Driver: Improve diagnostics for failed commands.

 - Not all tools give good error messages, and sometimes the tool can fail w/o
   any error (for example, when signalled).

 - We suppress this message when the failing command is the compiler and it
   failed normally (exit code == 1), under the assumption that it gave a good
   diagnostic.

For example, for a linker failure we now get:
--
ddunbar@lordcrumb:tmp$ clang a.c b.c
ld: duplicate symbol _x in /var/folders/cl/clrOX6SaG+moCeRKEI4PtU+++TI/-Tmp-/cc-bXYITq.o and /var/folders/cl/clrOX6SaG+moCeRKEI4PtU+++TI/-Tmp-/cc-6uK4jD.o
clang: error: linker command failed with exit code 1 (use -v to see invocation)
--

For a compiler crash we get:
--
ddunbar@lordcrumb:tmp$ clang t.i
Assertion failed: (CGT.getTargetData().getTypeAllocSizeInBits(STy) == RL.getSize()), function layoutStructFields, file CodeGenTypes.cpp, line 573.
0   clang-cc          0x0000000100f1f1f1 PrintStackTrace(void*) + 38
... stack trace and virtual stack trace follow ...
clang: error: compiler command failed due to signal 6 (use -v to see invocation)
--

But for a regular compilation failure we get the usual:
--
ddunbar@lordcrumb:tmp$ clang c.c
c.c:1:6: error: invalid token after top level declarator
int x
     ^
1 diagnostic generated.
--

 - No test case, not amenable to non-executable testing. :/

 - <rdar://problem/6945613>


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74629 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 6 deletions

diff --git a/include/clang/Driver/Compilation.h b/include/clang/Driver/Compilation.h
index 4985f30ad5..0e66796a6e 100644
--- a/include/clang/Driver/Compilation.h
+++ b/include/clang/Driver/Compilation.h
@@ -103,22 +103,26 @@ private:
 
   /// PrintJob - Print one job in -### format.
   ///
-  /// OS - The stream to print on.
-  /// J - The job to print.
-  /// Terminator - A string to print at the end of the line.
-  /// Quote - Should separate arguments be quoted.
+  /// \param OS - The stream to print on.
+  /// \param J - The job to print.
+  /// \param Terminator - A string to print at the end of the line.
+  /// \param Quote - Should separate arguments be quoted.
   void PrintJob(llvm::raw_ostream &OS, const Job &J, 
                 const char *Terminator, bool Quote) const;
 
   /// ExecuteCommand - Execute an actual command.
   ///
+  /// \param FailingCommand - For non-zero results, this will be set to the
+  /// Command which failed, if any.
   /// \return The result code of the subprocess.
-  int ExecuteCommand(const Command &C) const;
+  int ExecuteCommand(const Command &C, const Command *&FailingCommand) const;
 
   /// ExecuteJob - Execute a single job.
   ///
+  /// \param FailingCommand - For non-zero results, this will be set to the
+  /// Command which failed, if any.
   /// \return The accumulated result code of the job.
-  int ExecuteJob(const Job &J) const;
+  int ExecuteJob(const Job &J, const Command *&FailingCommand) const;
 };
 
 } // end namespace driver