opt was explicitly requested, but was not found">;
+def err_wasm_opt_requested_but_not_supported : Error<
+  "wasm-opt was explicitly requested, but is not supported with '%0'">;
 }
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 28d315f63e5c47..fab11f47492db3 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1520,6 +1520,8 @@ in addition with the pragmas or -fmax-tokens flag to get any warnings.
 
 def WebAssemblyExceptionSpec : DiagGroup<"wasm-exception-spec">;
 
+def WebAssemblyOptimization : DiagGroup<"wasm-opt">;
+
 def RTTI : DiagGroup<"rtti">;
 
 def OpenCLCoreFeaturesDiagGroup : DiagGroup<"pedantic-core-features">;
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 83cf753e824845..ba6e7ab9e11d06 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -8923,3 +8923,4 @@ def wasm_opt : Flag<["--"], "wasm-opt">,
   Group<m_Group>,
   HelpText<"Enable the wasm-opt optimizer (default)">,
   MarshallingInfoNegativeFlag<LangOpts<"NoWasmOpt">>;
+def Wwarn_wasm_opt_not_found : Flag<["-"], "Wwarn_wasm_opt_not_found">;
diff --git a/clang/lib/Driver/ToolChains/WebAssembly.cpp b/clang/lib/Driver/ToolChains/WebAssembly.cpp
index dc49fde378a9a7..e9820ce1d35995 100644
--- a/clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ b/clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -9,6 +9,7 @@
 #include "WebAssembly.h"
 #include "CommonArgs.h"
 #include "Gnu.h"
+#include "clang/Basic/DiagnosticDriver.h"
 #include "clang/Basic/Version.h"
 #include "clang/Config/config.h"
 #include "clang/Driver/Compilation.h"
@@ -20,6 +21,7 @@
 #include "llvm/Support/Path.h"
 #include "llvm/Support/VirtualFileSystem.h"
 
+
 using namespace clang::driver;
 using namespace clang::driver::tools;
 using namespace clang::driver::toolchains;
@@ -172,6 +174,11 @@ void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   bool RunWasmOpt = Args.hasFlag(options::OPT_wasm_opt,
                                  options::OPT_no_wasm_opt, WasmOptDefault);
 
+  if (TargetBuildsComponents(ToolChain.getTriple()) &&
+      Args.hasFlag(options::OPT_wasm_opt, options::OPT_no_wasm_opt, false)) {
+    ToolChain.getDriver().Diag(diag::err_wasm_opt_requested_but_not_supported)
+        << ToolChain.getTriple().str();
+  }
   // If wasm-opt is enabled and optimizations are happening look for the
   // `wasm-opt` program. If it's not found auto-disable it.
   std::string WasmOptPath;
@@ -181,7 +188,12 @@ void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       WasmOptPath = {};
     }
     if (WasmOptPath.empty()) {
-      printf("warning: wasm-opt not found but was requested\n");
+      if (Args.hasFlag(options::OPT_wasm_opt, options::OPT_no_wasm_opt,
+                       false)) {
+        ToolChain.getDriver().Diag(diag::err_wasm_opt_not_found_with_flag);
+      } else {
+        ToolChain.getDriver().Diag(diag::warn_wasm_opt_not_found);
+      }
     }
   }