wrappers: check for correct in mode plugin itself

Since i suspect the bash overhead to be the reason for the overhead
observed in musl libc that made clang-hash slower than recompilation.

src/clang-hash.cc

@@ -177,6 +177,15 @@ protected:
     const std::string PreviousHashString = getHashFromFile(HashFile);
 
     // Write hash database to .o.hash if the compiler produces a object file
+    if (CI.getFrontendOpts().ProgramAction != frontend::EmitObj
+        && CI.getFrontendOpts().ProgramAction != frontend::EmitLLVM
+        && CI.getFrontendOpts().ProgramAction != frontend::EmitBC
+        && CI.getFrontendOpts().ProgramAction != frontend::ParseSyntaxOnly
+        ) {
+        errs() << "No compile\n";
+        return make_unique<ASTConsumer>();
+    }
+
     raw_ostream *Out = nullptr;
     if (OutputFile != "" && OutputFile != "/dev/null") {
       std::error_code Error;

wrappers/CMakeLists.txt

@@ -9,17 +9,12 @@ configure_file(clang-hash-collect.in ${PROJECT_BINARY_DIR}/wrappers/clang-hash-c
 # - clang-ccache: ccache assisted clang
 # - clang-hash-stop: clang-hash assisted clang
 
-execute_process(
-  COMMAND "${CMAKE_COMMAND}" "-E" "create_symlink"
-    "${LLVM_C_COMPILER}" "${CMAKE_CURRENT_BINARY_DIR}/clang-normal"
-)
-
 find_program(CCACHE NAMES "ccache")
 if (NOT CCACHE)
   message(ERROR "CCACHE not found")
 endif()
+configure_file(clang-normal.in ${PROJECT_BINARY_DIR}/wrappers/clang-normal)
 configure_file(clang-ccache.in ${PROJECT_BINARY_DIR}/wrappers/clang-ccache)
-
 configure_file(clang-hash-stop.in ${PROJECT_BINARY_DIR}/wrappers/clang-hash-stop)
 
 

wrappers/clang-ccache.in

-#!/usr/bin/env bash
+#!/bin/sh
 
 exec ${CCACHE} ${LLVM_C_COMPILER} "$@" -Wno-extra-semi

wrappers/clang-hash-stop.in

-#!/usr/bin/env bash
+#!/bin/sh
+
+exec ${LLVM_C_COMPILER} -fplugin=${PROJECT_BINARY_DIR}/src/libclang-hash.so \
+     -Xclang -plugin-arg-clang-hash -Xclang -stop-if-same-hash \
+     "$@" -Wno-extra-semi
 
 # Wrapper for clang, that supports (only) fast hash-based
 # recompilation.
-
-if [[ ( " $@" =~ .*" -c".* ) && ( "$@" =~ .*" -o".* ) && ! ( "$@" =~ .*"/dev/null".* ) ]]; then
-    ${LLVM_C_COMPILER} -fplugin=${PROJECT_BINARY_DIR}/src/libclang-hash.so \
-                       -Xclang -plugin-arg-clang-hash -Xclang -stop-if-same-hash \
-                       "$@" -Wno-extra-semi
-
-else
-    ${LLVM_C_COMPILER} "$@" -Wno-extra-semi
-fi

wrappers/clang-normal.in

+#!/bin/sh
+
+exec ${LLVM_C_COMPILER} "$@" -Wno-extra-semi