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-rw-r--r--lib/Frontend/CompilerInvocation.cpp3
-rw-r--r--lib/Frontend/FrontendActions.cpp30
-rw-r--r--lib/Lex/Lexer.cpp125
3 files changed, 158 insertions, 0 deletions
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 00363d91fd..b007ac4bd3 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -331,6 +331,7 @@ static const char *getActionName(frontend::ActionKind Kind) {
case frontend::ParsePrintCallbacks: return "-parse-print-callbacks";
case frontend::ParseSyntaxOnly: return "-fsyntax-only";
case frontend::PrintDeclContext: return "-print-decl-contexts";
+ case frontend::PrintPreamble: return "-print-preamble";
case frontend::PrintPreprocessedInput: return "-E";
case frontend::RewriteMacros: return "-rewrite-macros";
case frontend::RewriteObjC: return "-rewrite-objc";
@@ -989,6 +990,8 @@ static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
Opts.ProgramAction = frontend::ParseSyntaxOnly; break;
case OPT_print_decl_contexts:
Opts.ProgramAction = frontend::PrintDeclContext; break;
+ case OPT_print_preamble:
+ Opts.ProgramAction = frontend::PrintPreamble; break;
case OPT_E:
Opts.ProgramAction = frontend::PrintPreprocessedInput; break;
case OPT_rewrite_macros:
diff --git a/lib/Frontend/FrontendActions.cpp b/lib/Frontend/FrontendActions.cpp
index 3a53dee806..4db9c11ee3 100644
--- a/lib/Frontend/FrontendActions.cpp
+++ b/lib/Frontend/FrontendActions.cpp
@@ -19,6 +19,7 @@
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/Utils.h"
#include "llvm/ADT/OwningPtr.h"
+#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
@@ -192,3 +193,32 @@ void PrintPreprocessedAction::ExecuteAction() {
DoPrintPreprocessedInput(CI.getPreprocessor(), OS,
CI.getPreprocessorOutputOpts());
}
+
+void PrintPreambleAction::ExecuteAction() {
+ switch (getCurrentFileKind()) {
+ case IK_C:
+ case IK_CXX:
+ case IK_ObjC:
+ case IK_ObjCXX:
+ case IK_OpenCL:
+ break;
+
+ case IK_None:
+ case IK_Asm:
+ case IK_PreprocessedC:
+ case IK_PreprocessedCXX:
+ case IK_PreprocessedObjC:
+ case IK_PreprocessedObjCXX:
+ case IK_AST:
+ case IK_LLVM_IR:
+ // We can't do anything with these.
+ return;
+ }
+
+ llvm::MemoryBuffer *Buffer = llvm::MemoryBuffer::getFile(getCurrentFile());
+ if (Buffer) {
+ unsigned Preamble = Lexer::ComputePreamble(Buffer);
+ llvm::outs().write(Buffer->getBufferStart(), Preamble);
+ delete Buffer;
+ }
+}
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 91b14f638d..2f11c37e65 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -28,6 +28,7 @@
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cctype>
@@ -247,6 +248,130 @@ unsigned Lexer::MeasureTokenLength(SourceLocation Loc,
return TheTok.getLength();
}
+namespace {
+ enum PreambleDirectiveKind {
+ PDK_Skipped,
+ PDK_StartIf,
+ PDK_EndIf,
+ PDK_Unknown
+ };
+}
+
+unsigned Lexer::ComputePreamble(const llvm::MemoryBuffer *Buffer) {
+ // Create a lexer starting at the beginning of the file. Note that we use a
+ // "fake" file source location at offset 1 so that the lexer will track our
+ // position within the file.
+ const unsigned StartOffset = 1;
+ SourceLocation StartLoc = SourceLocation::getFromRawEncoding(StartOffset);
+ LangOptions LangOpts;
+ Lexer TheLexer(StartLoc, LangOpts, Buffer->getBufferStart(),
+ Buffer->getBufferStart(), Buffer->getBufferEnd());
+
+ bool InPreprocessorDirective = false;
+ Token TheTok;
+ Token IfStartTok;
+ unsigned IfCount = 0;
+ do {
+ TheLexer.LexFromRawLexer(TheTok);
+
+ if (InPreprocessorDirective) {
+ // If we've hit the end of the file, we're done.
+ if (TheTok.getKind() == tok::eof) {
+ InPreprocessorDirective = false;
+ break;
+ }
+
+ // If we haven't hit the end of the preprocessor directive, skip this
+ // token.
+ if (!TheTok.isAtStartOfLine())
+ continue;
+
+ // We've passed the end of the preprocessor directive, and will look
+ // at this token again below.
+ InPreprocessorDirective = false;
+ }
+
+ // Comments are okay; skip over them.
+ if (TheTok.getKind() == tok::comment)
+ continue;
+
+ if (TheTok.isAtStartOfLine() && TheTok.getKind() == tok::hash) {
+ // This is the start of a preprocessor directive.
+ Token HashTok = TheTok;
+ InPreprocessorDirective = true;
+
+ // Figure out which direective this is. Since we're lexing raw tokens,
+ // we don't have an identifier table available. Instead, just look at
+ // the raw identifier to recognize and categorize preprocessor directives.
+ TheLexer.LexFromRawLexer(TheTok);
+ if (TheTok.getKind() == tok::identifier && !TheTok.needsCleaning()) {
+ const char *IdStart = Buffer->getBufferStart()
+ + TheTok.getLocation().getRawEncoding() - 1;
+ llvm::StringRef Keyword(IdStart, TheTok.getLength());
+ PreambleDirectiveKind PDK
+ = llvm::StringSwitch<PreambleDirectiveKind>(Keyword)
+ .Case("include", PDK_Skipped)
+ .Case("__include_macros", PDK_Skipped)
+ .Case("define", PDK_Skipped)
+ .Case("undef", PDK_Skipped)
+ .Case("line", PDK_Skipped)
+ .Case("error", PDK_Skipped)
+ .Case("pragma", PDK_Skipped)
+ .Case("import", PDK_Skipped)
+ .Case("include_next", PDK_Skipped)
+ .Case("warning", PDK_Skipped)
+ .Case("ident", PDK_Skipped)
+ .Case("sccs", PDK_Skipped)
+ .Case("assert", PDK_Skipped)
+ .Case("unassert", PDK_Skipped)
+ .Case("if", PDK_StartIf)
+ .Case("ifdef", PDK_StartIf)
+ .Case("ifndef", PDK_StartIf)
+ .Case("elif", PDK_Skipped)
+ .Case("else", PDK_Skipped)
+ .Case("endif", PDK_EndIf)
+ .Default(PDK_Unknown);
+
+ switch (PDK) {
+ case PDK_Skipped:
+ continue;
+
+ case PDK_StartIf:
+ if (IfCount == 0)
+ IfStartTok = HashTok;
+
+ ++IfCount;
+ continue;
+
+ case PDK_EndIf:
+ // Mismatched #endif. The preamble ends here.
+ if (IfCount == 0)
+ break;
+
+ --IfCount;
+ continue;
+
+ case PDK_Unknown:
+ // We don't know what this directive is; stop at the '#'.
+ break;
+ }
+ }
+
+ // We only end up here if we didn't recognize the preprocessor
+ // directive or it was one that can't occur in the preamble at this
+ // point. Roll back the current token to the location of the '#'.
+ InPreprocessorDirective = false;
+ TheTok = HashTok;
+ }
+
+ // We hit a token
+ break;
+ } while (true);
+
+ SourceLocation End = IfCount? IfStartTok.getLocation() : TheTok.getLocation();
+ return End.getRawEncoding() - StartLoc.getRawEncoding();
+}
+
//===----------------------------------------------------------------------===//
// Character information.
//===----------------------------------------------------------------------===//
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-08-03 02:05:42 +0000