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Support for macros in rewriter
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Extends the scope of 98b9097's fix to support macros anywhere in the
rewriter. All SourceRange objects are replaced to use macro expanded locations.
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@pchaigno
pchaigno committed Feb 26, 2017
1 parent a075240 commit c5c3b99
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Showing 2 changed files with 45 additions and 42 deletions.
85 changes: 43 additions & 42 deletions src/cc/frontends/clang/b_frontend_action.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -208,12 +208,12 @@ bool ProbeVisitor::VisitUnaryOperator(UnaryOperator *E) {
return true;
memb_visited_.insert(E);
Expr *sub = E->getSubExpr();
string rhs = rewriter_.getRewrittenText(SourceRange(sub->getLocStart(), sub->getLocEnd()));
string rhs = rewriter_.getRewrittenText(expansionRange(sub->getSourceRange()));
string text;
text = "({ typeof(" + E->getType().getAsString() + ") _val; memset(&_val, 0, sizeof(_val));";
text += " bpf_probe_read(&_val, sizeof(_val), (u64)";
text += rhs + "); _val; })";
rewriter_.ReplaceText(SourceRange(E->getLocStart(), E->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(E->getSourceRange()), text);
return true;
}
bool ProbeVisitor::VisitMemberExpr(MemberExpr *E) {
Expand Down Expand Up @@ -243,18 +243,23 @@ bool ProbeVisitor::VisitMemberExpr(MemberExpr *E) {
error(base->getLocEnd(), "internal error: opLoc is invalid while preparing probe rewrite");
return false;
}
string rhs = rewriter_.getRewrittenText(SourceRange(rhs_start, E->getLocEnd()));
string rhs = rewriter_.getRewrittenText(expansionRange(SourceRange(rhs_start, E->getLocEnd())));
string base_type = base->getType()->getPointeeType().getAsString();
string pre, post;
pre = "({ typeof(" + E->getType().getAsString() + ") _val; memset(&_val, 0, sizeof(_val));";
pre += " bpf_probe_read(&_val, sizeof(_val), (u64)";
post = " + offsetof(" + base_type + ", " + rhs + ")";
post += "); _val; })";
rewriter_.InsertText(E->getLocStart(), pre);
rewriter_.ReplaceText(SourceRange(op, E->getLocEnd()), post);
rewriter_.ReplaceText(expansionRange(SourceRange(op, E->getLocEnd())), post);
return true;
}

SourceRange
ProbeVisitor::expansionRange(SourceRange range) {
return rewriter_.getSourceMgr().getExpansionRange(range);
}

template <unsigned N>
DiagnosticBuilder ProbeVisitor::error(SourceLocation loc, const char (&fmt)[N]) {
unsigned int diag_id = C.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, fmt);
Expand Down Expand Up @@ -293,8 +298,7 @@ bool BTypeVisitor::VisitFunctionDecl(FunctionDecl *D) {
// Move the args into a preamble section where the same params are
// declared and initialized from pt_regs.
// Todo: this init should be done only when the program requests it.
string text = rewriter_.getRewrittenText(
SourceRange(arg->getLocStart(), arg->getLocEnd()));
string text = rewriter_.getRewrittenText(expansionRange(arg->getSourceRange()));
arg->addAttr(UnavailableAttr::CreateImplicit(C, "ptregs"));
size_t d = fn_args_.size() - 2;
const char *reg = calling_conv_regs[d];
Expand All @@ -304,8 +308,8 @@ bool BTypeVisitor::VisitFunctionDecl(FunctionDecl *D) {
}
if (D->param_size() > 1) {
rewriter_.ReplaceText(
SourceRange(D->getParamDecl(0)->getLocEnd(),
D->getParamDecl(D->getNumParams() - 1)->getLocEnd()),
expansionRange(SourceRange(D->getParamDecl(0)->getLocEnd(),
D->getParamDecl(D->getNumParams() - 1)->getLocEnd())),
fn_args_[0]->getName());
}
// for each trace argument, convert the variable from ptregs to something on stack
Expand Down Expand Up @@ -337,12 +341,6 @@ bool BTypeVisitor::TraverseCallExpr(CallExpr *Call) {
// to:
// bpf_table_foo_elem(bpf_pseudo_fd(table), &key [,&leaf])
bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
// Get rewritten text given a source range, w/ expansion range applied
auto getRewrittenText = [this] (SourceRange R) {
auto r = rewriter_.getSourceMgr().getExpansionRange(R);
return rewriter_.getRewrittenText(r);
};

// make sure node is a reference to a bpf table, which is assured by the
// presence of the section("maps/<typename>") GNU __attribute__
if (MemberExpr *Memb = dyn_cast<MemberExpr>(Call->getCallee()->IgnoreImplicit())) {
Expand All @@ -352,8 +350,8 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
if (!A->getName().startswith("maps"))
return true;

string args = getRewrittenText(SourceRange(Call->getArg(0)->getLocStart(),
Call->getArg(Call->getNumArgs() - 1)->getLocEnd()));
string args = rewriter_.getRewrittenText(expansionRange(SourceRange(Call->getArg(0)->getLocStart(),
Call->getArg(Call->getNumArgs() - 1)->getLocEnd())));

// find the table fd, which was opened at declaration time
auto table_it = tables_.begin();
Expand All @@ -372,8 +370,8 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
if (memb_name == "lookup_or_init") {
map_update_policy = "BPF_NOEXIST";
string name = Ref->getDecl()->getName();
string arg0 = getRewrittenText(Call->getArg(0)->getSourceRange());
string arg1 = getRewrittenText(Call->getArg(1)->getSourceRange());
string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange()));
string arg1 = rewriter_.getRewrittenText(expansionRange(Call->getArg(1)->getSourceRange()));
string lookup = "bpf_map_lookup_elem_(bpf_pseudo_fd(1, " + fd + ")";
string update = "bpf_map_update_elem_(bpf_pseudo_fd(1, " + fd + ")";
txt = "({typeof(" + name + ".leaf) *leaf = " + lookup + ", " + arg0 + "); ";
Expand All @@ -385,7 +383,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
txt += "leaf;})";
} else if (memb_name == "increment") {
string name = Ref->getDecl()->getName();
string arg0 = getRewrittenText(Call->getArg(0)->getSourceRange());
string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange()));
string lookup = "bpf_map_lookup_elem_(bpf_pseudo_fd(1, " + fd + ")";
string update = "bpf_map_update_elem_(bpf_pseudo_fd(1, " + fd + ")";
txt = "({ typeof(" + name + ".key) _key = " + arg0 + "; ";
Expand All @@ -397,16 +395,16 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
txt += "if (_leaf) (*_leaf)++; })";
} else if (memb_name == "perf_submit") {
string name = Ref->getDecl()->getName();
string arg0 = getRewrittenText(Call->getArg(0)->getSourceRange());
string args_other = getRewrittenText(SourceRange(Call->getArg(1)->getLocStart(),
Call->getArg(2)->getLocEnd()));
string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange()));
string args_other = rewriter_.getRewrittenText(expansionRange(SourceRange(Call->getArg(1)->getLocStart(),
Call->getArg(2)->getLocEnd())));
txt = "bpf_perf_event_output(" + arg0 + ", bpf_pseudo_fd(1, " + fd + ")";
txt += ", bpf_get_smp_processor_id(), " + args_other + ")";
} else if (memb_name == "perf_submit_skb") {
string skb = getRewrittenText(Call->getArg(0)->getSourceRange());
string skb_len = getRewrittenText(Call->getArg(1)->getSourceRange());
string meta = getRewrittenText(Call->getArg(2)->getSourceRange());
string meta_len = getRewrittenText(Call->getArg(3)->getSourceRange());
string skb = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange()));
string skb_len = rewriter_.getRewrittenText(expansionRange(Call->getArg(1)->getSourceRange()));
string meta = rewriter_.getRewrittenText(expansionRange(Call->getArg(2)->getSourceRange()));
string meta_len = rewriter_.getRewrittenText(expansionRange(Call->getArg(3)->getSourceRange()));
txt = "bpf_perf_event_output(" +
skb + ", " +
"bpf_pseudo_fd(1, " + fd + "), " +
Expand All @@ -415,7 +413,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
meta_len + ");";
} else if (memb_name == "get_stackid") {
if (table_it->type == BPF_MAP_TYPE_STACK_TRACE) {
string arg0 = getRewrittenText(Call->getArg(0)->getSourceRange());
string arg0 = rewriter_.getRewrittenText(expansionRange(Call->getArg(0)->getSourceRange()));
txt = "bpf_get_stackid(";
txt += "bpf_pseudo_fd(1, " + fd + "), " + arg0;
rewrite_end = Call->getArg(0)->getLocEnd();
Expand Down Expand Up @@ -451,7 +449,7 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
error(Call->getLocStart(), "cannot use map function inside a macro");
return false;
}
rewriter_.ReplaceText(SourceRange(rewrite_start, rewrite_end), txt);
rewriter_.ReplaceText(expansionRange(SourceRange(rewrite_start, rewrite_end)), txt);
return true;
}
}
Expand All @@ -471,49 +469,47 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {

vector<string> args;
for (auto arg : Call->arguments())
args.push_back(getRewrittenText(arg->getSourceRange()));
args.push_back(rewriter_.getRewrittenText(expansionRange(arg->getSourceRange())));

string text;
if (Decl->getName() == "incr_cksum_l3") {
text = "bpf_l3_csum_replace_(" + fn_args_[0]->getName().str() + ", (u64)";
text += args[0] + ", " + args[1] + ", " + args[2] + ", sizeof(" + args[2] + "))";
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(Call->getSourceRange()), text);
} else if (Decl->getName() == "incr_cksum_l4") {
text = "bpf_l4_csum_replace_(" + fn_args_[0]->getName().str() + ", (u64)";
text += args[0] + ", " + args[1] + ", " + args[2];
text += ", ((" + args[3] + " & 0x1) << 4) | sizeof(" + args[2] + "))";
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(Call->getSourceRange()), text);
} else if (Decl->getName() == "bpf_trace_printk") {
// #define bpf_trace_printk(fmt, args...)
// ({ char _fmt[] = fmt; bpf_trace_printk_(_fmt, sizeof(_fmt), args...); })
text = "({ char _fmt[] = " + args[0] + "; bpf_trace_printk_(_fmt, sizeof(_fmt)";
if (args.size() <= 1) {
text += "); })";
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(Call->getSourceRange()), text);
} else {
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getArg(0)->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(SourceRange(Call->getLocStart(), Call->getArg(0)->getLocEnd())), text);
rewriter_.InsertTextAfter(Call->getLocEnd(), "); }");
}
} else if (Decl->getName() == "bpf_num_cpus") {
int numcpu = sysconf(_SC_NPROCESSORS_ONLN);
if (numcpu <= 0)
numcpu = 1;
text = to_string(numcpu);
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(Call->getSourceRange()), text);
} else if (Decl->getName() == "bpf_usdt_readarg_p") {
text = "({ u64 __addr = 0x0; ";
text += "_bpf_readarg_" + current_fn_ + "_" + args[0] + "(" +
args[1] + ", &__addr, sizeof(__addr));";
text += "bpf_probe_read(" + args[2] + ", " + args[3] +
", (void *)__addr);";
text += "})";
rewriter_.ReplaceText(
SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(Call->getSourceRange()), text);
} else if (Decl->getName() == "bpf_usdt_readarg") {
text = "_bpf_readarg_" + current_fn_ + "_" + args[0] + "(" + args[1] +
", " + args[2] + ", sizeof(*(" + args[2] + ")))";
rewriter_.ReplaceText(
SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(Call->getSourceRange()), text);
}
}
}
Expand All @@ -537,11 +533,11 @@ bool BTypeVisitor::VisitBinaryOperator(BinaryOperator *E) {
}
uint64_t ofs = C.getFieldOffset(F);
uint64_t sz = F->isBitField() ? F->getBitWidthValue(C) : C.getTypeSize(F->getType());
string base = rewriter_.getRewrittenText(SourceRange(Base->getLocStart(), Base->getLocEnd()));
string rhs = rewriter_.getRewrittenText(SourceRange(RHS->getLocStart(), RHS->getLocEnd()));
string base = rewriter_.getRewrittenText(expansionRange(Base->getSourceRange()));
string rhs = rewriter_.getRewrittenText(expansionRange(RHS->getSourceRange()));
string text = "bpf_dins_pkt(" + fn_args_[0]->getName().str() + ", (u64)" + base + "+" + to_string(ofs >> 3)
+ ", " + to_string(ofs & 0x7) + ", " + to_string(sz) + ", " + rhs + ")";
rewriter_.ReplaceText(SourceRange(E->getLocStart(), E->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(E->getSourceRange()), text);
}
}
}
Expand Down Expand Up @@ -569,14 +565,19 @@ bool BTypeVisitor::VisitImplicitCastExpr(ImplicitCastExpr *E) {
uint64_t sz = F->isBitField() ? F->getBitWidthValue(C) : C.getTypeSize(F->getType());
string text = "bpf_dext_pkt(" + fn_args_[0]->getName().str() + ", (u64)" + Ref->getDecl()->getName().str() + "+"
+ to_string(ofs >> 3) + ", " + to_string(ofs & 0x7) + ", " + to_string(sz) + ")";
rewriter_.ReplaceText(SourceRange(E->getLocStart(), E->getLocEnd()), text);
rewriter_.ReplaceText(expansionRange(E->getSourceRange()), text);
}
}
}
}
return true;
}

SourceRange
BTypeVisitor::expansionRange(SourceRange range) {
return rewriter_.getSourceMgr().getExpansionRange(range);
}

template <unsigned N>
DiagnosticBuilder BTypeVisitor::error(SourceLocation loc, const char (&fmt)[N]) {
unsigned int diag_id = C.getDiagnostics().getCustomDiagID(DiagnosticsEngine::Error, fmt);
Expand Down
2 changes: 2 additions & 0 deletions src/cc/frontends/clang/b_frontend_action.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,7 @@ class BTypeVisitor : public clang::RecursiveASTVisitor<BTypeVisitor> {
bool VisitImplicitCastExpr(clang::ImplicitCastExpr *E);

private:
clang::SourceRange expansionRange(clang::SourceRange range);
template <unsigned N>
clang::DiagnosticBuilder error(clang::SourceLocation loc, const char (&fmt)[N]);

Expand All @@ -97,6 +98,7 @@ class ProbeVisitor : public clang::RecursiveASTVisitor<ProbeVisitor> {
bool VisitMemberExpr(clang::MemberExpr *E);
void set_ptreg(clang::Decl *D) { ptregs_.insert(D); }
private:
clang::SourceRange expansionRange(clang::SourceRange range);
template <unsigned N>
clang::DiagnosticBuilder error(clang::SourceLocation loc, const char (&fmt)[N]);

Expand Down

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