Fix WEXITSTATUS compile error on openbsd (and ubuntu)

I noticed that WEXITSTATUS was failing when compiling
sibs on ubuntu.
WEXITSTATUS uses address of input which fails if the input
is directly passed by return of a function call.

Also added error checking if the process was stopped/killed
by receiving a signal or if it failed in any other way.

2 files changed, 36 insertions, 4 deletions

diff --git a/src/Exec.cpp b/src/Exec.cpp
index b245fd4..37ffef5 100644
--- a/src/Exec.cpp
+++ b/src/Exec.cpp
@@ -1,5 +1,7 @@
 #include "../include/Exec.hpp"
 
+using namespace std;
+
 namespace sibs
 {
     Result<ExecResult> exec(const char *cmd, bool print)
@@ -20,9 +22,34 @@ namespace sibs
             }
         }
 
-        ExecResult execResult;
-        execResult.execStdout = result;
-        execResult.exitCode = WEXITSTATUS(pclose(pipe));
-        return Result<ExecResult>::Ok(execResult);
+        int processCloseResult = pclose(pipe);
+        if(WIFEXITED(processCloseResult))
+        {
+            int returned = WEXITSTATUS(processCloseResult);
+            ExecResult execResult;
+            execResult.execStdout = result;
+            execResult.exitCode = returned;
+            return Result<ExecResult>::Ok(execResult);
+        }
+        else if(WIFSIGNALED(processCloseResult))
+        {
+            int signum = WSTOPSIG(processCloseResult);
+            string errMsg = "Exited due to receiving signal ";
+            errMsg += to_string(signum);
+            return Result<ExecResult>::Err(errMsg);
+        }
+        else if(WIFSTOPPED(processCloseResult))
+        {
+            int signum = WSTOPSIG(processCloseResult);
+            string errMsg = "Stopped due to receiving signal ";
+            errMsg += to_string(signum);
+            return Result<ExecResult>::Err(errMsg);
+        }
+        else
+        {
+            string errMsg = "exec unexpected error on pclose: ";
+            errMsg += to_string(processCloseResult);
+            return Result<ExecResult>::Err(errMsg);
+        }
     }
 }
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index 151e5a5..b1982bd 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -9,6 +9,11 @@
 using namespace std;
 using namespace sibs;
 
+// TODO: Fail if multiple versions of the same dependency is used
+// as linking will fail because of multiple definitions of the same thing
+
+// TODO: Detect recursive dependencies and give error.
+
 void usage()
 {
     printf("usage: sibs COMMAND\n\n");