commit 206aa1a24869b9c69c5e79643d395fe84ec30984
parent fddfdf016caa1d7214037ecb3cd3fc06051bba8c
Author: kyle <kyle@getaddrinfo.net>
Date: Sun, 1 Nov 2015 14:29:55 -0700
instrument: rewrite original source file
- first, save original source file by adding .backup suffix
- then rewrite original source file with instrumented copy
- then call original compiler with original command line
- this is needed because object file name is based on source file name
- then, restore the original source files after everything is done
Diffstat:
5 files changed, 82 insertions(+), 44 deletions(-)
diff --git a/instrument/Makefile b/instrument/Makefile
@@ -1,3 +1,7 @@
+.ifdef SCV_PATH
+error_SCV_PATH
+.endif
+
CXXFLAGS += -I/usr/local/include
CXXFLAGS += -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS
CXXFLAGS += -fno-rtti
diff --git a/instrument/main.cpp b/instrument/main.cpp
@@ -3,7 +3,9 @@
#include <stdlib.h> // mktemp
#include <unistd.h>
#include <sys/stat.h> // mode flags
+#include <sys/wait.h> // wait
+#include <fstream>
#include <iostream>
#include <sstream>
#include <string>
@@ -26,7 +28,8 @@ static llvm::cl::OptionCategory ToolingCategory("instrument options");
// For each source file provided to the tool, a new FrontendAction is created.
class MyFrontendAction : public ASTFrontendAction {
public:
- MyFrontendAction(std::vector<const char *> &);
+ MyFrontendAction() {};
+
void EndSourceFileAction() override {
SourceManager &sm = TheRewriter.getSourceMgr();
const FileID main_fid = sm.getMainFileID();
@@ -35,6 +38,7 @@ public:
// << "\n";
SourceLocation start = sm.getLocForStartOfFile(main_fid);
+ std::string file_name = getCurrentFile();
std::stringstream ss;
// Add declarations for coverage buffers
@@ -42,11 +46,11 @@ public:
ss << "unsigned int lines[" << file_bytes << "];"
<< std::endl;
ss << "int size = " << file_bytes << ";" << std::endl;
+ ss << "char file_name[] = \"" << file_name << "\";" << std::endl;
TheRewriter.InsertTextAfter(start, ss.str());
- // Now emit the rewritten buffer.
- int fd = open(inst_files[0], O_WRONLY | O_CREAT,
- S_IRUSR | S_IWUSR);
+ // rewrite the original source file
+ int fd = open(file_name.c_str(), O_WRONLY | O_CREAT);
if (fd < 0)
err(1, "open");
llvm::raw_fd_ostream output(fd, /* close */ 1);
@@ -65,21 +69,14 @@ public:
private:
Rewriter TheRewriter;
-
- std::vector<const char *> inst_files;
};
-MyFrontendAction::MyFrontendAction(std::vector<const char *> &i) :
- inst_files(i)
-{
-}
-
class MFAF : public FrontendActionFactory {
public:
MFAF(std::vector<const char *> &i) : inst_files(i) {}
FrontendAction *create() {
- return new MyFrontendAction(inst_files);
+ return new MyFrontendAction();
}
private:
@@ -131,8 +128,7 @@ clean_path()
}
void
-instrument(int argc, char *argv[], std::vector<const char *> &source_files,
- std::vector<const char *> &inst_files)
+instrument(int argc, char *argv[], std::vector<const char *> &source_files)
{
const char *clang_argv[source_files.size() + 1 + argc];
int clang_argc = 0;
@@ -163,8 +159,8 @@ instrument(int argc, char *argv[], std::vector<const char *> &source_files,
// use the helper newFrontendActionFactory to create a default factory
// that will return a new MyFrontendAction object every time. To
// further customize this, we could create our own factory class.
- int ret = Tool.run(new MFAF(inst_files));
- // int ret = Tool.run(newFrontendActionFactory<MyFrontendAction>());
+ // int ret = Tool.run(new MFAF(inst_files));
+ int ret = Tool.run(newFrontendActionFactory<MyFrontendAction>());
if (ret)
errx(1, "Instrumentation failed");
}
@@ -173,56 +169,84 @@ int
main(int argc, char *argv[])
{
std::vector<const char *> source_files;
- std::vector<const char *> inst_files;
- char *exec_argv[argc + 1];
for (int i = 0; i < argc; i++) {
- exec_argv[i] = strdup(argv[i]);
-
int arg_len = strlen(argv[i]);
if (arg_len < 4)
continue;
// compare last four bytes of argument
if (strcmp(argv[i] + arg_len - 4, ".cpp") == 0 ||
- strcmp(argv[i] + arg_len - 2, ".c") == 0) {
+ strcmp(argv[i] + arg_len - 2, ".c") == 0)
// keep track of original source file names
source_files.push_back(argv[i]);
-
- char *inst_filename = (char *)calloc(PATH_MAX, 1);
- if (inst_filename == NULL)
- err(1, "calloc");
-
- strncpy(inst_filename, argv[i], arg_len - 2);
- strcat(inst_filename, "_inst.c");
-
- // source code rewriter needs to know this file
- inst_files.push_back(inst_filename);
- // native compiler uses this source file instead
- exec_argv[i] = inst_filename;
- }
}
// very important that argv passed to execvp is NULL terminated
- exec_argv[argc] = NULL;
+ argv[argc] = NULL;
// run native command if there's no source files to instrument
if (source_files.size() == 0) {
+#if DEBUG
warnx("no source files found on command line");
-
+#endif
clean_path();
- if (execvp(exec_argv[0], exec_argv))
+ if (execvp(argv[0], argv))
err(1, "execvp");
}
+ // backup original source files
+ for (auto s : source_files) {
+ std::ifstream src(s, std::ios::binary);
+ std::string dst_fn(s);
+ std::ofstream dst(dst_fn.append(".backup"), std::ios::binary);
+
+ dst << src.rdbuf();
+
+ src.close();
+ dst.close();
+ }
+
// run instrumentation on detected source files
- instrument(argc, argv, source_files, inst_files);
+ instrument(argc, argv, source_files);
#if DEBUG
- std::cout << "Calling real compiler " << exec_argv[0] << std::endl;
+ std::cout << "Calling real compiler" << std::endl;
#endif
-
- // exec native compiler with instrumented source files
clean_path();
- if (execvp(exec_argv[0], exec_argv))
- err(1, "execvp");
+
+ pid_t pid = fork();
+ if (pid == 0) {
+ // child, exec native compiler with instrumented source files
+ if (execvp(argv[0], argv))
+ err(1, "execvp");
+ }
+ else if (pid > 0) {
+ // parent
+ int status = 1;
+ int ret;
+ while (ret = wait(&status)) {
+ if (ret != -1)
+ break;
+ if (errno == EINTR)
+ continue;
+ // something bad happened
+ err(1, "wait");
+ }
+#ifdef DEBUG
+ std::cout << "parent: restoring files" << std::endl;
+#endif
+ // restore original source files
+ for (auto s : source_files) {
+ std::ofstream dst(s, std::ios::binary);
+ std::string src_fn(s);
+ std::ifstream src(src_fn.append(".backup"), std::ios::binary);
+
+ dst << src.rdbuf();
+
+ src.close();
+ dst.close();
+ }
+ }
+ else
+ err(1, "fork");
}
diff --git a/tests/fibonacci/Makefile b/tests/fibonacci/Makefile
@@ -1,5 +1,15 @@
+BIN = prog
+SRCS = fib.c
+OBJS = $(SRCS:c=o)
+
+$(BIN): $(OBJS)
+ $(CC) -o $(BIN) $(OBJS) $(LDLIBS)
+
test:
@sh test.sh
+diff:
+ @diff -u fib.c.inst fib.c.inst_good
+
clean:
- @rm -f prog prog_inst.c
+ rm -f $(OBJS) $(BIN) *.backup
diff --git a/tests/fibonacci/prog.c b/tests/fibonacci/fib.c
diff --git a/tests/fibonacci/instrumented.c b/tests/fibonacci/fib_reference.c
